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chaachee@hotmail<img src=/i/dc.gif border=0 width=35 height=15> wrote:
>I've got a 1991 Jetta GLi and I'm throwing around the idea of swapping the
>motor for a VR6, which I've seen at last year's Velocity show. It looked
>great. Then I saw it done to a new Beetle at the last VW Jamboree and the
>urge really hit me.
>
>I'm wondering how much of my car I'll have left after I'm done. Do I change
>the tranny (newly rebuilt)? What about the front axles (VR6 has 5 lugs)?
>Does that mean I'll have to change my wheels (brand new)? What about my
>springs, shocks, sway bars, strut bars? What about the fuel injection,
>computer, and MFA?
>
>What can I do with the replaced parts? Can I swap them up front for the VR6
>equivalent (plus some cash)? Will someone buy a used 16V motor, tranny,
>wheels, and other miscellaneous parts?
>
>What kind of money am I going to need? How much of it will I get back for my
>old parts? Should I go to a performance shop to have this done (ie ABD or
>Autotech) or should my mechanic do the work (he's amazing, he did the tranny).
>
>Anyone have experience doing this kind of project. Are there different
>versions of the VR6 motor, or are they the same from one model to the other?
>I'm really seriously thinking of doing this, but I'm not willing to spend
>more than buying a VR6 (GTI or Jetta) and dumping the Jetta altogether.
A guy named Eric Schumacher detailed putting a VR6 into his '85 GTI
awhile ago in this newgroup. I hope he doesn't mind me posting it
again. As you can see, doing this is not a simple weekend swap.
-------------------------------------
TRANSPLANTING A VR6 INTO A 85 VW GTI
by Eric Schumacher e.schumacher@worldnet<img src=/i/dn.gif border=0 width=35 height=15> 2-25-97
DESCRIPTION, BACKROUND AND GENERAL PHILISOPHY
The story that follows details most of the changes I had to implement
to repower a 85 GTI with a VR6 engine. This tale is organized as a
log that was written as each modification was completed. Actually the
task is more comprehensive than simply installing an engine it is more
like converting an A2 into a SLC Corrado in all but body style. When
the VR6 engine was announced my original goal was to drop one in an 82
Scirocco but I was intimidated when I found out about the mounting
difficulties that would be involved due to the lack of a subframe in
the A1 cars. If you have the option, the Corrado is the best choice as
a donor car since the A2 platform is the same as the Golf. In fact
the more Corrado stuff you use the easier the job becomes. However due
to the scarcity of suitable low mileage Corrado wrecks in the LA area
I opted for a Jetta GLX and took on some the engineering challenges
that result.
How much of the donor car to use in some cases boils down to a
personal preference and some changes having to deal with appearance I
chose not to make. For instance to keep the weight of the completed
car to a minimum I did not want the traction control/ABS, the 11 inch
front brakes and the five lug wheels. Others might opt for more road
holding but the choice of suspension will not fundamentally alter the
nature of the conversion. I started the project by buying a very low
mileage wrecked 95 Jetta GLX with a manual transmission. I was
careful to select a car with no damage to components that I knew I
would need. Many late model VW parts can only be obtained from the
dealer and they are very expensive. The engine and trans are the
heart of a swap but having all the other miscellaneous bits and pieces
in the garage next to the receptor car makes the job a lot easier.
If you have to make a parts run with cash in hand every time you need
some odd connector or bracket you are likely to find a junkyard dog
rooting around in your wallet pocket. These notes do not cover any
performance type VR6 engine or suspension mods since they are a
separate project and have been well documented by others.
The second step was to find a 85 GTI with a pristine body and
interior. Once a suitable car was in hand, registered and smogged the
engine compartment was completely stripped and the front suspension
removed. After bolting the GLX subframe in place the engine/trans was
trial fitted to see what would have to change. With this decided, all
non-required brackets were removed and the necessary new holes cut.
After the required dents were made and new brackets welded in place
the engine compartment was washed and repainted Alpine White.
FRONT SUSPENSION
In order to retain the stock 85 Golf GTI appearance I chose not to use
the plus suspension. . I did however feel the need for larger brakes.
The + A3 suspension differs from the A2 Golf in a number of ways:
1)The + control arms are longer and position the wheel hubs
differently both laterally and longitudinally.
2) The steering knuckles use 5 bolt hubs, different balljoints and
brake caliper mounting dimensions.
3)The tops of the front struts are 1084 mm apart on the Golf and 1110
mm apart on the Jetta GLX.
4)Both left and right tie rods are longer on the GLX.
5)The CV joints are similar in size but the splined output shaft on
the outer CV is larger on the GLX.
6) The + half shafts are longer.
7)The spring strut combination has a longer length on the GLX
Unfortunately the A2 Golfs use a caliper design that does not bolt to
the steering knuckles, rather the caliper mounting is integral with
the steering knuckle. Other than the ABS stuff and the number of
lugs, both of the Corrados and the Jetta GLX all use the same calipers
and 11 inch rotors. Unfortunately for me the 11 inch rotors and
calipers must be used with 15 inch wheels. Either VR6 Passat or G60
Corrado steering knuckles will mate with the ball joints that will
bolt up to A2 Golf control arms. Either A3 Jetta or 16V Passat
calipers and 10 inch rotors will bolt up to the G60 steering knuckles.
I had a brand new set of 16V Scirocco brakes with 10 inch rotors and
calipers that I was saving for this project but it turned out that
both caliper mounting and rotor offset on 16V parts will not quite
match up with any steering knuckles that will fit the A2 ball joints.
The components I ended up using that increased front brake rotor
diameter to 10 inches and maintained the stock 85 GTI suspension
geometry, while bolting up without modification, were as follows:
1.16V Scirocco half shafts and CV joints.
2.G60 Corrado steering knuckles and ball joints
3.95 Jetta GLX tie rod ends, front springs and upper strut bearings.
4.85 GTI springs and struts.
5.93 Jetta GLI calipers and rotors.
6.16V Scirocco brake master cylinder with a 22 mm bore.
7.Stock 85 GTI rear brake proportioning valve.
The VR6 upper strut bearings from the GLX were used by replacing the
upper spring seat plates with ones from a VR6 powered Corrado VW PN
1H0 412 341. These Corrado seat plates allow the use of the GTI
springs with the VR6 strut mount bearings. They have the additional
advantage of making it easy to correct for the extra weight of the VR6
engine. The front of the car was raised 3/8 of an inch by adding
washers between the top of the upper spring seat plates and the bottom
of the strut mount bearings.
ENGINE MOUNTING
The GLX subframe will bolt up to the Golf platform without
modification. The GLX subframe however has a rearward extension on
each side in the vicinity of the swaybar mounts. Each extension has a
hole for a 10 mm bolt that secures it to the car body. Not to the
platform directly but to a longitudinal stiffener. There is a
blockage inside the stiffener that prevents access beyond a couple of
inches behind the hole location. With forethought a PEM nut or some
such could be slid in place above a hole drilled in the stiffener at
the subframe extension hole location. Unfortunately I put this task
off too long. It was impossible to do with the subframe in place so
I settled for a couple of 6 mm thread forming screws into the
stiffener.
The A2 Golf subframe design is very similar to the Jetta GLX subframe
except that the right rear mount is of the oil damped type (PN 1H0 199
262K) as opposed to a larger version of the
horizontal-metal-sleeve-in-rubber type found in A1 cars. Contrary to
what I was told by many people the plus suspension of the Jetta does
not change any dimensions in the subframe. All important dimensions
are the same. VW created the "plus" by changing the dimensions of the
control arms and steering knuckles. When the VR6 engine was set in
the A2 engine bay on the GLX subframe the right side of the engine was
higher than the left with a slight interference with the hood. When a
5 foot straight edge was laid across the top of the engine one end was
slightly below the top of the left fender and the other end about 1.5
inches above the right fender. By lowering the right rear engine
mount 3/4 of an inch the top of the engine was horizontal and adequate
hood clearance was effected.
The right rear mount was lowered by chucking the top of the mount
housing in a lathe and cutting away the mounting flange with a cutoff
tool from the bottom of the mount housing. When this was done the top
of the mount could be dropped 3/4 inch deeper into the hole in the
flange and rewelded. The bottom donut (PN 3A0 199 201B) was replaced
with one from a C (PN ) and the bottom cup
deepened by cutting out its bottom. The above idea was suggested by
Paul McCallum in the UK who sells a modified mount for 80 pounds. The
end result is very clean with all rubber parts that wear remaining
stock VW.
The front engine support was next dealt with. The ideal is to obtain
a VR6 Corrado or VR6 Passat front engine carrier support (PN 1H0 199
201B or 357 199 201); it matches the Golf chassis on the ends and
provides a mounting pad for the VR6 oil damped mount for the front of
the engine. Because of the scarcity of this part I chose to use the
original 85 Golf front engine carrier and associated solid rubber
mount. I increased clearance between the right end of the carrier and
the air conditioner drive pulley by creating an indentation using heat
and hammer. The Golf rubber mount fit the GLX engine mount bracket
better by shimming the rear of it up by 3/16 of an inch. Clearance
between the hood and the engine under conditions that stress the
engine mounts was checked by putting a piece of open-cell Styrofoam
between the top of the engine and the hood. Engine movement crushes
the Styrofoam to a thickness that is equal to the minimum hood/engine
clearance.
The only remaining task was to indent the right frame rail about 3/8
inch to clear the top of the harmonic balancer on the end of the VR6
crankshaft. This was done with hammer work on the lower part of the
chassis frame rail, no heat was used. There is a horizontal stiffener
inside the frame rail. Achieving the required clearance is made easier
if a "peak" is first added to the center of the stiffener. The peak
was started by inserting a length of one inch pipe with a partially
flattened end inside the frame rail and twisting it.
FIREWALL INSULATION
The GLX aluminum foil covered padding was trimmed and installed on the
GTI firewall to insulate the interior from noise as well as well as to
protect engine compartment wiring and brake lines from radiated
exhaust manifold heat.
RADIATOR
I chose to use a G60 radiator (PN 535 121 251C) instead of a VR6 one
(PN 535 121 251E) for a 6% gain in core area. There is no particular
problem with accommodating the increase in width, it is the same size
as the a/c A2 GTI radiator but the I/O is on the left end instead of
the right. On Corrado radiators the top hose connection points toward
the right side of the car, not to the rear as in the GLX, so a VR6
Corrodo upper hose PN 535 121 101 H must be used. It looks like the
GLX lower hose should fit however there is just enough twist required
that it is in danger of flattening. To avoid this risk I chose to use
a Corrado lower hose (VW PN 535 121 051B) also. See separate post
for low cost alternatives to VW hoses.
COOLING FAN
THE Corrodo VR6 cooling fan shroud is reported to be a drop-in,
however since I didn"t have one, I chose to use the taller GLX shroud
and its associated fans. The space between the engine and radiator is
minimal, requiring that the electric PCV blower be relocated to
provide clearance below the intake manifold for the belt driven fan.
None of the cooling components are interchangeable between the Corrodo
and the GLX. Corrados have been plagued with cooling fan problems and
used fan motors are therefore suspect. The GLX radiator is several
inches taller (top to bottom) than the A2 radiator requiring that the
GLX fan shroud be cut down to fit.. This was done by trimming several
inches off the bottom of the GLX shroud and adding a stiffener on the
inside between it and the radiator support that also seals the bottom
of the shroud. The bottom of the shroud must also be either indented
or notched to clear the top of the front mount The top of the dip
stick tube was also relocated to be below and to the left of the
intake manifold.
..
BRACKETRY
To maintain a clean stock OEM appearance several mounting brackets
from the 95 Jetta GLX donor car were used in the engine swap. In
order to gain more clearance between the fan and the battery the
battery location was changed slightly. The GTI rear battery hold down
bracket was removed and the GLX battery platform installed so that the
battery was rotated about 30 degrees giving several inches of
clearance between it and the fan shroud. The negative terminal lead
must be extended when using the GLX harness. Generally VW uses
separate brackets for mounting such things as the radiator expansion
reservoir and power distribution box, power steering fluid reservoir,
engine ECU, etc. The brackets were removed by drilling out the spot
welds with a 5/16 bit and carefully prying the brackets off. After
repainting, the new brackets were re-welded in place through the 5/16
holes using a wire welder. A quick shot of paint over the weld and
the end result is very clean. In the case of the cruise control pump
there was no welding involved it was mounted in the GTI under the
bracket formerly used to retain the ECU in the left end of the cabin
ventilation plenum.
SHIFTER
The change over to the cable shifting system used with the VR6
transmission was a straight forward matter of un-bolting the old Golf
stuff and bolting in the new cable shifter from the GLX. The hole
pattern for the shifter in the Golf is slightly wider than the one in
the GLX shifter so the edges of the shifter were notched a bit with a
rat-tail file to clear the four 8mm bolts. The shifter was then
clamped in place using fender washers. The only other modifications
necessary were to drill an additional 8 mm mounting hole in the
platform and screwing on a Golf ball.
FUEL SUPPLY
The original 85 GTI fuel pumps (one transfer pump in the tank and one
external pressure pump) were retained. While the VR6 Motronic
injection system operates at a lower system pressure than the original
KE Jetronic this difference is taken care of by the new pressure
regulator on the VR6 fuel rail. The GTI fuel sender also seems
reasonably compatible with the fuel gauge in the VR6 instrument
cluster.
PEDAL CLUSTER
The VR6 engine uses a hydraulically actuated clutch in place of the
cable operated one on the A2 Golf. On the A2 Golf the upper part of
the clutch pedal (the part that would actuate the clutch master
cylinder) is to the right of the steering column. The clutch master
cylinder must mount on the firewall to the left of the steering column
to avoid interference with the brake servo on the engine side of the
firewall. The Jetta GLX pedal assembly could be made to work since it
has the required mounting and actuation for the clutch master cylinder
however it would be quite a bit of work to get it adapted into
position between the steering column, the fire wall and the dash. I
chose to buy a complete pedal assembly from a G60 Corrado. The C
pedal assembly bolts up fine with only a few rubs. Just cut a 1 1/2
inch hole for the slave cylinder and a mounting hole or two and its
done. I noted that while both the G60 and the GLX master and slave
cylinders were very similar the actuating rods on both cylinders were
different lengths and the bore diameters were different. I chose to
use all the stuff from the GLX (it was almost new anyway)
Unfortunately the GLX clutch master cylinder mates to the clutch pedal
arm with a ball and socket arrangement whereas the G60 uses a clevis
pin. I cut off the ball on the end of the master cylinder push rod
and fabricated a clevis fitting from a small piece of .35 thick
aluminum. In one edge I drilled a .22 dia hole for the rod to push
into and inline with it drilled a 8 mm hole for the clutch arm clevis
pin to pass through. The block is retained with the G60 clip and
clevis pin.
When the Corrado pedal cluster is used the GTI double jointed
connecting shaft between the bottom of the steering column and the
rack ends up being about 1/4 of an inch short. I dealt with this
problem by cutting the shaft in half and adding a sleeve of 3/4 inch
ID heavy wall steel tube over the shaft. The sleeve is held in place
with two thru bolts. Interestingly this same arrangement is used on
the GLX but the GLX shaft cannot be used since the spline on the rack
end is coarser than the one for the GTI.
The GLX throttle cable end that mates with the gas pedal is different
from the throttle cable end on the G60 accelerator pedal. Rather than
buy a Corrado VR6 throttle cable I cut the end off the GLX throttle
pedal and grafted it on the cable end of the G60 accelerator pedal.
As an aside the brake servo pushrod on the GLX also mates to the brake
pedal arm with a ball and nylon socket whereas the G60 like other A1
and A2 cars uses a 8 mm clevis pin.
STEERING COLUMN
There is a great deal of wiring associated with the steering column,
supporting such diverse functions as MFA control, hazard flashers,
cruise control, window washers and turn signals. The GLX column is a
tilt column that mounts from below on a beam about knee level while
the GTI mounts from above. Others have just welded a GTI style
bracket to a Corrado column however I thought it was cleaner to use
the GTI outer shell and put all the GLX stuff in and on it. The only
original GTI parts that were used were the wheel, plastic covers,
column tube with bracket and the ignition lock cylinder. The only
modification to the column tube is to relocate the tab that holds the
upper casting in place. Once the tab is removed every thing will drop
in place. The GLX uses a bushing with a spline inside and a second
larger spline outside to adapt to the air-bag steering wheel. When
this adapter is discarded it is necessary to add a means to retain the
upper bearing pre-load spring. The GTI uses a push ring. Not having
a push ring of the proper size, I drilled the shaft and added a small
cotter key over a washer to retain the compressed spring.
Judicious use of a Drermel tool was made to carve the interior of the
plastic covers to allow the many GLX connectors to fit inside. The
only externally visible modification is one hole in the bottom cover
required to clear the turn-signal-switch connector. The finished
appearance is very clean.
DASHBOARD
I like the OEM look and consistent with this preference my original
plan was to keep the Golf GTI instrument cluster, however when I
looked at having to deal with the speedometer and MFA problems I
reconsidered. The crux of the problem is that the GLX instrument
cluster is slightly taller and about 11/2 inches wider than the GTI
instrument cluster it must replace. Mounting the GLX cluster was
handled by cutting away the interfering behind-dash plastic structure
about two inches forward of the dash. New "hooks" that support the
mounting pins on either side of the instrument cluster were fabricated
and screwed to the stubs left intact when the plastic dash structure
was previously cut off. It is important that the cluster be rigidly
supported to avoid classic VW dash squeaks and rattles. The Golf
headlight/dash-lamp dimmer switch was replaced with a push/pull type
headlight switch/dimmer from a US Rabbit and relocated to the stock
hole located in a recess below and immediately to the left of the
steering column. I believe this hole is used for a cold starting
control on diesel powered cars. The black rubber knob from a late bug
was used for the HL switch. Moving the head light switch allowed for
the extra width of the GLX instrument cluster.
The cosmetic phase of this project is not yet completed so some of
this description is theoretical right now. It is my intent to
fabricate from 1/8 inch black Kydex (textured thermo-formable
acrylic-PVC alloy sheet stock manufactured by Rohm & Haas Co.) a trim
bezel to replace the GTI part. The fore and aft portion of the GLX
bezel will be cut away and then glued to the rear of the Kydex bezel.
Other VR6 swappers have installed the entire Corrodo dashboard which
apparently pretty much fits except for the ends of the dash near the
doors that need some trimming. Of course once you change the dash the
console will want to come with it. Not having seen one of these
installations I cannot compare the relative merits of the two
approaches other than to observe that it depends a lot on what parts
are available.
INSTRUMENT CLUSTER
The instrument cluster gave me fits at first but once I decided I had
no choice but to modify the dashboard it was very easy, at least
electrically. The GLX transmission has no mechanical speedometer
pickoff point and would be difficult to deal with, not to mention all
the various sensors that match the MFA in the GLX instrument cluster.
Once you accept the inevitable your course of action is obvious. There
is a single mega-wire cable from the fuse/relay panel (it plugs into
locations U1 and U2) to the instrument cluster. Electrically the task
is trivial since new wiring is not necessary, however mounting the
cluster and making the drivers-eye view beautiful is another whole
story.
To fit in the GTI dash the height of the cluster was reduced slightly
by removing the white lamp housing and green filter on the top of the
cluster. Green silicone boots were added over the lamps removed from
the housing and the lamps themselves moved into the slot in the top of
the instrument cluster. The slot was then covered with a strip of
aluminum tape. The repositioned GLX cluster mounts and is installed
and removed just like in the original VW installation, only its
positioning and location have been changed.
WIRING
When you first meet the wiring on the VR6 engined cars, typically by
removing the engine, it is a bit intimidating as you think about
having to get it all back together again. Its enough to make the faint
of heart turn to a brace of Webers. In the process of removing the
engine and behind-dash harnesses I counted and labeled almost 100
connectors. Once you get into it however you find that, with the
exception of the engine sensor connectors, practically all connectors
are unique. In other words almost no male will plug into an
in-appropriate female connector even if it has the same number of pins
and is of similar appearance. Needless to say, having either the
Bentley or the VW wiring manual for the donor car, obtainable from
Dymet in Strongsville, OH (216) 572-0725, is an absolute necessity
before starting this project. Caution is the watchword, blowing up
some of this solid state stuff due to a wiring mistake can really
divert cash out of your VR6 hopup budget fast.
My strategy for dealing with the extensive engine management wiring
was to use as much of the GLX stuff as possible and to only use the 85
Golf wiring for functions from the dashboard rearward (rear lighting,
fuel pumps, etc.) To this end all GTI wiring in the engine
compartment and behind the dash left of center was removed. The
wiring from the firewall forward (technically the fuse/relay panel
forward) uses the single GLX wiring harness for all functions. The
GLX engine harness mostly plugs into the GLX fuse/relay panel. The
GTI harness and fuse block were removed from the car and not used.
The mounting bracket from a G60 C was used to mount the GLX fuse/relay
block in the location formerly occupied by the GTI relay panel. New
holes had to be drilled in the bracket base to match the two mounting
studs in the Golf and properly position the bracket. The fuses and
relays are now accessed through a rectangular hole cut in the back of
the left cubby hole in the lower dash cover.
Disclaimer: All the wiring information below, while comprehensive is
not totally complete. There are bound to be small problems that must
be individually resolved. Even the VW wiring diagrams have a few
discrepancies. For instance my GLX headlight switch had two more
wires on it than is shown on the latest VW diagrams.
A short adapter harness was fabricated to go from the connector on the
end of the GLX instrument harness to the equivalent connector on the
GTI. This serves to enable the heater blower and air conditioning. The
GTI uses a relay normally mounted in the fuse/relay panel to power the
blower when the switch is in the high speed position while the GLX
powers the blower directly with a switch contact. A relay was added
in the adapter harness to perform this function. This jumper harness
consists of the fan switch connector, T10 Gray connector, GLX
connector T8 and the relay. I call the relay contacts A & B and the
relay coil C & D. The following table details the splices:
GLX CON PIN Conn T8 WIRE COLOR FUNCTION WIRE COLOR
GTI CON PIN Conn T10 Gray RELAY
1 bla/red Power yel/bla 4 A Cont
2 wht/gre ? - -
3 wht/blu Inst Lts - -
4 bro Gnd - - C Coil
5 green A/C signal to ECU gy/gre & bro/blu 6 & 8
6 green Turns on A/C bro/red 7
7 wht ? - -
8 - - - -
wht/red 10 B Cont
High Spd Contact bro/wht - D Coil
As mentioned previously in the DASHBOARD section the GLX instrument
cluster is wider than the GTI cluster opening so the GTI headlight
switch was relocated and replaced with one from a US Rabbit. Since the
Rabbit switch does not support some functions, such as fog lights and
switch lighting there are wires in the harness that are not used. The
following table details the connections:
RABBIT SW PIN WIRE COLOR FUNCTION GLX CON & PIN WIRE
COLOR
1 bro/wht Dome Light Gnd - -
2 gy/blu Inst Lights gy/blu
3 wht/bla Head Lamps bla/yel
4 gy/red Battery red/yel
5 gy Park & F Side Lts gy/bla gy/gre
6 gy Tail & R Side Lts gy/red
7 bla/yel Ign Switch bla/yel
gnd bro Gnd bro
Most of the GTI rear body wiring attaches to three connectors on the
GLX fuse/relay panel in connector locations K, L and M. A short
harness was made up with the K, L and M connectors on one end and the
GTI rear wiring connector (T10/gray) mate on the other end. The
following table details the connections:
GTI CON PIN Conn T10 Gray WIRE COLOR & SIZE FUNCTION
GLX CON & PIN WIRE COLOR
1 gy/gre #18 Parking Bk Sw L6
2 red/wht #18 Trunk Lt L5 red/wht
3 gre/bla #14 Fuel Pumps M2 red/yel
4 yel/bla #18 Fuel Sender M3 vio/bla
5 wht/gre #14 Rear Win Defog K12 wht
6 blk/gy #18 Backup Lts K8 blk/blu
7 blk/gre #18 R Turn Sig Lts K7 blk/gre
8 blk/red #18 Brake Lts K4 blk/red
9 gy #18 Tail & Lic Lts K2 gy/bla gy/red
10 bla/wht #18 L Turn Sig Lts K1 blk/wht
K11 bro
Dome Lt L7
The cable from GLX connector P goes only to the rear window defogger
switch and also needs an appropriate 85 Golf style connector put on
the switch end to match the GTI switch.
The method I use to splice wires in automotive projects is to strip
the ends of both wires, twist the stripped ends together and solder.
The joint is then covered with a short length of heat shrink tubing.
I find this technique neater and more OEM in appearance than crimp
type butt splices. If the splice is under hood or where water can get
at it, I cover the joint with a little silicone grease ( Dow Corning
#5) or RTV before shrinking the tubing over the joint for an extremely
reliable connection.
REAR WINDOW WASHER/WIPER
Since the GLX does not have a rear window wiper the
steering-column-wiper-control arm did not have a switch for this
function. I dealt with this by mounting a VW A2 type fog lamp switch
on the dash in the location formerly occupied by the emergency flasher
switch. The dash mounted Golf emergency flasher switch is no longer
required since this function is available on the GLX steering column.
The original GTI rear wiper relay is used and it is powered from the
fuse in location 16 thru a wire fed from connector/pin .
FRONT LIGHTING
All forward lighting power on the GLX is supplied by a single harness
that plugs into the engine harness. Adapting this lighting harness to
the GTI is a simple matter of replacing connectors for the GLX lights
with ones for the GTI turn signals and clearance lamps. On the GLX
the horns, ambient air temperature sensor and A/C pressure switches
are on the right side of the car and on the left on the A2 cars. To
deal with this I unwrapped the GLX lighting harness and split out the
horn and sensor wiring on the left side near the engine harness
connector. The harness was then re-wrapped. The right side of the
Golf was simply too crowded to conveniently mount the horns there.
CRUISE CONTROL
The cruise control system uses its own separate wiring harness and no
modifications were required. The pump was mounted in the old GTI ECU
location and the control box was mounted behind the dash with the
vacuum line and pump wiring going through the firewall by putting a
grommet in the old speedometer cable hole.
AIR CLEANER
I would have liked to use the GLX aircleaner but it is too wide to
fit in the space between the VR6 and the right side of the Golf engine
compartment. The VR6 Corrado air cleaner is a drop in. A short duct
was fabricated to get cool air from the space between the right side
of the radiator and the right frame rail. Many VW tuners choose the
reusable conical K&N filters and while the compact size was appealing
the thought of inducting hot under-hood air left me cold. They might
look like a good choice if you only do dyno runs with the hood up but
I try to avoid having the hood open when I want max power.
AIR CONDITIONING
I will not cover the A/C in detail since the choices are quite
individual. Corrodo hoses go across the firewall and approach the
condenser and compressor from the left while the GLX hoses go along
the right fender wall like the original Golf. This presents some
clearance problems when you try to run the hoses between the engine
and fan shroud. As I said individual solutions will vary. Note that a
non A/C serpentine belt is available for the VR6. I will be glad to
discuss these issues on an individual basis via Email sent to
EeeeeeS@aol<img src=/i/dc.gif border=0 width=35 height=15>
EXHAUST SYSTEM
The exhaust system was fabricated by using the GLX front resonator and
55 mm tubing and fabricating everything from there back from 2 1/4
inch tube. It is pretty roomy in that area so dimensions are not too
critical. The required twists and turns were made by butt splicing
pieces made from sections of tube and two 180 degree 6 inch radius
mandrel bends. The rear muffler I chose is a Walker DynoMax PN 17731.
The tubing used has a 60 thou wall and a bend radius of 6 inches. It
can be purchased from JC Whitney. How this is done to achieve a
professional result is another story in of itself but if done properly
the finished part is hard to distinguish from a continuous tube.
For those so inclined the parts I used were two back to back 45 deg
bends in a horizontal plane to go to the left of center followed by a
90 deg bend in a vertical plane to go over the axle. A vertical plane
45 deg bend hooks to the end of the 90 deg bend before heading to the
exhaust pipe opening in the rear skirt. There are a total of 90
degrees in phantom bends in the system achieved by twisting the
splices. One 45 degree twist is between the two horizontal 45 deg
bends and two more 22 1/2 deg twists on either side of the vertical 90
deg bend.
The fabrication outlined above requires a protractor and a chop saw
and is based on the geometric principle that if a mandrel bend is cut
on its radius (perpendicular to the axis of the tubing) the cut end of
the tube will describe a circle rather than an ellipse. The circle is
easily matched to either a piece of straight tubing or another section
of mandrel bend. This only works if the mandrel bends are of high
quality and the cuts are accurate. The tube is positioned in the chop
saw by a circular wooden plug the diameter of which is twice the
mandrel bend radius minus the diameter of the tubing. The plug is
bolted to the chop saw table with the saw blade aligned with the
center of the plug. If you can make a cut mid-way in a bend and have
the cut faces match when they are turned in relationship to each other
the fixture is set up properly.
The exhaust hangers were fabricated from the part used on the body end
of the rubber dounut used to support the CAT on a Rabbit. These are
plentiful in junkyards and match the Rabbit donuts and the hangers on
the 85 GTI body.
PARTS LIST
Following is a list of VW parts required to install a VR6 engine in a
A2 Golf body:
1.VR6 engine & transaxle
2.Shifter and cable mechanism
3.Subframe from a VR6 powered car
4.Front mount crossmember *1
5.Half shafts with 100 mm diameter inner CV flanges.
6.Steering column from a VR6 powered car.
7.Corrado radiator VR6 or G60
8.Corrado VR6 radiator hoses
9.VR6 powered dual fan radiator shroud assembly
10.High pressure radiator header tank and bracket
11.Air-conditioning stuff *2
12.Cat
13.Exhaust Stuff *3
14.Clutch master and slave cylinders
15.Corrado pedal assembly
16.Brake fluid reservoir with clutch cylinder fluid outlet
17.Engine wiring harness
18.Fan relay/fuse block
19.Instrument cluster
20.Instrument wiring harness
21.Instrument cluster harness
22.Grille harness
23.Miscellaneous connectors from the rear body harness that match VR6
fuse/relay panel
24.Main VR6 fuse/relay block
25.ECU
*1 The A2 crossmember can be used but one from a Passat or Corrado is
to be preferred.
*2 What is required to install air-conditioning will depend on whether
a R12 or a R134 system is desired. A serpentine belt is available for
use on an engine without an a/c compressor.
*3 The A2 Golf had a 2 inch dia system with ugly crimped bends,
presumably something more free breathing will be desired.
PRIOR ART
Listed below in no particular order are all other individuals and
tuners that I am aware of that have performed VR6 swaps into older
water-cooled VW chassis.
1.Max Nealon in the UK has a Rabbit with a much modified VR6. His car
apparently is very functional in appearance having the firewall moved
rearward and a rally car like interior with aluminum panels, roll
cage, etc. Max"s Email address is max@basing.progress<img src=/i/dc.gif border=0 width=35 height=15>
2.Rons Parts Inc in Canada has done several A2s and an A1 swap.
Employees" cars have been featured in European Car in the Jan 94 issue
and two later cars are featured in the May 96 issue.
3.EIP Tuning in N Carolina has a VR6/A2 featured in an issue of
European Car. Rich the helpful owner of EIP can be reached via Email
at EIPTUNING@aol<img src=/i/dc.gif border=0 width=35 height=15>
4.Stu also in NC has a 3.1 VR6 powered 86 GTI. He can be reached at
5.There is a turboed VR6 engined 89 Golf that belongs to a Jamaican
resident pictured on page 25 of the Aug 95 issue of EC. This engine
on this car has been modified subsequently by EIP.
6.Tim Styles Racing in the UK has a car featured in Cars & Conversions
and the car is mentioned on page 45 of EC Feb 96.
7.Paul McCallum of Deutschcar in the UK has his A2/VR6 featured in the
Aug 95 issue of Cars & Conversions, a UK magazine. He also offers
conversion mounts for sale.
8.Sandor Kruise, a VW technician in the Netherlands, has a wild
sounding Golf with an extensively modified VR6. Can be reached via
Email at digitech@ilimburg.nl
9.Wayland Gee is in the process of swapping a Corrado VR6 into an 85
GTI. Progress of his project can be seen on his home page at
http://userwww.sfsu.edu/~ebnacor/waytech.html. Wayland"s Email
address is wkgee@ucdavis<img src=/i/de.gif border=0 width=35 height=15>
10.Peter Haug of Redondo Beach, CA transplanted the drivetrain from a
94 SLC into an 88 Golf GTI. Peter can be reached at
peter.haug@alliedsignal<img src=/i/dc.gif border=0 width=35 height=15> or DR5LUG@aol<img src=/i/dc.gif border=0 width=35 height=15>
TOOLS & TIME
This seemed an odd question to me but enough people have asked so here
it is. Other than basic hand tools and an electric drill nothing else
is mandatory. An important factor is the availability of Corrado
parts. The more Corrado parts used the fewer the modifications and
the easier the job. Additionally the A/C and the external oil cooler
added quite a bit of work to make everything fit in the limited space
available. In the way of nice to have items that I used in this
project were the following:
A well lighted garage.
Engine hoist. I use a heavy duty coffin puller hooked to the rafters
in my garage.
Floor jack and jack stands
VOM to buzz out the wiring.
Acetylene torch to help with some the bashing.
Chop saw to modify brackets and fab the exhaust.
MIG welder to fab the exhaust system and attach brackets.
Dremel tool, indispensable for dash and steering column mods not to
mention undoing tack welds made by mistake.
Lathe used to cut down the right rear mount and make various fittings
and spacers.
The time thing is a lot more difficult to tell about since there is no
way for a reader to know what else was going on in my life and no one
else did anything on this project. I am told that for-money guys like
Rons Parts and EIP get it done in about three weeks using all Corrado
parts. The biggest time sinks for me were the A/C, oil cooler and the
GTI dash. A last crucial factor in stretching out the time for me was
that I shopped around a lot to avoid overpaying for some of the
necessary parts. Besides, speeding up the project would only shorten
the fun.
APPENDIX
In my quest for maximum road horsepower and lower underhood
temperatures I decided to stick with a R12 based air conditioning
system. Using similar components, a R12 system is about 50 % more
efficient than a R134a system for the same cooling effect. In simpler
terms you get more hp left for the road with R12 than you do with
R134a unless you don"t mind getting hot. VWs with VR6 engines built
after 1993 use R134a and a variable displacement compressor driven by
a serpentine belt system for the a/c. I couldn"t find a suitable
clutch that would fit a SD 708 compressor that would fit on the VR6.
In any case these parts would be pretty expensive. So after quite a
bit of on-line research, I established that the Sanden SD7V16
compressor that came on the GLX could be used with R12 by the simple
expedient of flushing all the PAG oil out of it and refilling the
system with R12. The only problem would be accommodating the
incompatible fittings on the compressor ends of the Golf hoses.
Because of the reduced clearance between the radiator and the VR6 the
fat low-side hose must also be extended. Both these goals were
accomplished by cutting the Golf low-side hose off just after the
in-line muffler and welding on the hose end from the GLX. The
resulting hose will now be long enough to reach around the left end of
the intake manifold and not have to go between the manifold and
radiator shroud. The smaller GLX high side hose was used without
modification by making up an extension from the aluminum parts of the
Golf high side hose. The extension was made by welding the switch and
service valve fittings removed from the Golf onto an aluminum line
from a Toyota that had the right fittings on both ends. When completed
the hose assemblies are rather resistant to twisting so be sure to
orient them optimally before welding the two ends together. The
resulting installation is very clean.
It cannot be stressed too strongly the necessity of completely
flushing out all the PAG oil, used in R134a systems, from the lines
and compressor before introducing mineral oil, used with R12, into the
system. Mixing the two lubricants, particularly in the presence of
steel which acts as a catalyst, will result in severe corrosion in the
system.
Since the GLX used a variable displacement compressor that regulates
the low side pressure to 29 PSI the temperature controlled switch on
the evaporator core that causes the clutch to cycle is not a strict
necessity however since the 95 Golf already has one I left it in place
in series with the compressor clutch. A new drier, evacuation and a
recharge with R12 completes the installation.
OILCOOLER
The article that follows outlines how to fabricate a very efficient
oil cooling system for the VW VR6 engine. The system described, while
in the strictest sense a bolt-on, needs to be fabricated. I have
described sources for the key parts and the modifications required to
make them all work together. The result is very low cost and gives
performance that cannot be bettered at any price.
If you believe even a tenth of the on-line posts on the subject, the
VR6 engine needs all the help in the cooling department it can get.
Like the diesels and 16V engines, the VR6 has oil squirters that
direct a spray of oil over the bottom side of the piston crowns to
maximize the cooling effect of the oil. VW choose to transfer this
heat to the radiator via a oil to water heat exchanger. This is a
cost effective solution on their part in that an oil radiator is
eliminated with the additional benefit of fast warm-up of the oil.
However it also provides hotrodders who live in hot climates an
opportunity to easily increase system cooling capacity. A well
designed cooling system has excess capacity and uses a thermostat to
set the operating temperature.
One of the best VW oil cooler systems around was the original factory
system used on the European GTIs. This system replaced the US style
oil filter mount with one containing connections for an external oil
cooler and a thermostat with a large diameter hot-wax actuated piston.
Like most OEM VW parts this is a very high quality piece not to be
compared with some of the after market stuff produced by obscure
manufacturers. This thermostat is of the same design as used in 911 &
935 Porsches with front mounted oil radiators. In fact the pistons are
interchangeable with the VW ones except that the Porsche thermostat
opens 15 deg C lower in temperature than the one VW specified for the
Euro GTI.
Lucky for us the Audi 5000 turbos use the same thermostat with the
added advantage that, unmodified, it will bolt up to the VR6 block in
place of the oil/water heat exchanger. Turbo Audis are plentiful in
junkyards and I only had to pay $3.50 for this fine item at my local
Pick-A-Part. The earlier turbo Audis had two filters on this mount and
turbo diesels have a cover where the second filter would go. I am
not sure but it looks like one filter is for the engine and the other
for the turbo. The mount I obtained ( VW PN 034 115 417) was off of a
86 Audi turbo and it differs from the earlier cars in that only one
oil filter is used and the oil lines to the cooler are1/2 inch while
the earlier cars, like the Euro GTI have 3/8 inch lines. The bad
news is that there is an interference with the upper of the two
ignition knock sensors on the VR6. Knock sensors, as implemented by
VW, are notoriously finicky about their mounting. Because of the
foregoing I was reluctant to alter the sensor mounting in any way.
The are numerous ways to make this accommodation and the path chosen
will depend upon the nature of the resources available. A simple way
would be to add a 1/4 inch thick disk as a spacer between the adapter
and the VR6 block. This would work well with the older two-filter
adapter but would require fabrication of a new longer mounting bolt to
use the 86 filter mount. I chose to lop off the filter mounting
flange and weld a cover over the hole. This allows the Audi adapter
to mount on the VR6 with the thermostat portion of the adapter
pointing straight down with plenty of clearance all around. The
turbocharger oil line hole must also be closed either by welding it
over or by plugging it with a 3/8-18 setscrew tapped into the hole in
the casting.
On the VR6 the oil inlet and outlet end up facing straight forward
where there is plenty of clearance, if 45 degree hose-end fittings are
used. Both VR6 water hose connections, that formerly went to the
oil/water intercooler, were closed with caps.
It is tempting to consider bypassing the canister filter that comes
with the VR6 and using a conventional spin on filter on the Audi mount
however I do not think that this is feasible. I am guessing, but I"ll
bet that VW engineers considered the maximum VR6 oil pressure
excessive for a spin-on type filter.
The oil cooler used by the earliest Audies is the same as the one used
on later Bug engines with the dog house oil cooler. Later cars use a
similar shaped cooler but with banjo fittings right on the cooler. I
don"t believe the Bug/Audi shaped cooler is optimum in form factor for
most VW applications since it has a rather thick core that is better
suited to a location with a high air pressure and on the Golf it is
hard to find such a location. An aftermarket cooler that is thinner
but with much more core area, mounted below and behind the bumper,
should be much more effective.
The cooler I selected came from a rotary powered Mazda. It is a
monster thing 5x19.5 inches with large I/O fittings. Conveniently the
threads into the aluminum fittings on the Mazda cooler are the same as
the threads on the older Audi oil filter mounts. Unfortunately they
come out on the side and I had to relocate the fittings to the right
end. In my installation in a 85 Golf the oil lines exit the
thermostatic mount from 45 degree fittings and go horizontally to the
right, past the a/c compressor and around the end of the radiator.
The two oil lines continue forward out of the engine compartment
through the 5 inch space between the right end of the radiator and the
frame and directly into the cavity in the backside of the bumper where
the oil cooler is mounted vertically by bolting its mounting tabs to
brackets that extend rearward from the top inside of the steel bumper
insert. The 3/4 inch thick aluminum brackets are secured by bolting to
PEM nuts (nutserts) installed in the top of the insert. The cooler is
positioned toward the drivers side of the car and protrudes slightly
below the bumper. The hoses lay in one continuous arc directly into
the right end of the Mazda cooler.
The Mazda oil cooler has a built in thermostat that I did not want to
use so I removed it and its associated spring and replaced them with a
2 inch length of 1/2 inch hose. When compressed by the end plug, the
hose is just the right diameter to seal the thermostat cavity. As an
aside the Mazda oil cooler with thermostat might be used with a simple
non-thermostatic sandwich plate type oil cooler pickup. The major
problem with this approach is that the hoses are subject to very high
pressures when the oil is cold. I rejected using the Mazda thermostat
to avoid the added flow restriction of the hoses to cold oil.
The plumbing for an oil cooler installation should be low restriction,
light weight, tolerate high pressures and be very reliable.
Personally I also add low cost to the list. To meet these
requirements I choose size 8 a/c hose fittings, the kind that use an O
ring to make the seal. The fittings are available in either aluminum
or steel in a wide variety of configurations. They seal well and have
very low flow restriction. If you are serious about an OEM look you
can have hoses made up at any a/c shop, other wise use clamps and a/c
fittings scrounged from your local junk yard. The aftermarket fittings
designed to work with clamps are the easiest to work with but the OEM
crimp-on fittings can also be used by cutting off the crimp-on ferule.
To connect the hose fittings to, on the right end of the cooler, I
welded on two female fittings removed from an old a/c condenser.
I used the hose ends from the Audi that match the fittings on the
thermostatic filter mount. The hose end fittings are odd metric things
that use a tapered ferule and O ring for sealing but they have nice
low restriction bends and will work on fractional-inch sized hose if
modified. The Audi oil hoses are rather nice steel braid covered
Teflon lined types but it is unlikely that a suitable cooler location
can be found on the VW that the hoses will reach
The hose ends on the late Audi are designed to be used with steel
braid covered Teflon lines however they are a little contorted for use
in a typical VR6 installation. I chose to use 300 PSI rubber covered
lines so I made fittings by silver soldering hose barbs on to the
cutoff ends of the Audi fittings. The contorted fittings can easily be
reduced to a simple 45 degree bend by cutting them off just past the
first bend and brazing on a hose barb cut from the end of a steel a/c
hose fitting. If you choose to use the early Audi oil filter mount,
the hose ends from the cooler end of the Audi hoses are just right
unmodified for use on the engine end of the hoses in a VR6
installation. They have the additional advantage that they are
designed for use with rubber hose and require no modification. Also
the threads on the early oil filter mount are close enough to 5/8 -18
to use standard AN fittings if so desired.
I have tried to provide some background leading to my decisions so
that my junk yard parts research could help other fabricators that
have unique installation problems in other vehicles using the VR6
engine.
VR6 Corrado RADIATOR HOSE
TOP HOSE
The top radiator hose PN 535 121 101H on a VR6 powered Corrado that
sells for over one hundred bucks at your friendly dealer can be
replaced with one from Trak Auto ( PN 71238 for $5.35) The fit is
good as purchased and was made perfect in my case by trimming 1/2 of
an inch from the radiator end. The bad news is that the 71238 has no
provision for the 8 mm air bleed hose. I remedied this by making a
fitting to tap into the plastic elbow on the top of the radiator. I
made the necessary fitting by drilling out the center of a 1/4-20
stainless steel bolt with a #30 drill and silver soldering the bolt
into a brass 5/16 hose barb fitting. The hose barb fitting I started
with was for 1/8 inch pipe. I cut the threads off nice and square
just past the hex and soldered the 1/4-20 bolt in the 1/4 inch hole in
the hose barb fitting. The plastic elbow was drilled and tapped with
1/4-20 into the mounting flange just above the O ring opposite the
inlet. Make sure the hole is perpendicular to the flange surface to
insure a good seal. A thin rubber washer on the screw for sealing
completes the fabrication. The bolt threads were coated with Permatex
"just in case."
Do not be tempted to omit the air bleed hose. This hose drains the
air pockets, that will develop at the two high points in the cooling
system, into the headertank.
BOTTOM HOSE
The bottom radiator hose PN 535 121 051B that sells for 50 bucks at
the dealer can also be replaced by one from Trak Auto (PN 70995 for
$7.49) The shape required is quite complex and I did not expect to
find one that would be an exact fit however to my surprise the 70995
can be installed without modification and function but the installed
shape is not very esthetic. The complex shape of the VW hose is
forced by the requirement that it go up and over the swinging weight
on the shifter just after the hose connects to the coolant outlet on
the block. To get a perfect fit I cut the hose in two and flipped the
top piece end for end and spliced the two pieces back together with a
2 1/2 inch long piece of 1 1/4 inch OD tubing. The hose as it comes
from Trak approximates a question mark in shape if held up vertical
with the 1 1/4 inlet at the top and the 1 3/8 outlet at the bottom.
The hose should be cut about 1 1/2 inches below the end of the curved
portion of the question mark and again about 4 inches below that. The
4 inch piece is discarded. The 1 1/2 inch stub just created by the
first cut goes to the engine outlet and the top part of the question
mark is spliced to the top end of the bottom piece of the hose. Trial
fit everything in the car before clamping anything in place. Get the
proper orientation between the top and bottom pieces of hose before
clamping them to the splice tube.
The thin wall 1 1/4 OD brass tubing used for the splice is available
in plumbing stores. It is intended for use above or below the trap in
a sink drain. Try to avoid the chrome plated stuff as it is quite
slippery.
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(Todd Walke)