TRANSPLANTING A VR6 INTO A 85 VW GTI by Eric Schumacher e.schumacher@worldnet.att.net 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 sub-frame 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 WIRE FUNCTION WIRE GTI CON RELAY PIN COLOR COLOR PIN Conn T8 Conn T10 Gray 1 bla/re Power yel/bla 4 A d Cont 2 wht/gr ? - - e 3 wht/bl Inst Lts - - u 4 bro Gnd - - C Coil 5 green A/C signal gy/gre & 6 & 8 to ECU bro/blu 6 green Turns on bro/red 7 A/C 7 wht ? - - 8 - - - - wht/red 10 B Cont High Spd bro/wht - D Contact 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 WIRE COLOR FUNCTION GLX CON & WIRE COLOR PIN PIN 1 bro/wht Dome Light - - Gnd 2 gy/blu Inst gy/blu Lights 3 wht/bla Head Lamps bla/yel 4 gy/red Battery red/yel 5 gy Park & F gy/bla Side Lts gy/gre 6 gy Tail & R gy/red Side Lts 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 WIRE COLOR FUNCTION GLX CON & WIRE COLOR PIN & SIZE PIN Conn T10 Gray 1 gy/gre Parking Bk L6 #18 Sw 2 red/wht Trunk Lt L5 red/wht #18 3 gre/bla Fuel Pumps M2 red/yel #14 4 yel/bla Fuel M3 vio/bla #18 Sender 5 wht/gre Rear Win K12 wht #14 Defog 6 blk/gy Backup Lts K8 blk/blu #18 7 blk/gre R Turn Sig K7 blk/gre #18 Lts 8 blk/red Brake Lts K4 blk/red #18 9 gy Tail & Lic K2 gy/bla #18 Lts gy/red 10 bla/wht L Turn Sig K1 blk/wht #18 Lts 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.com 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.com 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.com 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.edu 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.com or DR5LUG@aol.com 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.