GOLF RALLYE, blast from the late 80`s and early 90`s.
5000 were manufactured to satisfy FIA homologation for the 1990 world rallying championship originally. These were hand built for that purpose with a 1,763cc supercharged engine, and syncro four wheel drive system. Boxy and only in left hand drive, the square headlights are a dead give away to the period produced but, these cars are a thrill to drive and when most manufacturers were bolting on big turbo`s and sod the lag the golf rallye was a little different, incorporating a super charger for boost.
Above is only an example of an original car.
The car I am working on is even more special with a V6 fitted and a turbo kit from the states requiring much more plumbing in.
As you can see from the following picture there is very little room between the turbo and the bulk head, also the clearance between the steering rack, bulk head and rear prop shaft has caused some issues in getting the 3″ stainless exhaust round, down and through to the under side of the car.
Initially the biggest problem here was to build an exhaust from the turbo and get a tight enough bend through almost 180 degrees to swoop the gasses away round and down. This first part needed to also include a waste gate feed pipe and 2 lambda sensor bosses. The problem was that this radius was going to have to be “FT” (flipping tight) as we needed to twist the down pipe to thread it through the gap between the bulk head and the steering rack cover / sub frame.
The above image is what we ended up with a very tight, sectional sweeping bend that gradually scrolled downwards, shown here tacked up and set in position, leaving a minimal 10mm clearance between pipe work, bulkhead and steering rack. Luckily the engine mounts on this are uprated and pretty rigid thus reducing any movement and hopefully any clattering of the pipe work against nearby parts of the car.
Once past the tight spots and under the car I added a flanged joint before the straight run under the prop shaft which included a flexible section and a second flanged joint at the back just before the rear diff, where I had to then kick up the pipe and find a way through the sub frame and drive shaft (again with minimal clearance anywhere), this called for some “scalloping” of the 3″ pipe work to give some clearance as required.
Above image showing the flexi section after the down pipe before fitting the flange joint. Careful consideration needs to be taken with mounting points and support for a large diameter exhaust system such as this, and for this reason a mounting is fitted just after the flexible section(as above). additional supports at the rear of the car, 3 on the back box and an additional one near the diff help keep the exhaust stable and steady.
Back box (above) was a Magnaflow unit brought in and adapted to suit the car, this is a perforated straight through high flow box with oval rolled edge tail pipe – again modified to suit the car. Rubber mounting pick up points were made from flattened 10mm bar with small “tabs” welded to the ends to prevent the rubbers slipping off the end. Also shown is the flanged and welded flexi section.
Above image shows all sections of the fabricated exhaust with the exception of s short double slip joint section made to fit after the diff to the back box. Having built the section and tacked it all up that was to thread its way through the rear sub frame / diff and drive shaft area at the back, I found there was no way in the world I could feed all this through the gaps there were; in one piece? This meant that I had to remove a section and mate it up to the remainder and make it as a double ended slip jointed section to be able to feed in from the rear of the car, there was just no other way to get the pipes in back to the back box.
Rear section being modified to allow for scalloping and slip joint.
Down pipe following welding but, not including waste gate stab in. Note that I had to brace the bend before welding to prevent the sectioned bend from shrinking in to a smaller radius and changing the angle of the following down pipe. In areas where there was a wider gap purging the back of the joint with argon helped keep the internal welds as smooth as possible for gas flow purposes. Note the addition of 2 lambda sensor bosses which are needed to accommodate the requirements of the electronics running the motor.
The 2 images above show the final down pipe with waste gate stab in all fitted loosely into position. Due to the limited space and shape of down pipe I had to modify the position of the waste gate to exhaust pipe 3 times. This was due to the fact that you have to revolve the whole section around to get the flanged end through the gap and then roll it and twist it to get the connection to the turbo in line before clamping up. Once I added the waste gate pipe and flange the whole assembly got stuck and / or hit in other places preventing me from maneuvering the section down and through and then twisting to mate up to the turbo. All in fitting this whole section up must have taken 15 trials with mm minor adjustments each time to get it to work.
I haven’t done exhaust pipes for cars for some time as they are generally always a bit of a “pig” on modified cars, this one was a “wild boar”. It must have been one of the biggest challenges I have faced when completing an exhaust. Hence no one else wanted to take it on I believe.
I don’t think I will be doing any more on cars for sometime – give me a motorcycle exhaust any day!
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