S2 track car with A8/A4/susp & AAN engine

[Ryss]

After much sole searching I have decide to make a track car out of the S2 body I had started converting to A8 running gear. See S2 with A8 transplant

Work to date of A8 rear and front subframes with A4 shock towers will be finalized. Power will be provided by an AAN and 6 spd box, requiring A8 diff to be swopped over to the URS4.

Making good progress so far. Here is a teaser of the front wheel at max upward travel with a fiberglass S2 fender, merged to a fiberglass URS4 fender flare. Lots of work still required to shape and finish.

Axle center is a good 40 mm further forward than the original. All helps to improve weight distribution.

Huge amount of work I know.. but keeps me out of mischief.

PIcs and updates follow.....

[Ryss]

Here are some of the major steps to date>

Rear A8 suspension in place with A4 B6 rear bumper to see how well it matches.



Front shock towers cut out.


First test fit of the A4 shock towers.

[Mcstiff]

I've thought about how difficult it would be to go to a multi-link suspension. Not sure I'd take this route but I'm interested to see how it ends up!

[Ryss]

Mcstiff : Always many ways to skin a cat. So far this is working out quite well. Final set up will be with adjustable control arms made up by a local fellow who looks after a few racing A4's (one Quattro and one FWD). Very interested to see how the change in weight distribution, axle center and the effect of the double wishbone suspension, impacts on turn in and understeer.

Only thing that is worrying me is the access to top of gearbox when all installed. Jobs like access to things like clutch slave cylinder etc. may be even more difficult with the A4 steering rack in place.

Need to start some planning and research on oil surge reduction program. Dry sump is out of the question because of the cost.

Currently busy welding in reinforcements to chassis legs etc before finally welding in the new shock towers. Pictures will follow.

[mastermind]

Looking fwd to seeing the progress Ryss . Hope you have time to pop in for track day on Sat

[Ryss]

Well I have been very lax in posting pictures and as a result have not updated this thread. Will do so soon, but in the interim those on FB here is the link to my public project.
https://www.facebook.com/media/set/?...4487553&type=3.

Current status is the A4 shock towers are all welded in. steering rack, brake booster are mounted, the latter, inside the car and only master cylinder is on engine side of firewall.

Dropped engine in last week end and it fits over the A8 subframe. Sill want the engine to move back 40mm from standard position, so will need to trim the subframe a tad to allow this. Offset between gearbox output and front wheel hubs, which are also 40mm further forward, is 80mm. A8 subframe and A4 shock towers result in a nice 4 degree camber using the standard suspension arms.

Current problems are : Stainless steel exhaust manifold will not fit with engine moved that far back and with the bigger shock towers in place.

Existing engine and gearbox mountings on subframe are all close enough to use with standard mounting arms that drop off engine and gearbox, but will require some fabrication, work to a mounting that bolt onto the A8 subframe . Standard engine mountings on chassis were cut off the chassis, when the plan was to fit a V8.

Being a track car solid poly mountings will be used including and an upside down front mounting.
Anybody got any tips ideas on this aspect.

Also pondering wether I should change the head gasket and rod bolts with ARP units.
Motor has 180 000kms on the clock and RS2 turbo. Target Kw is 250 to 300.

[andy10v]

Good progress.

How did you mount the steering rack? Are you going to use a cast manifold if you are running rs2 spec if that would clear?

[Ryss]

Andy, standard A4 rack mounted under the piece between the two A4 shock towers.

Cast manifold I think will work with some tight bends.

[Thuppu]

That stainless manifold will crack anyway so it's only good that it doesn't fit in. You need to manufacture a custom manifold, mild steel is cheap and holds better than stainless.

Did you have the a whole A8 body? Why didn't you use it? Quite light body though.

[Ryss]

Nothing light about and A8 at 1800kgs. Anyway car was a write off.
Agree with you on the manifold. Will have one made up from steam pipe.

[Thuppu]

I mean stripped of course. The shell itself is light, aluminium make.

[Ryss]

Work continues but a bit side tracked with other projects. The fabrication of wide front and rear fenders and welding is very time consuming.


Manifold is being made, engine and gearbox mountings have been made, front mounted radiator fitted (Ex URS4).

Here is a pic of the fibreglass plug / front fender we are working on.