S2 with A8 transplant

[Ryss]

Pics will follow for sure. Just do not want to post pics of half finished progress, unless they are pertinent.

Got the chassis dimensions today. Looks good and will help especially with the front of the car, but still trying to figure out how to read the measurements without the chassis jig to which they relate.

Going to buy a DIY MIG welder as this will workout cheaper than hiring one, to do all the welding on the body, roll cage etc. that needs to be done.

[WabTheKing]

looks like a good project!!

[Ryss]

looks like a good project!!

Coming from you, I take that as a compliment as to the concept and not my work.

When you see me heading for a train smash, please feel free to say so.

[my2000apb]

loving this thread , lets see soem pics

[Ryss]

Before finally welding in the front mounts to the A8's subframe I thought I better just check that all was still good . This is what the presentation of the A8's subframe to the S2 body looks like.

.

Fitted in fine but not well centralized on the mounting bolts, so a will move the mountings to the outside of the car, so that the whole subframe can be moved left/ right or front/back. This is normal to allow for fine adjustment of tracking and alignment.

[Ryss]

Well the refitment went fine. However the chassis extension I made to pick up the rear subframe mountings, will have to be made over again.

The chassis extension needs to go further forward and be wider in the front so that it can be welded into the outside of the existing chassis. It has to then become narrower to leave enough space for the two silencers on each side. So back to the drawing board on this. Also would like to make the extension lighter, if I can.

Here is a pic of the offending knuckle that needed part of the chassis to be cutout.


The final fitment has required the wheel to be positioned further back in the wheel arch.


Could not get the subframe further forward without major mods and anyway reasoned that as the wheel well has to be modified, its easier to do to the back of the car, where the floor has already been removed. Most important however, was to align the shock mounting points under the existing shock towers.

The wheel will be in the center of the restyled and flared fender, which will have to be over 7cm wider.


I presented an old bumper from an A4 (B6) just to see. *Holds some potential as a base to complete a restyled bumper for the car.



Particularly like how the sides match the wider wheel base. That could save hours of shaping.

[Ryss]

Made new chassis extension a decided that it would be safer to mount the fuel tank over the rear subframe. between the shock towers,but will cover with a panel that seals the fuel tank from the interior of the car. Avialable space is 400mm x 250mm x 800mm and should give 80 Lts capacity.

The new chassis extension is just long enough for the rear subframe mounts.



In retrospect, I should not have cut the rear mountings of the A8's subframe, and should have cut out the existing rear mounting and the cross member. This would have made the job much easier.

Just need to weld on the mounting points, but before doing so the correct angle of the diff input flange needs to be measured and the height of the rear mountings needs to be correct although adjustments, in one direction, can be made with spacers. Then to weld the new chassis extension into the car.

The area between the rear subframe and the rear of the car will be reserved for silencers. The floor will be replaced with a flat steel sheet with spot welded reinforcing ribs. However first need to widen the rear of the wheel wells

Needed a change in tasks, so started work on stripping the rest of the A8. Removed the prop shaft and then engine gearbox and front subframe as one unit.



Pretty heavy, but moved it with the help of some short lengths of boom sticks between the two planks I used under the engine and gearbox.



I wonder if 4 guys can lift this by hand. Else will just move the S2 while I fit the front subframe or hire an engine lift.

Had a quite chuckle to myself about how much the A8's prop shaft will need to be shortened.Hope I can get away with out using the centre bearing, else I will need to shorten the propshaft in front and behind the centre bearing.

The rear mountings of the front subframe are going to need to be a bit further back but are set further to centre of the car, than the standard S2 mounting positions. This is a good sign as is will be easier to create the new mounting points in this position. Also indications are that up to this point there is enough width available for the engine and g/box. But I'm pretty sure that the external drive to the front diff. is going to be too wide for the tunnel

[vonbeck]

hats off to you keep up the good work and we all love picis!!!! brill project

[my2000apb]

sweeet progress

[WabTheKing]

with regard to your rear bumper idea.........here's one i made earlier!! hahaha

http://www.s2forum.com/forum/showthr...tt+rear+bumper

cheers
will

[Ryss]

Thanks for the comments, Guys.

WabTheKing... those are not exhausts they are drain pipes..:mischeif:. But a very neat set up. Thinking along the same lines but with a under body spoiler type centre feature... maybe!!. Would like to show off the diff if possible.

Can anybody help me locate a rear Torsen diff from an old V8?

Other progress is I went for some lessons in using the MIG welder today. Found out the lowest Amps are 40 but wire speed must be slow to weld thin stuff.

Moved the engine and stuff under cover last weekend and refitted the ecu's and other bits, just to test my memory as to what goes where. Engine needs a good clean and polish and then I will post some pics. All mountings are bust (due to accident) so I will have new ones made up. Planning a busy wekeend.

[Ryss]

Plan for this work session was to fit the rear mountings to the chassis extension . First we needed to ensure the diff input flange was straight relative to the car. In doing this decided to remove the remnants of the old chassis cross member as this was interfering with the height of the subframe and diff. See first pic below.

Finished welding the new chassis extension (with MIG) and then added the brackets for the rear subframe mounting points (arc Welder). Net result of all of this is that all the changes I did to the rear subframe mounting points were unnecessary.

Next job was to weld the new chassis extension to the car, could have done with more practice with the MIG welder before attempting this as its totally different from arch welding. However it went well. Tack welded until the whole seam was done and then took a quick run along the seam. Worked well and good penetration through the thin plate. New chassis extensions is now attached and no flexing but will add some additional braces and supports when the old chassis box is closed around the new extension.

Put the wheels back on and starting planning what cuts needed to be made to move the wheel arch backwards. First thing I realised is that before cutting out anything I had better brace the tail end of the car as a lot of strength will be lost when the rear 30% of the wheel arch is cut out. Spent the rest of the afternoon on this planning.

Inside wheel arch looks as follows.


Outside planning looks as follows.


I have being playing around with photo editor as well and looks like all the cut lines are correct. Effectively back section needs to move back 70mm, front by 40mm and the piece in the middle (30mm) needs to be added in.


Still undecided if the final molding should be done in steel or fiberglass. If I decide to fit a fiberglass skin it will join along the window, round the taillights, under the bumper and inside the door jam. So no join seams will be visible on the side of the vehicle. In this case the steel modifications do not need to look perfect as they will just serve to provide the structural strength.

Until next week

[WabTheKing]

surely gotta be easier to move the subframe and whatever is infront of it forward?
think id be chopping the floor before the body, you got a picture of the underside and the bit causing the problem?

cheers
will

[Ryss]

WabTheKing... Big factor that fixes the position is the top control arm shock mounting position is now directly under the shock towers. Any further forward and the shock mounting will be out of alignment. Bottom shock is typical Audi front shock with a inverted "u" attached to the bottom of the shock and which fits over the control arm, with a bolt that attaches the shock to the control arm. Must be mounted with the shock vertical to the control arm.

I am currently using the existing S2 front subframe mounting points with the A8 mountings moved inboard to match. Was initially looking at making new mounting points on the chassis, until I realized that the subframe can only go where it is now.

The widening to the wheel arch is not a major additional problem as it would have to be done anyway due to the wider track. I little more complicated to move it back as well as up and out.

Thanks for the heads up. Made me have a rethink..

[Error404]

bear in mind the stock coupe has a fair bit of positive castor angle on the rear axle though
The position and angle of the strut tower is not vertically central over the wheel arch.
I'm with Wab, surely its easier to move the subframe et al forwards?

Interesting project - my guess is you will end up with half a tubular spaceframe on this build to make it work