100S4 drivetrain into Coupe Quattro - possible?

[Toby_Unna]

Hello all, sorry to ask a question that's probably been done to death already.

I've been offered a 1992 100 S4 and would like to put the engine into my 1990 CQ 20V, and if possible the six speed box and matching rear diff.

Is this possible, or are there more suitable donor cars I should be looking for?

I'm guessing the engine won't be too much of an issue, but will the diff fit my subframe/will I have problems with the S4 prop being too long/CQ prop not fitting the six speed box etc etc...

Thanks very much in advance!

[Rusty]

Engine will fit, not sure about the rest. Could put it all into a typ85. Better to get a written off Avant or Coupe really.

[mcandmar]

Somebody asked this the other day too, AAN can be fitted into a CQ shell, fairly common conversion for the guys in the US. AAN motor is basically an ABY with a different sump, engine mounts, pulley setup and intake manfiold. You can easyly change those items to 3B/ABY versions. Sump and engine mounts must to be changed to fit into a CQ body.

To convert a CQ20v (which i will get to someday) your much better off with a complete 3B/ABY setup. There is a long list of bits you need to change, wiring loom, ecu, downpipe and exhaust, airbox and pipework, plus a million and one other differences. Everything is a bolt on conversion with the exception of the fuel lines, some custom work is involved there. 3B is the more direct conversion, ABY is a little more complicated.

Fitting a 6speed is another project in itself, to convert a 5speed CQ you will need the gearbox, mounts, front subframe, linkages, and rear prop from a 6speed coupe.

The way i did it was to buy everything under the bonnet from an ABY being parted out, engine, gearbox, looms, the lot. By far the easiest way to do it. Only mistake i made was rebuilding the engine, would have had it done years ago if i left it alone

[Error404]

BTW you won't need to change the diff.

I would say unless you paid next to nothing for the CQ or have done a lot of work to it / very attached to it then just sell it and buy an S2 - don't underestimate the amount of work / cost to do a high standard conversion - its all the little details that cost the money - believe me i'm in the middle of it as is Mcandmar above.

Think ab out it like this:

AAN engine into coupe you will need either convert AAN loom or buy ABY loom & ECU = £££
Use CBL gearbox you still need mounts, linkage, prop, subframe = £££
Still need all intake, airbox, downpipe, intercooler, cross member etc

Plus you'll need brakes in perfect working condition if standard or uprated = £££
CQ suspension IMHO is not up to the power, so all that will need upgrading, plus all the usual consumables like bushes etc etc etc


do the math.....

[mcandmar]

Then you want S2 struts, ARB's, steering rack, and 5stud hubs. It never ends....

But agree with the above, S2's are so cheap these days you better to change car. Me, i'm a sucker for punishment, but its all good fun.

[Toby_Unna]

Right, that's useful, thanks for that.

So, if I do decide to make things difficult for myself: can I bolt the S4 (AAN?) engine to the 20V CQ box etc?

Thanks again!

[Rusty]

Yeah, stock box will work, I think the ratios are quite short tho and not sure about strength, should be OK for a stock k24.

[Error404]

don't count on the CQ box lasting too long - might though if you are kind to it