APX engine swap

[Hillclimb and sprint]

Hi all,
New guy here.
I know this question has been asked of sorts but my situation is slightly different.
I currently use a TT for competing in hillclimbs and sprints, APX engine rebuilt with forged rods, hybrid turbo etc, currently running 325hp/340ftlbs.
The body itself is very tired and looking at a re shell.
After a bit of research I see that an A3 1.8t sport quattro weighs in at under 1200kg, the TT being 1450 plus.
My question is:
Could I just swap my APX engine/box/ecu into the A3 (have seen one for sale but don't know engine code yet) or is there anything more to be considered, am I over simplifying things.
I would also be swapping over running gear/suspension. I understand that the front subframe is the same as the TT but does/can the A3 use TT wishbones and hubs.
Many thanks in advance.
Frank

 

[<tuffty/>]

Not sure where you got you info from but the A3 quattro doesn't weigh that much less if at all to an S3 or TT... the FWD is lighter for sure though...

You can swap over all the engine/box etc to an A3 from your TT... just need to be aware that there is a difference in facelift/prefacelift as prefacelift will be narrowbad lambda like yours... face lift will be wideband

<tuffty/>

 

[<tuffty/>]

TT prop shaft is shorter btw as TT is shorter wheel base but the A3 will have all that anyway

<tuffty/>

 

[Hillclimb and sprint]

Cheers Tuffy,
My info re weight came from:
https://www.parkers.co.uk/audi/a3/hatchback-1996/18-t-quattro-sport-3d/specs/
I would be looking at an early A3, where else should I be looking for weight comparisons.
TIA

 

[<tuffty/>]

I'd weight it yourself tbh... drag out the corner weights....

I can tell you that I have weighed my S3 and it was 1475 with 1/2 tank of fuel... the lightest S3 I have seen was a totally stripped out one at around 1250kg and no cage... a stripped S3 is no different to a stripped A3 quattro realistically... they are essentially the same car underneath

<tuffty/>

 

[Hillclimb and sprint]

I'd weight it yourself tbh... drag out the corner weights....

I can tell you that I have weighed my S3 and it was 1475 with 1/2 tank of fuel... the lightest S3 I have seen was a totally stripped out one at around 1250kg and no cage... a stripped S3 is no different to a stripped A3 quattro realistically... they are essentially the same car underneath

<tuffty/>

Thanks, I have done a bit more looking, the listed kerb weight does seem to vary

 

[Hillclimb and sprint]

The car I'm looking at has an ARY engine, i believe this is a VVT, apart from the EGT and VVT wireing, is the pin out the same, could I use the ARY loom and my mapped APX ecu.
Thanks again

 

[<tuffty/>]

20v's for the most part are mechanically and electrically the same... a few subtle differences but nothing that can't be over come...

Can't say if an ARY has VVT... if its a 2001 on facelift then it should have, if older pre facelift then it shouldn't have... VVT and EGT is not an issue arguably as the APX doesn't have it...

The A3 loom will be geared up for having the throttle body and MAP sensor on the right hand side while your APX is all on the left hand side... the ECU is arguably plug and play but... there are a few subtle differences across some cars too... it would be advisable to see if you can hunt down a wiring diagram or at least buzz out the wires as part of the swap to be sure....

Engine relay and fans spring to mind where if there is no relay in the target car then you don't have throttle control and from memory there is an issue with a pin out on the ECU that can lead to the cooling fans pulsing on/off... don't recall the specifics as its been a while since I did any ME7 based conversions

You may have to use parts of each loom or try to swap the TT one in altogether maybe... but tbh the A3 should be fine once you have extended the wires as needed etc

<tuffty/>

 

[Marzo_NO]

I have a fully stripped A3 quattro converted with APX engine.
The engine is stock and when weight i had only fitted one bucket seat and had a stock passenger seat fitted temperately.
The wheels was road tires and not the lightest.

1240kg with half tank. The end result is around 1220kg i think.