Research phase of SL-C build- New user

Hello everyone!

I joined a month ago and was looking for some insight. I am researching a strange and custom build for track use only. I have a few ideas in mind, and wanted to see If I can cancel some of them out with some of the vast experience here on the forum. I will start out with I am very capable with fabrication, welding, mock up, body work etc. Some of the things I want will take some time and I am willing to spend the time and money to complete.

First idea, I wanted to do the 5.2 v10 out of an R8 or gallardo. It seems it will fit as I found a photo from heffner of a gallardo SL-c they did. I know the cost of a v10 vs a LS is HUGE, like more than triple, but I really want that v10 sound profile and power band. I would ultimately rebuild the engine to handle a twin turbo setup and Air to water coolers. Any reason this won't fit that anyone knows of?

Second idea, which I know will take a lot more time, money, and fabrication, would be a 4 - rotor 26b billet engine. This would also be a twin turbo gt35 with the air to water coolers and e-85 + meth injection. It seems as if the 4-rotor fully dressed mated to a graziano trans may be too long for the engine bay. Does anyone know if Fran can customize the SL-c Length during production and I can take care of the body work to accomadate the +3 or 4 inches of length? I know the one member put a 3 -rotor in an slc, but he had a longer transaxle that limited the engine location and axle driveline angles.

Any insight on these two ideas so I can focus and budget for each path would be awesome!

Thanks in advance!
The same engine is in Audi's S6/S8. May be less expensive to source it that way. They're all over the salvage yards for $4-7K, depending on mileage.

Search Results

And that sure beats the $30-50K for an actual Gallardo engine. Then you could spend some $$ on the Audi engine upgrading certain things if the 425-450hp wasn't enough, Gallardo's having 520-560hp.
Last edited:
Phillip, yeah wow! that is huge savings. I have to rebuild the weak internals of the gallardo engine anyway to acheive what I am after, so that is a no brainer. I will ask around to make sure the block is the same. I would probably upgrade the crank as well, at least balancing. Thanks for that. Totally forgot the 5.2 was in the s6's. :thumbsup:
For what it's worth from Wikipedia:

The engine in the C6 S6 is an even firing all-aluminium alloy 5,204 cubic centimetres (317.6 cu in) Fuel Stratified Injection (FSI) 40-valve (four valves per cylinder) 90° V10 (parts code: 07L, identification code: BXA). Compared with the related 5.0-litre V10 found in the Lamborghini Gallardo, Audi's variant has a longer stroke and wider bore which increases the displacement of the engine so that it produces more torque at lower revs and is thus more suitable for the larger and heavier S6. It produces 320 kilowatts (435 PS; 429 bhp) at 6,800 rpm and 540 newton metres (398 lbf⋅ft) of torque from 3,000 to 4,000 rpm. It uses twin chain-driven double overhead camshafts with variable valve timing for both intake and exhaust valves. The engine is managed by a Bosch Motronic MED 9.1 electronic engine control unit (ECU), which controls the mapped direct ignition, ten individual spark coils, common rail cylinder-direct sequential multi-point fuel injection, and drive-by-wire throttle.

So I'm guessing it's not the same engine but a variant of a Gallardo engine. But it may be close enough for what you're looking to do. Good luck with it.

This was also on Audi's Wikipedia:

There was also some speculation that the engine block of the original 5.0-litre Lamborghini V10 is closely based on the Audi 4.2 FSI V8, which Audi produces for their luxury cars. However, this was denied by AUDI AG, in their official documentation for their 5.2 FSI V10 engine, as used in the Audi S6 and Audi S8 - the Lamborghini 5.0 V10 has a cylinder bore spacing of 88 millimetres (3.46 in) between centres, whereas the Audi 5.2 V10 cylinder bore spacing is 90 millimetres (3.54 in).[3] The cylinder heads use the four valves per cylinder layout favoured by the Italian firm, rather than the five valve per cylinder variation formerly favoured by the German members of Volkswagen Group - including Audi and Volkswagen Passenger Cars. It was later confirmed by Stefan Reil of Audi's quattro GmbH subsidiary that the new 5.2-litre Lamborghini V10 does share technologies with the Audi 5.2 V10 engine, as is evident by Lamborghini's usage of Audi's Fuel Stratified Injection, and 90 mm cylinder spacing.[4]

And they're on ebay too. But just like the salvage yards, say R8 and the price seems to triple.

audi V10 in Complete Engines | eBay
Last edited:
Clint. What hp range are you looking for? Naturally aspirated, turbo, or supercharger?

Roger, I am after a reliable 900-1000 hp. Turbo charging isn't a must, both of my choices get close to that non turbo, but I want to for personal reasons. Racing E85 will be my fuel of choice and methanol injection for long WOT straights to keep IAT down.