Audi s8 d2 340hp AHC turbocharging

[fr3nzy]

Hello,
I am newbie at Audis and I want to know how could I boost the AHC engine. I want to boost it to 1 or maximum 1.2 bar. Will the engine cope with that boost? I searched the internet but I couldn't find info on that particular build. If i use thicker head gaskets to lower the compression how much boost could I use on the stock pistons? What about the aluminium engine block? How much could it handle, and at what boost should I use steel cilinder sleeves? Could I fit aftermarket forged pistons on aluminium block? I also wonder if I could use botton end from RS6 and use the higher flowing AHC heads?

Thank you in advance,
Peter

[Kieron20V]

I'm turbocharging my abz which is pretty much the same engine with slightly lower compression and less airy cams.

I am using 2x hesdgaskets to lower compression and that is all I will be doing with the bottom end. There's a drag car in the states using a standard block with forged rods and possibly pistons running over 1000hp on a gt50something turbo with lots of boost, so I think the block and crank are plenty strong enough.

You could pull the pistons and have them machined to drop compression. Really depends on how much you can drop the compression by as to what boost you can run.

Sent from my HTC One X+ using Tapatalk

[rs200]

you canot use rs6 block because it is not predicted to be on manual gearbox.. actualy it is not plug n play like on AHC engine block. you can do it but is too much work . you know that there is a whole for engine starter, this whole.. hosting is not at the same place on AHC and RS6 engine block!

there is not too much project with v8 turbo or biturbo at internet.
but here is one from my country , and I spoke with owner , few other guys confirm to me that on this engine is only double head gasket !
it is from a8 4.2 40v engine. with one turbo, don't know which one s now on engine , because owner change few of them. of course injectors are different , VEMS , etc.. but engine is stock !
at this moment (on video) it was maping time ! 500hp
now have around 800hp + nitro !

http://www.youtube.com/watch?v=dGxR7aUXv14

you can use 32v engine , but ABZ will be better because compresion ratio is lower that on AHC.
I thing that 32v is better than 40v for turbo . 32v dont have cam chain tensioner & hydraulic timing belt tensioner, they are weak point for massive Nm !
maybe you will get few HP lower than on 40V but it is more safe !
othervise there is problem to find AHC flywheel if you don't have it !

[sam80quattro]

There's a 200sx s13 on YouTube running a 40v with a big holset and from what I remember standard motor. 600+ bhp iirc

[fr3nzy]

My project car is an original manual 6 speed s8 d2 with AHC motor. So I will have to use as much of its parts to keep the costs down so the rs6 block is droped out as a solution. I think that I can find some ABZ pistons second hand cheaply and use them to further lower the compression ration, but If there are other pistons from v8 with lower CR I will be very happy to know from which engine I could source them.

Also somewhere I read that the rods of AHC are forged. If this is true I would only need the lower CR pistons and thicker headgaskets to make some serious engine for cheap without breaking the bank not considering the peripherals.

I wondered also if the AHC has piston oil squirters originally? If not is there a way to fit?

[Kieron20V]

The ABZ has oil squirters, so I would imagine the AHC would have as its supposedly a higher spec engine. Pretty sure the bottom end is identical apart from the pistons, so same rods. They are just bog standard 80/90s vag rods, same material and design as 8v/10v/16v/20v etc.

If youre serious about turbocharging the engine, id say youd be better off selling the S8 engine, and buying a cheaper ABZ. Youd probably make some £££ out of it that way too. The engines are identical really apart from the higher compression and cams in the s8, and youre reversing that anyway.

[fr3nzy]

Is it possible to mount automatic ABZ to a manual 01e transaxle from audi a6 2.5 tdi for example as these are easiliy attainable in my area? I also wonder if the s8 transmission is stronger than the 2.5 tdi or other similar 01e? Also isn't it better to use the AHC more agressive camshaft setup?