I have been reading that the 2.7L dual turbocharged engine that has gone in older A6, S4 and S4 avants, has only a difference of one tenth of a liter ( approx. 100cc) compared to the 2.8 30 valve V6 used in the A4 and A6. My '01 A4 2.8Q ( 2.8 L, 2771cc, 30V) engine produces 190 HP and 207 TQ. If only this one difference can create a usage of dual turbochargers on the 2.7L, how come it is not attainable to use that mechanism on the 2.8L? I am assuming there is a huge difference, but I do not know the answer and I am looking for a clear and precise answer. Any information would be helpful.

 

You want to add a bi-turbo to your 2.8 ?
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Correct me if I'm wrong, but aren't the cylinder walls on the 2.8 thinner, as well as the heads not up to the compression of a bi-turbo setup? I know apg can fill you in more on this because I remember a while back he was exploring this idea.

 

They used the 2.8 engine and made the thing walls of the 2.8 and down sized teh cylinders to the 2.7l. The walls are very thick now. But the block is the only thing similar. The engine was designed to be a turbo. U cant just add the turbo on. It took audi milions and millions of dollars to desgin this engine. If u have a 2.8 u would be better off just s/c it. It would prolly cost u around 15,000 just to get one turbo on there and with 2 on there ur engine would survive for long.

 

well, the walls arent THAT much thicker... I mean, figure they took out 100CC's from the motor... divide that through the 6 cylinders, and it isnt an enormous difference. BUT, it is a difference, and a difference that the audi engineers thought to be worthwhile.

And, as APG said... supercharging it is much easier, and, a supercharged 2.8 gets more than S4 horsepower. ... Stock S4 anyways

 

Headshok i thought that i read when they more making teh engine that actually started by making the 2.8 block with thicker walls and then down sized the cylinder.

 

is it an aluminum block? if thats the case you can just get it sleeved with what ever you want and find another weak spot. Just s/c it thou.

 

Cool. thanks for all the info guys. I was not sure, and I have thought about s/c the thing. Not sure about the longevity of adding one though?

 

the S/C is very very very reliable. I havent heard of any problems with the s/c. go to superchargedaudi.com and they all have them and can answer all ur questions.

 

if reliabiltity was your concern, supercharging is definately better than turbocharging... if you want brute power, the turbo's are the way to go... but yeah. Supercharge it, you'll be happy.