So I was looking into turbos upgrades for a built 2.7t engine. I am looking to make around 600-650whp and my primary interest was on the s4 platform but from research I have found that the biggest turbos you can fit in an s4 is the gt2871r without custom fabrication and even that may cause some spacing issues. I was wondering if the a6 had a larger engine bay and could fit a larger turbo? I would like to stick with a twin turbo setup.

 

I believe you would run into limitations from the stock A6 transmission. Even in the RS6 models that run around 450hp stock tend to develop transmission problems around 30,000 miles. I have heard of horror stories of some guys going through two transmissions while owning the car for only a short time while only putting a limited amount of miles on them.

Can you get 600whp out of the 2.7t? Probably. But I think there's a lot more to it than just slapping a larger turbo, bigger intercooler and tuning it to favor performance over economy.

I would look into a 4.2 chassis and see if that can be modded. The RS6 is a 4.2 with twin turbos, so I suppose if you were to get your hands on to an a6 4.2 chassis and slapped those turbos onto them you would be headed into the right direction. That would be my build if I had the time and money to go for it, at least.

 

I realize that there would be more to it than just slapping a bigger turbo on but what I was focusing on was the space issue. The gt2871r is a realy tight fit in the s4 and even with two of those it can be difficult to achieve my horsepower goal, but if there was rom to fit a gt30-35 size turbo it would not be difficult with a fully built engine. I can always swap out a transmission from an s4 to deal with the extra power.