Thread: Turbo downpipe

Do you have any way to measure pressure in the exhaust system pre and or post turbine? A pressure reading will give you a good idea of what's going on in your system. Do you have any pics of the manifold/downpipe?

I've seen some weird stuff happen with downpipes/exhaust before. For example, one customer had a well thought out setup with a T4 sized turbo capable of 750+hp. For some reason he couldn't make more than 400-500hp (don't remember the exact figures) on the rollers no matter how hard it was pushed. And it was pushed...everything would glow red hot, manifold/turbo/downpipe etc. Turns out, that the flex section in the downpipe had collapsed internally reducing the downpipe to the dia. of a quarter! You couldn't tell from the exterior though. All in all, the lesson learned was do not use internally lined flex sections on turbo cars lol.

Can't see anything in that pic but the turbo and the outlet for a few inches. Any better pics of the whole exhaust?

http://s730.photobucket.com/albums/ww310/bahamassr200/?action=view¤t=IMAG0036.jpg best pic I can get

Looks like you have room for a 3.0. in. If you go that route, it's best to use a smooth transition from 2.5 to 3.0 in. off the turbo along large radii bends for the downpipe.

You can also run 3.0 in. tubing straight off the T31 housing flange (standard 2.5 in. 4 bolt)...you just have to make room for the hardware by indenting the tubing. A 3.0 in. tube on a 2.5 flange has a little bit of a lip on the inside. The transition is not as smooth, but works just fine.

do you think it will make a night and day difference with a 3 inch. drove in my buddys car with a 2871r and his car pulls better than mine

it would make a day and night difference, its hard to say exactly how much power you might see from the 2.5- 3'' downpipe i would say anywhere between 25-50whp. its going to really open up your exhaust and allow for you to take advantage completely of the 3'' exhaust.

the difference should be huge

Thanks guys 25 + should take me to where I want to be 400hp daily

yeah night and day difference.

A friends EVO picked up like 100+whp from going from a 2" inches to a 3.5" exhaust...

You might not get that much gain but 30whp at least, maybe some fine tunning since the exhaust will flow a lot better now