Phil type 951

I made my own hard pipe for the intercooler on my a4 and I was thinking about redoing it in 2.25 or perhaps 2.5 size tube. right now I have 2 inch on the car and everything seems ok. i have pics of how i set up the fmic in my pic poster if anyone wants to check it out. eveything is tig welded and seems smooth on the inside. I think the stock intecooler pipe is about 2 inch so with my apr stage three perhaps I should go larger.

would i notice any power gains or faster spool by increasing my FMIC tube to say 2.5??

thanks

Audi2ptzero

Just remember that the more volume there is the longer it will take the turbo to fill up. This means you add a delay to the air flow hitting your manifold. The only time you want to increase the size of anything is when it because a limit to how much air flow you can move.

AggregatVier

Air moving too fast may not remain in contact with the cooling surfaces enough to transfer heat properly. Too slow and you lose pressure. There's a sweet spot for each system of trade offs that will favor a particular engine's air requirements under a certain range of conditions. It's a lot of trial and error even starting with cores and tanks of recognized superior design (although you're a lot closer to start off with such). Audi even uses a wind tunnel for IC R&D. Set up a system where you can test air/intake/outlet temps and pressures or you'll never know for sure. Happy experimenting!

WJM

2.25 from the IC to the TB would be good as first start

Phil type 951

you think its worth the effort?h

Audi2ptzero

to handle the CFM your turbo makes. The larger the tube the longer it will take for your turbo to pressurize them, causing a slight delay in power.