Question: Intercooler piping size

Onefast99gsx · 04-17-2005

My old system when i had the old 16g on consisted of all 2 1/2" upper i/c piping all the way to the tb elbow. My lower i/c piping from the turbo to the inlet of the FMIC was 2 1/4".

The outlet on a PTE 50trim compressor housing is like 2 or 2 1/4"(can't remember). Does anyone foresee a problem with using this 2 1/4" piping for the lower i/c piping? I just don't know if i need to convert to 2 1/2" for the lower. If the outlet on the turbo is only like 2 1/4", why would i want 2 1/2" Your system is only as good as the smallest point "bottleneck".

Thanks.

**JET** · 04-17-2005

Your turbo outlet is a 2". Actually piping isn't only as good as the smallest point. Piping losses are cumulative. That is why people can get away with running a stock TB on such high HP cars and not lose too much HP. It is only a short distance so the losses aren't as great as if it was an IC pipe that size. There is of course a limit to this and the smaller pipe will cause a larger loss.

Are you still running the stock SMIC? If so, the 2 1/4" pipe will be fine.

Onefast99gsx · 04-17-2005

Hi Jet- No i have a big Griffin FMIC that i got from RRE. Saying that, you still think I would be fine with my turbo setup and adding the fact that i probably would never boost past 23-25psi?

So i'd go from 2" on the turbo, to a 2 to 2 1/4" coupler, then my 2 1/4" piping, to a 2 1/4 - 2 1/2" coupler to the FMIC. All the upper is 2 1/2" completely.

Thanks.

**JET** · 04-17-2005

It might help a little to go to 2 1/2" for the lower too, but not much. I would just stick with the 2 1/4", unless your goals change. If you decide to crank the boost up more, it might be worth going to 2 1/2" piping. The griffin isn't real efficient though, so I would keep the 2 1/4".

niterydr · 04-17-2005

Piping size is directly related to efficiency. Its a nearly linear equation that is piping diameter vs. velocity, of course bends and bend radius's drastically effect the efficiency of the system.
I'll see if I can dig up some links I have...

Onefast99gsx · 04-18-2005

Thanks guys. I would think you would have more velocity through the smaller piping. It's kinda like the straw vs. the garden hose. You will be able to blow much harder thru the straw but the possibility of much more air through the garden hose because of the larger dia. Yeah if you could dig up some links that would be great.

Who sells mandrel piping in the cities?

**JET** · 04-18-2005

Quote:

Originally Posted by Onefast99gsx

Who sells mandrel piping in the cities?

I do, QPR usually has some in stock too.

Onefast99gsx · 04-18-2005

I'm gonna probably need a couple of 90 degree in the 2 1/2" then. Do you ship or only do local sales? What about payment, PayPal?

BTW- Here is an old webpage of mine of my piping. My brother and i did this project about 3 years ago for my old GST. I removed it all prior to selling it and that's what is going on my GSX. You can see the 2 1/4" lower piping, it's shape like a big "U".

http://mis15437.tripod.com/griffin_20x10.htm