Intercooler Pipe Sizing.

[Cubes]

The intercooler I have fitted is a bar and plate apparently optimal up to around 580HP.

The Inlet and outlet are 65mm in diamater.

I think the standard 32GTST piping is 75mm.

Reason I ask is I havn't got mandrel bends on the IC Piping but it they are very good bends which hardly squeeze in.

I was thinking of getting all of the piping remade as it steps to and from the larger standard IC Piping.

Also the standard IC Piping's bends have horrid ripples on the inside of one of the bends, I think it is the 90degree that comes from the IC to the plenium.

All in a quest to try and reduce lag as much as possible.

In Mild steel it is quite cheap.

SO......... What sort of performance gain or decrease in response is there with larger or smaller IC piping.

[Clint32]

Joel the standard piping is about the same size as your intercooler outlets or 2.5''. This is about the right size for piping and would be fine up to 500hp im guessing.

If your pipes have bad bends it may be worth getting them remade from 2.5'' mandrel bends, it would help improve the top end a bit i think. The only problem is that mandrel bends are not as tight as the std ones and you will have trouble making the piping in the stock location. hard to tell without looking.

Generally people say smaller pipes give less lag but its not really noticable i dont think.

Ps I have nearly finished my car, it started and ran fine, hopefully we can get it on the dyno thurs so i can drive it, i only took it to 4 grand and there was only 2psi boost.

[inark]

the inlet/outlet pipes on the cooler i got are 3"

is that going to pose a problem?

[Clint32]

its a GTR cooler im guessing, you just have to flare the end of the pipes out to 3'' where it meets the cooler no real problem. 3'' piping is to big to fit in the engine bay proparly.

[inark]

yeah it is

ok cool... thanks!

[Cubes]

Reason I say is i was reading a www site which they were making around 600hp and they dropped the ic piping to 65mm diam. to reduce lag... Apparently..

[meggala]

joel you dont need madrels on ic piping find other area's of the car to spend money on seriously they might make a difference at the 5-600 hpo bracket but not in the 300 hp bracket I dont evne have a modded dump pipe.

meggala

[lowlux]

hey but if your making it out of steel why not go for mandrels as there only like $12 each for 2 1/2" ive done all my pipeing in 2 1/2" except where its gone down the 2" for the turbo, and it cost me like $130 which i welded it all myself