would 3 inch ic pipes be a good idea

IJ.

Grumpy Old Man
Mar 30, 2005
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Cubic Feet of Air per minute.

If you're using XX turbo and it flows XX CFM it will need XX pipe size to keep it below a certain critical speed.

If you run too big a pipe you get a loss of velocity in the pipes and will get a perceived lag.

Too small a pipe and you go above the critical speed and you get heat from friction.
 

JNasty

i drive fast cars (supra)
Jun 25, 2005
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ok im going to do a 60-1 turbo and i have a 24.5x12x3 inch intercooler with 3" inlets but i haven't got the 60-1 yet still stock ct what do you think
 

IJ.

Grumpy Old Man
Mar 30, 2005
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I know a lot will disagree with me but I'm using 2.5" pipes on my GT3540R as that's what the math worked out to and it's backed up in the real world as it has brilliant throttle response on and off boost.

I can't see any CT Upgrade out flowing the GT so I don't believe 3" would be a good idea.
 

IJ.

Grumpy Old Man
Mar 30, 2005
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It's one of those cases were the Math works out in the real world!

I did the sums on 30 psi and that was getting a little close for comfort but at 18psi I'm well below the critical speed.

It's very easy to go for the big pipes but you'll pay in lag when they offer no benefit at all.

Gotta remember you're building a road car that has to pull from low down for day to day driving not a race car you can buzz hard and keep on tap.
 

JNasty

i drive fast cars (supra)
Jun 25, 2005
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k ill do 2" but do they have a coupler that will go from 2 inch to a 3 inch you know from the pipe to the intercooler