3 inch intercooler pipe too much?

[joey]

i have 3inch intercooler pipes layin around, and was wondering if i used them would i have any power gains? i am only running 18lbs of boost with a magnus intake, and front mount.

 

[RadDsm]

3" is a lot for that 16g, maybe trade them for some 2.5"

 

[eclipsetuner_21]

3" is way too much.... You should get some 2.5"....

 

[silver bullit]

I was thinking of running 3in on the cold side from the inter cooler to the throttle body. I plan on running 20+ psi. on my 14b.

Since i have done this before on 25, i am gonna try doing it on my fresh rebuilt 14b i just did.


You may notice a 100-300 rpm boost lag or none at all.

What kind of throttle body elbow are you running? Running a 2g or a different one than stock will net power.


What other mods are done to the car?

 

[1992awdlaser]

I don't think there wiill be a spool difference. You won't notice any power gains.

 

[delta448]

As far as lag goes, it will not make a noticeable difference what size piping you use. I'm running 2.75" piping with my large FMIC and little 14b, spools as quick or possibly even quicker than the 1G piping I was using and stock side mount. The extra volume of the larger piping just means less flow restriction. Not that a half inch piping diameter difference makes any more than hair-splitting differences at the low airflow a 14b or even 16g offers.

 

[Boost92awd]

Your 2.5 inch piping will work just fine. You dont really see any gains from using that big of piping unless you have a big turbo, gt35 or bigger. Thats all your going to do is make your set-up have more lag, and the gains will be so minimal that its not worth doing.

 

[brando12685]

boost92 is completly right, its just that much more volume your going to try and fill with a little bitty snail = LAG. code no joy. and down the line if you plan on going big turbo your going to have to change out your hot side most likey so it would just be a waste of $$. so save the cash for the stuff that is going to break. we all know its going to happen.

 

[fwdmaster]

Go with 2.5 piping

 

[andy4g63]

I've seen many cars running low 9's with 2.5" piping stock 60mm TB. Unless you run GT 42R or bigger turbo, there is no point at all of getting 3" IC piping.

 

[JusMX141]

I couldn't see how running 2.5" piping on the hotside then stepping up to 3" piping for 3 feet or so just to be necked back down to 60mm (2.36") at the throttle body could be beneficial at all; much like a Magnus SMIM with a 16G.

 

[delta448]

Thats all your going to do is make your set-up have more lag, and the gains will be so minimal that its not worth doing.

its just that much more volume your going to try and fill with a little bitty snail = LAG. code no joy.

Okay, just to prove how insignificantly piping diameter increases lag, here's the math.
Let's just say for argument's sake you need 10 ft of piping (exaggerated to the high side obviously to better illustrate the point and favor the lag argument by making the difference in piping diameter more significant).

10ft length x pi x r^2 = volume of piping
120" x 3.14 x (3"/2)^2 = 847.8 cubic inches = 0.4906 cubic ft
120" x 3.14 x (2.5"/2)^2 = 588.75 cubic inches = 0.3407 cubic ft
difference in piping = 0.4906 - 0.3407 = 0.1498 cubic ft

The 14b is at its highest boost pressure while still in its highest efficiency island of flow at 12psi and roughly 250cfm. That's 4.167 cubic ft per second, and roughly guessing about 210 crank HP.

0.1498 ft^3 / 4.167 ft^3/sec = 0.0359 seconds = 36 milliseconds to fill the volume difference

So at relatively low 12psi boost and flowing a wimpy 250cfm, it would take you about 0.0359 seconds, or roughly 36 milliseconds to make up for the difference in piping diameter.

Just for comparison, a 56 trim GT42R maxes out at 1200cfm. That would be 20 ft^3/sec. So it would make a difference of 0.00749 sec, or roughly 7.5 milliseconds more lag if you used 3" piping instead of 2.5".

The difference can be made even smaller if the length of piping is a normal amount. So I hope we can all see now how little the piping diameter affects lag. Performance would be hurt more by obstruction to flow, Justin hit the nail on the head with the comment on necking down from UICP to TB.

 

[joey]

i was thinkin the same. i will stick with the 2.50.

 

[JDMath]

i would not go bigger than 2.5 with a 16g

 

[ivatu]

everything they ^^^^^^^^ said is right!!!