i will be installing a 2nd gen intercooler on my truck. the pipe size is 4 '' on these not 3'' like the first gens i have a bunch of 4'' pipe laying around (exhaust pipe and such) so i was wondering if it would be worth it to make it out of 4"? will it hurt anything or will it just be way overkill?

 

cant see how it could. While your at it you should upgrade the intake horn too.

 

I think you need to get you're tape measure calibrated. 2.5" on 1st gen, 3" on 2nd gen and PS.

 

apwatson i must have been drinking when i wrote this, but yes now i remember you are correct. i will just be running 3 inch as i have a lot of that pipe laying around as well thanks

 

Alot of 1gens run 3" IC piping. I do & help for bettter flow cooler egt etc Bigger is always better . What is overkill anyways?? Is that in the dictionary?

 

ok so 4 inch is ok? if i can fit it i will run it!

 

Nothing wrong with 4" but I don't think you'll see any benefits.

 

It'll look cool

 

ok thanks guys wannadiesel i take your words to the grave so if you say it wont be an improvement i may not do it. however if i can fit it i will try it and let you guys know how it goes

 

if you run four inch intercoolers tubes you have to run 5 inch exhaust, just because.

 

I would run 3 inch. Intercooler and air horn restrict it to 3" anyways. Going to 4" will only hurt your spoolup and look really tacky.

 

i will run 3inch to popular demand i will save the 4 inch for something else like exhaust. however i do have another question. i was planning on running the intercooler upside down this would have no negative effects would it? thanks it will save me a lot of pipeing and such

 

I am running 3.5" pipes and it looks and fits good.
Larger pipes will lower your intercooler inlet and outlet temps at the cost of POSSIBLE slower spoolup but the top end will thank you.

You can get 3, 3.5 or 4 inch compressor outlets to accommodate.

Part numbers for each below. They are usually around $70-$100.

3" 90*........3918685
3.5" 90*.....3918327
4" 90*........3883977

Second gens use a 3" 73* elbow. When I tried to use it in my setup, it hit the frame.

 

you could get a turbo elbow off of an N14 cummins they have a 4" turbo outlet then it wouldnt look so bad coming off the turbo.

 

Less restriction will not slow spool up the less restriction will help in many ways but if the air passes through the intercooler too fast it will not shed enough heat.........no worries if the stock intercooler is used.When designing a new cooler or tanks it will become a trade off.If you can fab your tubes I am sure you can also fab an intake horn.The reduced velocity at the horn will help the air changing directions to be less turbulent.