Garage Storage Organization and Garage Cabinets

Garret · **Is 3inch I/C Piping Excessive?**

With my Hybrid I am using a Holset Hy35 turbo, 95 Cummins I/C and an intake manifold with a 5inch plenum and a 52mm TB(this will be upgraded to the larger one from a 4.0 dodge when $$$ permits), and I wanted to know if you guys think that 3inch I/C piping would be too big for this? should I keep it at 2 3/4 or just go up to 3inch?

shelbyplaya · 06-22-2005, 01:59 AM

garret, 2 more posts and you are at 2000

russ jerome · 06-22-2005, 10:35 AM

Quote:

Originally Posted by Garret

I wanted to know if you guys think that 3inch I/C piping would be too big for this? :

Does not hurt anything, what do you mean "too big"?
I have access to lots of 3" so everything on my car
is 3" from exhaust to IC plumbing, even made end tanks
from IC out of 3" aluminum tubing.

OmniGuy123 · 06-22-2005, 10:57 AM

IIRC the PTE front mount IC that they were selling a couple of years ago came with 3" piping, although they stated that it did not make quite as much power on the dyno with it, but it was included for asthetic reasons.

The piping can obviously be too big and not provide the "proper" velocity of charged air. However as Russ suggested, what you have lying around, and what fits well often negates what figres on paper would dictate.

Oh, and that IC was supposedly to support over 600 HP.

Mike Radowski · 06-22-2005, 12:00 PM

I have a bunch of friends making 500+whp and they still run 2.5" piping. I did not feel the need to run 3", but it shouldn't hurt performance.

Garret · 06-22-2005, 01:13 PM

Thank you for the feed back guys, I may just use 2.5 instead

*note this is my 2000th Post w00t*

iTurbo · 06-22-2005, 01:14 PM

I run 2.75" piping on my Omni GLH, with the big NPR intercooler. I doubt it had any affect on spoolup; it hit 270 WTQ on the dyno at 3200 RPM (2.5L w/stock TII turbo @ 14 psi boost).

I think the best approach is to use whatever size is most convenient and try to reduce the number of size transitions throughout. I went with 2.75" piping because that is what the intercooler I/O was, so I was able to get away with using less transitions (reducers) that way. Silicone reducers are expensive so it will save you a bit of money as well.

Mike Radowski · 06-22-2005, 01:30 PM

Agreed. My turbo outlet is 2.5", and my tb is slightly larger than 2.5", so that is what I went with. I modified my large npr IC to have straight 3" outlets, and have conical reducers that neck down to 2.5". Also, the cold side piping is only about 12" from the ic to the throttle body. No heat soak concerns there.