# intercooler piping size



## mk4vrjtta (Feb 3, 2007)

hey..i have some pipes for an intercooler, the inner diameter is about 2in...is this too small? or should i get some 2.25in?
thanks
edit: mods in my sig


----------



## VWBugman00 (Mar 17, 2009)

*Re: intercooler piping size (mk4vrjtta)*

I would use 2.25". You can get intercooler pipe kits fairly cheap, and make the route that you need. 2" would be too restrictive in my opinion. If you're going with 8 psi, I would even suggest going to 2.5" so that extra CFM has room to move. Don't forget your DV/BOV!


----------



## mk4vrjtta (Feb 3, 2007)

*Re: intercooler piping size (VWBugman00)*

it will be 10psi soon after the intercooler w/ water meth


----------



## mk4vrjtta (Feb 3, 2007)

*Re: intercooler piping size (mk4vrjtta)*

so 2.25 inner diameter, would be good then? i dont want to have a big pressure drop


----------



## VWBugman00 (Mar 17, 2009)

*Re: intercooler piping size (mk4vrjtta)*

I think that would work. I wonder how much CFM that thing moves at 10psi.


----------



## mk4vrjtta (Feb 3, 2007)

*Re: intercooler piping size (VWBugman00)*

anyone have any other input?


----------



## 92gtikid (Jun 4, 2004)

*Re: intercooler piping size (mk4vrjtta)*

I would go 2.5".
That's what I run on my VRT. 
Mostly everyone with a VRT is going to run 2.5" pipes. 
Pretty sure with the Stage 3 VF kit they supply 2.5" pipes with there kit. 



_Modified by 92gtikid at 1:52 AM 3-25-2009_


----------



## mk4vrjtta (Feb 3, 2007)

*Re: intercooler piping size (92gtikid)*

is that outer diameter?


----------



## 92gtikid (Jun 4, 2004)

*Re: intercooler piping size (mk4vrjtta)*

Yes.


----------



## mk4vrjtta (Feb 3, 2007)

*Re: intercooler piping size (92gtikid)*

mmk thanks http://****************.com/smile/emthup.gif


----------



## Tom Long (Sep 21, 2007)

*Re: intercooler piping size (mk4vrjtta)*

I'd go 2.5" for longer-term power goals, however, you can make over 500+whp with just 2.0" or 2.25" intercooler piping (see charge pipe configuration below)


----------



## mk4vrjtta (Feb 3, 2007)

*Re: intercooler piping size (Tom Long)*


_Quote, originally posted by *Tom Long* »_I'd go 2.5" for longer-term power goals, however, you can make over 500+whp with just 2.0" or 2.25" intercooler piping (see charge pipe configuration below)










yea im not going to be making anywhere near that kind of power...the most ill ever see is like 300 with this blower and a different tune of course...so im still on the fence about this...stick with the 2.25 that i have or get a 2.5in kit?


----------



## 92gtikid (Jun 4, 2004)

*Re: intercooler piping size (mk4vrjtta)*

Well you do have a charger. I'd just stick with what you have. 
If you went turbo down the road. I'd go with the 2.5" pipe for sure.


----------



## tommyjunior (Apr 2, 2004)

*Re: intercooler piping size (92gtikid)*

I would go with 2.25 if you plan on going turbo in the future. Any bigger is overkill and you will have a bit more lag. I was into Saab turbos for a while and the stock size piping is a bit over 2in, like 2.05 ID and with a gt3076 I still wasn't losing anything. That was with 505 whp. There are guys in sweden pushing over 600 with stock size piping.


----------



## [email protected] (Jul 2, 2006)

*Re: intercooler piping size (tommyjunior)*

There are no fast saabs in sweden.
Might be due to that stupid 2inch piping









Copy n paste from my old post
what is your power goal?
(This is HP not WHP)
pressure pipes 
"Did some fast calculation myself.
Could be incorrect due to all conversion from Lb/min to litre per min and from meter per second to mph etc.
BWTF .... Books say do not exeed MACH 0.4 
Mach 1 is ~761Mph
So MACH 0.4 is ~304Mph
304Mph is ~136meter per second .
So this is the aim to be below

At wot/redline My turbo boost ~56Lb/min = 25.4kilos a minute
1 kilo of air is ~ 1m3 or 35,3 cubic foot.
So its 25.4M3 or 896.6cubic foot per minute.
To get Mach 0.4 or 136m per second at 896cmf that could be anything from 500-590Hp depending on temp and fuel 
So 56Lb/min * something between 9-10,5 = Hp
60mm/2,36inch INNER diameter piping will result in 148meter per second.
This is normal thin whall stainless piping ...alu piping is often have thicker walls so its comparable to 2.75 inch outer.
So thats not what we whant for our 500hp project.

So what piping will keep ME under Mach 0.4 ?
A 63mm inner diam a.k.a 2.5 inch inner diam piping will do Mach 0.4 at 56lb/min.
So im going for 2.75 outer with ~65mm inner for HOT side
And 3 inch for Cold side .

No temp etc is in this calculation.
Max Hp before it goes way to high!
So its better to make a bigger dimater pipe with smarter shorter routing with less bends and less difference in area.
If you use alu piping make sure its required inner diameter.
Stailess steel is often in thin wall
500-550hp = 3inch piping with atleast 2,75inch inner diam
450-500hp = 2.75inch piping with atleast 2.5inch inner diam.
400-450hp = 2,5inch piping with atleast 2,3 inch inner diam 
350-400hp = 2.25inch piping with atleast 2.1inch inner diam
250-300hp = 2inch piping with atleast 1.8inch inner diam


----------



## mk4vrjtta (Feb 3, 2007)

*Re: intercooler piping size ([email protected])*

^^^
that was an intense answer!, but exactly what i wanted...so i will be sticking with my 2.25 piping..
thanks!


----------

