Hi all,

Although I have a Rover, and not a Ford, I was wondering if anyone could please help me with this query.

I am wondering if I would be creating any problems, flow wise, by using 2" ID pipework instead of 2.5" for the pipework run between turbo and throttle body. The car will be making circa 220bhp with a T28 (200SX) turbo, with 2x 2WD Cosworth intercoolers welded together to give a dual pass front mount.

Will 2" pipework flow enough for my requirements, or is it definitely necessary to use 2.5"? I'm not convinced the 'bigger is always better' argument applies here, if 2" is good enough. I already have the whole run in 2" ready to go on the car but need to know if I need to go to the expense of upgrading the whole lot to 2.5".

Thanks for the help.

Jim

 

Like anything where air flow is involved the smaller it is the more restrictive it can be. But again, like anything, its only as good as its weakest link, so if anything else in the path has a smaller diameter than 2.5" its pointless.

 

Makes sense.

The smallest restriction is in fact the compressor outlet, which is slightly less than 2". ID increases at intercooler to 2.5" on inlet and outlet, but not again until TB.


Jim

 

SafeChav not true. fluid dynamics ae very complicated, and the resistance to flow depends on the length as well as the cross sectional area, radius of bends, changes in cross sectional area, surface roughness of the pipes and much more

all it will mean though, is that if you want 2 bar boost at the throttle body or plenum or wherever you're going to measure it with your gauge or whatever, the more pressure drop between there and the compressor there is, the harder the compressor has to work.

if you make the compressor work harder, you make the compressed air hotter, which makes your intercooler more work to do.

everything is a compromise though

 

foreigneRS, i have to admit after posting that i did think about it again and remember about the factors like the length of the restriction, but realistically at the sort of power he is aiming for its not going to be that critical, IMO

 

I'm hoping to keep pipe runs as short as possible in comparison to standard, and hope to try and use at least the longest of the standard boost pipes (IC>TB).

Using 2x cossie intercoolers should offer a good gain over standard, plus a T28 will reduce intake temps further... so yes, everything is a compromise.