What is best for intercooler piping?

[Guest 79Datsun280zx]

Well i read though the turbo post for beginners at the top a few times and it stressed that you should dump money into the biggest and best intercooler you could find. It said Spearco's were the best. So i decided to put out the cash for one and bought a Spearco 33x10x3" with 2.5" inlets. Its so big im going to have to do some custom work on the front end of my car Anyway, i havent read that link you posted yet so this might be in there, but should i step up to 3" or 4" pipe after i get outside the intercooler? Or just pipe it all with 2.5"? I read through this link that was posted, learned quite a bit.

 

http://hybridz.org/nuke/index.php?name=PNphpBB2&file=viewtopic&t=29024

 

As for pipe should it be all metal for some reason? Of course this would help with heat loss. But i found this stuff on ebay that looks good and i could bend the stuff with a heat gun he says. Heres the linke

 

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=38634&item=2465484183

 

Or should i try and do as much metal tubing as possible? Could i maybe just use this and get some straight 2.5" or 3" exhause pipe for the rest.

[SleeperZ]

Personally I'd not go larger than 3" anywhere, provided you have a throttle body with a 3" opening. I run 2" into my intercooler, and open it to 3" to match my tb. Anything in between will work fine. The heat resistance and cost of steel exhaust piping is why I went with it. The ideal would be aluminum if you can weld it, but the main reason for metal is it won't expand on you under boost. It also is durable and handles the heat.

[johnc]

What Nathan said. You don't want to go too big on the piping because velocity is important. Usually the TB will be the biggest diameter opening in the intercooler plumbing. I wouldn't go any larger then the largest opening.

 

18 guage steel tubing is fine and is the cheapest. Even cheaper then silicon hose if you don't need any tight mandrel bends.

[Guest 79Datsun280zx]

Yep thats pretty much what i thought to. Resists heat? you mean transfers heat well? Or is durable against heat? Anyway yeah aluminum would be the best but i dont have a tig welder. And i thought about going to 3" becaue it would flow air better but the problem with going huge is the turbo just has more space to fill before you feel the boost. And then you end up with more turbo lag. I think ill go with 2.5" this is still 0.5" bigger then the stock pipe. Ill go with 4" or bigger into the turbo though. I do have some odd shaped bends id have to make so i may have to do a combination of silcon hose and metal. I bought a 33" intercooler and after putting it in the front theres only 2" of space left on either side of the inlets So im going to have to cut into the headlight section to run the pipes And yes i also considerd that metal doesnt expand, meaning less turbo lag. You guys are right im going to put as much metal in there as possible. Maybe getting custom bent peices wont be so expensive?

[SleeperZ]

I did mean "resist" heat. Plastic and rubber tubing will soften and swell, and eventually blow out. Usually volume of the intake is a second order effect on lag, meaning you won't notice. The intercooler itself is a large volume of air, and I noticed zero increase in lag when I installed my IC. So the size of the pipes will not play much a role in "increasing lag"; but flow velocity is important in maintaining throttle response. 4" pipe into the turbo will be fine - my turbo has a 2-3/4" inlet, and I modified my MAF with a 3-1/2" housing, so I just ran an air filter with a 3-1/2" ID to the maf, then gently necked it down to fit my turbo inlet.