It's been getting pretty hot here, and for the past few days it's been well over 100, epecially while rolling on asphalt. Anyway, I don't have an IC on my truck for various reasons, but I've been keeping the boost low at around 5-6psi. The other day I was getting on it pretty hard and my IAT's got up to 152*F. When I was just cruising and/or sitting at a light it only dropped to 150*F. I wouldn't drop any lower and I let the truck sit and idle for about 5min in the shade.

I questioned this while first looking at the kit, but why on earth does STS coat their plumbing? I asked them this and I didn't get a satisfactory response. As far as I know, this coating is similar if not the same as what is used on exhaust and headers. On exhaust it works very well to keep heat in the tube, and as far as I can tell it does the same thing for intake plumbing. IMO that's the complete opposite of what you want on intake tubing. It appears that once the air gets compressed and heated, the coating doesn't allow the air to dissipate heat into the tube at all. In addition the tubing gets heat soaked once it does heat up.

I personally think aluminum would be a ton better than coated steel. If it's a corrosion issue, well aluminum won't do that. It can't be a cost issue either, because ceramic coated steel costs way more than aluminum.

I understand a lot of you guys have IC's that drop you IAT's considerably, but the air still has to go through all that pipe where the heat is kept in. Imagine what your IAT's would be if the air could loose some heat before the IC. I think I'm going to ditch as much of the coating plumbing as I can in favor of some aluminum tubing while I continue to work on my IC.

So does anybody know why the tubing is done like this other than the bling factor?

 

I don't know why they use coated pipe but I agree that aluminum pipe would do a much better job of dissipating heat from the intake air to the atmosphere at least in the pieces under the truck. If it really is no more expensive then there must be some reason that they don't use it. It would be nice to know if it is worth it to switch it out for aluminum.

 

Are you running an open filter under the hood?

Jody

 

No, this is a rear mount setup, but it is an open element filter.

 

Here is were the air filter draws air.

(don't give me any crap about it being dirty, it's clean under there now, dirt roads are hell on these air filter ) FWIW, When it get hot like what your talking about mine does the same thing unless I'm cruising 40+ down the road and I have an intercooler. It's just heat soak. I really don't think they would gain anything with aluminum tubing, as you would still get the heat soak, maybe worse.

 

When I did my fmic last month, I went with HPC coated mild steel. I did a bunch of research on alum vs. coated mild steel and decided mild steel was the way to go. Aluminum does dissipate heat good, it also allows more heat soaking under the hood. Mild steel is easier to weld things to. Like welding BOV's or pipes together. The way I saw it, aluminum over steel, coated steel over aluminum.

Although, we don't have these high performance machines. I don't think there is gonna be that big of a performance issue between coated steel and aluminum.

 

Yeah but aluminum dissipates heat at a faster rate than steel. Look at the convective heat transfer coefficients. Aluminum is like 3 times better at it than steel. The tubing is getting heated from forced convection from the hot air coming out of the turbo. It then transfers into the steel tubing and where it can't dissipant via the ceramic coating, which has very similar properties to S/S steel. I don't think it'll get nearly as heat soaked, especially if you use a thicker walled tubing. It'd be a weight savings too.

 

Good bud of mine that is an engineer said I should wrap the pipe over the motor with that heat tape with a shiny foil on the ouside. He said that the engine heat is heating up the pipe and air just before the tb.

 

I had heat tape and the foil heat reflective,and fiberglass tape on a couple parts of my STS piping for a while. I
t reduced the heat soak on the under the hood section of pipe by maybe 20 degrees. Nothing to sneeze at really. I
also had the fiberglass tape on the section of exhaust right before the turbo, don't know how much it helped spool but what I really wanted to get at with this post is the tape will make your coated pipes rust and the coating peel off!!!
It happened to both of mine, the one under the hood has pitted rust marks on it and the section of the exhaust peeled like crazy. I think its the moisture that is there in more humid climates.
I would not use it again unless you don't care about the pipes rusting.
STS should really offer a stainless steel pipe upgrade for some bucks. People would be willing to pay it I think.
I know SS pipe is no where as easy to bend compared to mild steel but It could be done for a price.

 

Yeah, if it's anodized after you weld it. Think about us in the rust belt with bare aluminum. It would rot through by springtime. The polished 3" bends that I got on Ebay weren't anodized, and by the time I finished assembling them, and using water to cool each weld, they looked so crappy that I painted them.I doubt it would make much difference, the air moves too fast, except maybe at real low engine speeds.
Edit: I didn't read TGO2Z71's post before I made the above statement.