Would using mild steel exhaust pipes for the straight sections of my ic piping have any adverse effects besides weight?

 

steel tends to heat soak more than Al so if you use it, heat wrap it or ceramic coat it.

 

I don't see why not. Pipe is pipe for the most part. I have thought about using painted exhaust piping for intercooler pipes when my time comes.

 

Only bad thing I could think of would be weight, there is heat soaking.. but the air isn't there along enough to heat up. You should be fine. I'm currently using 3" mild steel tubing for my IC on my rx-2. No problems with heating soaking.. touching the piping after few hard 12psi runs.. and there cool to the touch.

 

The actual weight difference between 2.5" mild steel pipe and 2.5" aluminium pipe is 1lb/ft, so you might save 10lb. Hardly worth getting excited over.

The thermal conductivity of aluminium is 4-5 times greater than mild steel, so the heat soak theory suggested above needs to be reversed.

While aluminium is easier to work (because it's softer), it's easier to find someone who can weld mild steel.

 

I wont need somone to weld it, im just gonna use some midl steel straight sections and some mandrel bend al held together with couplers.

 

use a good wrap or thermal blanket

 

I'm gonna run welded steel pipes with thermal wrap out of the turbo...

 

Use stainless. The main concern is that moisture will get into the pipes (ever drive in the rain? ) and rot them from the inside. Stainless is not very expensive at all. Or, coat the inside of steel pipes with POR-15.

Aluminium is great, if you have the equipment to weld it (most don't).

 

POR-15?? Ill look into that. I only asked about mild because thats what the sell in the exhaust section at strauss where I can get it practically free.

 

Mild will rust aggressivly in an engine bay due to the heat and moisture. Pipe is easy to find and cheap if you look in the yellow pages. Check out "pipe suppliers" and "industrial tubing" and other variations on that. You'll be AMAZED what you can find for very little money.

 

thanks for the tip. Theres alot of welding, radiator, fencing, metal works places around my job i might try them for some al or stainless.

 

NZ is def right on the heat soak theory. Aarons got a good point with the moisture. Your filter wont stop all moisture and your pipes will rust from the inside. I would just use alum of ebay its not that much more money but depending on the grade of stainless it can be a lot more.

 

IMO Thermal wrap out of the turbo is USELESS... WHY... the compression of the turbo has heated the air up... you don't want to keep that heat in.. and engine heat isn't going to hurt it because the pipe is getting hot from the turbo anyway.....

Just sand the pipe and paint it.

on the COLD side of the INTERCOOLER... now there you want to thermal wrap it to keep the pipe from heatsoaking. I used the Cool-it Thermotech stuff with the one side thats sticky and the other is Metal Foil. (basically, its the same webbed stuff as the exhaust wrap, but with a reflective foil coating on one side)

My intake temps in traffic dropped about 10 degrees on average after putting the Thermotec on the cold side. So ther eis some merit to it.

Like So..




One THING... I run a light coat of Oil on the inside of the Mild Steel Pipes. Will keep rust from forming. I Take a shop towel and make it damp with gun oil (I got a big just of it from a surpluss store) then pull it back anf forth a few times through the pipe with a wire looped around the rag. Two years after making hte pipes, no rust on the insides.

The OUTSIDES.... holy Jezuz there's another story.. if you don't paint them, or cover then with heat wrap.. the will rust EVERYWHERE you touched them.. What you end up with is littel rusty fingerprints all over the pipes!!!

I'm switchin to a manual rack in the spring, adding a new turbo, and aluminum pipes with the BOV over by the T-Body.... So.. I don't wanna hear about routing the pipes under the PS pump or the placement of the BOV!!!!

 

Agreed. all but one point..... the heatsoaking of the aluminum....... Yes the conductivity is higher.. however, that also means it COOLS OFF faster.... so that once the pipe DOES heatsoak... (which BOTH are going to do) the aluminum will cool off faster.

Being that the aluminum pipes are also much THINNER that your average mild stel pipe.. there is also less mass there, and therefore less heat content to bleed off to the air charge once it doesn heatsoak, thus, it will impart less heat to the air charge...

BUT... Being that I can't wled aluminum just yet, I went witht he steel pipes myself and just thermotech's em..

Nothing wrong with steel pipes.. Unless you are unlitmately concerned about the "Bling" factor.. cause, while its EASY to polish aluminum pipes to look like chrome..... As Ropert Prosky said in "Christeen" ... You can't polish a Turd (AKA Steel)