i have a 89 tpi system, and ive seen the big tube runners for tpi's out there and there expensive. My question is is has anyone tried to make there own big tube runners

 

You need to find aluminum tubing of the correct size, a mandrel bender to get the exact angle and diameter of curvature, and a TIG welder

Very few on this board have the skills, time and equipment to do this and those that do would rather shell out the $300 for a new set than go through the PITA of making them

 

Does anyone know of the stock size runners compared the the big tube runners, and is the stock flanges to poreous to weld??? Sorry for all the ?'s i dont think i wanna shell out the mula for a new pair

 

I have considered this and have the source to get the 1 7/8" tubes bent on a 3" raduis.
Now to get the source for the flanges, then I will proceed.

 

http://cgi.ebay.com/HOT-ROLLED-STEEL...QQcmdZViewItem

Cheapest rate Ive seen and they do all sorts of materials including alum

 

why not make them out of steel?

 

I dont think that would work because the entire intake is made of aluminum. If you put steel runners in they would hold the heat in and they would expand at a different rate than the rest of the intake possibly causeing vacuum leaks.

 

You have somewhat of a valid point but just think people bolt aluminum cylinder heads to a steal block.

 

*Steel but its actually cast iron

The heat rates are not that big of a deal

 

I see no reason why steel would not work for this.

 

The steel parts that would expand at a different rate are on opposite sides of the intake, and the aluminum parts are also (top/)bottom vs side/side), so expansion/contraction would make no difference.

I’d be surprised if you could document an overall average difference in air temp resulting from using steel vs aluminum, the steel ones would just take longer to heat up and longer to cool.

Corrosion due to dissimilar metals could be a slight problem, but it wouldn’t be any worse than any other gasketed joint with dissimilar metals on either side. If you’re really concerned stainless steel and antisieze would take care of most of the problem.

Or buy aluminum bends that are the right size and TIG them.

Form them out of ‘glass or CF.