Exhaust fabrication

[GT6Steve]

If I flatten a round tube, oval it actually, do I need to go to a larger tube to compensate or is the ovalling essentially invisible to the gasses?.

To state the question differently, how should I handle tight areas under a frame to maximize ground clearance?

Thanx in advance...

 

[pmazza]

The pipe diameter can be the same if you have the equipment to ovalize and keep the area equivalent. Making the transitions smooth is also a challenge if fabricating yourself. I took the easy way out used parts from Dr Gas and Spintech. In order to run 3" all the way back I used oval 3" under the differential. About a foot of the pipe is oval and transitions back to round before entry into the mufflers. This a picture before I had the final fitting and tips installed:



Dimensions of 'ovaled' pipe are here:

https://www.drgas.net/catalog.php?catid=3

My .02.

Phil

 

[Twin_Turbo]

Burns stainless has it all in stainless, but he has burns prices too LOL

If you want to DIY, I have done it before. I take an oversize section of tubing and crush it flat in the hydraulic press. Then cut down so I have the crushed section and cut a bunch of slits in the end and hammer the rest in to create a smooth transition to the smaller OD you were using for the rest. It's a lot of work but cheap.

Pmaza, that's a pretty system you built there, very nice.

 

[mrvette]

I bought a 45* bend aluminum induction tube some time ago, and I had to reduce the ~3" diameter to a oval....

BUT, the problem was when trying to use dome wood in the vice to make a oval, that flattened sides got ripples in the surface.....I did not know how to straighten it....so curious how you all bent that pipe without making a mess out of the flattened surface....

 

[GT6Steve]

Thanx guys,
I went with the ovalled bit so as to keep moving forward. I reasoned it wasn't crushed enough to essentially change the shape.

I'm trying some new stuff with this racer so I'm trying to minimize the variables. Thanx for the input.

 

[pmazza]

TT:

Thanks, I have a pile of F'ed-up tube from the initial attempts to get it to fit right. lol.

mrvette:

I asked the guy at Spintech that same question, basically he said he has a special mandrel to make bends in the oval tubing. DIY bends without that have to be a major PITA.

Phil