I need something that is durable for rally and will seal without overheating gaskets. The rotary powered rally car needs some attention and I've tried everything, figured I'd poke the hive a touch.
- Traditional 2 bolt flange = heat blows the gasket and/or i over torque it and warp it
- various gasket materials
- v-band = the bolt catches some dirt and then it opens the exhaust right up to 100%
- reduce quantity of flange/gaskets
- move said flange/gasket 3' rearward in car to hope for cooler temps and avoid gasket failures
what are my other options? Ive seen bikes or A-mod cars use a spring mechanism style or a slip fitting I'm unsure on the durability for offroad abuse. I know I need to raise the height of the car to address the pancaking of the tubing but I want something that is durable and resistant to exhaust leaks.
The Samurai comes with a springloaded slip fitting (at the header to downpipe joint), they're actually great for offroad abuse because they can allow the exhaust to slip off if part of it is physically stressed, but then it re-seats itself. I've had to double up the gaskets in mine though, it could be that the springs are softening up over time. And I'm not dealing with unusually high exhaust temperatures.
V-bands work on rally cars provided you keep them up high- I wouldn't expect any flange below floor level to survive. Can you make it so that the junctions are all higher than the bottom of the skidplate and unibody rails? My RX7 rally car solution was to only have flanges up high, and the car was still low enough to break the exhaust off eventually.
¯\_(ツ)_/¯ said:
V-bands work on rally cars provided you keep them up high- I wouldn't expect any flange below floor level to survive. Can you make it so that the junctions are all higher than the bottom of the skidplate and unibody rails? My RX7 rally car solution was to only have flanges up high, and the car was still low enough to break the exhaust off eventually.
Unfortunately the exhaust is the lowest point in my car due to the exhaust header sticks below the frame rail by about 2" from there I try and bend it upward and out but its still a bit low. Part of the issue is my suspension because it certainty squats when i mash the gas. This issue will be fixed soon. My exhaust flange in the car is like at the back of the seat and at the block. just 2 spots. block is fine though :)
In reply to fidelity101 :
That sounds like your options are either to reroute the header, or build something to protect it and the flange- like a little skid coming off the trans mount or something. 2" below the frame rail is massive.
Use a heavy two bolt flange, make sure both sides are flat, and don't use any sort of gasket, unless you cut one from copper. A good, solid, flat flange may seep, but won't leak enough exhaust to make any extra noise.
Stainless band clamps with the bolts up high?
Streetwiseguy said:
Use a heavy two bolt flange, make sure both sides are flat, and don't use any sort of gasket, unless you cut one from copper. A good, solid, flat flange may seep, but won't leak enough exhaust to make any extra noise.
I've tried that before, forgot to add it to the list. it worked well for a bit but not well enough.
Patrick said:
Stainless band clamps with the bolts up high?
I was thinking that but I think this time I am going to try the slip fit
