• Registered: 2023-09-19
  • Posts: 20

Topic: Exhaust length

How far back does the exhaust need to go? Does it have to come out from under the car, turn out in front of the rear wheels, or go all the way over the axle and out the back?

  • Huskar
  • Ripened Lemon
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  • Registered: 2017-09-10
  • Posts: 117

Re: Exhaust length

Rules require the exhaust exits behind the driver and doesn't heat the fuel system.  We run side pipes that terminate in front of the right rear tire.  Use quality hangers, preferably no rubber even it it claims to be high temp.  Every race seems to have at least two cars that drag exhaust and get black flagged.

1975 Chevy LUV.  1 Corinthians 13:7
1999 Chevy Blazer
  • Registered: 2023-09-19
  • Posts: 20

Re: Exhaust length

ok, I found the rules about the exhaust. no less than 6 inches from the edge of the body and has to be at least past the driver.

4 Reply by etb1009 (edited by etb1009 2023-12-18 03:53 PM)

  • Registered: 2023-06-11
  • Posts: 70

Re: Exhaust length

Also make sure that you don’t weld the exhaust static, don’t ask how we know or found out, make sure there is some wiggle and flex to it, you will thank us later when stuff is not cracking

Team Captain: Highway to Schnell '06 VW GTI, it did run for a very short time! we will get there!
Team member: The Neighbors '89 Foxbody notchback 4 races, finished 2
no wins yet but hoping!
  • Mr.Yuck
  • Mr.Yuck
  • Lemons Staff Stalker
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  • From: Brookeville, Md.
  • Registered: 2013-12-09
  • Posts: 1,013

Re: Exhaust length

I would run it out the passenger side extending further than the body or out the back in the stock location. I wouldn't think of dumping it under the car.

"get up and get your grandma outta here"
  • From: Columbus, Oh
  • Registered: 2020-05-19
  • Posts: 322

Re: Exhaust length

"doesn't heat the fuel system"

Also, note that your fuel filler needs to be away from the exhaust as well. If you can help it, on the other side of the car from the fuel filler is best.

1989 Merkur XR4Ti: Project Merkur Space Program - Wins: Class C - Colonel and the Sinkhole 2023 | "Heroic Fix" The Pitt Maneuver 2023 | "Halloween Meets Gasoline" The Pitt Maneuver 2022
1980 Dodge Challenger: Most Extreme eLemonAtion Challenger (Rust Belt Ramble 2021 Dishonorable Mention)
  • Registered: 2013-11-15
  • Posts: 673

Re: Exhaust length

If you have a turbo car and shorten the exhaust and reduce restriction, you might get overboosting.  We did a 3" exhaust with a side exit and it would overboost past 5000 RPM.

Team whatever_racecar #745 Volvo wagon