Fabrication Custom fabrication ideas and concepts ranging from body kits, interior work, driveline tech, and much more.

Built a Transmission Crossmember For Dual 3" Exhaust

Thread Tools
 
Search this Thread
 
Old 07-01-2020, 06:44 PM
  #1  
Supreme Member

Thread Starter
 
383backinblack's Avatar
 
Join Date: Nov 2002
Location: Santa Monica, CA
Posts: 2,776
Received 8 Likes on 6 Posts
Car: '91 Camaro RS
Engine: F1R Procharged 383
Transmission: Tremec 600
Axle/Gears: moser 12 bolt, 4.11's 33 spline axl
Built a Transmission Crossmember For Dual 3" Exhaust

Hey guys, I've had a dual 3" exhaust setup for 18 or so years. Originally, it was fast, inexpensive, and it certainly got the job done. But the ground clearance was always horrible, and it hit on a lot of speed bumps and high speed dips. It was time to finally build a mandrel bent stainless setup with an X-pipe. The first step was fabricating a new Crossmember to allow the exhaust to stay in between the subframe, and not have to go around it (the cause of the lowest, most horrible ground clearance issue). Making this to the standard I wanted it was tough, mainly because you're working on 3 different mounting flanges which are at independent, compound angles. None of which are square with any of the others. That's not too big of a deal if you're working on a lift, and building one part, right on the car. I wanted to be able to duplicate it, if necessary though. So, I made a fixture for it.

In any case, it's still kind of tight on the passenger side, but there is enough room to run 3" pipe through there and have it be higher than the header collector and blowshield (praying that doesn't hit). The caveats here are I don't have a torque arm, I have SSM lift bars. (I'm aware of the Hooker crossmember with the torque arm mount, but I think it only works on LS swaps which are also using Hooker's motor mounts anyway). To be realistic, I think adding the torque arm mount to this wouldn't be a big deal. Also, my trans is a TKO 600, and it has the long, gangly speedo adapter, and it JUST clears that. With a different setup, it'd likely work even better. In order to do this on another transmission, I'd need a correct crossmember to get the trans mount location/height right on. I'd totally be into working with some people to do that though, as an experiment.










The following 2 users liked this post by 383backinblack:
Jaysz28 (07-02-2020), soloc4 (07-01-2020)
Old 07-01-2020, 11:24 PM
  #2  
TGO Supporter

 
soloc4's Avatar
 
Join Date: Nov 2003
Location: Lake Stevens, WA
Posts: 406
Received 229 Likes on 131 Posts
Car: 84 Z28, 92 C4 suspension F&R, ABS
Engine: 408 LS2, CNC LS3 heads, Comp Cam
Transmission: Magnum F, RTX clutch, Tick shifter
Axle/Gears: DANA 44, Tru Trac, 3:73 gears
Re: Built a Transmission Crossmember For Dual 3" Exhaust

Nice work, looks great. That is going to give you a lot more room to tuck the exhaust up. Post some pictures of the finished exhaust.
The following users liked this post:
Jaysz28 (07-02-2020)
Old 07-02-2020, 11:25 AM
  #3  
Supreme Member

Thread Starter
 
383backinblack's Avatar
 
Join Date: Nov 2002
Location: Santa Monica, CA
Posts: 2,776
Received 8 Likes on 6 Posts
Car: '91 Camaro RS
Engine: F1R Procharged 383
Transmission: Tremec 600
Axle/Gears: moser 12 bolt, 4.11's 33 spline axl
Re: Built a Transmission Crossmember For Dual 3" Exhaust

Originally Posted by soloc4
Nice work, looks great. That is going to give you a lot more room to tuck the exhaust up. Post some pictures of the finished exhaust.
Thanks, will do! ... I'm ordering all the tube and other materials now.
Old 07-02-2020, 12:26 PM
  #4  
Supreme Member

iTrader: (11)
 
scooter's Avatar
 
Join Date: Sep 1999
Location: NJ
Posts: 4,345
Received 298 Likes on 234 Posts
Car: 92 Firebird
Engine: 4.8 LR4
Transmission: T56
Axle/Gears: 3.45 9 Bolt
Re: Built a Transmission Crossmember For Dual 3" Exhaust

Looks like you just have two slots in the rectangle tube for the mount bolt? Hopefully you reinforced in between the holes? If not then eventually the tube will allow the bolt to distort the tube and it will get loose.
Old 07-02-2020, 12:40 PM
  #5  
Supreme Member

Thread Starter
 
383backinblack's Avatar
 
Join Date: Nov 2002
Location: Santa Monica, CA
Posts: 2,776
Received 8 Likes on 6 Posts
Car: '91 Camaro RS
Engine: F1R Procharged 383
Transmission: Tremec 600
Axle/Gears: moser 12 bolt, 4.11's 33 spline axl
Re: Built a Transmission Crossmember For Dual 3" Exhaust

Originally Posted by scooter
Looks like you just have two slots in the rectangle tube for the mount bolt? Hopefully you reinforced in between the holes? If not then eventually the tube will allow the bolt to distort the tube and it will get loose.
It is reinforced.
The following users liked this post:
scooter (07-02-2020)
Old 10-19-2020, 06:35 PM
  #6  
Member

 
86iroc504's Avatar
 
Join Date: Jun 2006
Location: Nawlins
Posts: 398
Received 11 Likes on 11 Posts
Car: 86 Camaro
Engine: '03 4.8 vortec
Transmission: 4l60e
Axle/Gears: 3.42
Re: Built a Transmission Crossmember For Dual 3" Exhaust

Do you have any pictures of your exhaust with your new crossmember?
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
86 406
Fabrication
8
02-22-2020 05:38 PM
cmiller2014
Suspension and Chassis
8
12-16-2019 09:40 AM
Ed1LE
Suspension and Chassis
20
09-22-2017 03:21 AM
A10Beav
LTX and LSX
4
02-13-2013 04:52 PM
85SILVERBULLET1
Organized Drag Racing and Autocross
11
05-09-2011 11:56 AM



Quick Reply: Built a Transmission Crossmember For Dual 3" Exhaust



All times are GMT -5. The time now is 08:18 PM.