Trackmouse
Trackmouse SuperDork
2/27/17 1:29 p.m.

Has anyone done some crazy exhaust work putting a header through a chassis or unibody? And I'm not talking an exhaust tip cutout. I mean. Sticking a header through the unibody area around or near the fender wells. I see pick up guys cut fender wells out completely. How safe? is rigidity lost?

rslifkin
rslifkin Dork
2/27/17 1:34 p.m.

It depends on the car and how much cutting you're doing. It's usually possible to add bracing to make sure you're not losing strength / stiffness when you cut.

STM317
STM317 Dork
2/27/17 1:44 p.m.

I think I'd probably want something like subframe connectors installed before I did to much cutting on a unibody.

Dusterbd13
Dusterbd13 PowerDork
2/27/17 1:49 p.m.

Mopar a body guys used to do this for fender well headers on big block drag cars.

Id add structure somehow if you plan to turn.

Chadeux
Chadeux Dork
2/27/17 1:49 p.m.

What I'm picturing here is fender well headers.

Usually on full frame cars with the inner fenders either cut to make room or removed.

On most unibody cars I've dealt with, that inner fender is usually something like a strut tower, which I wouldn't want to cut holes in.

Coming from me this is all theory though.

Also note that the example picture I found is an A-body Mopar...which is unibody.

GTXVette
GTXVette HalfDork
2/27/17 1:50 p.m.

removing a fender well isn't that big a deal on most cars some newer cars are even made of plastic, going through a firewall or side (door)or fender slso won't affect too much if you don't remove anymore than needed. some cars they are welded in place and I would consider that to be a structure move so be some what cautious. I've also seen frames that look like Swiss Cheese but then they had roll cages, the engine in my Vette is 13" back and they Have to go through the Fire wall area but again I have a Cage. so what kind of car or truck and what are you thinking of doing with as much Detail as you can Imagine to give an Idea of what you are looking to do.

BrokenYugo
BrokenYugo MegaDork
2/27/17 1:51 p.m.

Pickup guys don't cut the fender well out, they unbolt it, the frame horn is the only actual structure up there on a body on frame vehicle, you've usually got a lot more going on in that area of a unibody car, even with the early stuff.

Trackmouse
Trackmouse SuperDork
2/27/17 1:57 p.m.

Ok. Seems like I just need to be really fracking creative with the headers design next... thanks folks.

GTXVette
GTXVette HalfDork
2/27/17 2:08 p.m.

Call Out the Secret's Police he's hiding Somtin, Lol

Knurled
Knurled GRM+ Memberand MegaDork
2/27/17 4:53 p.m.

I've seen Shoenfeld 180 degree circle track headers in unibody cars, you basically cut a tunnel in the right side and you lose the ability to have a passenger seat.

GTXVette
GTXVette HalfDork
2/27/17 5:36 p.m.

Sir I am presently hunting a set of Big block 180's for my vette PLEASE if you know of some let me know and I have a WTB in 2017 classifieds,thanks

Chadeux
Chadeux Dork
2/27/17 8:42 p.m.

In reply to GTXVette:

I presently have no meaningful information to offer other than to say that what you seek is definitely a noble cause.

44Dwarf
44Dwarf UltraDork
3/1/17 12:35 p.m.

I had large diameter tube fender well headers on my 67 big block Dart but i had 8 point cage and back half'd the frame rails.

You'll need to log in to post.

Our Preferred Partners
HCqKhBcdrQukYCeoLyn10fL1YbD3VkfiRrN9C9aHQiIei1gutYiDyIG6XVyB9GNQ