Over Axle or Under Axle? New solution

[Steve Chryssos]

Well, what do you think? For the longest time, 4 link conversions and over axle exhaust clearance has been a challenge -- especially on Camaros and Firebirds. However, enthusiasts have been averse to running exhaust under the axle due to concern that the tailpipes would hang low. When developing our new rear subframe-based 4-link design for second gen f-bodies, we decided to address the issue. We reached out to our friends at Hooker exhaust. The Fix? A turn key exhaust system with under axle tailpipes that does not hang low. While it has been designed around our new 4-Link System, it is entirely possible that the design may work with other rear suspension designs.

Here are some pics plus a suspension cam video so that you can see the running clearance in action. We won't be running the Baja 500 any time soon, but rest assured the axle clears the tailpipes even with the rear wheels off of the ground and do not hang low, as the rear view pic below shows.

Feedback on under-axle exhaust is welcome. Maybe more kits will be developed...
Thanks,
Steve

Exhaust Kit details:
https://www.ridetech.com/applications/musclecars/1970-1981-camaro/1970-81-gm-f-body-ls-swap-2.5-stainless-steel-exhaust-system/

Unicradle 4-Link Details
https://www.ridetech.com/applications/musclecars/1970-1981-camaro/bolt-on-4-link-for-1970-1981-camaro-firebird/


https://www.youtube.com/watch?v=yGZRWJHwHU8

https://static1.pt-content.com/images/pt/2018/08/BH13177_Installed11-1.jpg
https://static1.pt-content.com/images/pt/2018/08/IMG_2631-1.png

[dontlifttoshift]

I prefer it over and do that when I can.

The reality is with most of these cars the real estate is tight over the axle and when you can stick a piece of tubing straight out of the muffler and clear the axle housing at full droop, what's the point in going over?

Before this kit was available, I built tailpipes just like that for the new four link. I've bounced the head pipes and the oil pan off the ground already, the tailpipes haven't see pavement yet.

[mklinger]

I struggled with this on my 2nd Gen build with a RideTech 4 Link. Went under the axle as tight as I could. Worked out well

155421

155422

[TheJDMan]

The only difference I see is that you moved the anti-sway bar from below the axle to above the axle.

[Steve Chryssos]

The only difference I see is that you moved the anti-sway bar from below the axle to above the axle.

Steve,
You mean between our old 4-link design and the new design? Totally different, but yeah the sway bar is in the way with the new design as a the rear subframe rails and the upper links. Looking at the exhaust kit, it might help with other brands as well.

[Ron S]

I didn't stop with exhaust, I put the frame down there. LOL

https://static1.pt-content.com/images/pt/2018/09/20180331_170719L-1.jpg

[cornfedbill]

I didn't stop with exhaust, I put the frame down there. LOL

https://static1.pt-content.com/images/pt/2018/09/20180331_170719L-1.jpg

That's my plan too.

[Schwartz Performance]

^^ What Donnie said.

Some people are confused by going under the axle thinking that it will get the rear end really hot....
Well at ride height it's nearly 2" away so definitely not going to boil your diff lube through the axle tubes.

-Dale

[MuscleRodz]

to each his own, but personally i hate how it looks, and makes it more difficult if you have to pull the rear axle when those tail pipes don't want to come back apart. Then you have to worry about axle drop on the lift and how low it has to be to clear that. I build lots of exhaust systems and many times it would have been way easier just to go under the axle instead of over it.

[jlcustomz]

Exhaust is a to each his own thing, but I,ve decided years ago I'll just go ender the axle on my lowered & modified el camino. I got several weld on v-band connectors to use for easy future removal. Though they are a little bit of time to install, it'll be way less time than my old plan of custom fabbing pipes over the axle.
As far as looks go ,paint it black on a lowered vehicle & it's not like you'll see them anyways.