couldn't find any information on search , so I decided to post . Hopefully after the busy holidays probably around jan or feb I would like to finish my exhaust system for my car. the pipe going towards the muffler goes over the differential / axles , has anyone that had a custom exhaust done go below it? I was thinking it would be less restrictive if you go from the bottom instead of the hump over the diff/ axle . I understand that if this is done it may cause problems going towards road bumbs and humps but if it makes more power im all for it. any inputs?? good idead ? bad idea ? more hp or less?

 

If it's a track only car, sure go for it. But if it's street driven it'll be a target for bad roads and obstructures(speed bumps, pot holes, etc.). I could see it getting bent and damaged

 

i went to the 2nd gen forum and checked out some of their exhaust systems and alot of their straight through exhaust hang pretty low. here is pic of one , planning on doing something exactly like this for my fb think it would look good?

 

That muffler belongs to steve84GS TII. If you search his name you should find some info.

 

I dont think it would be worth the hassle. Speed bumps and pot holes like ^^^ said would be an issue. I email Racing beat about the muffler section that arcs over the axle and if they just sold that piece and he said the gains (if any) from replacing that isnt worth it.

Interesting Idea but i wouldnt do it. Maybe do a side pipe??

 

I've been running a side-exit setup for a few months now. There really isn't much room for mufflers, even with the stock exhaust manifold. My two medium-length glasspacks barely fit. If you wanted to do a header it would be even worse. Plus, it tends to choke the passenger if they try to get in or out while the car's running. It's cool and I like it, but I probably wouldn't do it again.

 

Bad idea. By the time the piping is dropped enough to account for rear axle drop, it will be too close to the ground. The 2nd gens can run straight piping due to the IRS system, won't work with a live axle set up.

 

hmmm interesting

 

dang man this is what i was telling you when i was over there dude! Its cool though, i been looking for some mandrel bends some 45's and a 90*,so that i could get my exhaust redone. i beleive that if you mandrel bends you should no problems with flow. if its easyer that you want really no option unless you get prefab.
i got that oil cooler that i waas telling you about its from my SE b4 i put 2ng gen there and i ll have lil more cash for later this week.

 

Exactly what I was thnking. You'd have to position it low enough to allow for full suspension travel, otherwise you'll beat the hell out of it, if not rip it free of the mounts, when the suspension tries to do it's job. I don't know what you're running now, but I REALLY like the full racing beat set up.

 

the suspension doesnt drop on a solid axle car. the body moves above the axle. i run 2.5" from my rb presilencer back under axle and it's never ever hit anything. i put 200-400 miles a week on my car the only thing that scrapes is the stupid RB presilencer. there are turbo guys running 3" under axle FB's. search under axle in this section it has been done sucessfully many times.

 

Check the racing section. When the car is lowered enough, the shock stroke can be shortened (I did it on mine so the rear springs won't come loose when I jack the car). This keeps the axle from drooping as much and resolves the interference issue. It's all simple enough to calculate, and I believe some of the more heavily modded cars run like that.

 

Other than the sake of simplicity...

What point you would really to route the exhaust that way?

I can understand say a 3" inch exhaust.. even that I think will go fine through the bend over the axle...

I mean what a 1hp gain? Logically it seems only useful for looks...

 

I want to do it for both looks and horsepower gain if any seems like its going to be tough if I do the under axle.

 

well couldnt find any thing on " under axle " both info and pics through search , do you think you can link the information you were referring to ???

 

Weird. the search changed from yesterday to today...
here's mine. https://www.rx7club.com/nw-sale-wanted-classifieds-209/my-sick-ass-fb-exhaust-800083/
And there were other threads before, but I don't have the time to search for you.
Mazda ran under axle with all teh SA and FB IMSA cars. I have pics of it somewhere...

 

cool , but do you have any pics of the axle ??? I want to see how you did it , the angle and height ,I searched around and found this but this is from a gtu race car and it is LOW