Anyone run exhaust, either duals or singles under the axle?

I'm redoing my dual system for more clearance and am considering just running the pipes under axle on passenger side. Have plenty of room there and still have good ground clearance. Plus its easier to do and I'm being lazy. Tired of building just want to finish and drive!

I used to have it up over axle with the 10 bolt rear, but I have a 12 bolt that will be in later this year, and its wider at the center section. Dual 3" over axle is tight as it is with the 10bolt, I'm not sure how well things will fit with the 12 bolt. I have the upper panhard bar removed as it is just to clear everything.

So what are your thoughts going under axle? Look cheap/tacky? I figure it would be great for maintenance and keeping away from gas tank. Whole system is easily disconnected into few pieces so if I needed to get at the rear end, it be simple to drop exhaust. Plus straighter exhaust = less flow loss and restriction = should be more power in the end.

 

I would think that it would hang pretty low. You would have to run it so that the axle wouldnt hit it when the axle is hanging all the way down. I think it would be low enough that the exhaust would hit the ground when the suspension compresses and the car is all the way down in the suspension.

May just have to end it at the axle.

 

It wouldn't scrape unless you bent your axle, but something is telling me it wouldn't be a good idea...

 

I did it once. It works ok and is SO easy compared with over the axle. You just have to have room for suspension movement and be careful when you jack the car up. If I had to do it again though I'd stop in front of the axle so the pipes would sit higher. It does look a little tacky having them hung so low.

 

How far is your suspension traveling on a given basis? My car is lowered and stiff, and doesnt seem to have much suspension travel...it doesnt nose dive on braking so there isnt much rear end rise... at the strip it doesnt lift too much so I dont think the rear drops that far..

Hard to say without looking at it, but if I ever need to fully lower the rear while on jack stands, the exhaust section would be unbolted and taken off the car. But good points, I didnt really think how far the suspension would travel. Need to do some investigating.

IF I did this, it would be a small U shaped bend under the axle to allow some movement but I didnt think it be much more than a few inches if that, which still gives plenty of room from the axle tubes/sway bar.

I cant stop exhaust in front of axle, I need 4 mufflers on this car and 2 of those will be under the rear bumper so I have to get back there again. Oh well, I'll mock up some pipes and see. Just curious if anyone did this and had pics of it for quick reference. The dual exhaust thread doesnt seem to have anything other than an independent rear setup which works well with exhaust under axle.

 

orrr do cutouts upfront so u can shrink the size of the ex tubing were it would have to go over the axle. this way u can open the cutouts wheen needed so u get full flow threw the ex

and u do not need to leave room for suspension movement if u go under the rear
put a flex section on each side right before the rear, then use clamp on ex hangers on the axle tubes

problem solved

 

Not a bad idea there but i have too much 3" left over and a pair of nice ultraflo muffs to match. Still have room for cutouts but it be tight

 

I've been thinking of going under the axle but for a slightly different reason. With my car beIng lowered as much as it is, the passenger side axle tube actually makes contact with my exhaust. At ride height, the bottom of my axle tubes still sit higher than the floor pan so it would make sense for me to go under axle. As long as you limit your droop travel I think it wouldn't be a bad idea.

 

I was thinking of doing a setup very similar to this.

 

Sooo... when set up necessarily as in post #2, what happens when that encounters a speed hump?

 

Yeah that looks good and sorta how i want to do mine. Any other pics of that setup on the ground?

 

If you were going to do this idea I would at least make the section under the axle oval

 

Have a friend with a 67 Camaro that did it both come up under the license plate.
Looks kinda funky going under
Just run it over tailpipes if sized right make almost no difference if any in your times just noise.

 

Playing around with it last night, I think I'm going over the axle. I probably would have good clearance going under but it does look funny from the backside. Not exactly what I thought it would be.

Its not turning out to be all that difficult. I had dual 3" over before and am trying to reuse those pipes I had on it, just moved over abit to allow for the fatter 12 bolt rear. Its tight but I should have room. What makes it difficult is the V-bands I have there for disconnect. They are 4" wide or so, making it harder to place things. I didnt stagger them like I should have....

 

Looks tight on the Fbody Orr. Came close to going under myself but have the car on stands too much. Hoping new dual 3" fits the way it should.

 

yeah i'd be driving the car a week ago if I hadnt decided to redo the exhaust. But I'm glad. It hung way low for my tastes and I know I can do better so I took the time to do it. Its really up near the body now and I gained a good 1-2" I think which is HUGE on this car. Sits low as it is, only has 4-5" clearance in some spots as it is so any gain is a plus. Not bad for dual 3" down stock location with X-pipe and 4 mufflers

Plus the car was just too loud for a turbo car IMO. I'm shocked but the heads/cam are so huge + the larger turbo exhaust housing, its just breathing way too much air. Whats funny tho is that its taking in LESS fuel at idle so it may even be an efficient motor! haha

 

You just answered a question I was wondering about myself...you saw the post by big joe on less jet for porting heads?

Prior to my ripping exhaust off just bought 4 more jets thinking Id need it for the larger exhaust .Something tells me it may be right on the money the way it is....once I get this welded up. lol. Youd think it would be the other way around

Keep us posted. Becoming more efficient perhaps?

 

Yep saw that post. Design is now a full header with collector leading into the turbos instead of a half log/half header design. Probably better exhaust scavenging. Plus the larger turbo housing passes more air, less restriction is better scavenging. Ports air speed is likely alot slower than the AFR 195's but its a well developed port profile so theres probably an efficiency thing there. Air fuel mixture into cylinder is well mixed and spark plugs are in good location. Get a good burn with less fuel.

Cam is 4 deg split instead of single pattern so its favoring exhaust side alittle... just a few dynamics in the equation changed up this year and it shocked me to see this thing take so little fuel. Cold start hot start and idle are all much lower than before. And I mean a gooood bit less fuel

 

Wait, OP has a turbo car, what do you need exhaust all the way to the axle for?

 

https://www.thirdgen.org/forums/post...79-post16.html

trying to get pix now of it installed

 

Exhaust needs to go to bumper because its a true street car and i like tail pipe looks on these cars. Need 4 mufflers to quiet it down and no where to do that before axle

 

meh u dont need a full ex run the downpipes out behind the front tires like i did lol


in ur case stick 2 bullets upfront were the pipes run past the trans, and then a pair of ultraflows under the bumper

 

That is exactly what i am doin!!! Haha i just want it abit quieter than it was. With straight bullets it aint bad but i wanna give the car a sleeper sound

 

Orr the quietest sleeper muffler Ive ever heard are the Dynomax 20" case hemi super turbos. I mean QUIIIIET.

They discontinued the ones that fit mine so did 3" ultras like you. Worried they may still be too loud. If they are Im going to dyno the car with the ultras and make one of thier other Hemi turbos work. If the power drop is minimal Im swapping. Noone will hear you coming promise!lol.
It does not get stealthier than those.

Unfortunately they are discontinuing the line so get em while you can..if you like them. Just hung mine awhile ago now to get it towed in and welded.


Think its the sharp metallic "piercing" sounds that draws the attention of the men in blue these ultras seem to eliminate most that...hopefully

 

I've had the car started up with open downpipes, open straight pipes behind the axle, and with the ultraflo's. Ultraflos by far tame the sound the best but its louder than last years turbo motor combo that had bullets! Not as loud as my 383 was tho so thats a good thing. I just want it to sound like a mild cammed 350 now that the turbos are concealed underhood Dont mind that intercooler in the grille

 

What intercooler? Looks like a brand new AC condenser to me.....

 

Your picture shows an Auto shifter but your profile says T56 maybe an old picture. just curious.

 

Who you refering to? My profile says th400