3.5" exhaust

-
72scampguy

72scampguy

Well-Known Member
Joined
Apr 26, 2015
Messages
122
Reaction score
43
Location
Mexico Mo.
Anyone running 3.5"exhaust? My headers are 3.5 collector. Anyone make a mandrel bent x pipe for this or you think i should put cutouts on it and then run 3" on the rest.
 
There are size horsepower all over the internet but what I've seen the mufflers and bends are what kill power. The smaller tube you can use increases velocity.
Personally I don't like the look of 3.5 under the car and what I'm planning is 3.5" to the mufflers 3.5" mufflers and 3" over the axle with exits at the rear of the tires.
Exhaust cools and contracts the farther it gets away from the engine so tube diameters can get smaller the farther away you get.
I have a big block in the same power range.
 
72scampguy said:
Anyone running 3.5"exhaust? My headers are 3.5 collector. Anyone make a mandrel bent x pipe for this or you think i should put cutouts on it and then run 3" on the rest.
Click to expand...

I am running 3 1/2" , a slight double twist to clear the trans crossmember on the drivers side, to 3 1/2" bullit roundy round mufflers w/ 3 1/2' spirals slid about 1/2 way in them and welded , then to 3 1/2'' turndowns berfore the axle , fully wrapped w/ exhaust wrap from the headers back " just because I had it ." Don't have any floor bard heat !
 
famous bob said:
I have thot about it , but think it would just be extra weight in my case .
Click to expand...
That's certainly a consideration. Performance wise, several years ago we ran a test on a 400hp car with our 2.5" X connected to LT headers and then ran the same exact test with the X-pipe removed. The car dyno'd 10 extra hp to the wheels with the X-pipe on and nothing behind it! So in theory, you might add weight but you might still pickup a little extra in the quarter mile.

That being said, with X-pipes, there comes a point with really big motors where they may not increase your hp. We never tested a 3.5" X versus open headers. Some guys swear they work and some guys buy them strictly because of reduced decibels.
 
Ccas said:
That's certainly a consideration. Performance wise, several years ago we ran a test on a 400hp car with our 2.5" X connected to LT headers and then ran the same exact test with the X-pipe removed. The car dyno'd 10 extra hp to the wheels with the X-pipe on and nothing behind it! So in theory, you might add weight but you might still pickup a little extra in the quarter mile.

That being said, with X-pipes, there comes a point with really big motors where they may not increase your hp. We never tested a 3.5" X versus open headers. Some guys swear they work and some guys buy them strictly because of reduced decibels.
Click to expand...
Thanks for the offer. I will be calling you when the time comes. Gotta get that motor off the dyno and in the car first..
 
Ccas said:
That's certainly a consideration. Performance wise, several years ago we ran a test on a 400hp car with our 2.5" X connected to LT headers and then ran the same exact test with the X-pipe removed. The car dyno'd 10 extra hp to the wheels with the X-pipe on and nothing behind it! So in theory, you might add weight but you might still pickup a little extra in the quarter mile.

That being said, with X-pipes, there comes a point with really big motors where they may not increase your hp. We never tested a 3.5" X versus open headers. Some guys swear they work and some guys buy them strictly because of reduced decibels.
Click to expand...

505' 'r/b , don't think it would be worth its weight .
 
How much heavier (“Actual Weight”) can a 3-1/2 be over a 3 inch set up dumping at the rear axles?
Just the facts please....
 
Don’t know how y’all would even have clearance with 3.5” pipes. I can barely squeeze by with 2.5”. Lol

I’ve been thinking about going with 3” oval pipe... but I know.
 
rumblefish360 said:
How much heavier (“Actual Weight”) can a 3-1/2 be over a 3 inch set up dumping at the rear axles?
Just the facts please....
Click to expand...
I think the thought was to run open headers vs the X-pipe? The difference between 3" and 3.5" back to the mufflers is less than 2 lbs. A 3" X with 3" mufflers from the headers is around 35lbs total.

Just as an fyi, a full 3" kit from the headers; X, midpipes, mufflers, tailpipes, 4 big hangers, 10 heavy duty U clamps, packaging and the box it ships in is 70lbs.
 
You must log in or register to reply here.
-

Back
Top