I have a 66 chevelle with 396, I have headman headers going to 2.5" stainless steel pipes up to a pair of Borla mufflers but from the mufflers back i have 2" tailpipes. Here's my question , I want to make it 2.5" all the way to the rear of the car, will it make that much of a difference in sound and performance ? my car for me is a little to quiet for my taste, i want a little more sound any suggestions ?
2" or 2.5" thats the question
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My Camaro with a 355 had 2" pipes from the headers to the mufflers (Flowmasters), then 2.25" tail pipes. I replaced it with all 2.5" and took about .15 second off my ETs. Not huge but definitely worth it. I didn't notice much difference in sound though.
When I had swapped 2" tailpipes for 2.5" tailpipes with my 454,it did get a little louder.
...but in a good way
...but in a good way
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Your pipes are the right size for a medium-powered small block, not a BBC. You need bigger pipes man, and if I were you, I'd be thinking about a 3" system.
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I should think you will notice a performance difference. I had a 454 in a chevelle that was running low 12s at 110mph, switching to 3 inch picked up .5 seconds and 5mph. The 2.5 was not mandrel bent and kind of tappered over the rearend.
This depends heavily on what is in the motor. If its a stockish 396, then 2.5" headpipes are just fine- 2" tails are probably too small, but 2.25 would be fine.
Its a pretty common mistake to put way too big of exhaust on a car that doesn't need it. Makes it louder, but you lose low end toruqe.
If you are ordering new pipes, 2.5 tails will be fine- but don't hold your breath to feel a surge of extra power on the ole butt dyno.
I would go with atleast 2 1/2" all the way back, if not 3" from the headers to the mufflers, then 2 1/2" over the rear.
The larger the muffler and type of muffler will bring the biggest noise gain, but also more flow.
So in short the 2 1/2" tailpipe will gain a little sound, but not by much. I think it will be a good gain!
-Bobby-
The larger the muffler and type of muffler will bring the biggest noise gain, but also more flow.
So in short the 2 1/2" tailpipe will gain a little sound, but not by much. I think it will be a good gain!
-Bobby-
ditto! I ran a 355 with 2.5 complete and couldn't build enough torque to break the tire on the foot break.when i put this same engine in another car i didn't reuse the tail pipes and used a 2 1/4 and it would melt the tires like i added more displacement.I run a complete 2.5 system on my 454 mandrel bent. a good 2.5 mandrel bent system is better than a compression bent 3 inch system and will support over 500 ponies.http://video.cardomain.com/VideoPlayer.aspx?id=695269
YES. :yes:
And yes. :yes:
I think it was the difference in either total weight or front-to-rear weight bias rather than the tailpipe reduction that alllowed car# 2 to spin the tires easier. Not the tailpipe diameter reduction. :noway: You also have to consider any differences in the suspensions of the two vehicles in question. that would make a difference too. Not to mention that the lack of traction isn't neccesarily a measure of power.
To the originator of this thread: I agree that you should go bigger on the exhaust. In general, the larger exhaust pipe diameter not only tends to make it a little louder given the same headers and mufflers used, but also tends to deepen the exhaust sound (it tends to make the pitch of the sound deeper or with a bit more bass to it. Kinda like plucking the heaviest string on a guitar as compared to plucking the thinnest string).
If this is a Chevelle you're talking about, there's a place called Torque tech ( www.torquetechexh.com ) that sells mandrel bent 2.5", 3", and 3.5" exhaust set-ups for GM A-bodies including Chevelles. Great people to deal with also.
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