2.5" or 3" exhaust?
#1
2.5" or 3" exhaust?
Doing a heads/cam/intake/headers LS2 swap in my '67 chevelle. Probably have 100-125 n2o nozzle in it eventually too, so figure 500-ish at the tires. Will have true dual exhaust with x-pipe, hooker aerochambers, and tail pipes. 2.5" exhaust sufficient or do I need 3"?
thanks
thanks
#4
TECH Junkie
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First of all, I really hope you'll be making more than 500ish at the wheels on the juice. A h/c/i ls2 should be mid to high 400s right there...and with a 100 shot you should be close to 600 at the wheels.
Even without nitrous I think you will benefit from going 3". So with the shot you should definitely do 3", you will be leaving a good amount of power on the table at ~600rwhp with a 2.5".
Even without nitrous I think you will benefit from going 3". So with the shot you should definitely do 3", you will be leaving a good amount of power on the table at ~600rwhp with a 2.5".
#5
First of all, I really hope you'll be making more than 500ish at the wheels on the juice. A h/c/i ls2 should be mid to high 400s right there...and with a 100 shot you should be close to 600 at the wheels.
Even without nitrous I think you will benefit from going 3". So with the shot you should definitely do 3", you will be leaving a good amount of power on the table at ~600rwhp with a 2.5".
Even without nitrous I think you will benefit from going 3". So with the shot you should definitely do 3", you will be leaving a good amount of power on the table at ~600rwhp with a 2.5".
#9
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I believe 3" is a standard in the LS world. I don't think they even sell aftermarket headers that are less than 3" but I may be wrong. In the end, 3" will be plenty and leave you tons of room to grow. Besides, 2.5 is for Mustangs!
#12
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I believe 3" is a standard in the LS world. I don't think they even sell aftermarket headers that are less than 3" but I may be wrong. In the end, 3" will be plenty and leave you tons of room to grow. Besides, 2.5 is for Mustangs!
For headers you are right.
#13
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I was just using the headers as a reference by saying I don't think they make a header with a 2.5" collector for an LSX. In turn, you would need to reduce the collector size and I don't think anyone wants to take a 3" collector and mate it to a 2.5" tube. Also, the norm for any person with his setup, heads/cam/nitrous LS2 is 3" and above exhaust size. Plus, I've looked on 4 different sponsors websites and every H-Pipe, X-Pipe, or Y-Pipe for these cars are 3".....thus making it the norm.
Last edited by TurboStangJON; 03-07-2011 at 03:38 PM.
#14
Why are you going on a website and asking a bunch of people who dont know much about your car/setup to guess what exhaust you need?
Download PipeMax software, or if you cant locate it, go to www.speedtalk.com and ask somone who has it to run the program you need.
It tells you what primary size, primary length, collector size & length + the diameter of your tubing you'll need for your setup.
good luck
Download PipeMax software, or if you cant locate it, go to www.speedtalk.com and ask somone who has it to run the program you need.
It tells you what primary size, primary length, collector size & length + the diameter of your tubing you'll need for your setup.
good luck