I just bought 1 5/8 BBK longtubes, but i have to build the rest of my system. Im not going to run an h-pipe or anything, just headers, pipe, Spintech mufflers, and side exit tips. Question is, what size pipe and mufflers should i run? 2 1/2, or 3, or bigger? i dont know enough about backpressure so any help would be much appreciated!! I do 90% dragracing at the track. here is a list of my engine mods:
Trick Flow intake
24lb injectors
Ford Racing wires
BBK fendermount cold air
BBK underdrive pulleys
well, people are going to say that I am nuts, but I am going to say it any ways. with your mods, 2 1/4". You do not need 2 1/2" pipes until you are pushing 300 horsepower, and too large of a pipe WILL hurt your ET's buy killing your low end torque. The Ford 5.0 loves a little backpreasure
From what little I know about exhaust I'd agree with Twister on the 2 1/4" system. Problem is, no one offers an after-cat system that small, 2 1/2" is about as small as they come. From what you've said you're doing an after-cat isn't an option and you'll have to go the custom route. Go with 2 1/2" to pave the way for future mods, since the cost of upgrading a custom system later probably outweighs the slightly slower times you may see at the track now.
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1993 LX 5.0 notch
5 speed, Cobra R wheels, CAI, pulleys, Flowmasters, BBK springs. Pretty much stock but still a blast.
Originally posted by sedate88 From what little I know about exhaust I'd agree with Twister on the 2 1/4" system. Problem is, no one offers an after-cat system that small, 2 1/2" is about as small as they come. From what you've said you're doing an after-cat isn't an option and you'll have to go the custom route. Go with 2 1/2" to pave the way for future mods, since the cost of upgrading a custom system later probably outweighs the slightly slower times you may see at the track now.
I guess I wasn't aware of Dynomax's system. I've got a 2 chamber Flowmaster aftercat, 2 1/2" on mine, and I think I'm going to equal length 1 5/8" MAC shorties and a MAC h-pipe. I know it will hurt torque, but my options aren't too plentiful. Oh well, it's a stripper coupe so I have lighter weight on my side : )
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1993 LX 5.0 notch
5 speed, Cobra R wheels, CAI, pulleys, Flowmasters, BBK springs. Pretty much stock but still a blast.
ok, so i think im gonna go with the 2 1/2. heres another question....does the size of tailpipe make any difference? becasuse i have a feeling that 2 1/2 pipes hanging out of the side of the car might look a little "dinky." i was planning on some kind of larger stainless steel tailpipe. I know that when i had my Dodge Stealth i put on a muffler with a 4 1/2 tip, and i lost about .3 at the track.
what size exhaust? 
