Quote:
Originally Posted by zebra
in the higher rpm range
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It's my understanding shorties give power
way up top, like bike engine range, just like you've said. I wonder how big the primaries are since I know the length will be pretty short. Hopefully they'll be close to 1 3/4".
Quote:
Originally Posted by 383ss
about 10 hp. not much.
long tubes will be about 25hp.
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On LS1 F-bodies, I think they're right about where this post said. There was a guy on LS1tech (TrojanTA I think) who was working with BBK (I think) to get some 1 3/4-inch primary shorties CARB certified and he was going to add a 2.5-inch Y-pipe to see how close he could get to long tube (LT) gains. I don't ever recall if he ever finished what he found, if he actually determined anything, but this exhaust looks to be pretty optimized, from the pics' that we have.
FWIW, my brother's car ('02 F-body), with a lid, K&N, Borla catback (CB), and canned Diablosport tune, put down 327 to the tire, and after adding QTP LTs and their cat'd Y-pipe and tune, it put down 350+. My car, equipped pretty much the same, put down very similar numbers (as high as 366) so I think 20-30 RWHP is reasonable with a good tune and exhaust.
Quote:
Originally Posted by Jamestwilliams
Headers that easily fit in place of a stock manifold. And a partial gain in flow which allows for you to make the most of changes made via a tune or other additional parts. Long tube headers are of course much better at flowing exhaust gasses giving better high rpm horse power, while a more restricted exhaust actually produces better low end torque (restricted to a point).
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I can feel a little more low-end when I have my cutout closed than open, so I think that lends a little to this statement. It could just be a placebo, but this is a proven point. I'd encourage anyone who's interested to do research on dyno' test between shorties, LTs, and different primary sizes and lengths. It's pretty interesting
