Saying I'd like to see it. And to know how you go the tailpipes in place. Nothing else. Never said I didn't believe you. When I did mine last winter, getting the tail pipes in was a biatch. And they were 2.5" mandrel bent Stang pipes. Even had to ditch the stock fuel tank to make room.. Even after all that, I had to play with em to get the clearances it needed to insure nothing rubbed.
3-inch pipes will slow the exhaust down. I don't know why anyone thinks a 302 needs 3-inch exhaust pipes. I know they think it's really cool, but all it does is make more noise and less performance on a street smallblock.
Oh you used mustang pipes. That's why you had, a hard time. Using mandrel u-bends and j-bends from summit and cutting, slicing, welding I got them exactly where I wanted them. It wasn't that hard actually and theres plenty of room under there. I was dreading the project and when it was done I was surprised at how easy it was. I don't have any picture posting space left on this site but it you want pics I can send them to an address you specify.
Well, with all of the bends required to route the pipes that adds restriction. Plus start turning over 7,000 RPM or add a little nitrous and a little small block can easily utilize 3" exhaust. Or a stroker like my 347. Remarkably everyone seems to think that it will slow a car down but I have YET to have a car that didn't respond to faster ET's at a drag strip by opening the headers (even less restriction than 3" pipes). Shit, my first maverick I had as a teenager had a stock 302 with a 4 barrel and headers and it picked up more than .3 in the quarter mile by uncorking it. Granted it had 2.25" dual pipes and sonic turbo muflers.
Oh, and 3" pipes will slow the exhaust. How is that even possible? The exhaust is being forced out. ANY reduced restriction will speed it's exit.
It's called physics. Velocity (speed) is greater through a smaller opening. And if you look again at my previous post, you'll see I was talking a bout a street smallblock. You're talking about 7000+ RPM racing motors with spray, blah-blah-blah. At least compare apples to apples. You can't change physics. Slowing down exhaust does not produce more power. Never has, never will. We already know that too much restriction reduces power. Exhaust systems need to be matched to the rest of the components and intended use. But the "bigger is better" egomaniacs never seem to go away.
as the exhaust dissipates heat as it flows through the pipes it contracts and slows down. now this is a crazy high level of exhaust system engineering that goes far beyond street strip car concerns. really high end systems will have multiple sizes of pipe used through out. headers will have stepped tubes. h pipe and x pipe location needs to be located at a tuned location where the exhaust starts to slow in the pipes and creates a hot spot.
I still believe that a restriction is a restriction whether it speeds up the flow or not. I also know that open headers = no restriction and produce the best ET even on stockish engines. I'm very happy with my 3" exhaust and I'm sure it will run good at the track for what it is.
And you're the exception to the rule. 99% of street smallblock V-8s do not run spray or that much RPM.
I think all Larry was getting at is that the higher velocity of the exhaust gasses aids in scavenging(which is what I tryed to elude to without using those specific words) and can produce greater gains and can also extend peak to peak(TQ/HP) performance levels if properly matching the exhaust sizing to the intake tract size/length and cam timing. There's always a point of diminishing returns based on the usage model and scavenging almost always trumps restriction. The simple fact is that ALL engines have some level of scavenging going on irregardless of cam timing/overlap and going with too large a pipe for the AVERAGE power band can and often does affect overall ET, streetability, and throttle response. Basically, whether the spent exhaust is tugging on the intake mixture(overlap period) or reducing the pumping losses associated with pushing the exhaust out on the next round(no overlap).. scavenging is still scavenging. Just don;t expect 120% VE figures from a full street exhaust and take any and all you can get out of the deal.
Well having done exhaust and working in a family owned exhaust shop, what you said was easy is your opinion. Ditto on the "lots of room" under the car. It's very cramped in the area where the rear axle is trying to route the pipe up over the axle.
