How exhuast set-ups affect low end torque
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From: Rio Rancho USA
The number of pipes dont matter at all. Keeping exhaust velocity high and backpressure as low as possible is everything. Replacing a stock system with a better flowing setup that has properly sized pipes will build torque.
Going "too" big will not result in torque loss, it just moves further up in the powerband. Its still there, just in a different spot
Going "too" big will not result in torque loss, it just moves further up in the powerband. Its still there, just in a different spot
Last edited by kens64; Sep 16, 2004 at 03:43 AM.
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From: Houston, Texas
Originally Posted by kens64
Going "too" big will not result in torque loss, it just moves further up in the powerband. Its still there, just in a different spot
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From: shepherd
Originally Posted by kens64
Keeping exhaust velocity high and backpressure as low as possible is everything.
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From: Houston, Texas
what about a turboless 302 V8 with a single pipe ? lemme get a few things straight that i dont understand 100%
1. low-end torque = acceleration
2. fewer bends = higher exhuast velocity
3. backpressure is good because......
1. low-end torque = acceleration
2. fewer bends = higher exhuast velocity
3. backpressure is good because......
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From: suthern elinoees
Backpressure creating low end tourque is an old wives tale. It's evil. What you actually want is high exhaust velocity with the lowest backpressure possible. Just like kens64 said, he knows what he is talking about.
Backpressure is restiction and that is not what you want.
On edit, check out this thread-
https://www.ford-trucks.com/forums/s...essure+falcon+
What you actually want is high exhaust velocity with the lowest backpressure possible. Just like kens64 said, he knows what he is talking about.Backpressure is restiction and that is not what you want.
On edit, check out this thread-
https://www.ford-trucks.com/forums/s...essure+falcon+
Last edited by NascarNut; Sep 16, 2004 at 09:48 PM.
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From: shepherd
ok listen to them but one you get 3 inch or whatever which you probably won't you are going to hate it because your low end will be gone. if you got cats then you should be ok though.
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Yes you are correct, but not because of "low backpressure". A 3" on a low flowing motor like the 300 can allow the exhaust to "stack up" because of LOST VELOCITY. Lost velocity=lower speed. Higher exhaust speeds help pull the next pulse out w/ it (vacuum effect). Lower can make them bump into each other, slowing them even more (possibly creating turbulance). The cooling effect of the larger area also slows it down.
Last edited by tdister; Sep 17, 2004 at 02:05 PM.
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From: Rio Rancho USA
Your low end will not "be gone" because you go with 3" pipe. Only some torque is moved, not all of it..... Sometimes very little, it really depends on the engine. The torque moves up because, as the engine revs up, it finally makes use of the bigger pipe and velocity is good again.
Think about it, having a little more mid range torque can be a good thing if you're on the highway all the time. That extra mid range will help passing power, or pull a hill without having to shift down. Having the cats are not a help, they are a restriction, not a velocity producer, though I would leave them on or go with higher flowing units.
I would not go bigger than 2.5" on a mild 302. 2.25" is probably best for a stock 302.
HTH
Think about it, having a little more mid range torque can be a good thing if you're on the highway all the time. That extra mid range will help passing power, or pull a hill without having to shift down. Having the cats are not a help, they are a restriction, not a velocity producer, though I would leave them on or go with higher flowing units.
I would not go bigger than 2.5" on a mild 302. 2.25" is probably best for a stock 302.
HTH
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what ive had in mind for my set up i wanna save up for is having the pipe exit infront of the back passenger side tire, but with something closer to a 45 degree bend, as opposed to the 90 degree bend i usually see out on the road.
should this be okay? it should keep the exhaust velocity up right? is there anyproblem with this (assuming texas emmission laws say its okay to have the pipe exit there)
should this be okay? it should keep the exhaust velocity up right? is there anyproblem with this (assuming texas emmission laws say its okay to have the pipe exit there)
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From: Rio Rancho USA
It should be fine, and probably look beter than a straight cut pipe exiting there. Placement has nothing to do with velocity, its all pipe size and # of bends. I wouldnt worry about emissions either, as long as the cat(s) are not modified, you can have the exhaust exit anywhere you want.
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From: Houston, Texas
yea, the main purpose for exiting infront of the rear tire is to prevent scraping, ive already scraped the bottom a lil on some extremly angled driveways and streets, when i get a new exhuast set up i dont wanna damage it too much too soon, hehe.
the angle is cuz i didnt think having such a sharp bend would be too good for the exhuast flow.
the angle is cuz i didnt think having such a sharp bend would be too good for the exhuast flow.