do i need back pressure?
Trending Topics
No, back pressure is for torque and you want top end HP...LOL.
Depends, what is the engine setup? Stock? Yea, a little back pressure is ok, a big cammed big inch engine, less is more.
Depends, what is the engine setup? Stock? Yea, a little back pressure is ok, a big cammed big inch engine, less is more.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
No
Yes
No
Depends on who you ask some say you do most say you don't
Some will say if you dont have it you'll lose low end TQ most say thats BS
Here is a thread about it
https://ls1tech.com/forums/advanced-...re-torque.html
Yes
No
Depends on who you ask some say you do most say you don't
Some will say if you dont have it you'll lose low end TQ most say thats BS
Here is a thread about it
https://ls1tech.com/forums/advanced-...re-torque.html
TECH Addict
Joined: Mar 2009
Posts: 2,099
Likes: 3
From: Texas/Afghanistan
omg are there really ppl out there that don't know the difference between back pressure and exhaust scavenging?
back pressure=restriction. no car will ever benefit from restriction.
you want the proper diameter pipe to acheive the desired amount of scavenging for your power band/set up. the smaller the diameter of pipe, the higher the gas velocity. high gas velocity is good for low end torque. the bigger the diameter of pipe, the more volume there is to fill and the velocity drops. or at least takes longer to reach the higher velocity numbers, which is more beneficial to peak power.
its not rocket science.
back pressure=restriction. no car will ever benefit from restriction.
you want the proper diameter pipe to acheive the desired amount of scavenging for your power band/set up. the smaller the diameter of pipe, the higher the gas velocity. high gas velocity is good for low end torque. the bigger the diameter of pipe, the more volume there is to fill and the velocity drops. or at least takes longer to reach the higher velocity numbers, which is more beneficial to peak power.
its not rocket science.
my SS /stalled A4/bolt ons/ cam /stock heads/ LT with 3" collectors (with 23" of 3" pipe beyond collectors , opening plates are in the L bends of y pipe)
Going into full exhaust with limiter set at 6700 shifting @ 6500 will never hit the limiter IF running OPEN headers will hit the limiter ever time unless I set shifts at 6100.
This I do not understand unless with no back pressure it rives much faster so the trans does not have time to shift
Johnny
Going into full exhaust with limiter set at 6700 shifting @ 6500 will never hit the limiter IF running OPEN headers will hit the limiter ever time unless I set shifts at 6100.
This I do not understand unless with no back pressure it rives much faster so the trans does not have time to shift
Johnny
Last edited by SS SLP2; May 16, 2010 at 08:46 AM.
TECH Addict
Joined: Mar 2009
Posts: 2,099
Likes: 3
From: Texas/Afghanistan
read through the thread purple t/a posted. a shorter pipe will have a dramatic effect on the power curve. especially open headers. basically you are shifting all your power up top...so let that sink in....ok. you are going to fly through the RPM's faster the closer you get to peak because of the exhaust scavenging effect i explained earlier.
also anyone who reads this please delete the word back pressure from your vocabulary, as far as you are concerned the **** doesn't exist.
also anyone who reads this please delete the word back pressure from your vocabulary, as far as you are concerned the **** doesn't exist.
Last edited by brian_rs/ss; May 16, 2010 at 12:40 AM.
read through the thread pruple t/a posted. a shorter pipe will have a dramatic effect on the power curve. especially open headers. basically you are shifting all your power up top...so let that sink in....ok. you are going to fly through the RPM's faster the closer you get to peak because of the exhaust scavenging effect i explained earlier.
also anyone who reads this please delete the word back pressure from your vocabulary, as far as you are concerned the **** doesn't exist.
also anyone who reads this please delete the word back pressure from your vocabulary, as far as you are concerned the **** doesn't exist.
read through the thread pruple t/a posted. a shorter pipe will have a dramatic effect on the power curve. especially open headers. basically you are shifting all your power up top...so let that sink in....ok. you are going to fly through the RPM's faster the closer you get to peak because of the exhaust scavenging effect i explained earlier.
also anyone who reads this please delete the word back pressure from your vocabulary, as far as you are concerned the **** doesn't exist.
also anyone who reads this please delete the word back pressure from your vocabulary, as far as you are concerned the **** doesn't exist.
TECH Addict
Joined: Mar 2009
Posts: 2,099
Likes: 3
From: Texas/Afghanistan
anybody familiar with the law of conservation of energy? it states that energy can neither be created nor destroyed, only transferred from one state to another. essentially it has a flow. so keeping that in mind and realizing that hp and torque are a measure of energy, you would see how idiotic it is to assume that freeing up the flow of exhaust gases, would miraculously make your engine lose power. instead it would make more sense that because of the natural transfer of energy you would shift power from the lower RPM to the higher RPM. ei: you would see an over all peak hp/tq increase.
but you know who am i to question your cousins knowledge of automobiles
Depends on your Camaro.
I would say on a racecar where power is the objective, the less restriction the better, but on a streetcar, I don't think that is necessarily true. You don't want all of your torque to come in at a higher RPM in a street car, and basically have nothing in the lower RPM.
I would say on a racecar where power is the objective, the less restriction the better, but on a streetcar, I don't think that is necessarily true. You don't want all of your torque to come in at a higher RPM in a street car, and basically have nothing in the lower RPM.
I read a really good explanation on this a while back. Theirs some sort of calculation thing you can use to determine what is the best size pipe to run under your car. i will have to look for it. but it had some really interesting points, and dyno charts.
