Backpressure and cutout "theory"
Jun 29, 2006 | 01:35 PM
#12
hmmm...maybe build a relay in with one of the of EIO outputs, so when you are at 100% throttle the relay will open it for ya. That would be enough of a delay right? 2-3 seconds and you're out of the 60'. I only suggest this to keep you from having to "hit the switch".
Very intersting though. The only comparisons I've seen are on a dyno and track. Both are all or nothing in all cases. Cool experiment. Not sure what it will net you, but should prove to be interesting. How about this as a question, your 60' times...what are they with your cutout open and what are they with it closed? (question aimed at anybody who has this information)
Very intersting though. The only comparisons I've seen are on a dyno and track. Both are all or nothing in all cases. Cool experiment. Not sure what it will net you, but should prove to be interesting. How about this as a question, your 60' times...what are they with your cutout open and what are they with it closed? (question aimed at anybody who has this information)
Jun 29, 2006 | 05:17 PM
#13
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From: San Antonio
Originally Posted by dewmanshu
hmmm...maybe build a relay in with one of the of EIO outputs, so when you are at 100% throttle the relay will open it for ya. That would be enough of a delay right? 2-3 seconds and you're out of the 60'
I also wanted to point out that exhaust backpressure is always bad but the right diameter piping creates higher exhaust velocity at lower rpms which encourages scavenging, increasing bottom end power. Just trying to spread the good word.
Jun 29, 2006 | 06:07 PM
#14
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You should look at this from QTP. http://www.quicktimeperformance.com/...ller/index.php
Nice little toy.
Nice little toy.
Jun 29, 2006 | 06:12 PM
#15
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From: Ham Lake, MN
Originally Posted by Order 66
You should look at this from QTP. http://www.quicktimeperformance.com/...ller/index.php
Nice little toy.
Nice little toy.
Jun 30, 2006 | 09:13 AM
#17
On The Tree
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From: Indianapolis
Originally Posted by bluecajun5.3
there's only one way to see.
try them both!
try them both!
For what it's worth, after lots of dyno testing, we've never seen an increase in torque in any exhaust configuration after the headers on any application (but you can make big differences in torque with different header configurations). Matter of fact, we've seen a considerable increase from open headers every time we've tested and the more restrictive the exhaust, the lower both torque and horsepower numbers went.
In my opinion, the idea that "too much exhaust flow hurts torque" is an urban myth - backpressure is always, always, always a pumping loss that the motor has to work against. Tune the headers to the application, run as big a pipe as you can fit after the collector - especially if you run cats.
Jun 30, 2006 | 04:15 PM
#18
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From: Texarkana, AR
Originally Posted by FMOS Racing
Amen.
For what it's worth, after lots of dyno testing, we've never seen an increase in torque in any exhaust configuration after the headers on any application (but you can make big differences in torque with different header configurations). Matter of fact, we've seen a considerable increase from open headers every time we've tested and the more restrictive the exhaust, the lower both torque and horsepower numbers went.
In my opinion, the idea that "too much exhaust flow hurts torque" is an urban myth - backpressure is always, always, always a pumping loss that the motor has to work against. Tune the headers to the application, run as big a pipe as you can fit after the collector - especially if you run cats.
For what it's worth, after lots of dyno testing, we've never seen an increase in torque in any exhaust configuration after the headers on any application (but you can make big differences in torque with different header configurations). Matter of fact, we've seen a considerable increase from open headers every time we've tested and the more restrictive the exhaust, the lower both torque and horsepower numbers went.
In my opinion, the idea that "too much exhaust flow hurts torque" is an urban myth - backpressure is always, always, always a pumping loss that the motor has to work against. Tune the headers to the application, run as big a pipe as you can fit after the collector - especially if you run cats.
Jun 30, 2006 | 04:35 PM
#19
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From: From Houma La. Living n Ellisville Miss.
this all comes down though to not enough verter i gain on both ends with open cut outs with not enough verter flash you will lose bottom and you r right it would help u to close then open.
Jun 30, 2006 | 04:59 PM
#20
Originally Posted by FMOS Racing
Amen.
For what it's worth, after lots of dyno testing, we've never seen an increase in torque in any exhaust configuration after the headers on any application (but you can make big differences in torque with different header configurations). Matter of fact, we've seen a considerable increase from open headers every time we've tested and the more restrictive the exhaust, the lower both torque and horsepower numbers went.
In my opinion, the idea that "too much exhaust flow hurts torque" is an urban myth - backpressure is always, always, always a pumping loss that the motor has to work against. Tune the headers to the application, run as big a pipe as you can fit after the collector - especially if you run cats.
For what it's worth, after lots of dyno testing, we've never seen an increase in torque in any exhaust configuration after the headers on any application (but you can make big differences in torque with different header configurations). Matter of fact, we've seen a considerable increase from open headers every time we've tested and the more restrictive the exhaust, the lower both torque and horsepower numbers went.
In my opinion, the idea that "too much exhaust flow hurts torque" is an urban myth - backpressure is always, always, always a pumping loss that the motor has to work against. Tune the headers to the application, run as big a pipe as you can fit after the collector - especially if you run cats.
i really think it is more of a perception thing. the motor is making so much noise it just seems like it should be going faster but it isn't. someone show me a dynochart to change my mind.
i would post my old chart but i cant seem to find it and the thread is gone too
