gain or loss??
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Banned
Joined: Dec 2005
Posts: 265
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From: pittsburgh,pa
gain or loss?? i gutted the cats and installed a borla adj on my friends trans am. the only other mods she has is an slp lid/ k'n filter and a smooth bellow with a descreened MAF. now for my question, do you think i lost tq and hp because the backpressure differance? some people say i did and some say i make more hp and tq. just wanted to get some opinions from this site. thanks for the help
Engine has to breath to make HP, anything you can do to make it breath better will (in general) increase HP/TQ
Don't know where the misconception that you have to have backpressure came from, but it's pure BS, don't you think if backpressure helped increase HP, the pro race engine builders would be all over it
Don't know where the misconception that you have to have backpressure came from, but it's pure BS, don't you think if backpressure helped increase HP, the pro race engine builders would be all over it
11 Second Club
Joined: Feb 2003
Posts: 5,524
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From: The South
^^^ Correct, you do not need nor want backpressure.
What you do want is exhaust gas velocity. Basically, if the column of air in the exhaust is too large the mass of air is too high and it takes longer to get the gasses moving than it should, resulting in a decrease of low RPM power. This is why you may lose torque with too large of an exhaust.
Opening up exhaust you sometimes do lose power down low but usually make up for that with top end gains.
That's how I remember it, take with a grain of salt.
What you do want is exhaust gas velocity. Basically, if the column of air in the exhaust is too large the mass of air is too high and it takes longer to get the gasses moving than it should, resulting in a decrease of low RPM power. This is why you may lose torque with too large of an exhaust.
Opening up exhaust you sometimes do lose power down low but usually make up for that with top end gains.
That's how I remember it, take with a grain of salt.
Originally Posted by blkZ28spt
^^^ Correct, you do not need nor want backpressure.
What you do want is exhaust gas velocity. Basically, if the column of air in the exhaust is too large the mass of air is too high and it takes longer to get the gasses moving than it should, resulting in a decrease of low RPM power. This is why you may lose torque with too large of an exhaust.
Opening up exhaust you sometimes do lose power down low but usually make up for that with top end gains.
That's how I remember it, take with a grain of salt.
What you do want is exhaust gas velocity. Basically, if the column of air in the exhaust is too large the mass of air is too high and it takes longer to get the gasses moving than it should, resulting in a decrease of low RPM power. This is why you may lose torque with too large of an exhaust.
Opening up exhaust you sometimes do lose power down low but usually make up for that with top end gains.
That's how I remember it, take with a grain of salt.
