I do track lapping with a 2000 cavalier 2200 and i was interested in putting on a test pipe on it instead of the cat. I heard that doing this on some cars causes a loss of torque because there is less back pressure. Is this true for the cavalier?
Thanks.
yes it is, but you'll gain some extra ponies up top. All depends on what area of the rpm range you stay in msot
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Dave, whoever gave you that advice stop asking them about car stuff.
Phil... you should know better.
Putting a test pipe in will barely make a difference in power but WILL make a difference in NOISE.
Back pressure is not a GOOD thing. Ever.
Back pressure is not what makes torque, its scavenging.
There's a very big difference.. scavenging is good, back pressure is bad.
This is another one of those old hot rodder myths. Whoever tells you this, just nod, smile, walk away, and disregard everything they tell you.
DaFlyinSkwir(LS61) /PJ/ OEM+ wrote:Dave, whoever gave you that advice stop asking them about car stuff.
Phil... you should know better.
Putting a test pipe in will barely make a difference in power but WILL make a difference in NOISE.
Back pressure is not a GOOD thing. Ever.
Back pressure is not what makes torque, its scavenging.
There's a very big difference.. scavenging is good, back pressure is bad.
This is another one of those old hot rodder myths. Whoever tells you this, just nod, smile, walk away, and disregard everything they tell you.
I definitely hafta back-up Skwirl on this one, as the catalytic's case acts like an expansion chamber: A "box" with anti-reversion provision that's mounted in-line on a exhaust-pipe... that's of volume equal to all the cylinders feeding into a single exhaust pipe... that "tricks" the flow of exhaust gasses into thinking they've reached the end of the system, and aiding in scavenging.
Since this "contraption"... as many of you may think of it as... relieves the remainder of the system after it to only needing to effect (control) exhaust noise, the size of the pipes & parts chosen need only be done for amount of air-flow in relation to the horsepower the engine produces (2.2cfm@10.5in.hg. x 1hp). As for noise, well... that depends on what you choose for muffling.
Go beyond the "bolt-on".
Thanks alot for clearing it all out for me guys.
Thanks for the link madjack, really made things clear.
heres another question. if i have a bad cat can i replace it with a resonator such as a cherry bomb or is that a bad idea. if a bad idea what would be a good resonator for a 02 cavy eco. with a header, stock piping. and Dynomax Superturbo muffler??? wouldnt mind gettin it a bit louder and deeper sounding.
ive been out of it a long time, i havent kept up on all the good info.
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Rich Grayo Jr. wrote:Wojo wrote:heres another question. if i have a bad cat can i replace it with a resonator such as a cherry bomb or is that a bad idea. if a bad idea what would be a good resonator for a 02 cavy eco. with a header, stock piping. and Dynomax Superturbo muffler??? wouldnt mind gettin it a bit louder and deeper sounding.
clickme.
What about if u dont need a cat for emissions for your state would it be better to just stick a lets say 18" resonator in place of it and another 21" resonator right before the axel to keep things quiet but still perform good?
I had a test pipe in my sunbird with just a cherry bomb for a muffler...... The car ran fine..... but the noise of the exhaust was insane....
That car only had top end power... (really crappy low end)... but that had more to do with the engine....
If your state does not have the federal emissions check I would suggest taking out the cat as long as you don't mind noise. A straight pipe would work fine.
If your state DOES have the federal emissions check leave it in or get a high flow exhaust.
All the cat does is restrict air flow. Your already stuck with a muffler so why have 2?
And I laugh at the people that think back pressure helps in any way shape or for.
CLC wrote:Those cat's above suck
really? been running one for two years, no cel, and no rust. what more could you want from a cat?
JBO Stickers! Get yours today!
I have had a Magnaflow on mine for years.... seems to be a good cat..... no CEL or anything either...
And screw emission laws LOL.... The only reason my car has one is because its got a 2nd O2.
Although... I know Im technically wrong.... and people will point that out
Although.... Test Pipe + 2nd O2 = CEL most the time.
Rich Grayo Jr. wrote:CLC wrote:Those cat's above suck
really? been running one for two years, no cel, and no rust. what more could you want from a cat?
I agree ive had one for a year. No cel with 3" exhaust, no rust, quieted the car considerably.
