My cat's were already empty, but I decided to take them off anyway, to see if there would be a diff. WOW, the car is now honestly twice as loud. I have headers into a flowmaster Y-pipe for dual cat's, then into 3'' hooker cat back system. The problem is, I swear the car is now slower(sound stupid) it really feel's like I lost a ton of torque, and picked up some HP, Either way I am not happy about it. Has anyone else had this outcome?? From 3500 rpm to 5500, it seem's to pull harder now.

 

yea, the back pressure gives you kind of an added torque bounus and i noticed that after i put on a high flow and the hooker that some of the low end dissapeared, but i quickly forgot because i was doing about 70mph all of a sudden!! I noticed top end increasing and i can get up to crusing a lot faster now. ahhh i wana live in a non-smog state... i love the noise of no cats...

 

Its not back pressure, its velocity. Back pressure is 90% a myth.

 

So you felt a torque loss by putting a pipe in the cat, when before it was just hollow?

 

.. here we go.... the decrese in back pressure and increase in velocity of the exhaust is what gives the care more hp. Increase of back pressure by a cat, manifolds and stock exhaust produce backpressure, which is there; not a myth, and causes a feeling of added torque. You really dont lose that much, but the loss of back pressure will have you lose some low end torque, but will most likely increase the area under the curve.

 

This backpressure = torque junk never ends.

I gained 21rwhp and 8rwtq by opening my cutout (before cat) on the dyno.

 

lets clear this up once and for all. How about a sticky with just the phrase ANY TYPE OF BACKPRESSURE WILL CAUSE YOU TO LOSE HORSEPOWER AS WELL AS TORQUE!!!

 

lol..all you technical guys who have a diefin of backpressure and what it is...good for you....but for us NORMAL people who dont memorize vocab for all these words there is a rule of thumb.....by restricting your exhausts flow you have more low end torque...PERIOD...some people call restriction, backpressure...i mean itd make sense to most people....something effecting the pressure caused by the flow.....just give up the technical **** allready...we all know what he means

 

like I said, ANY TYPE OF RESTRICTION IN THE EXHAUST WILL CAUSE A LOSS IN NOT ONLY HORSEPOWER, BUT TORQUE AS WELL.

 

:hail:

I even got dyno sheets to prove it.

 

Based on what you're saying.....

Carl Lewis would run faster in the 50yd dash if he were to breath through a straw.

 

lol...noooo...more like poop through a straw....no but seriously....i dont mean it will make more torque...that is absurb....but it will move your powerband down to the lower rpms therefore creating the felt effect of more torque

 

you got the idea.... free flow might not give you that feel of that initial SOTP, but the area under both curves have increased. Area under the curve is what matters... not at any one point.

 

Thank's for the info guy's. I found it weird that I would loose any power at all. I was just wondering if anyone else had the same outcome?? Driving the car last night, I think it is close to what it was. The sound diff. just through me off I think.

 

i am happy i deleted my cats, i dont have to fool around with them clogging up or anything like that.