lose hp or gain hp with straight pipe or performance muffler? need help

**hmorris7000** · 09-13-2007, 08:38 AM

I gotta question guys I bought my 02 ss from a guy and he had it straight piped meaning it has cats by the stock headers then the two pipes come together as one go over the axle then split into two exit pipes i stay in good ole bama so no one checks emissions here i just wanted to know if i put a muffler on it will i gain or loss hp i like the sound and it doesnt bother me but want to know if i will lose power with a cat back

**nhraformula** · 09-13-2007, 09:24 AM

your not going to gain any power by adding a muffler, and you may lose a few h.p depending on what muffler you use.
if you like what you have, keep it.

**claytonr** · 09-13-2007, 10:24 AM

on the other hand if you put on a high performance muffler like a borla which will break you trying to pay for it then you will gain some hp..but if it already sounds good then i would just leave it..i bought mine with a borla so im lucky as hell

**nhraformula** · 09-13-2007, 10:44 AM

how is he going to gain h.p over straight pipes??
less restriction = more h.p

**hmorris7000** · 09-13-2007, 12:55 PM

the reaso i was asking is because im going to get long tubes and go cat less i thought i might need a muffler cause have no cats and longtubes is gonna make it extra loud what do u think nhraformula, claytonr and anyone else who wants to put in input

**N20LT4** · 09-13-2007, 02:28 PM

In my opinion, I perfer a good cat-back system 10 times over straight pipes. I've done straight pipes before, and the result is poor driveability on the street due to lack of low-speed torque, and a tremendously loud exhaust note. It's funny how people tend to act like straight pipes are mild sounding like a cat-back, but infact, a muffler is there for a reason. My straight pipe system was with the stock manifolds,y-pipe, and Random Tech High-Flow Cat, and was still too loud that it became annoying quick. I've heard both LS1- and LT1's with headers, o/r pipe, and straight pipe, and it simply sounds ridiculous. Most street guys end up throwing a muffler on there.

**Bottesini** · 09-13-2007, 03:01 PM

Originally Posted by nhraformula

how is he going to gain h.p over straight pipes??
less restriction = more h.p

Sometimes you need a little bit of back pressure for scavenging. I can't really explain the science of it, but I am sure there is more then one person here that can.

**N20LT4** · 09-13-2007, 03:28 PM

Actually nhraformula is right. Straight pipes do gain horsepower, but at the expense of low speed torque. That factor is often overlooked.

**nhraformula** · 09-13-2007, 03:46 PM

Originally Posted by Bottesini

Sometimes you need a little bit of back pressure for scavenging. I can't really explain the science of it, but I am sure there is more then one person here that can.

scavenging comes into play when you use an X or H pipe exhaust set up, not when you use a f-body style catback.

**nhraformula** · 09-13-2007, 03:47 PM

Originally Posted by N20LT4

Actually nhraformula is right. Straight pipes do gain horsepower, but at the expense of low speed torque. That factor is often overlooked.

ive never felt any lose of low speed tq personally

**nhraformula** · 09-13-2007, 03:48 PM

Originally Posted by hmorris7000

the reaso i was asking is because im going to get long tubes and go cat less i thought i might need a muffler cause have no cats and longtubes is gonna make it extra loud what do u think nhraformula, claytonr and anyone else who wants to put in input

you are going to need a muffler, i sugest the hooker aero chamber.
i have that with my catless headers and it sounds good, not too loud or quiet.

**N20LT4** · 09-13-2007, 03:55 PM

Originally Posted by nhraformula

ive never felt any lose of low speed tq personally

I have. On the above said '93 T/A, the dyno showed a total gain of +16rwtq@3050-rpm on the switch from straight pipes to B&B Tri-Flo cat-back - nothing else. It was worth a 1.5-tenths gain in the eight mile, .6 tenths from the previous best in the quarter.