back pressure????????????

[mrdirtyz28]

do ls1's need back pressure? i just took off my muffler and my dad said i will mess up my car.im scared any help? the guy at the muffler shop said they don't need back pressure.:help:

[ss~zoso~ss]

you have more than 1 muffler? Its not good for your car to not have mufflers, yet it wont hurt it unless you drive it like 100k without them

[BIG D's SS]

Most guys run cutouts. But there is still alittle bit of back pressure. I wouldn't leave it like that for ever.

[redls1bird]

you dont HAVE to have backpressure. although you will probably lose power without it. back pressure can actually create a scavenging effect on cylinders that helps draw in more a/f mixture during overlap. one way a n/a engine can have over 100% volumetric efficiency is with a tuned exhaust, even if it is only for a few hundred rpm's.

[ss~zoso~ss]

cool icon redls1bird

[ss~zoso~ss]

my sig isnt showing up

[bww3588]

some back pressure helps with torque. its like blowing through a straw vs. a papertowel roll. but alot of backpressure is like blowing through a pin hole in a piece of cardboard or somthing. ohh and tell the guy at the muffler shop that hes a moron. all cars need some backpressure to run efficiently.

[mrdirtyz28]

thanks so how long do i have to keep it like this? i dont' have any money to buy another muffler anytime soon.

[bww3588]

if you need a cheap alternative, awnser me this, do you have the stock system? with the muffler in the very back mounted sideways behind the axle? if so get a 15 dollar cherrybomb and some muffler clamps and clamp it up for the time being. it will sound like shit but it will be serving the purpose untill you can get a good one in place.

[mrdirtyz28]

i think ya'll are getting the wrong idea.all he did was take off the muffler and ran the exhaust straight to the back of my car.it's called straight pipe is that bad?

[bww3588]

no theres nothing wrong with that. no exhaust would be a problem for long term use.

[redls1bird]

thanks ss, its one of my favorite pics of my car

[ss~zoso~ss]

no prob

[Chevypowr]

if you have the stock manifolds y pipe and cat then you already have more than enough backpressure. Running headers to no backpressure can possibly burn your valves up after losts of use. its always good to have some sort of backpressure to creat exhaust scavenging which will in turn flow better than straightpipe any way.

[R&L'scamaro]

What about the stock manifolds and a race muffler. Is that ok or not worth time. Cause isn't that all the loud mouth kit is, just a race (tube) muffler and then tips out the back. Just wondering. Want better sound but can't do 900 dollars for borla exhaust.

[Chevypowr]

What about the stock manifolds and a race muffler. Is that ok or not worth time. Cause isn't that all the loud mouth kit is, just a race (tube) muffler and then tips out the back. Just wondering. Want better sound but can't do 900 dollars for borla exhaust.

No that will improve horsepower for sure. I have stock manifolds and cats with an SLP y-pipe, then 3" piping to a Borla XR-1 Race muffler- which I strongly recommend using! The muffler is the sporstman oval 3" in/out 12" long. repetative testing done by Borla proves that the Xr-1's patented design out flows straight pipe due to the scaveging effect that it creates. And it sounds awesome, very smooth and and nice tone. I've used this muffler on 3 of my cars, along with persuading many friend to try the Xr-1 out and they all are amazed at the difference it made in power and sounds. They run about 140-160 bucs all Stainless. www.borla.com (http://www.borla.com)

[bww3588]

anything with a muffler is ok. headers with an open y pipe may be ok but not for long period use. if you got stock manifolds and an open y you shouldnt have a problem. headers with a catted y and a muffler dumped is fine.

[Bombguy99Z28]

You don't need mufflers. Backpressure being good, in any amount is, well, false in todays engines. You need velocity, sometimes running too big of an exhaust will slow velocity down, but there is absolutely no reason to ever want 'backpressure'.

The muffler shop guy was correct.

I gained 5-8rwtq across the board running a cutout without cats in an otherwise basically stock application. Now, slapping longtubes, no cats, and no muffler on a near stock application, yes, you will lose power down low.

[mrdirtyz28]

thanks

[blk_jaws]

What about stock manifolds, ory pipe and a muffler? Is that ok?

[oneBADDz]

As long as you have something bolted up to your heads you won't hurt anything, if you go so far as to have a y-pipe on it, catless or not you definitly have enough. In answer to alot of the ?s in here, ANYTHING that runs out the back of the car is sufficient

[twozs]

there is a thing called an slp loudmouth (first virsion) that has no muffler at all . just an enlarged "chamber" for gas expansion like the chambered (no muffler) exaust systems that used to be special order on high performance chevys of yesteryears.

[SS#1531]

Taking your mufflet off is fine, you still have the exhaust manifolds and cats in there, and that's more than enough backpressure.