can i run straight pipe from converter?

razor · May 1, 2002

some guys at my job are running a straight pipe from the convert out .they are eliminating the muffler :0 does it effect the eingine or the computer?will my "SES"light come on or something like that?i was thinking of doing it

SilveradoWV · May 1, 2002

Not sure, I know a lot of people around here are doing it also. Seems like you would lose some torque or something because of the backpressure loss? I have no clue though, I would also like an explanation!

gandolphxx · May 2, 2002

As long as you have the cats and the two O2 sensors the truck will run fine, your traffic tickets will probably exceed the cost of a muffler.

Unless you have a supercharger or turbo with very large intake you will lose low end torque due to loss of backpressure. Be better to run with a muffler and get electrically controlled cutouts for "those moments".

Cheers

CMNTMXR81 · May 6, 2002

After the cats, the remaining exhaust components are purely for noise abatement and nothing more.

So if you want it loud, remove everything from the cat-back. Although a better and cheaper alternative would be a cutout that can be purchased at a vendor like T-Byrne. You could put this right after the post cat-O2 sensor and this would bypass the rest of your exhaust. The only way you'll set a "SES" light will be if you remove the cat(s) and don't insert an "O2 Simm" into the post cat-O2 sensor to trick the PCM into thinking all is well.

As far as law enforcement, the only ticket they can give you is for noise as long as your cats are in place and doing their job, you're legit.

jelisfc · June 4, 2002

I have a 99 Z-71 old style with no mufflers and 2.5" stainless duals out the back. My truck has true duals back to the muffler so that's where I cut. The pipes back to the muffler are around 2". I didn't notice a power change good or bad. What I gained by eliminating the muffler I probably lost with the bigger pipes.

Going with large tail pipes will deepen the sound and let you cruise at a comfortable noise level but she really cackles when you jump on it. Personally I love the sound and it keeps me out of trouble because I'm less likely to get on it places I shouldn't. I live directly across the street from a city cop and a state trooper and neither have said boo to me but I've always respected my neighbors and leave the hot rodding to the open road. The only thing I've run into this year is when I pull my new enclosed sled trailer down the highway it's loud all the time. With the heavier trailer my next truck will have less bark.

Straight pipes aren't for everyone. I'd play it safe and run mufflers.

hogger999 · June 6, 2002

Straight pipes aren't for everyone. I'd play it safe and run mufflers.

This is true.

I've been considering doing the same thing. If you decide to run mufflers you might want to run 12 inchers. They will be quit a bit louder than an 18 inch but not as loud as straight pipes.

I had a '91 4x4 Silverado 350 5 speed with true duals, 12 inch mufflers and no cats. That was the best sounding truck I've ever heard. Especially when you short shifted it. Even though it was a reg. cab I wish I had it back.

If anyone knows where we could hear some WAV files that would be cool

July 30, 2002

Like gandolf said: "As long as you have the cats and the two O2 sensors the truck will run fine, your traffic tickets will probably exceed the cost of a muffler."

This is absolutely true... straight pipes are Fuc*!# loud... If you want to see just how loud unbolt your exhaust behind the cat. Be careful if you do this though.. theyve got thread lock on em. I did it just to see how loud it would be... And its loud! I recommend tryin that before you go and spend money on straight pipes cause you may not like the results...

while were on that subject... why buy straight pipes? Just leave your exhaust unbolted if your going for noise... performance for that matter... I know a few guys who do that at the track with their LS1s... lowers ETs by as much to 2 tenths... And you can always bolt your muffler back up... Incase youre gonna be somewhere that you might get cited for no muffler. ;)

gandolphxx · July 31, 2002

If you really want that noise and effect, get dual cutouts and Qtec's - put them right after the cats and have fun - I have them and it is LOUD!!!, but nice - great at the track and I keep dreaming about dropping them in a parking garage and setting off every alarm in the place

BDBWTE · October 18, 2002

With straight pipes I hope you don't plan on pulling much or trying to destroy your tires....your truck will look up at you like bulls*%t my electronic mother inlaw is here and with out that back-pressure you have no low-end torque have a nice day..

Polaris Man · November 1, 2002

My exhaust on my 94 Chevy 350, is strait pipe, I had 2 1/2" Duals put on and it was too quiet, so I took the catty off and put a 24" piece of 3" pipe in. It fit perfect and the truck really didnt lose any low-end power, even when pulling. Its loud, but I like the way it sounds. I drive it through town and it does echo pretty good, but I have stopped at stop signs in town with cops setting there, I never got pulled over. Have had it that way for about 4 monthes now with no problems.

CMNTMXR81 · November 1, 2002

With straight pipes I hope you don't plan on pulling much or trying to destroy your tires....your truck will look up at you like bulls*%t my electronic mother inlaw is here and with out that back-pressure you have no low-end torque have a nice day..

Running straight won't kill your torque that much! The difference is what, 10lbs-ft at that? That isn't going to inhibit you from pulling a trailer!