I am thinking of having the muffler shop remove my stock muff and replace it with straight pipe. Has anyone done this? Will I lose/gain low-end torque? Will I lose/gain horsepower? Or will I notice no change except that it will be louder?

I can't seem to find any info (other than opinions) about the effect backpressure has on torque. I have found alot of credible info that reducing the backpressure will increase H.P., but it is torque that I am more concerned about. I want to keep or gain torque, not lose torque. H.P. is not as important to me as low-end torque. Loudness is not an issue either, as long as it doesn't sound obnoxious.

Please post any links to dyno tests or sites which have credible data on the effect of exhaust mods to torque as well as horsepower.
Thanks guys.

 

I was thinking of doing the same thing, but after reading the Board i m gonna replace my stock muffler w/ a Magnaflow 4x9x18 , came UPS fri and will put it on Mon

 

U are just replacing the muff only? Keepeing the factory piping out the right rear?
Post back after it is installed and let us know what you think of the sound and if you can tell whether you lost any low end.

Thanks

 

Rather timely post. I just replaced my Dynomax (#17688) after the inlet pipe rotted off. Thought about the straight pipe approach but instead went to a Thrush 45" long glasspack with the 2-1/2 in and out pipe (#24213) This is a LONG muffler but it is straight thru and the sound is VERY deep and mellow. Disconnected the battery to reset the computer, ate lunch then reconnected battery and went for a drive. Nice deep growl when on the gas, really makes the V6 sound like a large V6 with steroids. Seat of the Pants Horsepower is always subjective, don't think I gained much if any. The sound is very satisifying without the drone at steady throttle at highway speeds. Well spent $38.00....jeff

 

Just the Muffler, keeping the rest

 

Let us know how it goes man, is that Magnaflow the larger unit? I have been trying to decide if I want to do this also, I am looking for better performance with not so much sound.

-Brian

 

Magnaflow 4x9x18 installed and sounds just like i was hoping it would sound like.

A little quieter than i thought at idle, but it sounds good on aceleration and you can hardly hear it at speed, and no drone.

I'm very happy with the set up, horsepower gain, who knows, i'm sure i got a couple of extra horses but it ain't like not and day

 

Intel486 had that done i believe and he said it sounds pretty good. If i were you, Id pay the extra 100-150 and get a set of pipes and tips. It would look and sound much better...just my .02

 

That is there largest unit right? Therefore the quitest? I may go that route then if so..

-Brian

 

Negative,,,,,,,,,,,,

They make a 5x8x24 and a 5x11x22

 

This all makes for interesting reading, and I may go the magnaflow SI/SO route, but I still would like to hear from someone who had simply removed the stock muff and is running a straight single pipe.
Torque loss/gain? No change?

 

I've heard it is loud, but have not heard one first hand

 

Okay I just need someone with the SI/SO big (quieter) magnaflow muffler welded up to the stock pipes to drive to me so I can hear, then I may purchase.

-Brian

 

Previous lurker - first post.
rajuncajun,

do you know the part# for the Mag 4 x 9 x 18 and did you use the existing pipe from the muffler back?

thanks

 

Used all original exhaust, just replaced Muffler

Here's where i got mine, cheapest place i found:
http://shop.ivalueinternet.com/bigex...uct_id/527.htm

$58 plus $20 shipping

Model 11266 off set/offset


If your looking for loud, this is not the choice.