i got both ive been racing with the 4 in straight pipe do you think the muffler would help or hurt in the 1/4. its a mbrp system i can change them fairly easy.

This a good question. I've found bits and pieces of answers by reading many posts on the subject. I about to act on that and find the question very interesting.

- Many people said there's nothing to gain by going 4" and that the stock system with a good muffler is more than enough.

- I also read that straight pipe 4" is too open and you may actually lose some power.

- 3.5" Straight pipe is potentially better

No definitive answer but I would love to see someone with real experience (dyno, 1/4) give his opinion.

I run a straight pipe and I am happy with it. Sometimes it can be loud but it grows on you. I think you would like it better and the sound over a muffler. Many people run this over purchasing an exhaust to save money and keep the truck looking as stock as possible. Just my observations.

My truck with the stock tune is making 282rwhp and 501 rwtq. This is up from 246/440 when new. I attribute much of the gain to the 4" straight pipe exhaust.

Is the straight pipe right for you? It IS louder than stock, but not bad. If you need dead quiet, stick with a muffler. If you do not mind hearing a little motor when you are motoring, straight pipe it.

Has anyone disconnected the flange ahead of the muffler on a dyno run to verify the potential difference in horse power?

Robert

That's an interesting question. Can you seperate at the four bolt flange and run at the drags with out rear section attached? Fire hazard? Not enough back pressure?

Rob

i will be trying both ways out at the track on tuesday night will post some times with the straight pipe and with the muffler

Thanks Brett,

The local strip runs races at night some times and mufflers are needed. I'm very interested in your outcome.

Rob

so would unbolting the flange after the cat be a fire hazard?????

Nobody will know you don't have a muffler unless you tell them. These trucks are quiet. My vette with the factory muffler is louder than the truck with a straight pipe. The turbo acts like a muffler.

If fire comes out the 6' long exhaust tract, your problems are just starting.

If i were to unbolt the flange after the cat and drive around the neighbor hood just to hear what it sounds like, would it be ok? it doesnt sound like the best idea to me but it might be ok for a few minutes :confused: ?

Nope. Fuel tank is on the other side.

Hey Guys Got The Times In With The Muffler On And Off. Well Believe It Or Not I Ran The Truck 10 Times 5 With The Muffler And Five Without. With The Muffler My Times Were Consistantly Better Than With Out. My Best Time Without Were 13.56et 1.9 60ft @97.15 And With The Muffler It Ran 13.48 Et 1.840 60 Ft @99.12 And These Times Were Very Close In Each Of The Five Runs. I Know This Probaly Isnt The Best Way To Gauge It B/c Of Traction, Boost,etc But I Tried To Get It To Leave The Same Each Time. But My Times Were Not As Fast With The Straight Pipe. Just My 2 Cents!!

Nope. Fuel tank is on the other side.
nope it wont hurt or nope its not a good idea:confused:

Wont hurt it at all. I will say though it wont give you a 100% feel for the noise since with it dumping under the bed it resonates and sounds like crap. When I put my exhaust on I didnt have a way to slice it(didnt relize I would need to) and drove with the muffler and everything hooked up and no tail pipe, sounded worse inside the cab with no tail.

Duno if you can just unbolt it and leave it with a big gap and exhaust leak to get an idea or bolt the thing ofset or if you would need to yank the muffler/tail pipe. If you yank the muffler/tailpipe squirt the rubber hangers with a bit of wd 40 or the like to make em come off and on easier.

Hey Guys Got The Times In With The Muffler On And Off. Well Believe It Or Not I Ran The Truck 10 Times 5 With The Muffler And Five Without. With The Muffler My Times Were Consistantly Better Than With Out. My Best Time Without Were 13.56et 1.9 60ft @97.15 And With The Muffler It Ran 13.48 Et 1.840 60 Ft @99.12 And These Times Were Very Close In Each Of The Five Runs. I Know This Probaly Isnt The Best Way To Gauge It B/c Of Traction, Boost,etc But I Tried To Get It To Leave The Same Each Time. But My Times Were Not As Fast With The Straight Pipe. Just My 2 Cents!!


Interesting. The MPH is a bunch higher, that's about 20HP.

Thanks Brett, very interesting indeed. The extra time and money you guys go through testing has saved alot of people alot of $$$$$$$. Thanks to all for sharing.
Rob

well like i said this may be just a fluke but i never could get the truck to run as fast with the straight pipe.Both ways i was leaving w/ 9 lbs of boost, but i guess for now ill leave the muffler on , but the 4 in straight pipe does sound good.