Exhaust

[PCGUY112887]

96 Grand Prix coupe, dual exhaust stock... I plan on having 2 2.5" in/out Super 40's put in, do I need center/center mufflers or what?

Thanks.

[98malibu3.1]

I'd stay away from the Super 40's. They sound like ass with the bigger case. Loud as hell on the inside and not that loud outside. Get some Aerochambers or Magnaflows. Offset/center is what you're looking for.

[IsaacHayes]

x2. Dynomax Ultraflo is straight through and pretty mellow on my car. Dual's with larger pipe would probably just right sound. No drone or resonance, nice rumble. Allthough I hear the aerochamber might have more.

[PCGUY112887]

Well from what I have heard on exhaustsoundclips.com, all of the straight through mufflers sound like ASS on the 3400. I don't want a car that makes a buzz, I want a grumble and a roar.

I will have 2.5" from the header back, splitting off into both mufflers 2.5" for my 3500.

[PCGUY112887]

Well the aerochambers are looking nice.

Could someone do me a huge favor and look under their dual exhaust GP and tell me if their center/center or what? I could have swore they were, my 1 muffler on my 4 door is center/center.... I just wanna be positive.

How much should I be expecting to pay for all of this work at a small local shop? 2.5" all the way back, I would supply the mufflers and tips. Weld in an O2 bung, may have to modify the flex piece of the headers a bit since when you bolt it on it points down and to the drivers side a bit (I guess since it isn't made for this car). No cat.

[torq455]

check this thread out:

http://www.60degreev6.com/showthread.php?t=29021&highlight=sound+clip

[Superdave]

Aerochambers good!


i've had 2 different ones and i couldn't be happier with the sound and performance. The regular style ones are a little deeper sounding and flow better.. the Crossflow Camaro style have a very nice WOT sound on a 3400 and neither resonated inside the car very bad.

even with my 3" exhaust/built 3500 i can roll up the windows and have a chat with the wife on the highway.. can't say that about any of the Flowmaster setups i had in the past.

[PCGUY112887]

OK, I got the hooker aerochambers... found a random GP on the road today, stopped and looked under it (tryin not to look suspicious hah!) and the orientation is offset inlet, center outlet. Thanks 98malibu! I could have swore they were center/center, I'm glad I double checked.

[98malibu3.1]

Post up some clips when you get them installed. I had those on my 98 Taurus w/the 3.0L dohc V6 and with the factory resonator, they weren't really any louder than stock. Pulled off the resonator and they sounded horrible!! Magnaflows on that car really woke it up. Perfect blend of tone and loudness. Here's a clip of my Malibu w/a Magnaflow, 5x8x14 case 2.25" inlet/outlet with offset in/ center out and dual 3" tip in factory location.

[IsaacHayes]

There are several factors with the pipe that will change the sound of the muffler. Straight through fart cans don't sound good on anything IMO. You will get drone with them and buzz since they don't have a pipe coming off the end. They won't be that deep or rumbly since they have virtually no space inside the case.

My Ultraflo is a lot shorter than the stock muffler but the case is big so you get the deep rumble and no buzz. I have the muffler all the way by the axle, so you don't see it (its mirror stainless though) and a tail pipe coming from that to Z26 tips. The tail pipe gets rid of drone (it will be a deep tone without it 1500-2000rpm) and gives it more sound at WOT.

Having dual mufflers will change the tone more and be louder than 1 muffler. 2.5" dual mufflers from 2.5" pipe will be pretty deep I'd think. Not sure what other affect it will have on the sound doubling the pipes at the same size like that. Normally you go with smaller dual pipes after a split to keep the velocity close to the same so you don't get turbulence and gasses slowing down at low rpms.

[PCGUY112887]

Yes I knew it was a odd decision to not go with dual 2.25" out, but I wanted to be different. Plus on a Borla system I helped install before, it was 3" all the way back, then split to 2 3" all the way to the tips. I was going to do 3" back then split off to dual 2.5", but to go from a 2.5" flange on the headers, to 3", then back to 2.5" seemed stupid to me.

[98malibu3.1]

There are several factors with the pipe that will change the sound of the muffler. Straight through fart cans don't sound good on anything IMO. You will get drone with them and buzz since they don't have a pipe coming off the end. They won't be that deep or rumbly since they have virtually no space inside the case.

My Ultraflo is a lot shorter than the stock muffler but the case is big so you get the deep rumble and no buzz. I have the muffler all the way by the axle, so you don't see it (its mirror stainless though) and a tail pipe coming from that to Z26 tips. The tail pipe gets rid of drone (it will be a deep tone without it 1500-2000rpm) and gives it more sound at WOT.

Having dual mufflers will change the tone more and be louder than 1 muffler. 2.5" dual mufflers from 2.5" pipe will be pretty deep I'd think. Not sure what other affect it will have on the sound doubling the pipes at the same size like that. Normally you go with smaller dual pipes after a split to keep the velocity close to the same so you don't get turbulence and gasses slowing down at low rpms.

That is true for the generic Autozone/Advance Auto Parts "mufflers" but Apexi, HKS, Greddy and Magnaflow all make good sounding straight through mufflers. What usually makes them sound like ass is pipe diam. that's either too big or too small. As you can hear in my video clip, my Magnaflow is very deep sounding and it has all of about 12.5" of tailpipe from muffler outlet to end of tip. It sounds really good. Having dual mufflers will NOT be any louder than one muffler as you have 2 mufflers doing the same job as one. The sound is absorbed/dampened by 2 of them instead of 1. 2 smaller mufflers will be louder than one bigger one but 2 mufflers of the same size/style will be equal or quieter than just one of the same. @ 3" off the header collector, you could have used a 2.5" venturi reducer from Flowmaster and used 2.5" all the way to the rear and split it out to dual 2.25". That would increase flow substantially over stock but would still maintain velocity. 3" is waaaay overkill on our little engines. Consider that F-body's use 3" from the cat back and they make well in excess of our hp. You have to match pipe size to engine size and hp/rpm as well.

[IsaacHayes]

98malibu yeah I was talking about the ones that look like a coffee can and have no tips just the "muffler" at the very back bumper and the inside is like 4" with no space for fiberglass/etc.

Yeah 3" is too big. You're not going to be turning 6,000 rpm all day long with this, I imagine it's gonna be a street car, and the 2.5" will help keep velocity up.

[torq455]

if you're going to be pushing 300+hp then you'll benefit more from 3"--if going all out. which means adding a turbo.

[PCGUY112887]

If I was Turbo then I would have done 3"... I am fairly sure 2.5" will be fine though... if not it can always be changed later.