3" or 2.5" X pipe questions - Lateral-g Forums

6D9 · #1 06-21-2006, 02:39 PM

I currently have a Pypes 3" X pipe with 3" Super 40 Flowmasters. No tailpipes. Needless to say its very loud. plus the system hangs very low because the systems rear legs do not tuck into the rear tunnel area. So I am planning on a new set up. My motor is a 408sbc making approx 475hp. I was thinking about going with the Dr Gas X with the 3" in/2.5" out. Then running 2.5" tail pipes. Or should I just go 3" all the way and deal with the noise. Mufflers are going to be Hooker aerochambers.

Blown353 · #2 06-21-2006, 06:16 PM

Assuming your headers have 3" collectors, run 3" pipe all the way to the mufflers including the X-pipe.

If you want to quiet it down a little run 2.5" tailpipes out the back of the mufflers or at least over the rear end and dump them between the leafs and the 1/4 panel. Once past the mufflers the reduction in diameter won't hurt and getting the exhaust out from under the car will really help with the sound, both outside and interior resonance.

Haven't seen your car around, I'm in town from time to time. Based on the pics you posted are you over west of I-5 in the new Spanos development on 8 mile? Houses look quite familiar.

6D9 · #3 06-22-2006, 07:07 AM

Yeah...I meet you a while back at Royce Farms. I was talking to you about my project 69 Camaro. I was drooling over the Procharger and the all around set up of your car.

As far the the exhaust goes I guess I will stick with the 3" all the way and try it with the tail pipes and aerochambers. If I step up the power I dont want to have to redue the exhaust again!

ProdigyCustoms · #4 06-22-2006, 08:39 AM

One word, SpinTech! Oval is the answer. Every lowered pro touring car should use oval pipe for ground clearance, and flow. You can get a oval X pipe in 3" that will only be less then 2" thick, more ground clearance, more flow. Get 3" oval inlet, 2 1/2" round outlet mufflers, and use 2 1/2" tailpipes. Quite, husky sounding, and no power loss.

We can hook you up with SpinTech stuff at GPSuperStore.com

www.spintechmufflers.com

Blown353 · #5 06-22-2006, 07:42 PM

Ah, I remember you now!

Back to what Frank said... the Dr. Gas ovalized tubing is really nice but spendy. I wish I would have done it on my car. I do run a Dr. Gas X-pipe though and the quality is excellent, especially the siamesed transition, it is much smoother and more well matched than any other brand I've seen.

However, my experiences with Spintech mufflers haven't been so good. Their fab quality seems a bit lacking (i.e. poor looking case welds) and I now have 3 friends who have all had baffles come loose inside the mufflers in under a year and start rattling. They were all replaced by the installing shop who is a Spintech dealer under warranty.

They do sound mean though, spintechs have a unique and very deep and rumbling without the hollow "ping" of 2-chamber flowmasters. They also have much less interior resonance than Flowmasters. I like how they sound on my friends cars but they're too loud for my tastes though so they're not on my car. In the end I still prefer a straight through style muffler like Borla, Magnaflow, Straightline Performance, Dynomax Ultraflo, etc. Just about all are quieter and have less interior noise than the Spintechs.

6D9 · #6 06-23-2006, 06:57 AM

Blown353, Are you running the 3"x2.5" or 3"x3" X pipe?? I remember your car was very quiet and stealthy....

. Just a nice little whistle coming from the front of the car...

Blown353 · #7 06-23-2006, 10:46 PM

Prior to the supercharger I did the exhaust using a 3 by 2.5 X-pipe and then used 2.5" tails out the back.

About 2 months ago I cut the tapered 3 to 2.5 reducers off the back side of the X pipe, now it's 3" from the headers all the way back to the mufflers. Still using 2.5" out the back of the mufflers.

I can't tell a difference in loudness and it change the sound any, and I didn't notice any seat of the pants difference and didn't see any A/F ratio differences when datalogging after the change. I just figured opening the system up to 3" all the way back to the mufflers was a good idea with the amount of exhaust volume I'm flowing.

It's only somewhat quiet at idle and light throttle, at night a friend can hear me over a mile away if I'm making a pass...