[oldblueponcho]

Has anybody inhere tryed a pypes x-system with built in dumps on a 2nd gen bird yet? I need to upgrade my exhaust on this build & that system sounds really appealling to me. Really tired of my off the header race readies bottoming out on everything in sight.

[torqjunki]

See no need for the dumps. The car will run the same or slower dumped and sound like crap!! Tested this many times on Pontiacs.

[jotrout]

torqjunki:
I thought the cut outs would act like open headers and provide for less restriction, and more HP?

Joe

[oldblueponcho]

I been using dumps on my car for 3 seasons now. It always runs faster with them open, usually about a 10th. Besides, I like the noise when I'm racing. I prefer to keep it as quiet as possible on the street, hence dumps.

[Ron H]

I have the 3" with x change and race pro mufflers on my 68 firebird. Doug's headers. 455. I pick up 2 tenths with the caps off.

[oldblueponcho]

Originally Posted by Ron H

I have the 3" with x change and race pro mufflers on my 68 firebird. Doug's headers. 455. I pick up 2 tenths with the caps off.

Thanks Ron, hows the clearance? Are they high enough for speed bumps etc?

[Ron H]

Depending on you ride height to begin with. I have 28" tires on the rear with 24" on the front. The major bumps will scrap but with most speed bumps I have been ok. My drive way is on a hill and has a big climb over the sidewalk so I have to go real slow without scrapping. The guy who installed mine turned the cut out plates so what should be the top bolt(like the header collector) is down and the side ones are above. That way I could undue them easily with the frame connections rails I installed. He could have also had them up about a 1/2" higher too. I had my system welded. As long as you take it easy over the big bumps you should be fine.

[Ccass]

Originally Posted by torqjunki

See no need for the dumps. The car will run the same or slower dumped and sound like crap!! Tested this many times on Pontiacs.

not necessarily true depending on the application and with the dumps positioned after the X. 10 hp on a 325hp GTO on the dyno.

[Ron H]

I gained 12 HP and 11 lbs Torque removing the caps on a mustang dyno, back to back pulls. I also gained 2 tenths back to back runs at the track removing the caps. There is an increase in performance.

[oldblueponcho]

Thanks guys, but the original question was about clearance. To my experience, I've always picked up performance with open exhaust myself. Thanks much Ron H, I'm running taller front tires than you (27's) and my new rears will be about 28's. I have connectors too. They're bolt in CE's. Probably about the same as your's? I was also wondering about fit back there and you answered that. My biggest fear was in the cutout clearance. I'm using flow tech race readies now on my collectors, and had to turn them down about 30* to clear my subframe. This is where I've run into clearance probs on speedbumps. Going over high sidewalks like yours is just impossible. Hung up on the one infront of my sister's house. It was pretty funny to watch I guess. There will be a lot of changes with my new combo and I'd like to eliminate as many probs as I can before I cause them.

[Ron H]

The cut outs on mine are very tight to the x so they don't extend out to the frame connectors. The pipes they send will have to be cut down to fit. Try and keep the x as close to your header collectors as possible and tighten the cut out side inward so you have the room. You should not have to turn them down. I think you will be fine, just got to watch the BIG bumps and dips, which i am sure most if not all of us do with our cars anyway.