soupcan

Mix a New Flowmaster Exhuast kit bought at a swap meet for $75, with a welder that has been collecting dust for 3 years, a rare day off and a little blood,sweat and beers. You get this. Hopefully worth the effort.

svp928

Nice! You'll like it...

Bill Ball

Can't argue with the price.

Was there no way to make the X further forward? I think it loses effectiveness as far back as you have it. Also, there doesn't appear to be much common siamesed area for mixing. Easy for me to criticize - I can't weld at all.

soupcan

I read an article years ago written by the guy that designed the exhaust on Sterling Marlins nascar team before he won the 1994 & 1995 Daytona 500's. In short i remember that the further back you merge the two banks the more torque, closer more HP. The same as a Short collector on a drag car gives you more MPH(HP) and a long collector gives you better ET(Torque). I was hoping the placement would help the low end and the size of the pipes the top-end. The X-pipe has a 4" long, 2" high opening where they merge. Another point in the article about building an X-pipe was that the merge was just a pressure dump so the opening was not a big issue if the primary pipes were of sufficient size for the given engine. The article was great and it went into far greater detail about different exhaust designs, i wish i would have saved it. The most important thing is now when i warm the car up in the morning it annoys my neighbor, the neighbor who just has to rev his Harley 50 F@cking times when he comes home at 4:30 in the morning.

Ketchmi

Just a quick note from experience and testing, the location of the merge in my crossover was very critical to power production. Moving it 1" rearward lost 10 horsepower. The power was down across the board, not just exchanging horsepower for torque as in the collector length idea. The size of the opening between the pipes was relative to engine displacement and the inlet/outlet angles were also very important to efficiency/power. It looks nice, hope it dyno's well.

The merge is not just a pressure dump if the system is correctly designed, it can be a true scavanging system if done right. The exhaust pulse from one bank will actually pull the exhaust from the other bank. The timing of the "pull" is where power comes from. The factory "H" before the cats is just a pressure dump and inefficient as hell for power production.

I initially designed our crossover using Dr. Gas's facilities. They saw the factory cat system and an Ott crossover and said that they could gain an additional 10hp with their generic "X". They actually lost 10hp from Louie's configuration. A dozen prototypes and a couple hundred dyno runs and you now have my crossover. An article from "years ago" is just that, old news.

Imo000

So the setup above is as good as a regular H pipe? If it is, it's still better than nothing.

backnblack

Nice work but how loud is it ?I can't afford any tickets and like to be a little more stealth.

Can anyone tell me if if I can get into one of these x pipe units, add horse power and still keep my car as quite as stock or close to it.

Matt

Ketchmi

Yes you can, I have one on an 87' with no cats but retaining the rear muffler and it is very quiet and polite. With cats it will sound almost exactly like stock.

soupcan

It's not stealth, sounds good to me, but i like them on the loud side. Feels stronger to me, didn't dyno but, ran car at local 1/8 mile on the 14th. I will run again next week when they reopen to see if the exhaust helped or hurt.
Average of 4 runs.

60' 2.209
1/8 9.174
MPH 79.86

backnblack

Thanks guys for the info. Don't get me wrong I like em loud and proud but I wasn't sure if the no cats and the stock muffler would still be quite enough but I think that the way I will go. Good luck Brian please post your numbers from the track/dyno when you get them, I would be interested to see the improvement.
Regards
Matt