Just curious, is there a performance increase using an x-pipe vs h-pipe? Does the X-pipe significantly change the exhaust tone? The reason I ask is, the one I installed has a real high pitch at high rpm. Has any one else experienced this? Any thoughts or theories?

The X-pipe actually pulls the exhaust out making it flow much more efficiently.(Performance increase) The sound will vary depending on the diameter of the exhaust pipe and headers. The smaller the diameter the higher the pitch, larger the lower. If the X-pipe is restricted where they cross this could cause the high pitched tone.

There was an article not that long ago in a magazine concerning exhaust technology. The article went pretty in depth in theory and then did dyno tests to test the theories. The X-pipe gave about 20 ft-lbs or torque down low over duals and averaged around 12 (I think) throughout the entire testing range. They did report that the X-pipe does emit a higher frequecy exhaust tone. Did you notice any seat of the pants difference after you installed the X-pipe?

Bravewink, I defenitly noticed a difference, feels like its pulling a lot harder. The exhaust tone is also a much higher frequency at higher rpm, its hard to compare to any thing because most systems are pretty deep. It kind of sounds like a winston cup car at higher rpm. The system is 3", about 6" behind the end of the gearbox the X begins, just following the X I installed collector flanges, from there dynomax ultra flows. Needless to say its pretty loud, compared to the 2.5 with super turbos. Its got an atttitude now.

Hey does this really work? Would it help my 396? Can anyone post a picture of one that is installed? Is this like the tube that was used on Mid 60's Fords that ran from side to side on the front pipes or is it a x??


's

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johnny

I got to thinking about the exhaust pitch and think you may enjoy this little story. There's a 347 stroker Mustang that shows up at the Norwalk track quite often. He races in a Street Outlaw class (DOT tires and mufflers). He runs low 9's in the 1/4 and the damn thing sounds like a chainsaw. Seriosly, the exhaust tone is like NOTHING I've ever heard before in my life. Maybe he's running an X-pipe. Why didn't I think of that before.

an X-pipe is where the pipes form an X and balance out exhaust flow and actually accelerate it.

Who sells "X" pipes?

X-pipes http://www.drgas.com/
and I think Hooker might sell some

Rob

Oops, I spelled seriously wrong.
Sorry for that.

67ragtp,
What type of engine combo do you have in your car? What size headers?

Orench,

My X-Pipe was custom made using 2 90deg mandrel bent 2.5" tubes. They are cut out at the bottom of the turn and welded together.

Thanks "ScottB", thats the solution I'm definitively going to use. The budget is way out of limits.

Bravewink,
The engine is a 383 stroker w/ported AFR's/Hyd roller cam / Demon 750 / Hooker super comps 1.75" primary tubes. The engine made 528.8ftlbs @ 4500 and 524.2HP @5500 on the dyno. The exhaust really woke it up a bit.

My X-pipe was also fabricated very similar to the way ScottB described.

Hope you all had a great turkey, Im stuffed!

Wow, impressive numbers. It sounds like you have yourself quite a ride. I was curious if the X-pipe changed the pitch at idle or does it have the low pitch rumble/muscle car idle? What RPM do you really start to notice the pitch change? I'm definately going X-pipe when I change the motor this spring. Also, the X vs H pipe article I read was in the November 2000 Hot Rod in case you're interested.

bravewink,

Mine sounded like a winston cup car when I started it without mufflers. With mufflers (spintech) it still has that crisp sound, just not as loud. It is a higher pitch than an H -pipe or no cross over.

Bravewink,
At idle it still has the low pitch rumble of the muscle car, and at cruise speed you dont really notice it to much. The frequency changes drastically at 2500 rpm to 6000 rpm full throttle. I think the low pitch at idle is the result of the muffler, the dynomax ultraflows are straight through not much restriction there. At high rpm the pressure and velocity of exhaust gas going through that X must be a major contributor in the frequency change.

ScottB and 67ragtp,
Thanks for answering all of my silly questions. I've learned alot.

ScottB,

Why are the crossover pipes bent at 90 degrees? Why not just run two straight pipes attached at 45 degree angles?

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'69 Restification

JonT,

Sorry, my mistake, they are 45 deg.

No prob...any chance of getting a pic? I'm having a hard time visualizing where the two pipes get welded together.

http://www.chevelles.com/showroom/chaas4.jpg


This is a 3.5"x3" system using the Dr. Gas Xpipe. If you are going to home brew this system, the holes you must cut in the two halves of the X are elliptical not round. I think more and more folks are making these know;I saw a co. in Brooklyn with X's for $110.

H pipes do nothing for HP/TQ, but lower db's. X's lower DB's less, but add HP/TQ.

The exhaust note is decidedly different and neat as the above system tunes out at 3500 rpm, which is where my cam starts its pull.

You run it to 6000 and it sounds like 7500. Whern I take the old rat to 7000, folks think its gunna come ungluewd! The X makes it sound like you;re really winding.

Match the inlet side of the X to your header collector size. Behind the X, whatever your pleasure, but IMHO 3" headpipes are MINIMUM for any performance application.

YOU WILL NOT LOSE TQ BY GOING WITH LARGE HEADPIPES. All the boys said I would, Dr. Gas said no, " its' like a torque tube".

Damn right it is. I felt the diff from 1500 on up over a 2.5" system. Also added 1" of engine vacuum.

These things are the CatsAss and I highly recommend them.

[This message has been edited by 427TRI (edited 11-28-2000).]

Whoa!!! I've got to have one just for the cool look...thanks much for the pic and detailed explanation.

427,

Nice exhaust system. Does the "X" qualify as a driveshaft loop at the track? Seems like it would accomplish the same thing and would be at least as strong as some of the stuff I have seen people selling.

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Pearl blue & white 69 Camaro with supercharged 350, Tremec TKO, and 3.73 12-bolt

See my website updated 9/01/00 at:

www.geocities.com/gheatly (http://www.geocities.com/gheatly)

ScottB,

How is the the spintech muffler made inside?? I contacted Mr. Gas and never did get a picture of its construction??

gheatly,

Good point about the drive shaft loop and the "X" pipes, right on!! pdq67

pdq67

Here is the spintech web sight.
http://www.spintechmufflers.com/spintech/spintechindex.asp

Gheatly, I dont know if it does, but I thought about it. But, I had a loop fabbed up that bolts onto the crossmember using the tranny bolts. It might not look like it from the pic, but this car is a
"stock" 67 Chevelle SS and I didn;t want to put holes in my floor.

I dont have it geared enough for that ol L88. http://www.camaros.net/forum/frown.gif Its freiggin slow. ( 12.7 @117)

427,
The exhaust system looks awesome, I was curious when you installed the system did you need to re-jet your carb, due to the increased flow? When I installed mine I developed an off idle stumble, I had to richen up the idle circuit and increase squirters.

I've seen the holes for the X cut in a band saw. That will make the required elliptical hole.

I also run the Dr. Gas X-over. 3" head pipes, 3" into the mufflers, 3-chamber Flowmasters (now wish I had Spintech), 2 1/2" out of the mufflers and tailpipes to the rear of the tires. Sounds just plain mean.

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Click here to see see my car and hear 5-speeds. http://www.geocities.com/casanoc

Jeg's is selling them for about $100.00 in the new catalog...

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...Dennis
The Cars:
'69 RS Convertible w/SS trim (http://www.camaroslimited.com/memberscars/den.htm)
'96 Z28SS #1679 of 2410 (http://www.camaroslimited.com/graphics/memcars/96ss.jpg)
The Club:
Camaros Limited Nor-Cal (http://camaroslimited.com)

Well worth the buck (100) ladies and gents.

67Rag. Yup. Mine was already set rich in prep for the new exhaust.

Dr Gas even said I might be wanting a smaller cam. ?? They dont know that I'm a freak and am putting a solid roller in the street car. But again, they said that it might require less duration. I monkeyed with opening my lash 2 then 4, but ended up leaving it alone.

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Gene C.
67 Chevelle SS 427/L88 (http://www.chevelles.com/showroom/chaas00.jpg)