408 with tti's. Do I go with H or X pipe exhaust

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mistreta

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Just put a Stroker in an 70 Duster, and I want to do the exhaust. I hear a 2 1/2 exhaust with an X pipe is the way to go. I heard the X works better than the H. Anyone have the X pipe on an A body? I'm concerned about the fit, do I have enough room?

Tony
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X is always better then H for performance to the best of my knowledge.

I have the same set up with the X pipe and a 4 speed, no fit problems.
 
mistreta said:
Just put a Stroker in an 70 Duster, and I want to do the exhaust. I hear a 2 1/2 exhaust with an X pipe is the way to go. I heard the X works better than the H. Anyone have the X pipe on an A body? I'm concerned about the fit, do I have enough room?

Tony
[email protected]
Click to expand...

I have a X on a 67 cuda with no issues. The pipe comes off the headers are 3" and is reduced to a 2.5" at the X pipe.
 
Go with the x-pipe. There should be no clearance issues...Any half-way competent shop can get it lined up for you...
 
yes X is a little better...just a few mmore $$s
 
I forgot to mention I have TTIs also. The X will quite down your exhaust big time. It did for me anyways. So expect that. The X causes less savaging and thats why it tames the exhaust down.
 
I have an x-pipe with the new 2.5" system that is under my 360 powered 68 Barracuda. Prior to that I had a 2.25" system with an H-pipe. By the butt dyno there was no difference in the power and the engine makes around 370 HP based on 102 mph trap speeds in the 1/4.

The biggest advantage to to either is the noise reduction. They allow you to run a less restrictive muffler and keep the racket down to an acceptable level. To gain any real power advantage they have to be positioned correctly and in 90% of the installations they are placed based on where there is room.

Since installing the system with the x-pipe I have had to remove my tranny twice. The x-pipe is a definate disadvantage there, you need to remove the pipes from the mufflers forward for clearance.
 
dgc333 said:
To gain any real power advantage they have to be positioned correctly and in 90% of the installations they are placed based on where there is room.
Click to expand...


Just curious. How would you even know where to put the X pipe exactly to gain any real power advantage if you had just absolutely all the room in the world?
 
I have read that you can put a strip of crayon down the pipe and the point at which it no longer melts and burns off is the place to put it but I have also read that that isn't accurate either.

I am quite sure race teams like NASCAR that use them do analytical modeling with CAD software then do testing to fine tune. The position is going to vary for every engine/exhaust combo so even a kit from a reputable company is going to be a compromise.
 
I just got mine done and have a 2 1/2" SS formed X pipe with TTI headers and electric cut outs going into Flowaster 40 mufflers

I was wondering if I had enough room and it turned out great

I'll get some pictures and post soon


this is what it use to look like with the hooker headers

cutouts.jpg

X pipe made at the muffler shop, cutouts in the wrong place

cutouts.jpg
 
dgc333 said:
I have read that you can put a strip of crayon down the pipe and the point at which it no longer melts and burns off is the place to put it but I have also read that that isn't accurate either.

I am quite sure race teams like NASCAR that use them do analytical modeling with CAD software then do testing to fine tune. The position is going to vary for every engine/exhaust combo so even a kit from a reputable company is going to be a compromise.
Click to expand...


Wow! Engine exhaust can be a complicated thing. I guess that is why you hear "tuned exhaust".
 
I have a 3" X-pipe and Dynomax Ultra Flo mufflers ending at the rear end housing of my 360 Dart Sport race car. I had to do a little trimming, fitting & twisting of the pipe angles, but it works great. The X-pipe joint is directly under the end of the trans tailshaft housing. I may have had to put a little dent somewhere on top of the X to insure clearance. I don't think you'll have much room to move it around. But every indication is that it has helped performance over open headers. So I kept the system on and removed the 60 lbs of weight it all added from other areas of the car to maintain my minimum race weight.

I have to drop the system from the collectors on back to change the transmission. But it's just the 6 collector bolts and 2 hangers above the rear end housing.

As for scavenging, I believe that an X-pipe is more effective in that respect and also makes more HP than an H-pipe. Unfortunately I don't have any direct info or other data to support the scavenging belief. But a vac-u-pan system works best with the tubes at a 45* angle (X) to create a vacuum & scavenge the crankcase as opposed to a 90* angle (H), and I'm running my carb leaner than I ever had before. I'm under the impression that each side of the "X" helps scavenge the other side as the exhaust pulses alternate from side-to-side. But I'd be interested in hearing about other opinions/theories.
 
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