which is better X or H

[nmdart]

Finally got my 74 swinger up and running, Fresh 318 with MP 484/284 cam, ported 302 heads with 1.88/1.60s, Rpm Air gap, Hedman headers and 2600 stall. I am going to run deltaflow 40s with 2.5 inch pipe, which would be better for all out performance an X or an H pipe? Also I have talked to the local muffler shop about exiting in front of the rear tire, they told me this is not wise, what are your opinions on this?

[dwc43]

A merge type X pipe is the only way to go. In all test it will always produce a large gain in torque and some increase in Hp. An H pipe has to be properly placed and sized for the engine used including cam and header selection too. Some times an H pipe will show no gain, little gain, and sometimes a loss. Even at an H pipes it's best, the X pipe will beat the H pipe.

Side exit is not a good idea. It heats the tires and with each heat cycle it gets them closer to the end of there life. Fumes can be pulled back into the car along with blackening the side of the car.

A set of X,J, or U heads with 2.02 valves would be a much better set up too with the right dual pattern cams. Small blocks like the dual pattern cams better than anything else.

[Slingshot383]

The X pipe is better than the H pipe, and you want to try to get 12" of pipe after the muffler. It helps with the harmonics and will make the system a lot quiter than with less pipe after the muffler.

[nmdart]

Thanks for the info guys I am going to put an X pipe on it and run it out the back. I cant wait to get this thing on the street.

[dwc43]

Welcome, anytime. One other thing, don't use a muffler shops home made X pipe either. It needs to be smooth and contoured and a speed shop piece is the way to go. Go to www.drgas.com for all the answers on X pipes from the guys that came up with them to start with.

[DartGT66]

Since importing those pieces here is pretty expensive, I contacted one manufacturer and asked him about doing the X myself when I purchased some other parts. He said it shouldn't be a problem, just slice 1/3 of the pipe diameter on the center of two 90 degree mandrel bends and weld them together. In my previous car, I converted from 3.5" individual duals to a 3.5" x pipe and in that case picked nothing. But it makes the sound more pleasant to my ears.

[dwc43]

That's because you don't need any more than 2.5" pipes unless you make more than 600 hp at the flywheel. That's why you did not see any gains. The homemade X pipe wont make as much power as a production model.

[DartGT66]

I made 780 hp through 3" duals & mufflers, but I had a very marrow operating range at teh strip because fo a slipping converter, and that may be one reason why there was no difference. Currently I have a 3" X set up with four mufflers with the engine and it works great & is quiet. If it is built the same as a factory built X, it should perform the same, wether it's done at home or in a factory shouldn't matter.

[dwc43]

Well, most homemade joints are not as smooth or bent as well as a production piece. At least the ones I have seen. Mandrel bends help the flow a lot and ther fewer the better. I've seen some pretty crappy stuff before, that's why I said go with a production piece.

[Stus300]

mandrel bend pipes from home depot Nuff Said.

production pipe if you can find it, be easier for install..

jsut member to measure twice cut once =)

[nmdart]

The shop that is going to do it is also a custom rod shop and their x is pretty nice, looks like a smooth free flowing piece. Thanks for all the info. I will let you know how it turns out, going to the shop tomorrow.