[HemmiGremmie]

Would there be or should I even consider this for my supercharged sbc in my Gremlin?
I hear about this all the time, but whats the gains, whats the reasoning behind it?
It looks like my 1 3/4 inch headers into 3 inch pipes straight out the back would be better.
Any oppinions? Hg

[61 chevy]

the x or h pipe is for scavanging the cylinders better, equilizing exhaust press..blah...blah...blah......your puffer will do this for you.

[454C10]

Cross over pipes don't do much for performance. But they really help with sound control in the cab of the car. A H-pipe makes a lower note and the X-pipe make a higher note. If you plan on some long road trips get the x-pipe.

[ztoy]

"Cross over pipes don't do much for performance. But they really help with sound control in the cab of the car. "-


Am afraid I have to disagree, 454c10, but there have been lots of studies done to prove that 'H' pipes do seem to improve performance and 'X' pipes make an even bigger improvement in performance. My 'X' pipe setup made alot more power for me.

[454C10]

Well I have seen many dyno runs some showing very small improvements and some showing none at all when using cross-over pipes. It depends all on the set up.

I even had some discussions with a local nascar engine build and he says no improvement.

But, where cross-over pipes really shine is in noise reduction.

Here are a few articles.

At chevy high performance, they say sometime there is an improvement in power and sometimes there isn't.
http://chevyhiperformance.com/techarticles/67698/


Here is another article with an exhaust system on a vette. They pick up around 2 hp and 2 ftlb of torque with the x-pipe But the big story is sound reduction. 2 hp/ftlb could be found or lost just by re-dynoing the engine.
http://www.vetteweb.com/tech/0307vet_xpipe/

So, if you are looking for more power, a cross-over most likely isn't a good investment. However, if you are looking for noise reduction, then it is the way to go.

[jimfulco]

http://www.pontiacstreetperformance....p/exhaust.html

The bottom of p.2 and p.3 have some info on H- & X-pipes, both power-wise and sound-wise.

A friend of mine put a Bassani X-pipe on his Mustang Cobra, and it sounded much like the old GM Camaro/Nova transverse dual-in/dual-out muffler system, only a little louder. It's an old rule-of-thumb that the more pulses in the exhaust noise, the easier it is to quiet it down. I think the X just mixes the 4 on the left with the 4 on the right to get the noise down. The 5.0 Mustangs used a very short H crossover, and they have a much smoother sound than a car with a long H-pipe, almost as smooth as the X gives.

[ztoy]

Thanks for the link jimfulco. I had lost it when I changed pc's. I did a ton of reading, asking questions, and the consensus is as one of the sentences in this link says.."Functionally, the difference between the X and the H is, the X type forces the exhaust to cross between both sides. Based on the performance increases we noted with the X crossover, the scavenging forces created by the gasses crossing over in this way appear to be stronger and more effective across a wider range of engine speeds."

I have felt the difference (in the seat of my pants) by changing to the 'X' type and there are several guys on this board who said the same thing. Another on nastyz actually did a 'with' and 'without' test at the strip. He ran quicker times with mufflers on while using the Dr Gas 'X' pipe that he did with his headers opened. And it does help to have great flowing muffs as well...Of course different setups will respond differently.