I'm planing out a new system for may NA and wanted to know if any one has tested a X or H pipe and dyno tested them for results. I don't know if the scavenging gain would be worth the loss of flow.

my plan was to uses a magna flow dual in dual out muffler as a pre silencer. the one i was looking at is a perforated X pipe that is covered in steal wool.

Looking for input. as i don't want to spend the 80+ install cost to find out it will hurt out put a lot more than two wool pack's.

also what is the best over all size for a stock port. street/auto-x car. something like 2" header to 2.25" or is that to small?

thanks.

 

Another one of these...
Wait till Mazdaspeed7 find this thread...

Racing Beat claims best power out of a true dual.
Others will claim otherwise.
I still haven't seen the gains on the dyno from these crossover systems.


-Ted

 

I have never seen anybody race an X-pipe or H-pipe, so I would imagine that it has not worked out well. However, short collected and long collected exhausts have been popular for racing for a very long time, and these would have a similar effect to an H or X-pipe. For extra noise suppression at the cost of extra weight, you can use a long collected exhaust with dual muffler outlets, which would basically be an X-pipe configuration. See the Racing Beat website for pictures, and also take a look at their 1Gen exhaust systems. The Racing Beat catalog also has a lot of recommendations for exhaust systems.
http://www.racingbeat.com

1.8" inside diameter primary tubes is usually recommended, but you can gradually use larger diameter piping as you reach the tailpipe if you like.

?

Racing Beat has claimed best power from collected exhausts for decades. It's only recently that they have even offered an uncollected (true dual) exhaust. Is their endorsement of uncollected exhausts something new that I missed, or were you thinking of Mazdatrix? Mazdatrix claims best power on non-ported NA engines with the uncollected exhaust.

 

I searched and found no thread on crossovers.

I may go ahead and get it. also have a h pipe and some regular pipes made up and have a dyno day. I think it would be interesting to try. I'll need to see what it would cost.

also dose any one know if the new RB presilencer is uncolected?

 

Yeah, maybe...
I'm not an NA person.


-Ted

 

Don't know much about street legal just full race car.
But a short header with a 3 inches pipe works the best,and I did the dyno test and saw a 21hp difference between a loong header like the racebeat and my shorty one.

here is a link of my exhaust.

http://images.realride.com/cgi-bin/i..._Benny/exhaust

benny
realride.com