Just thinking out lond, but why hasn't anyone tried a velocity stack header?

I'm thinking that if you could get the diameter of the tubes just right you could increase the rate of exhaust flow while at low RPMs, and while up very high the system would be able to flow enough without restriction.

I'm thinking you could make the farthest port lead out with a very large diameter pipe, and then have the middle joined port lead into this large pipe in the center. The pipes would be sized that when the middle port pipe joins into the farthest port pipe the usable area will be slightly larger than stock.

Below are two quick designs, The first seems to be the most cost effective and will still produce gains.

While the second appears to be grossly more efficient but very compex to manufacture because the middle is split and incorperated into the two different ports. I'm thinking that a 3 + 1/2" exhaust, a supercharger and some exhaust porting would accompany the later very well.

 

To be able to design a proper header we should know how much exhaust flows out of each port. The front and rear ports flow the same but I dont think the siamesed middle port flows double (as it would be if the port sizes were the same).

Anybody knows?

 

I will be dyno testing my prototype header for RX-8 in about a week. It has really short primaries and small collector id and of course tapered 7 degree flange. Hope to acheive a solid +10 hp.

/Lasse

 

If it works put me down for one!

 

Charles Hill, about 1 year or more ago, said he had an idea about a header for the car. Things changed in his life and I haven't heard anything more about it.

 

If you haven't seen this, it's a good read. Better sit down for it though, it's one of Rotarygod's longest .

https://www.rx8club.com/series-i-tech-garage-22/another-one-my-insanely-long-exhaust-tech-articles-73332/

There were a couple header threads a while back. The info may be out of date now, but they might be worth looking up. (search for posts by Rotarygod in a header thread, he posted in both).

 

https://www.rx8club.com/showpost.php...0&postcount=96

there is no overlap on the Renesis intake/exhaust port timing, common header rules don't necessarily apply

 

^^ at least you had the advantage of knowing where to look. i tried to look for that real quick a little earlier and had no luck. thanks for saving me the grunge work