Smoothed H pipe. Will it work ?

[elliotaw]

Ok, I'm about to make up a balance pipe for my project. I will have a twin system from front to back and I like the old school sound of a pure separated system but appreciate the advantages of having a balance pipe.

Now, i'm not a fan of the x pipe types because I personally believe that it gives too much of a monotone result soundwise. I also think that a harsh 90 degree H pipe disrupts the airflow too much, so I am considering a slight modification of an H pipe setup.
Did a real quick rough sketch...

http://i1001.photobucket.com/albums/af134/elliotaw/arse.jpg

I would cut up some 90 degree bends and weld them together. Then weld use some reducer cones and then a smaller dia pipe in the centre to join the two together.

My idea is mainly to smooth out the flow somewhat to reduce distrubance in the airflow. Any comments on doing such a system ? Will it produce more negative effects than positive ones ?

Thoughts appreciated

Elliot

 

[JBrady]

Well, experimenting can sometimes produces surprising results but I would say WHERE you place the crossover will be more important than WHAT kind of crossover you use.

An H pipe crossover is (IMO) simply presents the flow with a larger volume area. This area sends a signal up the pipe and the engine feels like the crossover location is the end of the pipes from a tuning perspective. If the placement is good you will make gains if in the wrong place it can hurt.

The sound frequencies will also be altered as the attached piping will muffle the sounds much more than a straight unbroken pipe.

Aerodynamically since there is no meaningful flow through the H crossover I don't think you need to worry about smoothing the flow path and in fact creating even more volume at the H may hurt overall flow.

Again, theory is one thing and application another. You may wish to experiment and see what you think. I would suggest doing so with mild steel as if the results are not good it will be cheaper to re-do.

Now each crossover design works differently with a BIG difference in the various X pipe designs in terms of flow and function. A Y pipe works very much like an X pipe and there are big differences in Y pipe designs.

Believe it or not the stock Lexus Y pipe is a GOOD pipe.

 

[elliotaw]

Thanks for the reply. I can see what you mean by the exra volume at the H if I use cut up bends and the negative effect it could have.

So my next stupidly obvious question is.... if I decide to go with a plain H setup, how do I select the crossover pipe length and dia ? and as you say the position... are there any calculations I can use or internet links you know of to read up on theory ?

Elliot