jp-3 on an rb s-3?
 

will the jp-3 work well on the 3 port rb?

It will work fine. The JP-2 will be a little smoother and have a better top end. The JP-1 will make the most power with that engine but you will not have a very far extending top end.
All in all, the JP- pipes perform well with the Sport RBs.
You might also give the 053 Dynamite pipe a try.
Personally, I would and do use the 053 and the JP-2 when I run those motors....
Hope this helps!
TEX

The JP-3 works really well on almost all engines and better than average in the worst case scenario. You can't really go wrong with the pipe.

Anyone ever try the 086 on this engine?

I finally got to run my new RB S5 motor with my JP-3 and i have just flat stupid bottom end. Pretty good top-end to boot. Never thought i could get the kind of bottom end i have now. I am actually considering making my clutch less aggressive just to save the tires.