Since day one of my JRSC install, I have had this problem with my low end:
The torque curve should be flat in the low end, but as you can see there is some sort of problem. This can be felt during driving. The engine makes a lot of noise, but doesn't seem to want to go until 5k rpm.
Then PreludeSH157 posted his dyno, which shows he has the same problem:
We have almost entirely different setups. He uses the stock JR management, I use the PMS. That ruled fuel management. We have different exhaust systems. He was pulling timing with his JR BTC, while I was running stock timing during my dyno (oops), so that ruled out ignition tune. Both are a/f curves though the problem rpm range were about 12.5:1, ruling out fuel tune. We both have the Hondata IM gasket (he has a custom made one, not from Hondata), so I thought maybe EGR blockage was causing the trouble. Mine is blocked. Turns out his had the hole for the EGR port. We have one piece of equipment in common: the J&S UltraSafeGuard.
I bypassed my ignition wire from the J&S, giving the ignition system a direct signal from the ecu (sans PMS, of course), and took the car for a drive. The problem seems to have gone away. The engine seems to rev very freely through 3k-5k rpm now, and seems much stronger. I stress the word
seems because I think I might be experiencing the placebo affect: I want to find the problem.
Not sure exactly what the root problem is. Perhaps I don't have a decent ground for the J&S (I'm certain the ground is fine), or perhaps it is poorly designed, causing noise on the ignition wire. I'm not an electrician, so it's difficult to say.
Only way to know for sure now is to hit a dyno. If it does turn out to be the problem, I may remove the J&S and dyno tune the car conservatively.