Michaelk9090

Hi, I have a Jackson Racing m45 gen 3 kit on my 99 miata. Car runs great and pulls hard, but I am stuck at 5psi. Here is everything I have tried: Full boost leak test at ~10-15 psi with a diy leak tester (Found leaks, fixed them, nothing now), tightening the belt with no success, trying the bypass in all adjustments (I am positive the bypass is working). I have not been able to figure this out at all. No play between rotors, coupler feels good, no play when turning it and holding the rotors still. coating on the rotor tips is perfect, slight damage to the coating on the valley of a rotor on one side. The car is running ms3x, stock injectors and all, TDR belt tensioner, 62.5 TDR pulley, stock crank pulley, no intercooler (IAT between 110-145) Everything I read indicates that I should be seeing between 7-8psi. Tolerances are 0.003" between rotor and housing, and 0.006 between rotors. Front and rear of the case show no signs of bearing damage. I can take pictures and provide any info that would make this easier. Any help would be appreciated. I could also take logs and post if needed.

mlouque

I have the same setup as you. I only make 4-6 PSI here in Colorado @ 6-10,000ft in elevation. Supercharger boost is relative to atmospheric pressure. Are you far away from sea level by chance?

Michaelk9090

unfortunately not, only ~200ft above sea level

rascal

Remember that boost is a measure of restriction, not power so your engine may just breathe better than others.
fwiw my motor made more power at less boost when it was rebuilt with good bits.

so if “car runs great and pulls hard” then don’t get hung up on a specific boost figure..

sixshooter

iTrader: (12)

Rascal is exactly right. The same setup on a NA8 would likely be more restrictive than your NB1 and therefore show more boost but be less efficient, and less powerful.

A more restrictive air filter prior to the charger will also reduce the boost because of the flow reduction.

Michaelk9090

That was my first thought but I read on the track dog website that it should make more. I think you are right though, I'm not going to sweat it, thanks everyone for the advice, im still kinda a newb with this stuff lol

Michaelk9090

also i just cleaned my air filter and saw .5 psi increase, thanks six