i bought the kit used, about 10k on it

went in for dyno tune today and found out that i had a bad fmu(brand new tho) so ill send it out for service

but i have a vafc so they were messing around with just the injectors, they maxed out at around 6k without FMU.

for some reason the s/c makes boost really slow, and at about 6-7k, it was only at 5psi
from what i heard s/c makes full boost at around 4k-ish.

maybe its my s/c itself? it does rattle when its cold, but it sounds fine once it warms up, i think its gearlash but maybe im wrong?

TIA,
Cliff

 

I dont know about everyone else, but I dont make full boost until nearly 9k, which is the way it should be.

If you're running a stock kit and hitting 5psi at 6-7k rpm, then 5psi isnt your peak boost.

 

Supercharger boost is in direct relationship with RPM, with it hitting its maximum boost at maximum rpm.

 

You have a centrifigal supercharger not a roots type.Simply put you will not make peak boost until redline.What you describe is normal .They tend to be a little noisy,almost like a cement mixure.

 

defiantly roots type you are talking about, which will have full boost around 3-4k, unlike Cent. SC it will gain full boost at the max rpm the engine can spin

 

that makes me feel a lot better...now i just have to buy another fmu and i should be ok

anyone sellin a used fmu?