okay i have a jmd s5 block that runs off a microtech lt8s and is boosted by a stage four bnr. When i got this car it ran rough at low rpms and when coming into boost. But then it would run hard and clean from 5psi on. A friend and i did a little tuning and now it runs great until 10 psi at any rpm. as soon as it hits 10 psi it breaks up compleatly. I have no idea what it could be. it runs so well until it hits that mark. any ideas?

 

okay i have a jmd s5 block that runs off a microtech lt8s and is boosted by a stage four bnr. When i got this car it ran rough at low rpms and when coming into boost. But then it would run hard and clean from 5psi on. A friend and i did a little tuning and now it runs great until 10 psi at any rpm. as soon as it hits 10 psi it breaks up compleatly. I have no idea what it could be. it runs so well until it hits that mark. any ideas?

 

do you have a wideband?

what size injectors?

 

yes i have a wideband....can't really tell because at the point of break up it just starts to blink....

the injectors are stock.....i'm sure they can't handle alot but i've heard they can handle 12 pounds.....i'm just trying to make it driveable. does anyone know what is the lowest boost the stage 4 will make?

 

I have the same damn problem except I have 720 secondaries, it is rather irritating

 

my car does the same thing, except its an s4 and i have 720 secondaries so its not your injectors.