Greddy Profec B

[ians13]

I just Installed a greddy profec B spec boost controller and went out for a spin set the boost in 3rd gear I was seeing 11-13 psi and it feels good, now the problem am having is from a dead stop first gear is good at about 11psi in 2nd gear about 4500rpm it just goes flat back fires and starts going again then it's fine is this fuel cut for some reason , and if so why can I see up to 13psi in 3rd gear but hit fuel cut in 2 gear, can some one help me with this can it be the gain on the controller needs to be higher or some type of boost spike,

My mods are 3" turbo back exhaust intake filter kit
Aem wide band
Safc2 untuned
Greddy spec 2 turbo timer
Greddy profec spec B boost controller
Modded MAF for higher fuel cut?

This on JDM 7m with titan gasket @ 85ft

I see 10 on the wide band under full boost so I know it’s not leaning out.

 

[IwantMKIII]

watch your boost gauge, make sure it holds boost through the RPM range and doesn't simply bleed out. Also, be on the look out for erratic boost readings (*boost spikes) most noticeable at the start of boost

 

[ians13]

the boost is a some what erratic am going to try and tune it this week end, how bad is fuel cut will it cause serious engine damage, not that am going to try to hit it again.

 

[IwantMKIII]

the key thing here is, do you hold boost throughout the upper RPM range?

 

[Fletch124]

What are your AFRs like?

 

[flubyux2]

he said 10's.

how are you shifting when you are hitting fuel cut. is this an auto tranny car? if its an auto tranny car, your boost will spike during upshifts. the ecu doesnt pull timing between shifts to limit power. so when the trans goes into the next gear, it Forces the RPM's to come down. as this happens, the load increaes and spools the turbo even more. boost will spike during hard upshifts on an auto.

also, if its the knob-style B-spec, mess with the balance knob. if you turn it all the way to one side, boost will come on very slowly. if you turn it all the way to the Other side, boost will come on very quickly and over-shoot/spike. you have to use this knob to improve spoolup but reduce spiking/overshoot or an erratic boost level. sometimes if its tuned too aggressivly, the boost will come on hard and youll see the boost level fluctuate.

 

[ians13]

i got to work on it this week end when i can get out speed some were

 

[atlpd3147]

any update on the issue you were having?

 

[ians13]

any update on the issue you were having?

yea for the most part it's good, I turned the balance more to the sharp, side and it holds 12psi in 2nd gear to 5th but in 1st it only makes 10 I don't under stand this , but if I get it to make 12psi in 1st it spikes in 2nd and then fuel cut kicks in so am happy with it now but it would be nice if I could get it to make 12psi in 1st