I have one of those cockpit adjustable Hallman manual boost controllers...it works great, problem is I can't keep the boost in check in cold nights even with it dialed all the way back (that's how I popped my first motor)....I'm creeping past 14 with the midpipe

any options, aside from just upgrading to a profec b? is that THE solution? will larger diameter vacuum lines help increase pressure in the wastegate actuator line and decrease boost?

 

I don't think the problem is the boost controller. It sounds like the problem is that the wastegate itself is too small (ie, needs to be opened up).

Sonny

 

a profec b will not control boost creep since it works on the same principle as a manual boost controller. you need to port your waste gate when you run a mid pipe if you want to control creep. the problem is that your waste gate is not big enough and can not flow enough air to control your boost. search waste gate porting and you'll see what i'm talking about.

 

https://www.rx7club.com/3rd-gen-archives-73/boost-creep-control-26389/

 

I shouldn't have mentioned the word "creep", I knew that would throw people off....the creep is not that bad at all

the real problem is I get almost 14, like NOW, immediately, in 2nd and 3rd on a cold night, which means I will get more than 14 in 4th, because 4th always gives you an extra 0.5 psi

wasegate porting is not an option right now anyway, I need to control instantaneous boost

I'm running a Pettit ECU

 

The phase "creep" doesn't really mean the boost will come on slow. However, if the boost goes up to 14 and doesn't come back down, then that's "boost creep".

If it's a spike, the boost will go up to 14 (or where ever it spikes to) and then back down to your pre-set boost setting. The bost is not going back down after the spike, then it's not a spike, it's creep.

 

GReddy Relief Valve

 

I'm well aware of what creep and spike are....it goes to 14 and is rock solid with very clight creep, so this is more of a overall overboost issue, at least for the Pettit ECU....relief valve may be part of the solution

 

then your best bet would be to get rid of the mid-pipe and put on a high-flow cat or even a stock cat. i don't believe the pettit ecu is tuned to run a mid pipe anyway.

 

actually it is....I've been running a midpipe for over 2 years now....it's fine up to 13 or 14-15 with race gas Pettit says

 

hell yeah, reliefe valve. that **** is the bouncer and he aint lettin creep through. is your istallation correct on the mbc? cuz i have th ehallman setup as per damians thread on boost control and that **** doesnt stop smacking creep around.

 

huh?

english....do you speak it?

 

i might be wrong but i think what people are trying to say is that with the MBC dialed all the way down it would be really unlikely that you'll get 14psi. I would suggest try running a straight line and see what kind of psi your are getting. I think stock was like 7 psi? and work from there

 

problem FIXED (wish everything were this easy)

I swapped out the vacuum lines between the actuator solenoid and the boost controller (which is basically a glorified pressure relief valve and needle valve) with larger I.D. lines and boom....right back in the middle of the "window" of adjustment....awesome....rock solid 13 psi with very slight creep

I didn't think the vacuum line I.D. made that big of a difference in the pressure signal!