If I get an octane booster, will it be OK to run with 20-21 psi of boost?

Thanks a lot for the help.



STI

 

Octane boosters will help very little if at all since it only raises octane a few percentage points at most. I would just leave the MBC at 20 psi and you should be ok on 93/94 pump.

Like Malibu said if the car feels like it is falling flat on its face it's probably knocking so I would adjust the boost down slightly in that case. Like I mentioned earlier, last night at the track I was getting good timing retard from knock and actually needed to drop the boost to 17 psi in the warm/humid weather, the car felt faster on the next run.

 

I think you guys are right. Stock boost was down because of heat and humidity yesterday. No wonder it read 14-15psi max!!! I will turn it down to 19-20.

Thanks!!!

STI

 

This maybe stupid but I thought you had to turn the boost up when it is warm and down when it's cold? I always thought you made better boost when the air was cold and dense and had to turn a MBC down when the temp drops.

Just bought a MBC and will be putting it on this weekend. Guess I will find out.

 

I installed my mbc differently. One hose to the wastegate and one taps into the line going to the intake manifold. I capped off the nipple on the turbo housing and capped off the nipple under the intake tubing. Whats does you boost gauge read in all the gears at wot? I wonder if the different hose locations makes a difference in how we hold boost.

 

You can run more boost when it's cooler out since the resulting intake charge is cooler (more efficient), knock is reduced and timing advance is more aggressive so the car feels faster. You lower boost when it's warm because the intake charge is obviously much warmer and the threat of knock increases, leading to timing retard, call falls flat, etc. Weather has no direct control on boost, you raise or lower boost depending on the weather to tune around knock. The goal is to always tune the car to the edge of knock (detonation) thereby making the most power. Problem is you can't really tell what's going on without a logger.

 

In theory the way you did it is supposed to reduce boost spiking, I think someone mentioned this earlier in the thread, but the really short hoses and the location close to the turbo housing (in our case on the turbo housing) could have that effect, however my experience I have not experienced boost spike, and my boost stays rock solid at whatever I set it (it will vary because of heat and humidity levels) What I did notice was faster spool-up this way as compared to the other way... I would think that boost spiking would actually show up the other way only because of the slight increase in delay before the intake charge shows boost at a location in the manifold as compared to immediately after the turbo. It also makes sense to get the boost pressure before the intercooler since after the intercooler the density of the air could affect boost pressure slightly.

Its all academic though, if it works for you, then it works... I think the source of boost pressure will have more of an affect if your tuning an EBC, since an MBC doesnt dynamically adjust settings..

 

Does he know that the other end of the T (not the one going to the wastegate actuator and the stock boost solenoid) is the same pipe as the intake manifold (before the intercooler)? It's the same thing, but cnnecting it to the intake manifold requires a longer hose.

 

Im happy wit my blitz

 

what about tapping into the BOV line? Seemed to work for me.

I have a T at the BOV.
Then i have the wastegate tapped into by MBC