Hey guys, just wondering if anyone had ever run into a similar problem. For some reason my car will not boost over 24psi at the track. I can set my hallman manual bcs to 33psi on the sreet and hit it every time, but at the track it will not boost over 24. I am wondering if I need a different bcs. Any help would be greatly appriciated.

 

Ok. How can you "set" an MBC at 33psi exact?

You need to clear things up a bit....why don't you use your street setting and go to the track. I doubt the car knows it's at the track and goes " Hmmmm I'm only running 24psi today".

 

I always set boost levels before I get to the track when I am turning up the boost to 30psi on C16. So I will be boosting 30psi the whole way there, then make a pass down the strip and it will only be pushing 24psi at the same setting. The only difference is I am on the dragstrip instead of the street. I originally thought that it was a heatsoak issue, but now with the Buschur BFIC I highly doubt it. I know that there will be a little bit of a diff btween street and track, but no matter how high I set the boost at the track it will only do 24psi. I have checked just about everything that I can think of and it all checks out.

 

I didn't know that I needed to explain how set mbc to desired psi. Turn the knob 1/2 turn redrive, turn the knob, etc. etc. Sorry not trying to be a smart a... just figured this was understood.

 

Anyone?

 

This is either a non sequitur, or an oxymoron. Don't try to interconnect an MBC(manual boost controller) and a BCS(boost control solenoid) in the same engine bay. Please clarify your terminology. Do you mean Hallman MBC? You don't still have your factory BCS hooked up, now do you?

 

At the track, you are launching at high rpm. On the street you probably do a pull and see full boost(30psi) at 4k rpm. When you get to say around 7k, the boost will fall down to 24 which is what you see at the track.

 

Sorry about that, what I meant was MBC.

 

Bambooi, thank you, I really never thought about it that way. I will have to make some more runs and watch the boost. Typically I have only had about 3psi of taper by 7500 rpm when making runs from launch to top of third gear on the street. Thank you for your help you have given something to look into.

 

I don't think you can hold 27 psi at 7.5k on a evo9 turbo with an MBC unless you have a spring mod on the wastegate arm. I think you may peak 33 psi on the street and then taper to 24 by red line.

 

I thought you had to re tune a car for maximum performance when it comes to adjusting boost

 

What is your max boost setting for street driving? Is your HKS BOV vented to atmosphere or recirculated? Are you on the factory WGA?