How much boost will the MS3 hold before it will cut out

[MS3Zoom24]

I ve been trying to look up this info and havent found it in the forums yet. so does anyone know at what boost psi will the ecu tell you no more. And for the noobie question is boost cut the same as bleeding off the excess pressure or is it more of a drastic action that you can notice instantly?

thanks

[Bravnik]

18PSI is the magic number. If you hold boost for longer than a few secs above 18PSI you will get boost cut.

I run my MBC at 17.8 PSI using my DashHawk without issue.

[MS3Zoom24]

So If you run the MBC it will hold boost up to 17.9. My other question was after say 17.8 psi does it just bleed off the rest off the boost and stay held at 17.8 if the mods allow it to build more than 17.8???

[AutoXRacer]

I got boost cut with stock boost levels... 15.6-16 PSI.

[lestat13]

I am getting cut as soon as I cross into the 18+ range.

I was looking into getting a mbc, but to help control boost, not necessarily raise it. Is that true then that you can use a mbc to limit boost, or can you creep past that? Also, will it hit that in first and second gear, cause I really don't want extra the extra boost there......

If so, sign me up, I'll order one tonight! ;]

[mazdaspeedster3]

LOL... Just more boost and maintain that boost longer is what I am looking for. I know I need a BPV now as I can see on the DH how drastically it looses boost.

[~JoJo~]

actually to my boost guage I am boosting at max 21. I only have intake and bov, what's wrong?

[AutoXRacer]

I am getting cut as soon as I cross into the 18+ range.

I was looking into getting a mbc, but to help control boost, not necessarily raise it. Is that true then that you can use a mbc to limit boost, or can you creep past that? Also, will it hit that in first and second gear, cause I really don't want extra the extra boost there......

If so, sign me up, I'll order one tonight! ;]

The MBC will replace the factory electronic boost control. You can't use them together. You set the MBC to whatever boost you want; 10, 12, 14, 15, 17, 18, 20, etc... You shouldn't creep past the boost you set it at.

And yes, with a MBC, you will hit full boost in 1st, 2nd, and 3rd gear...

[AutoXRacer]

actually to my boost guage I am boosting at max 21. I only have intake and bov, what's wrong?

According to your sig, you have a Defi boost controller...

In a stock setup, you should not be boosting higher than 16.5...

[lestat13]

The MBC will replace the factory electronic boost control. You can't use them together. You set the MBC to whatever boost you want; 10, 12, 14, 15, 17, 18, 20, etc... You shouldn't creep past the boost you set it at.

And yes, with a MBC, you will hit full boost in 1st, 2nd, and 3rd gear...

Is it dangerous to hit full boost in 1st and 2nd gear, like for the engine, tranny, etc.... or is it same and people shy away just because it will be harder to get traction and control the vehicle??

Also, a mbc means I wouldn't need a map clamp unless I go above 18psi then right? Good, the car is finally coming together!

[Speed3Rookie]

And yes, with a MBC, you will hit full boost in 1st, 2nd, and 3rd gear...

Are you sure about this??

[AutoXRacer]

Is it dangerous to hit full boost in 1st and 2nd gear, like for the engine, tranny, etc.... or is it same and people shy away just because it will be harder to get traction and control the vehicle??

Also, a mbc means I wouldn't need a map clamp unless I go above 18psi then right? Good, the car is finally coming together!

I don't think it's dangerous...its more of not needing anymore boost on the first two gears due to limited traction. It will be definitely harder to launch with full boost.

You may end up needing a MAP clamp...since the ECU will sense you are holding higher boost up top, it may trigger boost cut.
But you won't know until you try it.

[AutoXRacer]

Are you sure about this??

Yeah, you are taking out the factory boost control which controls boost.
The MBC will only limit the boost to where you set it at...it can't vary it.

Now, your ECU can over-ride throttle input...thats why you need CP-E's Full Throttle Control; 100% throttle plate opening baby!! (2thumbs)

[~JoJo~]

According to your sig, you have a Defi boost controller...

In a stock setup, you should not be boosting higher than 16.5...

yes I do have a boost controller but I actually don't know how to use it (humpleg)

Is there a way I can dial the boost down? I am even holding on 21 boost too.

[AutoXRacer]

yes I do have a boost controller but I actually don't know how to use it (humpleg)

Is there a way I can dial the boost down? I am even holding on 21 boost too.

There has to be a way to turn it down...but I have no clue.
Is it a mechanical or electrical boost controller...?

[~JoJo~]

it's electrical.

[AutoXRacer]

You should be able to just dial it in from the cabin...

Anyone in here have any experience with Defi boost controllers?

[Corndogler]

Kind of on a different note. With the stock 15.6 psi that most people say they hold steadily, is that in 6th gear? Because I sure don't hold 15.6 in 3-5.

[MS3Zoom24]

And yes, with a MBC, you will hit full boost in 1st, 2nd, and 3rd gear...

Ok this doesnt make sense the MBC contols the top limit of the boost not to exceed a certain psi, the limited boost in 1st and 2nd should be controlled by the ECU not by the Stock BC, plus you also have Stability/traction control that will apply the Brakes to the Rotors if you do start loosing traction. agian this is just my hypothesis on the suppject as i dont have a mbc, but it doesnt make sense. MORE INSIGHT please or help on what im missing if this is wrong

[Bravnik]

Ok this doesnt make sense the MBC contols the top limit of the boost not to exceed a certain psi, the limited boost in 1st and 2nd should be controlled by the ECU not by the Stock BC, plus you also have Stability/traction control that will apply the Brakes to the Rotors if you do start loosing traction. agian this is just my hypothesis on the suppject as i dont have a mbc, but it doesnt make sense. MORE INSIGHT please or help on what im missing if this is wrong

When you install an MBC you bypass the cars EBC (Basically you disconnect the vacuum line too it). Thus the ECU no longer controls boost but your MBC does. Thus you set the MBC for the max boost you want and you have max boost in all gears. HOWEVER, you will not hit max boost in 1st thru 3rd but you will hit more than with the ECU BC. The most I ever seen 1st thru 3rd was 12-13psi (1st and 2nd) and 16-17 PSI 3rd with 4th thru 6th hitting around 18-20PSI depending on settings.

I use to run a 2 stage MBC. I used the first stage for valet parking or shop visits. 1st stage is MBC OFF which means I was running off of the WasteGate only boost which for our car is 10psi max. In stage 2 MBC ON I was at 19PSI.

However, I have it disconnected now running stock boost again as with my mods I get more than factory PSI and really anything over 18PSI on our car is just blowing hot air.

I hope this all makes sense to you??!!

[~JoJo~]

so how do I change the boost level from the defi boost controller? I really don't want to run this rich (max 21)

[lestat13]

Bravnik, this is my first turbo car even though I've helped other people work on theirs, but got a question. About to install a mbc on my car, how much harder would it be to put in a 2 stage? Then what, you just pop the hood and flip a lever to the other setting? Good to go?