Boost variability

[Wingman21]

Im just wondering why my UltraMeter Gauge shows boost sometime at 6.9, sometime between 6 and 6.9 and sometime even under 6 (drunk) !??? Isnt the wastegate suppose to always open at the same boost level (dunno) !? By the way my MSP is all bone stock except for an intake.

 

[03MSP]

Boost will always drop off in higher RPM....get an exhaust, harpipes (or FMIC kit), and electronic boost controller and you will be able to keep it more steady.

Mine goes from 9-9.5 down to 7.5 at redline

 

[kNOWfREED0m]

im running with a cat-less exhaust CAI and colder plugs, at 10psi. i drop to about 9 at redline

 

[yashooa]

Well I have the stock pipes and exhaust with new lines that Mazda put on.
The only problem I have had is holding TOO much boost!
It starts at 10PSI and just shoots up past 15PSI if I keep my foot on it which I don't. Heck, I have to give it part throttle and shift early so I won't go over 12PSI. I have never boosted high in 4th or 5th only to 10-12PSI
I am going to back my MBC off some more. I hope I can get it to only hold 10-12PSI not any higher. I would like my car to stay in one peice (crazy)
It has over 40k miles on it now and it has been flawless for the entire time @12PSI except a few bushings, and an exhaust.

 

[03MSPRO]

Well I have the stock pipes and exhaust with new lines that Mazda put on.
The only problem I have had is holding TOO much boost!
It starts at 10PSI and just shoots up past 15PSI if I keep my foot on it which I don't. Heck, I have to give it part throttle and shift early so I won't go over 12PSI. I have never boosted high in 4th or 5th only to 10-12PSI
I am going to back my MBC off some more. I hope I can get it to only hold 10-12PSI not any higher. I would like my car to stay in one peice (crazy)
It has over 40k miles on it now and it has been flawless for the entire time @12PSI except a few bushings, and an exhaust.

you have an entire different problem there

 

[03MSPRO]

Im just wondering why my UltraMeter Gauge shows boost sometime at 6.9, sometime between 6 and 6.9 and sometime even under 6 (drunk) !??? Isnt the wastegate suppose to always open at the same boost level (dunno) !? By the way my MSP is all bone stock except for an intake.

All MSP's do that. At stock boost, it does the exact same thing even after hardpipes, DP and exhaust.

 

[yashooa]

you have an entire different problem there

Oh not really a problem I just need to adjust my MBC out.
I had it off for a few months because my wastegate was out of wack after Mazda replaced my turbo hoses. It was running 15PSI stock.
After they fixed it my car ran 5PSI spot on like it did before so after a bit I dusted off the old Joey P MBC and put it back in.
It is defintely not leaking I've just been having fun with it at part throttle
I will back it out some tonight and really test until I get it back down to a surviable pressure..