Ok well im new to mazdas and new to boosted cars. i just picked up my 9 mazdaspeed 3 about 3 weeks ago. it had 2 busted motor mounts from the get go and i just replaced them today with minerva mounts. wich imo are not that bad and they dont vibrate very bad at all. well when i got the car it had a fmic injen cold air and hks bov manual boost controller and a boost gauge. ive noticed that in fourth gear if i do a pull the boost will hit around 15psi and when i get close to 5k the pressure starts to bleed of and hits 12psi at about 5.5k i was just wondering this is normal or if its just pulling boost because maybee tha fuel pump is maxed out and it cant hang? I do not have N acces port yet but im saving for one now so i cant monitor anything atm... any advice would help and if i misspelled anything im sory im posting from my pos phone
boost pressure question
- Thread starter jaymz199
- Start date
tuOdekcalB
Member
- :
- 09 Mazdaspeed 3
I have heard the optimum shifting is like 5500-5800 zone.
oaklandopen
Member
Those pressures seem a little low to me. Could be from the extra plumbing for the fmic.
In any case you should be spiking to generally 17psi and tapering down to about 14-15 on stock tune and equipment
with a different tune you can hold boost higher for longer, as well as a general increase in psi across the full rpm range
In any case you should be spiking to generally 17psi and tapering down to about 14-15 on stock tune and equipment
with a different tune you can hold boost higher for longer, as well as a general increase in psi across the full rpm range
speed3 britz
Member
- :
- 07 Mazdaspeed3, 93 B2600i 4x4
This is about what i hit with my gauge, and im pretty much almost still stock
oaklandopen
Member
Ummmm....i really wouldnt do that with this car. There are some good tuners out there that will increase your boost along with changing other parameters so you can increase boost safely.
I have the hypertech tuner which i think increases pressure to around 18 for a spike, then tapers down to 16 or so. But along with that increase i keep power for longer (higher rpms) instead of the stock tune dropping off a few thousand rpms before redline
I have the hypertech tuner which i think increases pressure to around 18 for a spike, then tapers down to 16 or so. But along with that increase i keep power for longer (higher rpms) instead of the stock tune dropping off a few thousand rpms before redline
oaklandopen
Member
I cant be certain about any of that. But i think the wastegate actuator as well as the boost solenoid are ecu controlled. So the stock parameters are still functioning even when manually upping your boost
but thats he reason why i say forget the manual controller and get a tuner. With the way these cars (and many others) are now you cant just mess with one aspect and get good, or even lasting results
but thats he reason why i say forget the manual controller and get a tuner. With the way these cars (and many others) are now you cant just mess with one aspect and get good, or even lasting results
oaklandopen
Member
I personally would
I agree. Pull the MBC for the time being to see where you are on the stock tune. You should see 16-17 psi, maybe even 18 on the boost gauge when coming up on boost, with a gradual taper to 15 at about 5,500 rpm. After that, the ECU forces the throttle plate to rapidly close to protect the small turbo which becomes inefficient at higher rpm. I'd avoid the MBC altogether and wait for your money to accumulate so you can get the Cobb Access Port or some other tuning solution. If you are not familiar with turbos and are worried about making a mistake with maps and tuning in AP, consider the plug and play Hypertech. It produces a nice bump up in performance and does it safely. AP can produce a little more power, but if you don't know what you are doing, you can get into trouble.
BTW, load cut does come on at 17.5 psi on stock tune under most conditions and MBC does not let you work around that. AP or Hypertech give you higher load limits without cut.
