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elementsk8erq
04-07-2009, 02:48 PM
I just got a tune for all my mods but was wondering if I dial down the boost with mbc will it change anything on the tune or AFR. My guess is that you will only expierence power loss is this true. Thanks.

Kings Fan
04-07-2009, 03:39 PM
Yes you will, why would you wanna dial down your boost for which you were tuned at?

marq
04-07-2009, 04:13 PM
Shouldn't he be tuned for a certain air/fuel maximum? So if he turns down the airflow, the ecu should also draw down the fuel to keep in that certain A/F ratio range? So yes, you'll lose power because you are losing airflow (good for increasing fuel economy). I'd call up whoever tuned you and ask if it's ok to turn the boost down from let's say 25psi to 18psi daily driver.

RREVOVIII
04-07-2009, 06:25 PM
it depends what your Timing and Fuel Maps look like, some tuners only adjust the area that the car hits (ECU Load) on WOT, and some really take there time smoothing the whole map. cause dropping the boost, ECU would hit lower loads than what your tuned at...

Who tuned your car??

elementsk8erq
04-07-2009, 09:17 PM
Paul at EIP tuned my car.

elementsk8erq
04-08-2009, 12:29 PM
I was just wondering if GST 3 port boost solenoid would be able to compensate for boost changes in the difference in temp. For some reason my car is very sensitive to temp. It is almost 4 psi difference morning and afternoon and I only live in the bay area.

Kings Fan
04-08-2009, 12:46 PM
If the ecu boost correction is set correctly it should be able to compensate. You would encounter the same temp problems when using an MBC. What PSI range are you seeing?

cornercarver
04-08-2009, 08:29 PM
You will see a psi increase no matter what you use, mbc or ecu control because the air is cooler and more dense in the morning. If you are not knocking, you should be fine. But all of our cars are touchy with changes in weather.

Your gauge may also be inaccurate by as much as 2 psi....

stockIX
04-09-2009, 09:26 AM
Based on what I've read, the most accurate way to determine boost is the JDM (or similar) MAP sensor.

That being said, I'm not sure how EIP tunes. It's possible to set boost using ECU controlled psi boost targets if you have a JDM map so boost is controlled using a closed feedback loop and not set based on engine load. If this is a real concern, there's a thread on evolutionm.net that shows how to do this and Bryan at GST can probably do it too. For me, if I'm going to run 25ish psi I would definitely run the closed loop boost control. The 3 port would allow for better boost control and response but it still needs to be programmed in the ECU as to what boost levels are hit.

What does EIP use to tune?