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DRFTR8
07-20-2004, 02:05 PM
hey guys here is my question...what is the safest PSI can have on your EVO when your using a MBC... i know that you can fix that with a P2 flash but for those who cant afford the flash right now (like me)what is the solution.. Im thinking of installing one that i have lying around in the garage.... i have a DP, works AB and Injen intake...so what do you guys think...like i said i would love to have that P2 done but im moving to Dublin with my lady and for those who met me im getting the ball and chain...so money is tight....

EvolvedDSM
07-20-2004, 02:09 PM
I wouldn't go above 18PSI on 91 octane w/o some sort of fuel management and/or logging device.

DRFTR8
07-20-2004, 03:24 PM
well right now the car is pushing 20psi on 91...so can i go over 20?

carbonevo8
07-20-2004, 03:32 PM
i have a simalar setup but i have a p2 93 brain flash and i run 21psi but on 95 octane so i wouldnt try it on 91 octane

BluEvo
07-20-2004, 03:39 PM
if you push over 21 constant, you might start hearing some knocking.
*knock, knock* :? stay safe with 18-19psi

DRFTR8
07-20-2004, 04:32 PM
if you push over 21 constant, you might start hearing some knocking.
*knock, knock* :? stay safe with 18-19psi

i dont have the MBC installed yet...after the upgrades..intake,DP and the works AB its hitting 20 constant and that not spiking either

Whooopasss
07-20-2004, 05:28 PM
I got 20psi on a MBC but tapers to 19 on red. 91 oct.

BluEvo
07-20-2004, 05:42 PM
if you push over 21 constant, you might start hearing some knocking.
*knock, knock* :? stay safe with 18-19psi

i dont have the MBC installed yet...after the upgrades..intake,DP and the works AB its hitting 20 constant and that not spiking either
it's gotta be tappering down to 16 or so after hitting 20. what i mean is if you are holding boost at 20-21 constant and only tappering down 1-2psi, which is what it it would do using a mbc.
not saying its not possible to run higher, but the question was to run safer. :wink:

EvoVIII
07-20-2004, 08:31 PM
I just got a EBC wonder whats the difference on a EBC and MBC :roll: all I know is it's gonna take forever to learn how to use the EBC... but hope it will hold boost better then MBC, and running 21psi is safe or should I change a bigger fuel pump too?

MitsuMan
07-20-2004, 08:31 PM
I raced a guy w/ a red evo that works at stevens creek BMW and he ha int. exh. and a boost contoller and he was just a tiny bit slower than my vishnu stage 0 I asked him if he was tunned and he siad no but I didn't have time to ask what psi he was running I'll try to find out more

ob4
07-28-2004, 12:12 AM
with a mbc you are probably just setting the mid range peak boost, it will most likely taper towards redline. with the stock boost control solenoid, i was getting peak boost at around 20psi with dp+exhaust, and taper down to 15-16psi. After i did my xflash, i was running 21-22psi peak at mid-range rpm and taper down to 19psi near redline, and this is with the boost tube provided with xflash. now i have a mbc to replace the xflash boost tube so that i can lower boost during winter and up boost a little when i run race gas. with the hallman rx-pro mbc, i still see a taper near redline, my mbc now set to peak at 21psi in the mid-range and taper to 18psi, this is with cams and cam gears. Also, you will notice that with 4th/5th gear pull, you will always see a higher mid range spike... so tune the mbc accordingly. With most ebc, you get close-loop boost control, so whatever you set your boost at, the boost controller with try to maintain, but of course the boost will still move around a little. this reminds me of the dreaded ee control system class...

-ob4