right now im on a stock tune in my 03 evo. with out a mbc i would only see 18PSI spike then taper down to 15. i installed a Dejon tool MBC, i set it so i would spike 20 and hold 18. is that ok with stock tune? or can i go higher? 21Psi to much


on 91 pump gas


thanks

 

lots of guys run 21 stock.

 

I would be very careful turning up the boost without a tune and fuel pump... 20 psi should be fine though.

 

with a tune i could run like 23 right?

 

keep it at 20 also think about the gas you are running. Next you should get a fuel pump and tune

 

not with 91 oct. 21 22 is a safe bet. But I would stick with 21 with a tune just because of your low oct rating

 

Would this be the same for an 06? (MIVEC)

 

06s can run more boost for a given octane, not because of the MIVEC, but because of the coolant passages in the head. I suggest you keep your boost right where it is at 20psi until you have the proper supporting mods like an exhaust to free up the backpressure and a tune to ensure that your AFRs and timing are in order. With a tune on 91oct, you can run 21-22psi very safely on a IX. Some people run 23-24psi on 91oct but with lesser timing and AFRs (generally). You would have to be specifically tuned for that psi, and I would only suggest doing so with a custom tune at that boost level.

Since the OP has an VIII, here are my suggestions:
No tune = 20psi
Base flash = 20-21psi
Custom tune = whatever psi the tuner prefers based on his tuning preferences (21-22psi likely)

A IX can push the envelope further, but I never recommend above 22psi on any Evo without being specifically tuned for that boost level.

 

Plus, you'll probably hit fuel cut with anything more then 20psi until you get tuned.

At least I did. My car was very sensative to the little bit of overboost. Now I run 22psi on 93 all the time with the Dynoflash.

 

thats interesting to know, i was just dynoflashed with a basic tune, and was wondering how much i could run. i figured 22 or more psi with my supporting mods.

 

are you guys wondering if you can spike to 22psi , or hold at 22psi? does that mean its ok to spike to like 24 and hold at 22?

 

No, we always refer to peak boost as the boost setting, which is the spike point.

Donmeca, you mean 22 or less, not 22 or more...

 

I'm running a test pipe, catback, and panel filter and I always run 94. what kind of boost can I run without a tune?

 

warrtalon, so your saying 22psi is the max it can be put up? you mean the max on 93 octane? or can it be set higher with some race gas?

 

Max boost on 93oct, of course. We're talking about daily driving here. On race gas, you can crank it for the most part...

MaxR, 22psi, man. Please read.