this weekend i put on a hks bov and a perrin manuel boost controller. and i set it at 1.55 bar which is right about wheremy stock boost was at in my mr.(i figured if i didnt go much higher that where it was at at stock i couldnt go wrong regardless if my gauge is accurate or not.) but when i was done tuning at my friends house and started my drive home. i starting having problems. i was crusing along is sixth gear(MR) and i wne i am passing traffic sometimes i dont down shift. i just push it to the floor. and the next thing i know is i looked over at my gauge and i am sitting at what appears to be about 1.7-1.8 bars . so needless to say i backed off it. pulled over to the side of the road and turned the boost down to where when i am crusing in sixth and punch it it only goes to that 1.55 bars like it peaks at when it was stock. but when i am running her hard through the gears. i peak at 1.3 bars which is exactly where it would settle too when it was stock after the taper. needless to say. i would be faster stock becasue even though i am tapering down. i still have those few seconds while it is tapering of higher boost. so my question is what can i do to fix this. did we install this part wrong or something. i wont to run 1.55 bars of boost all the time. or am i just going to have to turn it back up to where it is 1.55 when i am running here hard and whn i am crusing just make sure that i dont take the gass pedal to the floor. any help that anyone can provide would be great and i am sorry about all the writing

 

what kind of gas are you using boosting that high?

 

i am using 94 octane gas

i dont know how accurate that 1.55 bars is on my evo. i just know that is what it done bone stock and so i figured i would keep it there for the mauel boost controller. pretty much to sum it up i am tring to get rid of the tapering.

 

Turn up the boost until you blow the head gasket, then back it off a quarter turn...

 

Lol!

 

punctuation is a good thing

 

come on someone has got to be able to help me here. instead of just wise remarks that do nothing for me

 

keep it between 1.4 -1.55 (20-22approx)

in 6th gear its going to peak(spike) at 1.7-1.8..just go to red line, it should drop to 1.5

 

yah that is what it ws doing peaking way up to there. what i wont to know is it safe to drive it like that or should i turn it down. right now i have it turned real low. i was waiting to here some responses on here before i mess with it again. i think right now i am boosting 1.2-1.3 psi. which is lower than where it tapers too when it was stock.

 

also today when i went out for a ride i opened here up a bit and i am still getting this boost taper. is this something that i will always have. it is tapering. just not as much as the stocker but itis there none the less. by the way i have a perrin manuel boost controller

 

I have the Perrin MBC in my '03 and was getting boost taper at first. I noticed the nipples on the MBC are kind of large and the hose they sent me was very thick. I put a small wire tie over the hose on the nipple going to the turbo inlet cause I think I had a small boost leak. It holds steady now with no taper right to redline. Also, Evos usually have higher boost in their last gear, 5th on my '03, 6th on your MR. My car usually runs .1bar more boost in 5th than in any other of my gears. I'd just check and make sure you have no boost leaks by your MBC. Try and maybe use a small wire tie and see if that helps.

 

 

Same thing happens to me, I have a hallman MBC that spikes as high as 1.5 bar @ 4000 rpm in 5th gear but only hits 1.3 bar in 1-4th.