Im looking into alky kits and i was wondering what's the highest boost i can run with my stock IX diverter valve. Will it hold up to 30 psi?

 

I went to the local track one night (SIR, Tucson) with the stock BOV on the Evo 9. I put 2 gallons of 104 Sunoco to an already exiting 4 gallons of 91oct with the boost adjusted to 27PSI.

After I finished from running the car at the track I was driving on the HWY. I turned the boost up to 27psi (peak)and the car started leaking at 27psi(peak) while driving in 5th gear pedal to the floor at around 60-70mph. The BOV will open and close in a vibrations mode while the boost gauge would flutuate slightly +/- 1psi while making the psssshhhhhh noise. My boost gauge also records boost and plays it back(Defi plus controller)

I can only speak for myself and my car, I don't know what others can run, I am just saying what I have seen on my Evo 9. I hope that helps you

Mods on the Evo 9:
3"TB, Dynoflash mail-in,Buschur Cone,Unos MBC

Carlos

 

Carlos, if it clears after about 4000 or so RPM I get the same (if I run that sort of boost level) and it is compressor surge.

 

jcsbanks,


My observation is that it holds the 27psi most of the time while in tall gears only at a midrange rpms (4000rpm would be appropiate to say on this case). Anything much higher rpms wise and the boost vanishes, anything much less and you can build enough boost.

I am sure people might have their reservations believing me but it is OK. I live in the desert and I go testing my cars all the time, I record everything, weight, temp, boost and other factors.

I know that not many people ran 27psi without any kind of methanol/alcohol but I ran 27psi peak on a race gas mixture and the car held the boost in 5th gear no problem for a few seconds.

JCSbanks, what part of UK are you from?, I raced at Santa Pod, it is a nice place there.

Carlos

 

mr valve starts to leak @22-24 psi (pressured tested on a bench , not on the car) , you can run more psi but it leaks...

 

well that sucks :/

Anyone try crushing it?

 

^----one guy did (search the dynoflash-forms) and he talked about the driveablety getting worse

Look into to a Forge RS bov there spoes to be the "bees-knees" when running high psi

 

so whats the best diverter valve for evo 8, holding like 27psi and not costing tons of money??

i was thinking bout getting oem ix valve for my evo but if it leaks at like 24psi its pointless