Does anyone happen to know how much boost a stock Evolution 9 Blow off valve can handle?

The reason i ask is because i am taking my Evo 8 to the track next weekend and i have a stock Evo 9 bov on my car, i usually run 25 psi on race gas and was wondering if it can hold that boost. Before i ran a Forge RS BOV but they dont hold boost very well. so i am going to try my Evo 9 BOV.

 

it seems 25/26 is as far as you want to push them before they start to leak

 

you must not have had the bov adusted very well for it(the rs forge) to not hold boost very well. i put 25 psi to it daily with not problems

 

I run 25.5 lbs on race fuel autocrossing with the 9 bov and it works flawless with all the on/off throttle that put it through. You should be fine.

 

+1 from all that I read, you should be fine at 25...

 

Let us know how it goes

 

26, some will work higher than this, some may work a little lower. Not all are equally the same.,

 

I have tested three EVO9/EVO8 MR BOV the other weekend with modvp. All three held boost up to 30psi +/- the error of the gauge while pressure (boost) is applied.

They did differ in how they held the boost once pressure generation stopped.
One was able to hold about 21psi and bleed down to 0psi in about 30 secs and the other two would only hold 15spi and bleed to 0psi in about 30 secs.

The first one (that held most boost once pressure generation stopped) was purchased from gruppe-s before the EVO 9's were out. The second one is from an '06 EVO-9. The third was purchased from gruppe-s last week. All 3 had the same part number.

 

We also tested the plastic BOV from the 03-05 Evo's. It held boost up to 23-24 and unlike the MR BOV's, it bled down to 0 psi almost immediately once the pressure source was removed.

The MR bov is the *****, all 3 performed well. To reiterate, they all held to exactly 30 psi.

 

Most 9's diverter valves should hold till 25-26 but all are not created equal.

 

well thank you all for your replies. I will do a boost leak test tomorrow and see if i get any leaks, then at the track i will bump the boost to 25 psi. i will let you all know how it worked out for me. thank you again

 

Ive gone as high as 28psi. Didn't seem like it was leaking

 

25psi no problem

 

Im boosting 23 PSI on my OEM EVO MR IX BOV with no issues.

 

yes, 25 or 26 is the max, they are right. I wondered the same thing and had to ask turbotrix