Try a Synapse Engineering BOV at http://www.synapseengineering.com/. The is NO DIAPHRAM and is pressure tested to 100psi. My friend running 40psi on his 1g talon is using just one with no problems what so ever.

If you goto youtube and watch it its just amazing at how fast it reacts and no matter how the throttle is used it whistles NOT FLUTTERS!!!

 

Sorry i didnt understand. The HKS racing does fine partial throttle as well. We've gone through plenty of Mtn. runs that required to run partial throttle of course and had no surging.

 

here a video of the last track event we went to you can here the blow off valve surging when i am trying to modulate the throttle
http://www.youtube.com/watch?v=cfoX8-3FjuY

 

those videos are RIGGED like no other...
these will give you an idea of partial boost/low throttle/high boost/WOT reactions of the TiAL

http://youtube.com/watch?v=8-JTfgpFKrM

check that out, then all the response vids

 

I like them, but I wouldnt put them on a MAF car. I had the version 1 on my turbo Miata and it stalled every time. Ended up going right back to the forge unit.

 

so what spring rate would recommend for the evo that boost 24psi daily for the tial 50mm bov ????

 

what is your engine idle vacuum when the car is warm? exact reading please

 

i think it around 725 or 800 warm up at idle and the vacuum is around -8psi

 

-8psi = -16.2in/hg = -9psi spring

 

what the downside of using the stiff spring Tial has a 12psi spring. so in theory by using an incorrect spring can cause compressor surge or a delay in valve opening??

 

correct, too stiff = it will only crack open or open very slow causing surge (if you look at the synapse vids it's a perfect example of what not to do, he uses a spring that is too stiff for the vacuum the car is producing)

 

so let lets say my version 2 hks ssqv is using to stiff of a spring that why it surgin at times but by using to soft of a spring the BOV might not hold all the boost right for hi boosting cars ?!

 

Just use your stock BOV. It has no "rating," but it does start to open around 25psi, however, it's nothing that will affect you noticeably, and it will have wonderful part-throttle response.

 

yeah stock is nice but i am planning to find a blow off valve that you can use with stock turbo and an upgraded turbo for the future so you don't have to buy two or three different blow off valves. But i do agree with Warrtalon that stock is good enough for 25psi

 

that i can't tell you, i'm not familiar with that bov, but i 'think' it has an adjustment screw?

as far as i know, ours is the only BOV you adjust with a different spring.