Wow, talk about a POS. My factory plastic BOV was leaking profusely. I had my HKS EVC set at a duty cycle of 80 to atain 19.5 PSI. I install the new BOV and went for a test drive. Car kept cutting out. Well DUH, The EVC was dumping pressure cause my car was over boosting!!! . Turned the EVC down to 62 and BAM. Done deal. Thats how much i had the EVC turned up to compensate for the leaking. Moral of the story, is buy a UTEC!!! But before you install it and start tuning, make sure your car is in good working order, or you will spend alot of time chasing your tune..... Later, gotta go re-tune!!!

 

Ray,
Glad to see that the upgraded BOV is working out for you. Did you get the RBV-h34? That's the one we recommend for the EVO.

We had the same thing happen to a customer the other day. We installed an Rbv-H24 and ended up having the car over-boost.

With any luck we’ll have new software to you very soon that eliminates the fuel cut so you can enjoy your extra boost pressure.

-Nathan
www.turboxs.com

 

nmyeti:

I got the same BOV, but I am wondering how many chip(spacer,shim) I should put inside the BOV ?? I am running 21 psi now. thanks

 

H34 leaks like a *****. Repalcing mine with Greddy Type S on Monday. Really sucks. blah!

 

With the soft spring installed we typically use 4 to 6 washers.

It should be noted that the H34 does have a small bit of leak down due to the nature of a metal to metal seal. When comparing the leak to the flow rates of even the smallest turbocharger you'd run into its not significant. If you are comparing it to the flow rate of a hand pump, then it is difficult for the hand pump to overcome the leak.

Think of it this way. 1 CFM to a 600cfm turbocharger is nothing, but 1cfm to a 2cfm pump becomes substantial.

We use the RBV-H34 and BOV-h-RFL valves under high boost conditions (35+psi) that will turn a diaphragm valve to mush.

 

it says in the instructions that the BOV is designed to be open at idle. I dont understand that one, also how do you know when you are shimmed right?? I hear a whistle at 75 mph cruise. I give it a bit of gas and it seals or i let off and it seals. I only have 1 shim in. Ill add 3 more in the morning......RRR

 

For the EVO you are better off running the valve a bit stiffer. I want the RBV-h34 to be fully closed at idle when it is installed on an EVO.

Go ahead and add in those shims.

-Nathan

 

I have 5 shims in mine. I tuned it for the best response while not running into compressor surge during daily driving. I had six in there and if you were just controlling your speed while driving and lifted on the throttle a little I would get a momentary surge. Put 5 shims in and it is perfect. 4 also works pretty decent, but 5 is better in my opinion and for my car.

 

So the Type H R34 is a good valve for the EVO? Will I need a special mounting kit for it? Please tell me what these shims are and how they work.
Thanks!

 

The RBV-h34 works very well for the EVO8. The valve has a spring inside of the piston and we use packing washers to adjust the spring pressure.

 

i have tried every combination of washers and 5 works best. I have no issues with mine....Works great and looks even better. I did have to get a longer hose comming from the intake to the BOV. The typhoon intake is a little different than stock. But i will reinstall the stock intake Sunday. The aftermarket intakes are sending us backwards in power......RRR