Hey, hey all.

After two weeks of waiting, I finally received the letter from HKS USA concerning the HKS SSQ BOV and our Evolutions.

In this letter, I requested information about:

-The proper setting on the BOV.
-The mysterious stalling and bogging issues concerning the valve in recirc or VTA.
-The final word on the fluttering ... normal or not normal.
-Are all HKS SSQ BOV's universal?

Here it is....I hope this helps all of us and puts many rumors to rest concerning the HKS SSQ BOV.

__________________________________________________ _________________


thank you for contacting us regarding your HSK Super Sequential Blow-Off Valve. I hope the following answers your questions.

1.) The blow-off valve should never make any sound while accelerating. The only time it should ever be audible is when it's activated by throttle lifts. There are some cars that will experience a vacuum/pressure/vacuum/pressure change in the manifold under part-throttle lifts. This rapid positive to negative pressure change can cause the valve to open and closed repeatedly, giving you this "fluttering" sound that you described.

2.) Yes, all of the Super Sequential Blow-Off Valves are universal, and all of our vehicle specific kits use the same valve.

3.) If you are recirculation the valve on your EVO and are still experience "stumbling" problems, I would check the installation. Make sure the rubber O-ring is in good condition and is seated properly. The second thing to check is the C-clip (expansion ring). The C-clip has a top and bottom to it. If you look closely one side has a flat surface, and the other side has a round surface, be sure that the flat side goes towards the flange (O-ring side) and the round side towards the valve. You will need C-clip pliers (expansion ring pliers) to do this.

4.) Do not touch the nut on the back of the valve ! (I wish we never put that on there ! ) Adjusting that nut does NOT change the opening rate, efficiency or timing of the valve. HKS valves are "pull-type" valves, meaning they have to "pull" open against the boost for them to open. The more boost you run, the more the boost pushes them closed. Some vehicles have more vacuum than others. If high enough, it is possible for a vehicle's vacuum at idle to accidentally pull the valve open, causing a vacuum leak. It is for this reason that HKS employees an adjustment nut on the back of the valve to allow the spring tension to be adjusted, ensuring that the valve is closed and not leaking while the vehicle is idling. If you have played with this nut, I would suggest getting it back to the middle adjusting point while being VERY careful NOT to let the nut fall out, or turn it too tight as to puncture a hole in the blow -off valve diaphragm. As long as it's not leaking at idle, your fine.

5.) To test your blow-off valve, start the car, let it idle, and open the hood. While looking at the valve, rev the car quickly once and stop. Although no boost is ever generated at idle, this throttle on-off sequence should be enough to engage the blow-off valve, and you should be able to se the valve actually open and then close. If it does not do this, check all that I have mentioned above.

If you are still in need of assistance, please feel free to contact us.

Thanks

Ryan Bates
Sales & Tech
HKS U.S.A., Inc.
(310) 491-3307