well, it was a try, it doesnt work now, so i was trying to help you with your problem, i modify everything i own to work for me. ive increased tension on bov's before, and have also cut coils before, but not on an hks unit. so good luck and dont try anything new?
my cam timing was on, but my motor was very tired, valves didnt pass pressure test when i pulled the head, rings and cyl were toast, but it still made boost and hauled a$$ when i wanted to (but filled up my catch can to fast).
taft stage 2. 5spd
so how safe is it to cut a coil off the spring? will it relieve pressure just as good?
so i messed with my adj cam sprocket, and managed to get 17" out of it. the bov seems just a bit better, but not great. car feels awesome when driving out of boost, way less effort to get going. so it probably was off a tooth, i want to try cutting off a coil but not sure if there are any negative effects.
I've seen more aggressive cams pulling 14-15" of vac. You say you have an adjustable cam gear, have you degreed the cam to see if the marks on it are correct? Some of them were built out of alignment so you really have to know what is going on with them.
i get 18 inches of vac on a taft S3 cam. its currently advanced 2 degrees
nope.Originally Posted by cordes
You may want to look into it then.
wow, i guess i would really try to get your cam timing on track first, get the vacuum up, i wouldnt modify your bov if you dont have to, i just assumed your setup was ok? i have removed coils from 2 type-s valves, but i havent opened and hks before. at 18" of vacuum that bov should work fine (or at least better), i think you should be able to pull 20" no problem if you have mostly stock parts and a motor thats not to tired. check your ignition timing also, it cant hurt?
DO NOT modify the spring in the BOV. Cutting a spring would not change the opening pressure; it would simply shorten the spring and perhaps prevent the valve from sealing under boost. The newer HKS SQVs are supposed to be self-adjusting. That being said, I had difficulties with my HKS working because I have an automatic car; in gear I only get about 11" of vacuum in drive. I have large cams, and I still get 17" of vacuum with the car in park/neutral.
Vince 2011 Ford Mustang 5.0 I miss my Plymouth Duster. :(
the hks valve is designed to seal with boost pressure, not spring pressure, the spring is only there to keep the valve shut at idle. and yes, cutting the spring will change pressure, but it may increase the pressure. i metioned in my first post to look for a softer spring, maybe the hks unit has shims in it, i dont know... he wont either til he opens it up...
i did open it. didnt see any shims
The HKS unit should not have shims in it in the first place. The SQV is "supposed" to work at all boost levels without shims or adjustment.
If you're confident the BOV is functioning correctly, there's something else going on. But I'm going to tell you that the EXACT same thing was happening to me when I had an HKS SQV, and putting a TiAL "Q" BOV in instead fixed all of my issues.
Vince 2011 Ford Mustang 5.0 I miss my Plymouth Duster. :(
Ya, I've been wanting a Tial bov anyways, to match my wastegate.
well, you got me dusty, it does work at all boost levels, just not all vacuum levels. the fix will be a new bov that is adjustable to work at lower vac. levels.
csx153, id try to get your vac levels as high as possible first with correct cam and ign. timing, make sure there is no other vac leaks, you could possibly need a valve job, but it would suck to pull your top end down because your bov doesnt work. so have fun with a tial bov, they are an extremely nice (quality machined) and well enginered piece of equipment.
But it does work, just not from 0-3ish boost ha.
ive looked them up on you tube before (hks) they all seam to do this pretty bad, i couldnt get my friends subaru with an hks not to do it either (but he had big cams), so i guess its just an inherant fault with these bov's. they are meant to HOLD boost, i guess they just dont release well?
The old style one which I have never has any surge on any car I have had it on.
One thought for the OP though. How do you have it mounted? I have mine on an HKS flange which is welded to the 2.5" pipe.
same, right before the tb
Dang. That should be about the easiest spot for it to vent too since there is less to release after the pressure drop caused by the IC.
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