Old 02-08-2015, 10:50 PM
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Jackal Jackal is offline
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Location: Winnipeg, Manitoba ,Canada
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Default HKS BOV Info

O.K I am looking for any info on HKS IV Super Sequential Blow off Valve specific model made for Ralliart and Evo MR. But would like to hear about anyone's experience troubleshooting, disassembly, inspection etc.. on any HKS BOV.

In a nutshell I figured since mine has been on my car almost 6 years I would disassemble clean and rebuild it. What I learned.

Important info. 1. No rebuild kit available to fully take HKS fully apart. There seems there was at one point for certain models,but no longer available.

2. That pieces inside main center housing are pressed on. There is no threading on shaft or snap ring etc.. on diaphragm or piston assembly.

3. Basically you can take output side apart to change from vent to air to full re circulation or swap Centre pieces to make different sounds if vta.
Or take diaphragm side apart if you absolutely have to change springs but I would warn against it.

4. Found from my attempt to take apart main body piston assembly apart I now have shaft end play. I will be putting it back together once I get the housing pieces back from powder coating but I'm afraid that 6 years of use along with my attempt to disassemble something not made to take back apart will cause me to have to buy a new BOV.

Lesson learned. When you Google How to disassemble HKS BOV and the only thing to really come up is a You Tube video where even a dumb punk warns you not to take apart the rest of it other than the safe output side where you can change the sound making rings or VTA adaptor.

Worst case scenario, if I rebuild and it no longer works properly, then what BOV should I buy considering I will be upgrading to a bigger than stock Evo X Turbo? Boost Max will most likely peek between 19 and 24 so nothing too crazy.
Yes I have Goggled, searched multiple times on multiple sites and most people are telling me to go with

synapse DV (cause it's the best for performance) and I will set it up to recirculate 100%. Excerpt from their manual:

Synchronic DV has the ability to vent to atmosphere for MAF
vehicles by staying normally closed under operating vacuum.
As you can see from the previous chart, there is only one
recommended configuration that will allow this setup. You will have
to apply nearly maximum spring pre-load adjustment (Clockwise)
until the valve is closed under idle conditions. Although, you
CaN, vent a MAF car to atmosphere, you SHOULD recirculate
for maximum performance. It should also be noted that applying
maximum pre-load, slows down the response of the valve. This
setup is a mere compromise for customers that seek to maximize
the audible discharge of their BOV, in exchange for maximum
performance. Use at your own discretion

Would like to hear everyone's opinion, but keep this in mind. I am going to be turning 50 in a few years, not 19. So regardless of type or brand I will be recirculating 100% for max performance. No need for funny whoosh noises. Thanking you in advance for any light you might be able to shed on this.
Instagram #Evosoulralliart 1/4 mile @ 12.7 seconds @ 104 MPH.
Too fricken much to list. Check out my build thread

Last edited by Jackal; 02-09-2015 at 06:23 AM.
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Old 02-09-2015, 05:58 PM
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NFSLancerRA NFSLancerRA is offline
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Location: Durham/Orlando
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The Synapse Synchronic is a GREAT BPV. The only two BPV's that I would consider are the Synchronic and the TiAL QR (which I have and love). You cannot go wrong with either one. But, based on your 1/4-mile, you would probably do just fine with a crushed Evo stocker.
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Old 02-09-2015, 09:30 PM
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iralli_iskustvo iralli_iskustvo is offline
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I would recommend Turbosmart dual port bov. Works great, holds pressure very well. Tial QR would be my future upgrade.
RA - Built head - Built SST - ID1000cc - GTX3576R - GSC S2 cams - GSC beehives/Ti retainers - Timing Chain kit - ARP head studs - AMS fuel rail - AMS Widemouth dp - TurboXS exhaust - DrivenFab oil catch can - MAP oil pan - MAP cast manifold - AEM wideband - COBB 3 port EBCS - Tial QRJ - Sakura 3.5 intake - Kozmic Walbro 450 fuel pump - Depo Racing fmic/licp - TS engine/exhaust mounts - Cusco bar - D2 RS coil - Megan Racing control arms/toe - Whiteline sway bars - Brembo 6 piston

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Old 02-10-2015, 06:34 PM
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Markspd6 Markspd6 is offline
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Location: CYPRESS,CA
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Never like the Hks for this reason, its all cheap plastic inside, id go with almost any other over the HKS, ive had at least 7/8 diff ones on my mazda, all woked about the same, TS was the best built and highest quality..
Ralliart/EVO rear fender rolls and tab grinding $100, guaranteed fitment(when possible, you should always do the fitment research first)

minimal partial rolls $60(no tab grinding)

So cal fender roller rental $10 per day(3 day min) with $200 cash deposit. Includes Eastwood fender roller, heat gun and heavyweight carry bag.
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Old 02-11-2015, 07:05 PM
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Jackal Jackal is offline
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Location: Winnipeg, Manitoba ,Canada
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Thanks for the input Gentlemen!
Instagram #Evosoulralliart 1/4 mile @ 12.7 seconds @ 104 MPH.
Too fricken much to list. Check out my build thread
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