Tantwoforty

Hello people. im doing a KA-T build and im about at that point where im looking into blow off valves.

i have done a bit of looking around and i noticed zilvia hasn't had a bov thread in a long time, and the ones i did find were not very informative.
so i thought we could compile some information and options and experiences so people would have a information base to use to help decide witch blow off valve is the best choice for them.
For my specific set up, i want to run atmospheric blow off. i would like to mount the bov in such a place where reserc would be possible in the future when the coolness of my first turbo car sounding cool wares off, call me lame... i dont give a damn.

Moving on, im open to anyone giving me more to add to this main post, so please feel free to have me add things.

What i would like is for you to post what bov your using now, how you feel about it, dose it leak? dose it flutter? dose it cause surging? how dose ti sound? is it too loud? too quite?

What other bov's have you used or do you have experience with?

What bov would you recommend?

How is your throttle response?

Are you getting any lag from it, dose it open slow and allow a bit of flutter?

Are you stalling or feeling bog on deceleration?

list your engine, turbo, bov, bov location, reserc, recerc location, charge pipe diameter, tune.. and anything else that you think we should know.

Picking the right bov is very important, venting too much air is bad, venting it too late is bad. to soon is bad. too little is bad, too long is bad, too short is bad.. the bov can cause lots of problems aswell, boost leaks, loss in power, stalling ect..

There are videos on you tube of people installing bov's and gaining 25+hp/tq

Here are some of the top BOV's i see today...

Synapse Synchronic Blow Off Valve Pull Type $209.95


From Frsport.com
"Synapse SB001 Blow Off Valve is a quick acting pull-type relief valve. The patented design uses a multi-tier piston actuator that self centers under pressure and seal tightly as boost increases. This design was created to greatly reduce or prevent compressor surge and boost leak at critical moments. This BOV is universal and can be fitted in many vehicle applications by utilizing different weld-on flanges. Synapse offers a variety of flanges to adapt into your vehicle when you already have a BOV flange welded such as Greddy Type R/S/RS, HKS Racing, HKS Racing Type II, HKS SSQV, Tial 50mm, Mitsubishi flange, and VW / Audi."


HKS Super Sequential Blow Off Valve SSQV3 -$229.95


From Frsport.com
"HKS new generation super sequential blow-off valve is here, dubbed The Super SQV 3. This blow off valve features nickel-plated, die-cast metal secondary valve, which is swaged to the primary valve. A stainless steel C-Clip is used for increase sealing and durability. The new design incorporates a holographic HKS logo on the back of the valve along with HKS logos cast onto the body structure for authenticity. Don't be fooled with the fake ones floating around on the internet. FRSport only carries authentic parts straight from the manufacturer.

The Super SQV 3 utilizes the same mounting flanges as previous generation SSQV's to assure compatibililty with all HKS SSQV optional hardware, including recirculation fittings and recirculation kits. Replacing your old SSQV has never been easier! This blow-off valve is sure to wow people eye's when shown during meets or even at the race track. It performs well and looks sexy in your engine bay!"

Tial Sport Q BOV Blow Off $254.95


From Frsport.com
"Tial Sport's new Q Blow Off Valve is a newer version of the original 50mm BOV. Featuring an improved design through countless hours of R&D, Tial was able to increase 60% more flow than the original design. This is now believed to be the highest flowing on the market. Made from 6061 aluminum alloy with a 50.5mm valve and V-band clamp mounting, this new version just got better.

Springs available:
Pink -11 PSI (-22 in/HG)
Un-painted -10 PSI (-20 in/HG)
White -8 PSI (-16 in/HG)
Black -6 PSI (-12 in/HG)"

Greddy Type RZ Limited Edition Blow Off Valve $237.95 ( this is a SE of the type RS but the RS diddnt have a price)


From Frsport.com
"The Greddy Type RZ is based off Greddy's popular Type-RS valve with a stealthier, black/gunmetal look. The Type-RZ has adjustable dual springs, excellent valve to diaphram ratio, and the ability to blow off to atmosphere or re-routed back into the intake via a recirculation fitting. Recommended for 100-400HP range."

From the RS
" was made to be the most reliable blow off valve system available to the market. This Blow Off Valve has a new style featuring great response with a big 40mm valve diameter for maximum flow. The Type-RS blow off valve is CNC machined to have 8 discharge ports that draw in the surrounding air to amplify the blow-off sound. "

Thats most of the major name brand choices there are. there are variations of these bov's in slight model changes ect.
there are also knock offs of all of these except the synapse.

If you are running a knock off ebay one, post up here. tell us how its working and tell us the story. were all so scared to use ebay stuff, and in my time with a hks knockoff it was all bad, but its still nice to have some feedback on things.

Of if you run no bov, tell us about your turbo and your throttle response.. have you killed a turbo? have you checked for more shaft play?

Hopefully we can get a good amount of people to post here and eventually we will have most available bov's written up here in one easy place.
Please keep the thread clean dont post useless crap, take it to pm please

annnd go..

karl wasabi

Synapse... done and done...

Synchronic Blow Off Valve

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Tantwoforty

Yea I just veged on like 2 hrs of videos and such from them...
that looks like it's going to be my choice.

zerodameaon

I liked my RZ before it was stolen, simple to set up and easy to dial out surge.

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karl wasabi

haha. I did the same. I don't want a blow off valve for cool sounds, I want it to protect my turbo and improve drive-ability. A cool sound is just a bonus.

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TheRealSy90

THE dopest blow off valve available.

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ruthlessef-9

Greddy type-R

ixfxi

i think this, much like the oil catch can thread, is over-hyped bullshit

a BOV is not science, its a fucking pressure relief valve. based on X amount of pressure it releases X amount of air.

i have an old school greddy, fuck if i remember what type it is (type s?).. it was purple till i blasted it, now its peened silver. all i know is one thing, recirculate. thats what im doing with it, recirculating. if you're venting then you're wasting and losing air.

some people dont care about wasting that air, i personally think its beneficial.

one thing that caught my attention were those new efr turbos with built in BOV. i must admit that these sounded interesting, though i have not seen much discussion on the forum about these setups.

pandaroo

i have heard people say bovs aren't needed and have seen videos of big name sponsored cars just straight surging. honestly i rather not have just because its one more thing i have to buy and deal with ect, but will run if necessary. whats you guys opinion on this?

docslide

Turbo Surge=
But its hard on the turbos as i understand.
if your ever around some of the cummins/powerstroke/Duramax guys and they are pushing 40+psi with no bov. but their turbos can take the abuse.

lflkajfj12123

No BOV man

1337

I always heard that the Greddy-rz leaks. my friend has one on his car and it leaks baddddddd

DrIvEsldEwAyS

hks ssq version 1...had it for 5-6 years now with everything from a t25 to my current gt35r and no problems.

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-1990 240sx hatch sr20det- gt35r, blah blah blah

240zach

type s ftw!

1337

tabasco122

i have an hks sswhatever. it doesnt leak or surge, and it has no adjustment. venting to atmosphere currently.

$nicklefritz

hks ssq version 3 , switching to a tial bov , i got an insane amount of surge

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VUIL-GEBOOSTED GANG$TA

Jakob

borg warner efr, bov integrated in the compressor housing

29psiHybrid

Diesels don't have throttle bodies to 'stop' the air when they let off...

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Robbie S.

Quail

All the factory equipped CA18 S13s over here came with no recirc. They don't munch turbos (just big-ends )

Most people I know with SRs don't run anything at all. May reduce the overall life of the turbo, but not sure rest of my car will be up to 200,000 miles anyway.

My BOV only opens at high boost (not deliberate), so I get both stall and VTA dump, depending on how hard I'm driving.

Uprated recirced BOV will always give the best performance. VTA and nothing at all will cause overfuelling on overrun, but meh, no biggie in my eyes.

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MrFairlady

I'm in for this.
My Nissan (GT2860), since I switched to PBMAX HMIC i have not been using a BoV.(I have a HKS that was on it for my old FMIC VTA) Had no issues what so ever (stalling,tune etc) on a Enthaply tuned ECU.PBM says Blow off valve is not needed.

My 1JZ singled turbo car I have the Synapse (due to Expense of Turbo). It really does its Job.Even on Slight throttle Lift with Light accel you can hear it.
I heard alot of surge On my Nissan with HKS.
may not run a BOV still with my New Tomei ARMS/PE1420 turbo I'm planning on getting but Thats some expensive Shit to Risk damaging.

if you look on any Drift tengoku,HyperRev,etc. No BOV's at all if any.

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z-tERty-2

Om1kron

I ran my car without a blow off valve attached for the last year and some change. A t25 turbo don't need it.

Ball bearing I would probably run one due to the chra cartridge. when you get that surge you risk twisting the rod that holes the fins together on both ends like licorice. That and it's really hard on the oil seals.

My turbo runs like a champ, but the oil seals are toast, it's peeing oil on my heat shield now and I need to rebuild it.

Borg Warner EFR turbo will replace my setup and rid me of wastegate and bov shit as it's all integrated to the turbo.

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Wayne

tinys s14

i recommended tial..... ran it on a stock sr never had problems never leaked

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OLDSCHOOLRICE

Complete/Proper recirc set-up(valve, hotpipe and hoses) cost me ~$200. Cheaper than any of the blow-off valves alone listed above, and my car performs much nicer than with the previous set-up.

Engine is a SR running a MAF. I was previously running a ARC BOV vented to atmosphere. Sounded cool, but thats about it. Compressor surge at less than 5lbs boost(supposedly no big deal). The biggest problem I had was the SEVERE bucking I had when letting off of the throttle at higher RPM's. It really sucked when driving aggressively, or even when just trying to merge onto the freeway. Stumbled at idle when cold.

New Set-up:
Forge 007 diverter valve(popular in the european car world) $135 new(I got a new one on craigslist for $90)
Blank hotpipe and silicone couplers $80
1" OD aluminum piping bead rolled and welded on to the hotpipe $20
Random radiator hose with 1"ID $10

Still have a "cool" sound when recirculating at boost above ~5lbs.(don't really care though). No more stumbling at idle when cold. No surging. Most importantly NO MORE BUCKING when letting off of the throttle. Drivability when driving aggressively is worlds better. I can now come out of a turn, in a certain gear, and hold that gear into the next turn if I want to, without having to upshift in between to avoid the bucking.

Main point I'm trying to get out there, is that properly recirculating a MAF system drastically improves driveability.

ixfxi

lots of things arent needed, but they were created because they serve a purpose. it should be obvious that manufacturers go through the trouble and expense of manufacturing and including these items (factory installed) for a reason.


unless you have a stand alone with a map setup that doesnt need that air. but from what i gather amongst the porsche community, recirc'ing that air gives you more air which allows for more fuel which allows for more power. tossing that air away is rather stupid.

the other debate we should be discussing, is which side is it better to vent, hot or cold? i believe s13 vented (recirced) hot side while s14 vented (recirced) cold side. i am leaning towards taking the cold (intercooled) air and tossing it back into the intake


wayne, do they offer a replacement EFR turbo that fits the stock t25 sr manifold? i wonder what the costs are.

wow, you just answered my question in another thread. welp, staying s15 turbo for me.

slow40sx

i loooooooove ball bearing compressor surge its fantastic but if i had to get a bov i would definitely get a Greddy Type R

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pinkarrowsnow

tial. every crazy drag racing high hp race car uses them for a reason. its quality ive had one on a build ka it was probably the best thing i ever put on that setup helped turbo spool so much made the car so much better to drive. On my sr i have a blitz now and it works just fine also.

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Teddy

I will definitely not be running a BOV on my track car, and probably a recirculated Blitz or Greddy one on my S13.

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smelly240

i havent run a blowoff valve for the better part of a decade...

turbo doesnt complain about it.

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HREs on a S13 - check, 6262 - check, Girlfriend.... - nope

smelly240

crazy HP drag racing cars dont even use a bov. And for those of you that see a wastegate on drag cars charge piping - its because they open the wg with compressed air so the turbo can free spin and then its released and whoopee we have boost...

compressed air is used for that (with a 3 port vented solenoid) - and also used to hold wastegates on the manifold shut so exhaust doesnt shove it open early.

tial makes good parts - but its just another part to fail/leak if youre abusing a car.

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HREs on a S13 - check, 6262 - check, Girlfriend.... - nope