Reason not to own a cheap bov, Evo 8 dyno runs with Greddy RS
 

Interesting dyno runs from the past weekend. Many probably understand or already know this but don't cheap out on a bov on a turbo car. Your probably leaving a good bit of WHP on the table as well as putting extra stress on the turbo. BOOST LEAK TEST your car before putting it on the dyno or before street tuning, or when you plan to up the boost.
http://www.youtube.com/watch?v=KhzxpN8SLgQ

This Evo 8 was put on the dynojet for baseline numbers and we quickly realized the bov was leaking. The greddy RS has the "soft/hard" adjustment on the top so we tightened it up between the next 3 runs and ended up gaining 18whp & 30ftlbs with it still leaking. The car should have easily made 300whp the way it sat.

The owner went & purchased a upgraded upper ic pipe with Tial QR bov to fix the issue the next day. Hopefully have the car back on the dyno soon for a re-tune.

If this legit Greddy RS bov can leak this bad it makes me wonder how bad the ebay bov's are. Not saying every Greddy is bad but in this case it just shows that you should pick your parts wisely.

Thats pretty cool.

Talk about slow spool! POS Greddy BOV!

Exactly! Evo people especially can seee & understand how bad it was.

With almost 100 views and only 2 comments i guess a lot of people are a little bitter about what bov they own lol jk

In all fairness to Greddy, the RS bov is not designed for 20psi+. The RS, like a lot of other valves on the market are there for the noise and are not intended to be used on high boost/race applications. The Tial Q or 50mm is hands down the valve to have if you plan on running higher boost levels. The SSQV is also a very good valve and I would say is only second to the Q for holding a lot a boost. Either of those would be my suggestion for most street cars that see more than 20psi.

I had my metal IX bov on my car with an FP Black turbo boosting 28psi. I reviewed the logs with petey turbo and he felt that the loads didn't look right so he told me to buy the new tial QR. Honest to god, i never touched my Hallman MBC. installed the new TiAL and I hit 41psi on 309!!! I was ****ting my pants thinking i was gonna blow the motor. Had to turn it way down to get back to 28psi. Just wanted to throw that out there.

I've never been a fan of the SSQV myself, and i kno of a few locals who had real ones that leaked. The tial is hands down the best, which by now i would think would people would realize especially with the choice for the QR to re-circ it.

I just see a flaw in selling the greddy to not handle 20+ psi when they make it with the adjustment on top anyway plus there marketing it to evo/subarus etc which are running 18psi from the factory and with intake exhaust are at 20 anyway. Most who buy them are looking for the noise anyway but i'd expect it to be somewhat reliable at 20psi. This particular Evo started at 20psi and we turned the boost up then realized it had an issue, so it wasn't like the owner was shooting to run 25+psi.

When it comes to buying a BOV, TiAL is the only one. There's really no guess work. Unless you're on a budget and can't afford one then you make do with what you can.

Chip, how did you figure out the RS was leaking? I have boost leak tested to 25psi on my RS and haven't found a leak. My adjustment screw is set in the middle also. If you have another way of checking I'm interested.

I guess I'll be buying a tial bov in the summer haha. I already run a tial 44mm wastegate so might as well match up the BOV

K.P. Tuning (karl) which I'm pretty sure you know was driving/datalogging. After the first pull and watching the boost gauge you could really see something was wrong. I figured it was some boost leaks else where but the Evo owner just tightened the clamps (front bumper was off in the shop) & went over things seconds before strapping the car down, so i knew it could only be a few other possibilities. Immediately Karl was like have you ever messed with the bov & the owner said no. We grabbed some tools tightened it & gained some hp so we figured we were onto something. Tightened again for next pull and made more hp, then tightened again for the final pull & made the power you see. The Run were i videoed the gauges was actually the last run so you can see that it is still leaking. I think it was a hunch & just knowing that the greddy's notoriously leak.

I'm really not bashing Greddy as i ran the Type-S without problems but just wanted people to see what could be there. I don't expect or beleive everyone out there is leaking or is bad & it looks like yours has been good to you. There may also be some other leaks on this Evo (TB seals, upper pipe somewhere, etc) since you obviously can't visually see them on the dyno so this isn't a end all test but something to think of.

Basically i should of also stated in the original post to BOOST LEAK test your stuff before putting your car on the dyno in addition to not cheap out of crucial parts.

Definitely interesting. I know your not bashing just making a PSA, haha. I had the Type-S before also, and picked up the RS. I haven't had any real issues, other than I think I may actually have it set to tight with alot of flutter on 4th/5th gear light throttle. But I guess that's better than boost leaks.

+1 for the TIAL BOV's there really isnt any comparison to them IMHO. With the different springs that you can swap in and out of them in under 5 minutes, is rediculous. I was running one of those stupid SSQV's and my tuner said to get the Tial. Put in on the car, and she made more power with .5lbs less boost and earlier. The SSQV's and especialy the APS BOV's leak like a mutha effer!. I say if your on a budget, spend the money on the right parts including the TIAL. I would even say the New line synapse has now is actually really good. my buddy has one on his 06 STi with a 20G and it works flawlessly and has the adjustment for soft or hard.

I have never experienced or heard a bad thing about any Tial products. I have had good luck with the Synapse stuff as well on higher boost apps.

I love my SSQV. It's a pull type, so odds of it leaking is very low...

I agree with that since it's been the standard thought for a long time but i know a few personal friends not friend of friend story online BS that actually had them leak and cause issues. Both were replaced with Tials, but no back to back info or dyno runs to provide.

tial on evo ftw


thread/

would DVs do the same if they are a piston based DV?

i have a forge splitter set to full recirc and im never quite sure if i have it set right :/

anyone anytime can do a leak test to see if their system is leaking...

very easy to do.. and can save you lots of headaches.

go buy a coupler, pvc cap and a tire air valve...

boom leak tester

link for those who dont know
http://www.youtube.com/watch?v=atretf9u-Mc

Yes!

Actually, on my turboxs, the tension of the spring seemed weak, idk what its supposed to hold, but i got afroclever and tossed some nickels down in the piston to put extra tension on the spring and weight the piston down.

its holding boost like a champ and doesnt really fade off too much