in general i would like to know: What is "best" blow off valve performance wise?

but since i own an Rx7 i should probably ask: What is the "best" blow off valve for my 7 or for any rx7?

if you can answer both questions that would be nice, thx again guys

 

uhh they all work the same. old school blitz bov's suck, i would go with SSQV cuz every ricer loves it and it works great

 

Well most aftermarket Bov function almost the same. It just comes down to two main factors. 1. How much boost you are running, so that you can choose the right Bov, and 2. Basically you want a bov that has the biggest Valve possible to ensure the disposal of unwanted air quickly and also not leak.

 

Greddy....



Period.

 

Best?
Tial 50mm.


-Ted

 

im a fan of the greddy type S....it doesnt have the traditional whoosh, more like a series of high whistles and whoosh....makes it great for an unsuspecting ricer

 

+1 for TiAL. They dont make anything that sucks....

 

Well ebay knockoffs do suck, but otherwise the main thing you have to worry about is your blowoff valve leaking boost. That's usually only a problem if you're running 20+ pounds, and even then you can usually adjust the blowoff valve so it won't leak.

 

wow thx again guys yall rock

 

well i asked this because one of my friends drives an Impreza and u know, those have a 50/50 BOV and when he explained it to me, it sounded like that would be the best type of valve, performance wise anyway, and +1 to the ssqv's and whistle sounds, love em on supras lols i'll think about that Greddy S bov

 

if you can find the discontinued greddy type-r bov you are the man!

 

do rx7 need to recirculate or can we use atmospherics bovs?

 

It is recommended to recirculate if you are running the stock ECU. If you run a atmosheric Bov you will run into rich spot (i.e in between shifts) cuz you are dumping metered air while the computers thinks its being recirculated. Worst case scenerio is that you will have back firing everytime you shift from gear using the stock Ecu.

 

With a Mass airflow setup, the BOV would need to recirc. The air is already registered by the MAF and fuel is accounted for. That is, if you dont minda backfire and possible stall at a stop after boost, then you could go open atmosphere.

 

i didnt read anything already posted but anyway.

1) BOV's dont do anything "performance" related. Sure they allow the turbo to maintain a high rpm between shifts to help reduce the time elapsed in the boost threshold, but no power is gained unless it was causing a problem.

2) if using the AFM then the best choice is the SSQV as it does not open under vacuum.

 

I see a lot of blow of valves such as the ssqv that say 10-25 psi. I am running stock ... like 5 psi boost. Would it be a bad idea to upgrade to an ssqv at this point?

 

An aftermarket BOV is not an "upgrade", at least not until you're making enough boost to make the stock one leak or you're experiencing compressor surge. They don't do squat for performance; most of them are just noise-makers for people who want attention.

 

The only reason mazda installed one was to redeuce noise, so really they aren't required at all...

great thread on running no BOV's on AusRotary which has me convinced.. http://www.ausrotary.com/viewtopic.php?t=17113

both scientific evidence and experience in that thread which shows the bov to be useless...

 

stupid question..
what does recirculating and not recirculating mean?
are you talking about the tip (greddy rs is the big blue or purple thing on the end)
or the little hose on the top??
im just wondering....

 

Actually that would be every manufacturer in the last 20 years.

Great thread. I thought I was the only one who realised the only people telling you BOV's are needed are the people making money from them.

Years ago I read a magazine article about upgrading the stock BOV on a Ford Sierra RS Cosworth. They used a pressure transducer and a high-speed logger to measure manifold pressure , and it showed that after gearshifts pressure built up in the manifold quicker with the stock BOV than the not-cheap "upgrade". Oops...

All factory BOV's vent back into the turbo's intake, i.e. the air is reciculated. Most (but not all) aftermarket ones are open-vented, i.e. the air is vented to atmosphere instead of being reticulated.

 

i got the ssqv and love it. great sound.

 

hands down if u are blowing off to atmosphere there is not "performance bov"
if u are running a bypass valve (recirc back into the front of the compressor) go with a RFL-H34 it works the same and sounds the same as a rfl if u want to blow to atmosphere but instad of a trumpet it has a nose on it so u can connect a hose and recirc it.

hands down the rfl line is one if not THE fastest at expelling air in the charged system.

 

and you know this since you have a turbo car?^^