BOV's

[jimnielsen]

Anyone got any pics of how they have fitted aftermarket 'blow off valves' to their Q4 - I need to decide exactly where mine is going to go.. What about 'type' what style should I go for?

jim~

[AlfaJack]

Single piston type in the original location is fine.

[1NRO]

Theory and logic has it that the release of air might as well come from the pre intercooler pipe, hot air being released from near the turbo which you are trying not to stall. In practice mostly anywhere will do for anything other than trying to find the final few %. A recirculating type might well be better located in the pipe after the intercooler if it suits the plumbing.

Nik

[arjunior45]

mine is a single piston one too, 'adjustable' and located to the oem position.
I kept it as recirculating valve {as I was told that gives less lag than to have it as blow to air} and adjust it not to 'blow off' only at idle speed.

Not much of an improvement {replacing this valve} in any case - as long as the oem one is in good working order.
Only the psssssss sound fi you have it 'opern to air'.

[jimnielsen]

I think i am going to go for one like this...

http://cgi.ebay.com.au/TURBO-BLOW-OFF-VALVE-BOV-FOR-MAZDA-RX7-FD3S-MIATA-MX5_W0QQitemZ370225052939QQcmdZViewItemQQptZAU_Car _Parts_Accessories?hash=item563321fd0b&_trksid=p4634.c0.m14.l1262&_trkparms=|293%3A2|294%3A30

...I need one that can bolt to a flange that is welded onto the intercooler pipework. Its too difficult to vent it back to the intake pipework. So it will be making a lot of 'whoosing' noises.

[SteveNZ]

I used 2 OE type Bosch valves venting to atmosphere for years. works just fine. I later upgraded them to OE Mitsubishi VR4 that have a much softer spring. these helped with a surge issue I had with 1 particular compressor wheel I was running.

Most brands will work fine on a Q4. Just get something that is well made.

[arjunior45]

it is funny to hear the noise and I was tempted to leave to air but ... I decided not to.
The only thing that's important is not to keep it too hard so that the pressure does not slow down the turbine!
I think this one {on ebay} is just fine.

[mindus]

the price is very low for this ebay BOV, I would question the quality of this thing..


I think i am going to go for one like this...

http://cgi.ebay.com.au/TURBO-BLOW-OFF-VALVE-BOV-FOR-MAZDA-RX7-FD3S-MIATA-MX5_W0QQitemZ370225052939QQcmdZViewItemQQptZAU_Car _Parts_Accessories?hash=item563321fd0b&_trksid=p4634.c0.m14.l1262&_trkparms=|293%3A2|294%3A30

...I need one that can bolt to a flange that is welded onto the intercooler pipework. Its too difficult to vent it back to the intake pipework. So it will be making a lot of 'whoosing' noises.

[Juan AR155Q4]

I?m using a Greedy RS mounted in the OEM location with a home made flange, vented to air, no problem at all.

[jimnielsen]

in the end.. I went for this one...


http://www.gofastbits.com/index.php?parentid=products&option=products&sub_option=bovs&sub_sub_option=basic

jim~

[SteveNZ]

Will do the job, at least it's a recognised brand. General theory is to fit it close to the throttle body, so it will eliminate the hammer effect as early as possible.

[Ditlev]

I'm using a Forge FMDV004 dual-piston valve, venting to air, mounted in the original position. Works like a charm, and gives the added bonus of the nice "psssssh"-sound.. ;)

[Evodelta]

The big question is, do you really need a DV? I've driven with and without and not noticed any difference, only the weird noise it makes without.....

[jimnielsen]

well, I am hoping that it won't be too noisy - as to 'need' - its a fair question that I don't really have an answer for, as I have no data or lap times that could compare the performance of the system with and without a BOV. But.. as I am in the process of building the intercooler pipework 'as we speak' It is as easy to integrate it in now.

Attached is a picture of my intercooler piping "kit" its simply 2.5" straight stainless steel tube (1.1mm thick) and 90 degree mandrel ss bends (also 1.1mm thick) I have looked at a thousand ways of routing the pipework - but in the end their are really few viable choices.

question.. what hoses do I need to disconnect / connect to ensure that that turbo only makes its 'base boost' (as governed by the wastegate spring..)

question.. how close to the intercooler should the air temp sensor be (before the intercooler) - it will connect to the datalogger.

cheers, jim..

[SteveNZ]

Temp sensor can go anywhere, it wont matter as long as it's before the IC

Connect the wastegate actuator hose straight to a boost source after the compressor. There is usually a nipple on the compressor cover itself.

[juamin]

Ive used a SPA turbo vented to air 3 months ago, but i got tired of the sound, now i m running with the original blow off with a K&n filter,. I havent noticed any difference in performance in both .

Video with the original one and K&N filter
YouTube - Foroalfaromeo Track Day - Q4s Preparando la pista