is a re-circ bov better then a non-re-circ?

[dan.h]

just wanted to know is a re-circ bov better then a non-re-circ?

[Driftlimits Performance]

Depends I think. At what, where you thinking?

The recirc, in theory, as you putting more air back into the intake. And the standard bov is a very clever bit of kit. A lot more sophisticated than your atmospheric bov's. But, the air you're recirculating is hot, its come straight from the turbo and back into the intake. Can't help intake temps.

I had the stock bov on my rev 3. Then I fitted a baileys, then a blitz ss, now I'm on an hks ssqv and I wouldn't go back to recirc unless I needed to .ie rev1/2's.

I like the noise though. Some don't. On rev3's its really personal preference.

[Cliff]

I had the stock bov on my rev 3. Then I fitted a baileys, then a blitz ss, now I'm on an hks ssqv and I wouldn't go back to recirc unless I needed to .ie rev1/2's.

I will probably be buying a Rev 2 MR2 Turbo soon and plan to replace the BOV with an aftermarket atmospheric unit.

Is it not possible or is it harmful to the REV1/2 MR2 Turbo if I fit an atmospheric BOV to it??

[Cliff]

Their is another thread about this in the Modifications section of IMOC, but the answer still seems to be unconclusive.

[craig]

I have a Blitz SS (latest version) Twin piston, no problems whatsoever.

In this complex topic mate, it's up to you!

[conor-mr2]

check out this link. Tis a good read
http://www.jekylhyderacing.com/bov.htm

Personally on a Rev1/Rev2 Id stick with the stock as its (IMO) the best one for the job!

Rev3+ you could put in dump to atmosphere ones if you want to.

[Cliff]

Still dont understand/can't see where it highlights why it's ok to install an atmospheric BOV to a REV 3 and not 1 and 2.

(Sorry if its a stupid question and the answer is mentioned in the link above).

[raptor95GTS]

Still dont understand/can't see where it highlights why it's ok to install an atmospheric BOV to a REV 3 and not 1 and 2.

(Sorry if its a stupid question and the answer is mentioned in the link above).

rev3+ measure the air volume using a MAP sensor located in the manifold after the BOV whereas the rev1/2 use an Airflow meter which is before the BOV.

[Driftlimits Performance]

As Alan said, a revision 3 has a map sensor. This is after the dump valve, and a revision 2 has an afm before the dump valve. Because its before the dump valve, when you dump to the atmosphere, you are losing measured air. So the car thinks its getting a different air/fuel ratio than it really is. Lots of people with rev2's say this has a negative affect on performance. Borrow someones and decide for yourself.

Maybe an Apexi twin chamber bov? You can dump and recirv IIRC.

HTH
Luke

[pecky]

rev2 wiv trd bov works fine for me

[Driftlimits Performance]

TRD bov? Haven't got a picture have you?

[Cliff]

Thanks for the info everyone!! .

[Chris Downes]

I have the HKS SSQV on my car (Rev 2). In terms of performance there was no difference between stock re-circ and the HKS. In terms of fuel consumption there is a big difference - the re-circ obviously being better due to correct A/F Ratio.

Unfortunately I threw the old Recirc away when I fitted the HKS, so have had to buy the adaptor kit to recirc the HKS one!

My personal preference would be to stick with the stock one unless you really really want to go PSSSSSHhhhhhhhhhh.

[Cliff]

By re-circing an atmospheric BOV, do you still get the ptsch? (hope you guys know what I mean).

Also, what's the difference between a twin chamber BOV and I guess a single chamber?!?! (I obviously not now much about this sort of stuff ).

[BenF]

just wanted to know is a re-circ bov better then a non-re-circ?

Re-circ is better for a Rev1 and 2 - vent to atmos causes some cars to stumble, definitely takes longer for the turbo to spool back up again - somone on the Yahoo List has a switchable setup and doing back to back tests the difference was noticeable.

[raptor95GTS]

Depends I think. At what, where you thinking?

The recirc, in theory, as you putting more air back into the intake. And the standard bov is a very clever bit of kit. A lot more sophisticated than your atmospheric bov's. But, the air you're recirculating is hot, its come straight from the turbo and back into the intake. Can't help intake temps.

I had the stock bov on my rev 3. Then I fitted a baileys, then a blitz ss, now I'm on an hks ssqv and I wouldn't go back to recirc unless I needed to .ie rev1/2's.

I like the noise though. Some don't. On rev3's its really personal preference.

apparently under no boost situations the stock BOV allows air to be drawn straight from the air filter housing into the intake bypassing the turbo completely! Will need to dig it out

edit go here

[DeusMR2]

hi Allan, jekylandhyde (forgot his real name), billwot and some other bloke on the american board found out recently (by experiment) that the stock BOV doesnt have a bypass feature as they had previously thought. I think theyre still working on what actually happens under negative pressure conditions. I'll try and find the thread

-edit here are the links (long read!)

Part 1 http://www.mr2oc.com/showthread.php?t=45429

Part 2 http://www.mr2oc.com/showthread.php?t=46565

[raptor95GTS]

cheers bud - some light reading later methinks