Cars without BOV's

[sanchi]

Just been wondering, I have been looking on the net at some old school Jap motors well not that old school but mr2 turbo age mid 90's and noticed some of these big tuners didn't run BOV's.

I wanted to know what the benefit of this was as we know that it creates compressor surge. Is there some sort of benefit or idea with using it with an external wastegate setup?

If I blocked my BOV port and just used my external wastegate setup would it kill my turbo very quickly or can it be used that way?

[ej2_sir]

I would imagine the cars you were looking at were running steel shafted/different turbo's to the toyota ct range. With them being ceramic, they can be quite brittle so not having a bov will destroy them pretty quick! Even with a steel shaft/impellers, I wouldnt think it would do the lifespan of the turbo any good...

[ej2_sir]

and dont a lot of the bigger turbos have anti surge compressor housings designed to relieve the pressure build up?

[Tubby]

Wouldn't they of run recirculating bov's??

[sanchi]

Been reading up on this and there is no definite conclusion whether to use a bov or not. Its really a 50/50 situation with regards to peoples opinions on the net, this is the impression I have got reading through all the stuff.

Hmmm, might give it a shot...

[jimGTS]

If you've a stock turbo, it's not recommended at all.

My came from japan with no bov. I have however got one now fitted.

Benifits are keeping the pressure in the system for when your on the throttle again. Instead of releasing that air/pressure with a bov, your maintaining a bulk of the pressure and in turn can willmean better spool after a gear change.

Coming from someone who's tried both, I will say there is an advantage on say a drag strip. I could hit instant full boost after a gear change if I shifted fast enough. With a normal vent to atmos bov you'd have to be even quicker to match the boost reaponse.

That was my experience, and it's am sure the reason you see many drag Japanese monsters doing it. Hell if they can afford to mod the crap out the car to 600-1000hp, then they can afford a bov. But chose not to.

Downside, I 'heard', is that it puts pressure on the turbine which can lead to early failure.
HOWEVER I've never seen anyone experience this sort of failure. Infact not heard of any experiencing side effects other than good.

Do at own risk, but pretty sure my turbo ran no bov for quite a while before I took purchase of it.

Just my 2p

[sanchi]

If you've a stock turbo, it's not recommended at all.

My came from japan with no bov. I have however got one now fitted.

Benifits are keeping the pressure in the system for when your on the throttle again. Instead of releasing that air/pressure with a bov, your maintaining a bulk of the pressure and in turn can willmean better spool after a gear change.

Coming from someone who's tried both, I will say there is an advantage on say a drag strip. I could hit instant full boost after a gear change if I shifted fast enough. With a normal vent to atmos bov you'd have to be even quicker to match the boost reaponse.

That was my experience, and it's am sure the reason you see many drag Japanese monsters doing it. Hell if they can afford to mod the crap out the car to 600-1000hp, then they can afford a bov. But chose not to.

Downside, I 'heard', is that it puts pressure on the turbine which can lead to early failure.
HOWEVER I've never seen anyone experience this sort of failure. Infact not heard of any experiencing side effects other than good.

Do at own risk, but pretty sure my turbo ran no bov for quite a while before I took purchase of it.

Just my 2p

Thanks Jim.

That's the kind of response I've been hearing and reading quite a few people have said what you said and its very 50/50 biased on the net/other forums.

The only reason I'm is because I'm not using a stock turbo. I've got a blitz kkk k3t turbo with an external wastegate so I thought I might give it a shot.

[Andy F]

Neither me or Chris ran BOVs on our cars for years, and didnt have any problems, inc fast gear changes on the strip!
I wouldnt run without on any CT but on a GT ect theres no problems

[sanchi]

Neither me or Chris ran BOVs on our cars for years, and didnt have any problems, inc fast gear changes on the strip!
I wouldnt run without on any CT but on a GT ect theres no problems

Funny enough when you sent me the above message I was in a waiting room waiting for my MOT on a van and I was reading an old Banzai they had and saw Chris's feature, very nice indeed!

Thanks for the info. My turbo has an external wastegate setup and has a 360 degree journal, it is an old school turbo so no ball bearing. I'm going to give it a shot with no BOV!