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I have a bltiz BOV that vents to the atmosphere. Quite loud and annoying. I would prefer something more stealthy. I believe that the SP uses a recirculating type of BOV? Can anyone shed more light on this....some photos would be nice. Particularly interested in seeing where/how the BOV hose connects on the hot side of the IC.

Tia

J

It's a stock standard, used on most European factory turbo cars, black plastic Bosch BOV. They are available with various spring rates depending on what car they are used in. A Porsche one has a sligthly stiffer spring than the one used in the SP for example. Volvo, Audi and VW also use them.

On the SP the inlet is attached to a nipple welded onto the intercooler pipe just before the throttle plate. The outlet is a nipple attached to the turbo intake pipe about half way between the AFM and the turbo. In my opinion it should be closer to the turbo to reduce the effects on the AFM. The BOV is controlled by a vacuum line from the vacuum point on top of the throttle body.

They have a reputation to leak over time, especially in high boost applications and aren't very reliable in high heat areas like in some VW's. They are relatively cheap to replace though.

In my opinion there are better products available.

Thanks for the response Garry.
I have a side pipe on the inter-cooler to throttle pipe that the Blitz BOV is currently using. I would use this side pipe to connect one side of the re-circulating BOV to and the other side I'm think of attaching to something like the Turbosmart TEE pipe, as shown below.



I would use the Tee pipe to replace an existing short 2 inch pipe that currently acts as a joiner between the turbo and inter-cooler.

I'm also wondering if it is a good idea to divert hot air from the turbo to the throttle (by passing the inter-cooler) when the BOV is activated. Can this cause issues when the temp sensor picks up the temp change,as it may briefly try and reduce the amount of fuel due to the possible higher temp reading?

J

The BOV outlet has to go to the inlet of the turbo ie between the air filter and the turbo.

Do not mount it after the turbo or the turbo will continue to presurise the intercooler and pipe work.

When the throttle plate closes you need to create a loop from the turbo, through the intercooler, through the BOV and back into the turbo.

Daz 27 wrote:Turbosmart make a range of BOV's which are designed to be direct replacement for the Bosch type OEM BOV's.

Indeed they do, I have one of these fitted to my car and can highly recommend them. Adjustable, and made of metal so won't split or crack like the Bosch ones can! Same 25mm dia fittings as the Bosch, so will fit straight in the factory location.

NMX516 wrote:Indeed they do, I have one of these fitted to my car and can highly recommend them. Adjustable, and made of metal so won't split or crack like the Bosch ones can! Same 25mm dia fittings as the Bosch, so will fit straight in the factory location.

Any chance of a pic on your setup NMX516?

Peter Howe wrote:

NMX516 wrote:Indeed they do, I have one of these fitted to my car and can highly recommend them. Adjustable, and made of metal so won't split or crack like the Bosch ones can! Same 25mm dia fittings as the Bosch, so will fit straight in the factory location.

Any chance of a pic on your setup NMX516?

Sure, but it's not on an MX5... Let me know if you still want a pic as I'll have to go and take one.

NMX516 wrote:Sure, but it's not on an MX5... Let me know if you still want a pic as I'll have to go and take one.

Na thanks. I wanted to see how it fits in a 5.

Peter,

I have a GFB plumb back one in my car. It's all aluminium and is adjustable and looks very strong and well made and is just a drop in replacement fit for the Bosch one. It's a little bigger and heavier but you dont need to make any modifications to the car to make it fit. You can have a look next time you see me if you like.