Nick/Andy,

I have been running the HKS valve for over 12 months now with no problems what so ever. If you are concerned about it venting to atmosphere you can get a recirculating kit from David Reid at DRMotorsport (very helpful chap) at about £12.

I purchased one of these (from DRM) just to compare running under both conditions, although I cannot yet comment as I have not had a chance to get around to fitting it.

I have no ties what so ever to DRM but I would like to say that b 4 approaching David I spoke to three "well known and thought of" companies who all told me that the recirc kit was unavailable, and would not look at sourcing one as they did not exist. Great customer service chaps!! I saw that DRM sold HKS kit so I rang David and a week later I had one on my doorstep......<B>thankyou very much David Reid.</B>

 

A friend with an EVO VI has just upgraded to an HKS Super Sequencial BOV which, he says, has given better performance at low revs and better pickup after changing gear. it also goes "pssscccccchhhhhhhhhhhhhhhht" rather nicely.

Is there any advantage in fitting such a beast to an MY00 Impreza Turbo? I seem to recall paranoia about dump to atmosphere stuff; is there a basis for this?

Nick.

 

Nick,

I thought the reason that dump to atmosphere was bad, as they run the car richer (hence flames when coupled with a de-cat exhaust), but will make the car idle lumpy. I've been told (but may be wrong) that the turbo spool up time is improved with a dump to atmosphere dump valve.

I changed mine for a Forge recirculating dump valve, as the car is running a smidge more boost than standard. For me, flames aren't as important as the car running right!!

Andy

PS - If any of this is wrong, please correct me!

 

Cheers Mo. I've used David's excellent service before for PIAA lights, so I'll give him a bell.

Any other opinions? Any benefits?

Nick.

 

I use an APEXI atmosh. BoV, and have used various BoV with a decat exhaust for the past couple of years with no problems.

I did have erratic idle at one point, but the BoV has knackered.

Lag is much lower. Dunno about MPG as I can't remember what I used to get with my re-circ dump valve.

Running 1.3bar day in day out with no problems exc. 18MPG on SUL :-(

Mark.

 

Thanks Mark. Any ideas why lag should be lower? I can't understand why changing a BOV does this, though accept it happens as it works in my friend's EVO VI!

 

Why is lag lower ?

As far as I'm aware (I have been wrong.... 27 PSI boost was VERY very wrong ) the pressure on the intake side builds when changing up as it has no where to go causing turbo stall especially at high boosts. The pressure tries to spin the turbo the wrong way. Effectivly a BoV allows the turbo to spin freely when coming off the throttle. Thus when you apply the throttle when changing up the turbo is already spinning.

Get out clause.

I have been know to be wrong...very wrong at great personal expense. Please don't take my word as gossple as it will cost ya a fortune if it all goes pear shaped.

Mark.

[This message has been edited by Blackscooby (edited 04 May 2001).]

 

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