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Power lost after installing aftermarket blow off valve (HKS SSQV) on STI7 with PPP.

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Old 08 July 2003, 02:23 PM
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@nton STI7
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Hi,
I've installed HKS SSQV on STI7 with PPP. After SSQV installed I have a feeling that I've lost some engine power.
I've tried the Blitz blow off as well an the result was the same.
Is it phizically possible and what can be the reason?

P.S. Unfortunately I still have no boost gauge to check the boost levels before and after.

Thanks!
Old 08 July 2003, 02:28 PM
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I aint no expert on this but it sounds to me like the BOV is either stuck open or is too weak and is bleeding off boost pressure. I'm sure some of the more experienced folk on here can answer better than me though.
Old 08 July 2003, 03:27 PM
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nom
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Sounds about right (bleeding air), but very unlikely, especially twice! The SSQV thingy I would be especially suprised with as it actually holds it shut (air pressure) rather than relying on a spring.
My guess would be tubes not connected quite right, or for some reason a panicking ECU that is pulling back boost?
BOVs shouldn't affect power at all if they're doing their job right.
Old 08 July 2003, 04:54 PM
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@nton STI7
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As it happened twice I don't think it's a problem of defective Blow Off Valves. It should be a problem caused by ECU or smth else.
But I don't understand how it can be an why?
Old 09 July 2003, 10:45 AM
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@nton STI7
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1) to save the turbo
2) to have a sound
But can overfueling decrease the perfomance on all rev range?
it looks like the car has become lazy after SSQV installed.
Old 09 July 2003, 11:35 AM
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nom
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The SSQV does - I know, I've had one - not affect any power when you're in a gear, but does (slightly ) improve 'between gear' speed, ie the turbo does appear to come on boost faster (changing back to the standard BOV after I'd got used to the SSQV made it feel as though something was wrong with the car). Nothing like with the speed of not having a BOV at all, though .
And before you ask, I changed back to the standard one briefly when changing from a TMIC to FMIC (with different BOV) rather than there being anything wrong with it!
Old 10 July 2003, 08:47 AM
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1) to save the turbo
?????

Matt
Old 10 July 2003, 09:50 AM
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Cool

I've read that installing open blow off helps to prolong a life of turbine.
Old 10 July 2003, 11:57 AM
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I doubt there is hardly anything in it over the life of the turbo/engine. Most standard Scoob engines/turbos are good for a good 100K without this being an issue!

Matt
Old 10 July 2003, 12:08 PM
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Steve vRS
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You need a blow off valve, but the Impreza comes with a re-circulating valve as standard. The vent to atmosphere adds a nice whoosh noise.

Steve
Old 10 July 2003, 06:42 PM
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mutant_matt
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...and adds overfuelling too...
Old 07 September 2003, 09:14 AM
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BOVs shouldn't affect power at all if they're doing their job right.
Well you could argue that the extra overfulling that results is going to momentarily reduce performance as you re-apply the throttle though?

Why did you decide to fit the BOV?

Matt

[Edited by mutant_matt - 7/9/2003 9:16:58 AM]
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