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- MP5T / 944
I Do not have Turkey...Turkey! (lol2)03MSPRO said:
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what BOV's have worked for you
- Thread starter wicked
- Start date
david_shea
Member
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- 03 mp5
i use a raptor BOV from turbonetics and it works fine. (2thumbs)
Glowmunkey
Member
I have no turkey at all... Turbo XS recirc bov and HiBoost front mount...
The blow off valve does not increase performance. In fact the best performance increase can be gained by not having one altogether, the WRC cars do not run one.
BUT...
...the main advantage of the blow off valve is to reduce stress upon the turbo blades when you lift off of the accelerator to lets say change gear. The turbine is still spinning and thus pumping gas into the input...but the engine is off power. So what to do with the excess. A blow off valve set to a certain pressure releases this excess. A vent to atmosphere allows it to go to air giving the characteristic pfffft, a recirculating one feeds it back into the input of the turbo thus keeping the system pressurised. When you hit the accelerator the vented system then needs to momentarily build up the pressure again whilst the recirculating system doesn't.
Without a BOV the turbine can actually stall or air is drawn back through the wastegate in the wrong direction. The turbine is spinning but there are no exhaust gases coming out of the engine, so it either stalls or draws airthrough the wastegate from the exhaust side.This is the chirp you hear on the WRC cars. The stress on the bearings is quite substantial and in a completely different direction to that which the turbo is designed. The turbo in the WRC cars has a 360 degree bearing surface to counter this (and the turbo is changed and refurbished per rally if not sooner), the road going turbo does not.
After market BOVs are adjustable, and the pressure at which they blow can be set higher than standard which means that there is more pressure retained at gear change.... BUT how high can you go, what is a safe setting and will it ultimately shorten the life of the turbo?
The other reason an aftermarket BOV is selected is if the system is running more boost than stock and the stock BOV can not operate at the elevated levels.
Finally the main reason I can see a BOV is fitted is because people want that characteristic PFFFT! which probably loses them performance rather than gain it as they are dumping turbine pressure everytime they change gear.
One other negative thing about vent to atmosphere BOVs is that the ECU monitors the air into the system via the MAF. This is in the input before the recirculating pipework reintroduces the gases back into the system. Thus the ECU takes into account this recirculated air in its calculation for fueling, and ultimately over fuels for a VTA-BOV and won't do the turbo much good or any following catalyst in the exhaust.
BUT...
...the main advantage of the blow off valve is to reduce stress upon the turbo blades when you lift off of the accelerator to lets say change gear. The turbine is still spinning and thus pumping gas into the input...but the engine is off power. So what to do with the excess. A blow off valve set to a certain pressure releases this excess. A vent to atmosphere allows it to go to air giving the characteristic pfffft, a recirculating one feeds it back into the input of the turbo thus keeping the system pressurised. When you hit the accelerator the vented system then needs to momentarily build up the pressure again whilst the recirculating system doesn't.
Without a BOV the turbine can actually stall or air is drawn back through the wastegate in the wrong direction. The turbine is spinning but there are no exhaust gases coming out of the engine, so it either stalls or draws airthrough the wastegate from the exhaust side.This is the chirp you hear on the WRC cars. The stress on the bearings is quite substantial and in a completely different direction to that which the turbo is designed. The turbo in the WRC cars has a 360 degree bearing surface to counter this (and the turbo is changed and refurbished per rally if not sooner), the road going turbo does not.
After market BOVs are adjustable, and the pressure at which they blow can be set higher than standard which means that there is more pressure retained at gear change.... BUT how high can you go, what is a safe setting and will it ultimately shorten the life of the turbo?
The other reason an aftermarket BOV is selected is if the system is running more boost than stock and the stock BOV can not operate at the elevated levels.
Finally the main reason I can see a BOV is fitted is because people want that characteristic PFFFT! which probably loses them performance rather than gain it as they are dumping turbine pressure everytime they change gear.
One other negative thing about vent to atmosphere BOVs is that the ECU monitors the air into the system via the MAF. This is in the input before the recirculating pipework reintroduces the gases back into the system. Thus the ECU takes into account this recirculated air in its calculation for fueling, and ultimately over fuels for a VTA-BOV and won't do the turbo much good or any following catalyst in the exhaust.
wow,this thread has a lot of good info for people,but it's not anything new to me.
I know why it stalls,and how to prevent it ,what I was looking for was to know which BOV are duel piston.
WHY? because,yes,I need that lovely sound.
most people here mod there car as a hobby,seldomly taking it to the track.and part of it is for attention,and I am proud to admit it.
Don't get me wrong I like doing things right but the sound of your ride is just as important as the looks,or anything else.if that wasn't the case then we wouldn't have bought this car,we would just get a honda like everone else.
by the way I moved my MAF to the charge side,and ordered a HKS SSQV.
FMIC DONE!
I know why it stalls,and how to prevent it ,what I was looking for was to know which BOV are duel piston.
WHY? because,yes,I need that lovely sound.
most people here mod there car as a hobby,seldomly taking it to the track.and part of it is for attention,and I am proud to admit it.
Don't get me wrong I like doing things right but the sound of your ride is just as important as the looks,or anything else.if that wasn't the case then we wouldn't have bought this car,we would just get a honda like everone else.
by the way I moved my MAF to the charge side,and ordered a HKS SSQV.
FMIC DONE!
that is true but it would take some time (like a few years) to do.Autox MSP said:Oil from your turbo seals will ruin your MAF sensor also the air after the turbo is turbulant which will get the wrong readings.
A K&N filter can do the same,along with most filters on the market,including INJEN,and AEM.
jurgs01 said:I am completely anti-ricer, but I have to admit a part of me has fun when the greddy lets off a loud scream as I'm shifting at 6K rpm and scares everyone around.
It aint a rice thing,it has more to do with how I grew up:big blocks,and noise.
by the way,your hood,now thats rice.=)
sickspeed94
Member
- :
- Spicy MSP
what about the turbosmart dual stage thingamajigobobber! it vents to atmosphere and then at idle it recircs air back into the intake, i liek it it's JDM TYTE YO!!!!!!!!!!11!!11ONE111!!WON!!
nah i just use a turboXS H25, kills turkey, is slightly louder and i didn't have to buy hardpipes or flanges or have stalling issues or anythign of that sort.
nah i just use a turboXS H25, kills turkey, is slightly louder and i didn't have to buy hardpipes or flanges or have stalling issues or anythign of that sort.
the turboXS H25 comes with 25mm inlet/outlet. how did you reduce it to the 19mm hoses for our cars?sickspeed94 said:what about the turbosmart dual stage thingamajigobobber! it vents to atmosphere and then at idle it recircs air back into the intake, i liek it it's JDM TYTE YO!!!!!!!!!!11!!11ONE111!!WON!!
nah i just use a turboXS H25, kills turkey, is slightly louder and i didn't have to buy hardpipes or flanges or have stalling issues or anythign of that sort.
I Need A Blow Off Vaule
Hey Im New To This And I Need A Blow Off Value For My Mazdaspeed Protege 2003. I Live In Southern Cali!! So Smogs A b**** And I Want To Be Able To Put The Stok Back On For Smog With Very Little Work To Do! I Dont Want To Have To Do All This Cutting And Custom s***. Let Me Know Please Lol!! Heres Some Motor Shots.. Thanks
Hey Im New To This And I Need A Blow Off Value For My Mazdaspeed Protege 2003. I Live In Southern Cali!! So Smogs A b**** And I Want To Be Able To Put The Stok Back On For Smog With Very Little Work To Do! I Dont Want To Have To Do All This Cutting And Custom s***. Let Me Know Please Lol!! Heres Some Motor Shots.. Thanks
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