Best free mod for those with dump valves
#31
Scooby Senior
The TD's are stronger than VF's basically.
Back in the day when i had a Scoob, i had a VTA which felt no different to the OE item when driving. It did however make sure the fueling was interesting which in turn made for some fantastic flames
Back in the day when i had a Scoob, i had a VTA which felt no different to the OE item when driving. It did however make sure the fueling was interesting which in turn made for some fantastic flames
#38
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Unless you have an induction kit fitted.
The vta ones do make the car run rich as the valve is venting metered air out of the system, causing the car to over fuel to compensate.
#40
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There are two types of valve
1.a recirculation valve, that puts any dumped boost on throttle lift off back into the intake tract, keeping the air system secure so the ecu can fuel accurately
2. a vent to atmosphere valve, that vents any excessive boost on throttle lift off directly into the air, putting air that has already been acounted for by the ecu out of the intake tract.
The ecu will see this as an air leak due to the air beeing essentially leaked out. Thusly the ecu will add more fuel to the mix, resulting in the engine running richer thsn it really needs to be.
It's designed with a recirc valve, it should have one. If you are running big boost and keeping the original design intake tract, just fit an uprated recirc.
1.a recirculation valve, that puts any dumped boost on throttle lift off back into the intake tract, keeping the air system secure so the ecu can fuel accurately
2. a vent to atmosphere valve, that vents any excessive boost on throttle lift off directly into the air, putting air that has already been acounted for by the ecu out of the intake tract.
The ecu will see this as an air leak due to the air beeing essentially leaked out. Thusly the ecu will add more fuel to the mix, resulting in the engine running richer thsn it really needs to be.
It's designed with a recirc valve, it should have one. If you are running big boost and keeping the original design intake tract, just fit an uprated recirc.
#41
Scooby Senior
iTrader: (41)
FMIC piping has DV outlet connection for which you can use OEM or aftermarket recircs. Mine is welded to hold the simtek sensor and thus running a DV delete. Mapped mafless and to expect the AFR. Makes for a more responsive gear change. Not a fan of VTA's for the simple reason OEM run better on standard cars.
#42
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There is also the twin vent ones which IMO are better than the std blow off valves. I have the one below & it can be set to open at whatever pressure you set it to.
http://www.airpowersystems.com/wrx/blow.htm
"Ports Closed - Under open throttle conditions where turbocharger boost pressure is required, the bronze BOV piston is held shut in order to supply the maximum amount of charge air to the engine
Primary Port Open - Under light load conditions where the throttle opening has been reduced or shut, the piston moves partially up the bore travel and opens the primary port to vent charge air back into the inlet tract. This ensures smooth engine operation and alleviates the rich condition and subsequent backfire when utilizing a BOV construction that vents100% of charge air to atmosphere.
Both Ports Open - Under high load conditions where the throttle has been shut, the piston travels fully so that both the primary and the wide mouth secondary ports open to vent the maximum charge air possible. Air vented through the primary port is routed back into the inlet tract. In addition, additional excess charge is air vented through the wide mouth secondary port to atmosphere"
http://www.airpowersystems.com/wrx/blow.htm
"Ports Closed - Under open throttle conditions where turbocharger boost pressure is required, the bronze BOV piston is held shut in order to supply the maximum amount of charge air to the engine
Primary Port Open - Under light load conditions where the throttle opening has been reduced or shut, the piston moves partially up the bore travel and opens the primary port to vent charge air back into the inlet tract. This ensures smooth engine operation and alleviates the rich condition and subsequent backfire when utilizing a BOV construction that vents100% of charge air to atmosphere.
Both Ports Open - Under high load conditions where the throttle has been shut, the piston travels fully so that both the primary and the wide mouth secondary ports open to vent the maximum charge air possible. Air vented through the primary port is routed back into the inlet tract. In addition, additional excess charge is air vented through the wide mouth secondary port to atmosphere"
#44
#45
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The age old debate of whats better
Ive had a recirc, blanked off and VTA one on mine and the original recirc makes for a better smother gear change imo. I now have a VTA one on, that only dumps boost when im at high boost (Turbosmart wound right in) This seems to work well.
Im interested in the fuel saving though so next fill up i will swap over as 30 miles is alot when im only getting 240 to a tank
Ive had a recirc, blanked off and VTA one on mine and the original recirc makes for a better smother gear change imo. I now have a VTA one on, that only dumps boost when im at high boost (Turbosmart wound right in) This seems to work well.
Im interested in the fuel saving though so next fill up i will swap over as 30 miles is alot when im only getting 240 to a tank
#46
MY first scoob! can't believe people dont like the noise? I love driving this car. its a theatrical experience, burble, burble, vroom, whoosh, clatter, pop, vroom! Its one of the reasons I went for a scoob, its makes me feel... the last car to give me such a buzz was classic tuned mini when I was young...
I love the reactions I get from friends and family when they first ride in it ... if the noise doesn't bring a smile the acceleration always does...
I love the reactions I get from friends and family when they first ride in it ... if the noise doesn't bring a smile the acceleration always does...
#47
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MY first scoob! can't believe people dont like the noise? I love driving this car. its a theatrical experience, burble, burble, vroom, whoosh, clatter, pop, vroom! Its one of the reasons I went for a scoob, its makes me feel... the last car to give me such a buzz was classic tuned mini when I was young...
I love the reactions I get from friends and family when they first ride in it ... if the noise doesn't bring a smile the acceleration always does...
I love the reactions I get from friends and family when they first ride in it ... if the noise doesn't bring a smile the acceleration always does...
Well said
im glad to see the scoobies still making new owners smile
p.s i love my d.v its well loud with fmic
#48
Im not a chav and have a bailey dumpvalve fitted, always had them fitted to my turbo cars and ive had a few, only car i did not fit one on was my RS500 Cosworth, my scoob is my daily drive but also my track tool, i just find the standard car so boring.
Really liked the turbo flutter i got on the cossies through the induction kit but dont have one fitted to the scoob, do you get that on a scooby with an induction kit fitted?
Really liked the turbo flutter i got on the cossies through the induction kit but dont have one fitted to the scoob, do you get that on a scooby with an induction kit fitted?
#50
anyone have the bmc carbon cold air intake system on their cars? mine is a 99 uk turbo and just wondered what they were like, with a bit of flutter through the induction the dumpvalve will be off
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