00 ta installed d1sc kit, wont run with maf connected
05-20-2006, 10:28 PM
#1
00 ta installed d1sc kit, wont run with maf connected trying to tune 00 ta with d1sc kit, with maf hooked up car stumbles, when unhooked car runs much better, still occasional slight stumble at low rpm and throttle position but overall good performance but the service vehicle light came on. not the ses light but the service vehicle light.
05-21-2006, 09:16 AM
#3
i believe so, it runs pretty well with the maf disconected forcing the car to run in speed density.it makes the proper amount of boost and when I let off the throttle i get that fluttering sound associated with the valve working properly
05-21-2006, 01:27 PM
#4
Do you have a bypass valve or a blow-off valve. The reason I ask is because of the fluttering sound you describe and that you only experience the problem at low rpm and throttle positions.
The bypass valve remains full open under vacuum. It allows the un-used air from the charger (during cruising/idling) to either re-circulate back to inlet hat at the blower or if you've chosen, vented to atmospere.
The blow-off valve is used mainly in turbo applications. The difference is it doesn't remain full open under vaccuum. It takes a pressure wave (like when the throttle body snaps shut) to overcome its seat spring pressure. It can however be adjusted to open easier (less pressure).
The reason it doesn't need to be open all the time is because the wastegate in a turbo system controlls the psi. The blow-off is just there to get rid of that initial pressure wave in the intake piping when the throttle snaps shut. Without it that wave would go all the way back to the turbo and slow the impeller causing serious lag between shifts.
The issue is the charger is creating a specific cfm of air based on rpm due to it being driven by the motor as opposed to the turbo being driven by exhaust gas. Its not regulated by a wastegate. Your car is not using all of that when you are cruising/idling. With no where to go, this pressure backs up through the intake piping all the way to the blower.
Just like the turbo the pulse/buildup in pressure acts like an air brake to the blower since its trying to work against it. Instead of affecting spool/lag like the turbo, it's going to cause the car to stumble since the blower is attached to the motor.
If a blow-off valve is what you have, it can be adjusted to open easier. It's still not optimal though because the openings on it probably aren't big enough
(depending on model) to vent the excess air during part throttle/cruise.
This puts a greater strain on the blower bearings and seals. Over time it can lead to pre-mature failure of the unit.
Even though its been done and some may have success, bypass valve for blower and blow-off valve for turbo.
If you already knew all of this just dis-regard. I figured I'd throw it out there just in case.
Good luck finding the issue.
The bypass valve remains full open under vacuum. It allows the un-used air from the charger (during cruising/idling) to either re-circulate back to inlet hat at the blower or if you've chosen, vented to atmospere.
The blow-off valve is used mainly in turbo applications. The difference is it doesn't remain full open under vaccuum. It takes a pressure wave (like when the throttle body snaps shut) to overcome its seat spring pressure. It can however be adjusted to open easier (less pressure).
The reason it doesn't need to be open all the time is because the wastegate in a turbo system controlls the psi. The blow-off is just there to get rid of that initial pressure wave in the intake piping when the throttle snaps shut. Without it that wave would go all the way back to the turbo and slow the impeller causing serious lag between shifts.
The issue is the charger is creating a specific cfm of air based on rpm due to it being driven by the motor as opposed to the turbo being driven by exhaust gas. Its not regulated by a wastegate. Your car is not using all of that when you are cruising/idling. With no where to go, this pressure backs up through the intake piping all the way to the blower.
Just like the turbo the pulse/buildup in pressure acts like an air brake to the blower since its trying to work against it. Instead of affecting spool/lag like the turbo, it's going to cause the car to stumble since the blower is attached to the motor.
If a blow-off valve is what you have, it can be adjusted to open easier. It's still not optimal though because the openings on it probably aren't big enough
(depending on model) to vent the excess air during part throttle/cruise.
This puts a greater strain on the blower bearings and seals. Over time it can lead to pre-mature failure of the unit.
Even though its been done and some may have success, bypass valve for blower and blow-off valve for turbo.
If you already knew all of this just dis-regard. I figured I'd throw it out there just in case.
Good luck finding the issue.
