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Discussion Starter #1
What are the ill effects of pulsing a T-brake solenoid for staging a turbo car ?

Its a Hipsters if it matters .


Thanks .
 

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You are putting the weight of the vehicle, by stopping its movement on the internals of the trans.....
 

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Discussion Starter #5
While the solenoid is pulsing it creates a line pressure drop and can cause big problems on some transmissions.


Hutch
Has it ever been used successfully ?


Read this recently :

fast xfi
Copied from the fast help files.

Normally, after a trans-brake is enabled, a vehicle could only move after the trans-brake is released. A benefit in drag racing is that all available power may be applied to the engine while the vehicle is held stationary with the trans-brake and a vehicle can move on command within a very short reaction time via a button controlling the trans-brake. The XFI adds additional functionality to the trans-brake by allowing the brake to be released in a controlled, variable amount rather than the on/off (all or nothing) method which is the typical method of control. The XFI can “pulse width modulate” the trans-brake solenoid in such a way that the trans-brake will “slip” and the vehicle can “creep” in a controlled fashion and for a controlled time.

Using the trans-brake control feature of the XFI, a driver would be able to engage the trans-brake from the “pre-staged” position, apply the desired power, and then use the trans-brake control function of the XFI ECU to allow the vehicle to roll (creep) into the staged position under the operator’s control or under automatic control allowing the driver to concentrate on the “tree” for a better and more consistent reaction time. This should be especially useful for turbocharged applications where the time required to “spool” the turbocharger may be a deciding factor in the outcome of a race.
 

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It is the weight of the car being stopped by applying the trans brake , when it is being stopped it puts stress on the planetary gearset and some stress on the clutches/ band......
 

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Discussion Starter #7
It is the weight of the car being stopped by applying the trans brake , when it is being stopped it puts stress on the planetary gearset and some stress on the clutches/ band......
Do you mean grabbing the t-brake while it creeps forward ? Would the same stress be there when foot braking it in ?

From this I thought that if it uses a PWM , it will never fully engage the brake and it will just " slip "

Quote from fast :

“pulse width modulate” the trans-brake solenoid in such a way that the trans-brake will “slip” and the vehicle can “creep” in a controlled fashion and for a controlled time.
 

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Here's the deal from my side. You have a glide lets say it has and needs 250 psi to hold on the clutch's and or band. You now start the pulse width of the solenoid and the pressure drops. Something has to slip and something has to wear. Slip and glaze the band a few times and its done.


Hutch
 

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Discussion Starter #9
Here's the deal from my side. You have a glide lets say it has and needs 250 psi to hold on the clutch's and or band. You now start the pulse width of the solenoid and the pressure drops. Something has to slip and something has to wear. Slip and glaze the band a few times and its done.


Hutch

Thanks .

That makes sense . Damit ! I thought I had a project .
 

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Do you mean grabbing the t-brake while it creeps forward ? Would the same stress be there when foot braking it in ?
Foot braking is not the same internal action in the unit as applying the transbrake..
The PWM concept is in its infancy and will evolve and improve as time goes on, just be prepared to replace more parts more often...
 

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Discussion Starter #11
The PWM concept is in its infancy and will evolve and improve as time goes on, just be prepared to replace more parts more often...

Is the XFI fast the first to integrate it into their product ?

It seems to me like it would be old school technology . Is this kinda what NLR was doing ? And do you know why they stopped ? Patent problems or just that it failed in testing .
 

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Discussion Starter #12
left 4 dead;4002229 Foot braking is not the same internal action in the unit as applying the transbrake.. QUOTE said:
I meant is it like grabbing the t-brake while still moving forward on the footbrake ?




Thanks guys for your replies on this .
 
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