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Discussion Starter #1
How can I configure my dump valve output to stay active after release of trans brake, (a period of time after release)? I would also like to reactivate the dump valve with my shifter output. Activate it when the shifter output deactivates, again with a time base for the dump (a period of time after shifter deactivates).
 

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I have seen others that have done this at the shift. What is the goal? To avoid knocking the tire loose briefly at the shift? I do get a little driveshaft speed increase at the shift briefly.
 

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Discussion Starter #6
I have seen others that have done this at the shift. What is the goal? To avoid knocking the tire loose briefly at the shift? I do get a little driveshaft speed increase at the shift briefly.
Yeah, to loosen the convertor a touch.
 

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Discussion Starter #7 (Edited)
If I made three separate outputs and physically wire them together (can't stack outputs in pin map) I guess would be the only way I can think of to control it on time the way I'd like it to be.
1)Dump Valve: trans brake / enabled
2)Dump Valve Delay: trans brake / at input release with active time
3)Dump Valve Shift: "Linked Output" shifter / enabled with (sart delay .2) (active time 1.5)
That way I can control the time after I leave. And the time after the shift.
Would there be an issue with back feed from one output into another? Maybe that's why Zbrown asked +12V or ground?
 

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no if u watched video Ryan does similar for shifter. sets up different outputs and ties together. I use it like that and have no issue
 

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Discussion Starter #9
no if u watched video Ryan does similar for shifter. sets up different outputs and ties together. I use it like that and have no issue
Yes, I noticed he said grounds. That may be the safest thing, for me to change my current dump to ground and go that route adding the other outputs.
Thanks
 

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Discussion Starter #11
are you running a relay? if so just have them tie together and trigger relay.
Yes, Currently run a 12v signal to relay. But it wouldn't really be an issue to move to an unused ground activated relay on the same board. I thought it would be less likely to be an issue to tie ground outputs together. Ryan mentioned using grounds as signals in the video.
 

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I was under the impression that the dump valve should be closed at the release of the TB or as soon as its spooled .

Why dump pressure under full boost
Not something I am suggesting, but a top dragster fella showed me his driveshaft data using one at the shift, and the little hump I usually get when I shift was gone....data smooth. He also was using it at the hit to keep wheel spin at a reasonable level. This was a big blower car with blg block.
 

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Discussion Starter #15 (Edited)
Not something I am suggesting, but a top dragster fella showed me his driveshaft data using one at the shift, and the little hump I usually get when I shift was gone....data smooth. He also was using it at the hit to keep wheel spin at a reasonable level. This was a big blower car with blg block.
I would like to try dumping at the shift signal to lesson the that hump, lower the chance of striking the tire. BUT I am concerned about the drop in servo pressure at the shift being to low to hold while dumping and shifting. My dump doesn't seem to affect the servo pressure (at current dump rate). The servo stays 250-260 full run other than the 150-160 valley at the shift (100 psi drop). That valley is typically .1 seconds. I've thought about trying it and just be ready to abort if I don't feel warm and fuzzy when it shifts. But that would be to late but once may not hurt.
 

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Converter dumps don't respond real fast. Timing is typically used to control wheel speed. A quick timing dump at the shift will do what you need.. same with off the transbrake..
 

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^^^^ X2 ^^^ I was thinking the same thing. My BS3 in the old car is not very capable so I use shift retard in the MSD Grid. It is very simple to setup and you can control the shape/time how the power is reapplied. You should have a lot of options with the Holley system. Haltech is really flexible and you can do a lot of control based on the race timer.
 
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