Sifting on time instead of RPM
#1
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Sifting on time instead of RPM
I have a BBC super comp dragster with a powerglide. Right now the transmission shifting is being controlled on RPM (7400) by my Biondo Mega 450. I would like to figure what time interval I should enter into the box, for a starting point, to allow the shift into second gear when the box is controlling the shift by time. I am not using the throttle stop at this time.
#2
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Re: Sifting on time instead of RPM
Originally Posted by kod99
I have a BBC super comp dragster with a powerglide. Right now the transmission shifting is being controlled on RPM (7400) by my Biondo Mega 450. I would like to figure what time interval I should enter into the box, for a starting point, to allow the shift into second gear when the box is controlling the shift by time. I am not using the throttle stop at this time.
FYI its illegal nhra and ihra to shift the car by the mega 450 rpm and have the tach wire hooked to it :shock:
#3
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Re: Sifting on time instead of RPM
Originally Posted by hammertime
Originally Posted by kod99
I have a BBC super comp dragster with a powerglide. Right now the transmission shifting is being controlled on RPM (7400) by my Biondo Mega 450. I would like to figure what time interval I should enter into the box, for a starting point, to allow the shift into second gear when the box is controlling the shift by time. I am not using the throttle stop at this time.
FYI its illegal nhra and ihra to shift the car by the mega 450 rpm and have the tach wire hooked to it :shock:
Thanks, David. I haven't looked at the playback tach yet. I assume it shows time and RPM? When I had the chassis certified the NHRA inspector told me that I had to not only unhook the tach wire from the box but cut the dash enough so the tech inspector would be able to see the tach terminal on the box. I assume this is only for sanctioned events?
Does anyone shift their dragster manually? Is it possible without causing damage?
#4
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Re: Sifting on time instead of RPM
Originally Posted by kod99
Originally Posted by hammertime
Originally Posted by kod99
I have a BBC super comp dragster with a powerglide. Right now the transmission shifting is being controlled on RPM (7400) by my Biondo Mega 450. I would like to figure what time interval I should enter into the box, for a starting point, to allow the shift into second gear when the box is controlling the shift by time. I am not using the throttle stop at this time.
FYI its illegal nhra and ihra to shift the car by the mega 450 rpm and have the tach wire hooked to it :shock:
Thanks, David. I haven't looked at the playback tach yet. I assume it shows time and RPM? When I had the chassis certified the NHRA inspector told me that I had to not only unhook the tach wire from the box but cut the dash enough so the tech inspector would be able to see the tach terminal on the box. I assume this is only for sanctioned events?
Does anyone shift their dragster manually? Is it possible without causing damage?
You can shift manually but its not consistent, add a rpm switch and be done with it.
#5
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Re: Sifting on time instead of RPM
Originally Posted by kod99
Originally Posted by hammertime
Originally Posted by kod99
I have a BBC super comp dragster with a powerglide. Right now the transmission shifting is being controlled on RPM (7400) by my Biondo Mega 450. I would like to figure what time interval I should enter into the box, for a starting point, to allow the shift into second gear when the box is controlling the shift by time. I am not using the throttle stop at this time.
FYI its illegal nhra and ihra to shift the car by the mega 450 rpm and have the tach wire hooked to it :shock:
Thanks, David. I haven't looked at the playback tach yet. I assume it shows time and RPM? When I had the chassis certified the NHRA inspector told me that I had to not only unhook the tach wire from the box but cut the dash enough so the tech inspector would be able to see the tach terminal on the box. I assume this is only for sanctioned events?
Does anyone shift their dragster manually? Is it possible without causing damage?
#7
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Originally Posted by chevyfireball
You wouldn't want to be shifting by time would you? If you have any launch problem it may shift too soon.