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Lowering Shift Points

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Justa6MB

Member
Joined
Nov 14, 2011
Messages
224
I've been chasing what I believe is false knock retard. It is RPM related and starts at about 5700. Last year my car was shifting 1-2 at around 6,000 and stalling at 4,000 at 0 boost. So I sent the lock up converter back to PTE to have it tightened it up. Dusty instructed them to drop it 400 RPM. I haven't checked what it's at a 0 boost, but I am still seeing 5700+ RPM on the 1-2 shift - and sets the knock sensor off as soon as it hits 5700. Also this is with lower boost - 15 psi as I'm just getting going this year. My question is will increasing the boost increase the shift points? And what is involved with lowering my shift point(s) 200 or 300 RPM to get me out of the 5700 range? A friend of mine has a non lock up from Dusty and he never gets above 55-5600 I'm pretty sure - and he's making more power than I am.
Thanks
D
 
What valve body and governor are you running.

I would be inclined to add a bit of weight to the high speed governor weight. I believe it is the smaller one. Maybe a gram to see where it puts you.
 
The trans shift points are determined by the governor pressure and shift valves. The governor works via centrifugal force. The higher the driveshaft speed the higher the force. Sounds like your converter is not correct for the application. Your flash stall is too high and yes the more torque you put into the converter the later it will couple which is why you are seeing high shift rpm. The driveshaft speed is too low relative to engine speed because of poor converter efficiency so the governor pressure isn't high enough to act on the shift valves.
 
I uploaded a PL file which shows it is flashing to 4960 on the 1-2 shift and 48-- on the 2-3 shift - at 15/16 psi. This was just some road passes - nothing too long. Last fall at 20 psi it was shifting at 6,000 and not dropping below 5800 on a 1/4 mile pass. I don't know what valve body and governor is in there, the tranny is from EA. I was debating on going to a non lock up converter vs restalling the lock up - and I went with the latter. Maybe shudda came up with the money... How hard is it to add some weight to the high speed governor?
 

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Justa6MB said:
I uploaded a PL file which shows it is flashing to 4960 on the 1-2 shift and 48-- on the 2-3 shift - at 15/16 psi. This was just some road passes - nothing too long. Last fall at 20 psi it was shifting at 6,000 and not dropping below 5800 on a 1/4 mile pass. I don't know what valve body and governor is in there, the tranny is from EA. I was debating on going to a non lock up converter vs restalling the lock up - and I went with the latter. Maybe shudda came up with the money... How hard is it to add some weight to the high speed governor?

There's no way to get a converter that loose to work properly behind one of these engines. I would go to a PTC 9.5". The converter is
The problem.
 
Crap, that's what I was afraid of. When I built up the car my goal was to have it capable of running in the high 10's, but would typically be running 11.50 somewhat reliably because I don't have a roll bar. I was told the 10" PTC lock up could do that. So that's why I had it re-stalled instead of dropping $1,000 on a 9.5 non lock up.
 
Crap, that's what I was afraid of. When I built up the car my goal was to have it capable of running in the high 10's, but would typically be running 11.50 somewhat reliably because I don't have a roll bar. I was told the 10" PTC lock up could do that. So that's why I had it re-stalled instead of dropping $1,000 on a 9.5 non lock up.
 
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