518 soft shifts

[Leanburn]

 I've had a 518 for a few years now, I've never liked the way it's shifts. Way to soft, it has a transgo shift kit but it's still shifts really soft/ slow especially at high rpm. When I'm racing I have to shift 300- 400 rpm lower than the actual desired shift point.  Is there a way to adjust high rpm presssures or something ?  Completely oblivious when I come to tranys

[1 Wild R/T]

Start by increasing the length of the lockdown linkage..... You do have lockdown linkage don't you?  Assuming you do try making the linkage maybe 1/4" longer & report back...

[Cuda Cody]

You and me both.     I'm curious if the longer rod will help.  Keep us posted.   

Completely oblivious when I come to tranys

[Katfish]

I wondered about this as well, I also had the TransGo kit put in when I had my 518 rebuilt.
I have the Bouchillon cable kit for my kick down set-up.  Seems self adjusting, no way to lengthen?
Interested if you see any improvement with the stick KD rods.

[Brads70]

When I ran the 727 I drilled a hole closer to the fulcrum on the lever arm on the transmission
( shortening the arm).  Maybe that would help? 

[Leanburn]

 I'm running the bouchillion cable as well. I set it so at wot the kick down lever is fully engaged. 
Are you saying to set the kick down lever so it's not fully engaged at wot ?

[1 Wild R/T]

I'm running the bouchillion cable as well. I set it so at wot the kick down lever is fully engaged. 
Are you saying to set the kick down lever so it's not fully engaged at wot ?

No, you want more throttle pressure not less....  More throttle pressure will cause later firmer shifts... But for that to work you either need a different ratio on your linkages which your cable controls Or you need a spring that allows the throttle to continue to travel after the lockdown hits it's travel limit....

For testing purposes just add more tension to the cable & see if it improves your shifts...

Shifts are controlled by throttle pressure trying to overcome governor pressure which allows line pressure to actually apply the power transfer elements...

[Leanburn]

 Sorry, I'm a little thick sometimes, I'm not understanding.  I already have the kick down set so it's fully engaged at wot.  I understand what your saying by tightening the cable for test purposes but that will only help at part throttle??   the part throttle shifts are ok, it's wot shifts that have a delay.

[1 Wild R/T]

Actually it's me that misunderstood, Increasing throttle pressure will firm up shifts and tend to delay shifts.... Sounds like you are getting into an area where your Throttle pressure is higher than your governor pressure so the governor pressure is holding the gear longer than you want..... Or it just could be the timing off the valves... Either way if you want it to shift exactly when you move the shifter you might be better off with a full manual vale body.....  Automatic shifting means the valve body is controlling shift timing.... Sounds like you want positive control, that takes the auto functions out of the picture..... That or consider going to a trans with a electronic control package like modern cars....