700R4 2nd to 3rd shift; how can I speed up this shift?
Looking for some advanced technical information on 2-3 shift timing:
I data log RPM during my 1/8 mile runs at Irwindale(appro 7.26 ET). I had to slow my car slightly so all shifts now occur in D3. My 1-2 shift is very sharp, but my 2-3 shift is slightly lazy - but does not flair at all. I realize that 1-2 is just a band engagement while 2-3 is a combination of band release and clutch engagement, so maybe I can not have as sharp an RPM drop during the 2-3 shift. I am hoping the trans experts help me out so I can be sure I am doing everything right. I am no threat to the great rebuilders who help with this site, just an enthusiast that rebuilds and tunes engines, trans, diffs, suspension, etc.
My Det (WOT) line pressure in D3 is 225PSI (I just fine tuned this due to a minor flair at 170PSI). My 1-2 band feed orifice is .110 and I have the Corvette servo with the Trans-Go modifications. My feed to D4/D3 which goes through the manual valve, then to the 2-3 shift spool, and then on to the 3rd clutch is .116.
Is this .116 orifice 3rd clutch orifice large enough? Can it be larger?
Could I be loosing flow through or around the white rings on the input shaft?
Is there some other restriction in the path of the 3rd clutch oil, or a restriction to the release circuit of the 2nd servo?
I see posts discussing double feeding the 3rd clutch, but I think they are for another trans?
What changes would best ensure fast oil flow to the 3rd clutch?
Thanks, any ideas would be appreciated!
Last edited by Rick Johnson; May 6th, 07 at 1:13 AM.
Reason: clarity improvement