WOT SHIFT POINTS & POWER LOSS

[boostmaster]

I went to the track last night to have a show down with one of my coworkers that has a 03' Mach 1. I really did an injustice to the turbo buick reputation. Best run all night was a 14.3@91mph. I was scratching my head all night trying to figure out were my power loss was coming from, as I would leave everybody in the dust off the line only to watch them just blow by me. Even got smoked buy a couple slow ricers. Trust me it's not a tuning issue i was running 22psi of boost with 0 KR. I gave up trying to post some good times and just started trying to figure out what was wrong. So I had my buddy to ride with me and look @ the data while I drove. What he noticed is that my WOT shifts are wayy low 4200 rpm, what's even more funny is if I lock the tranny at the line the shifts are even lower 3800 rpm. Is this my power loss ? Seems like when it shifts gears I just can't recover. Also tried to manually shift it and if I lock the converter low 1 wont hold when the rpm's come up but will hold unlocked. the tranny shifts fine otherwise and all shifts are crisp and firm with no slippage. Also I tried adjusting the TV cable and have no more clicks left.


BQ trans alto wide band with superior shift kit and super servo.

 

[TurboBuickGNX86]

definitely think you are losing out on alot by short shifts ... find someone to modify ur governor to shift around 5100rpms

 

[boostmaster]

It has a stock gn governor, and the part throttle shifts are perfect. Just wondering if there is anything else that can cause the short shifting.

 

[TurboBuickGNX86]

thats wat i mean... adjusting the TV cable will only do so much... get someone who knows about the 2004r tranny to check the govenor and modify it so that it will shift at the shift points u want it to .... that is the main thing that controls the actual shift points...

 

[boostmaster]

Since it already has the stock governor I'm afraid there would require too much modification to get to the shift points I need. I'm wondering if this has something to do with the tv or tv limit circuit. Also I notice with my pressure guage attached that after the trans heats up I loose tv boost in reverse and manual L1 & L2 could this be part of the problem.

 

[boostmaster]

Need special help with this one please.

 

[87GN_70GS]

Sounds like not enough "MTV up" pressure. Did the shift kit say to leave that spring out? Did your stock VB have that spring in? How much line pressure at WOT do you have?

The hydraulic valve inside prevents locking the convertor in first no matter what you do electrically.

 

[77 cruiser]

The reason the trans. shift @ a lower RPM with the conv. locked is due to the slip of the conv. itself. The trans. shift points are controlled not by engine RPM but output shaft RPM.

Did you put the shift kit in your self?
What RPM did it shift at before?

 

[boostmaster]

Installed the shift kit myself, isn't the first one I've installed, also not the first trans I've built. The trans used to shift @ 4900-5200 rpm. Pressure @ wot is 200psi in all gears. As I mentioned before all my shifts are firm but I have been having a problem with pressure loss in reverse & manual L1 & L2 after reaching operating temps. Normal pressures when cold are 120 psi min tv & 270 psi max tv in reverse, 200 psi min & max in manual L1 & L2. After warm up I get very little boost in reverse 90-150 psi & 150 psi manual L & L2. I don't know if this is part of my problem just giving all the facts.

 

[boostmaster]

I hate to do this but, TTT !!!!!

 

[77 cruiser]

I wonder if it's possible that there's a leak is the circuit that doesn't show up when cold.
Could try another boost valve, maybe??