Jump to content

Shift speed chart?


eclipse5302

Recommended Posts

Does anyone have a shift speed chart for the TGP trans? I've got a 90 TurboSTE (duh), and I need the TPS% / speed chart so I can set the TV cable correctly. I've already tried pulling the cable all the way back, then pushing the Throttle to WOT to set the cable, but it feels like it's shifting too late. It might be shifting just right, but I'd like to verify the shift speed. This chart would be located in any 1990 GM Grand Prix service manual. I've got the GM service manual for my 91 Cutlass, but the shift speeds would be different for the Turbo trans. And there is no chart in my 90 STE supplement.

 

Jason

Link to comment
Share on other sites

WOT and the tach works great, no need for TPS coordination, just know the tach is over by 200 to 400 rpms, so 5,200 rpms at the engine can look like 5,400 to 5,600 rpms on the gauge cluster tach. Since you know about adjusting and getting to that damn TV cable, adjusting it is not such an unknown. You want your WOT runs to shift into 2nd gear at about 5,400 rpms on the tach, lower is always better as this is a torque motor, and lower revs area easier on the engine AND the tranny, besides there is nothing to use/gain by revving too high. Push the TV cable button down (I use a long screw driver to reach that button), and make sure the button does indeed become depressed enough to release the cable, then push the cable in, to lower shift points (that is what worked on the last 2 TGPs I needed to adjust). Test the WOT shift points till you can get a nice low tach read of 5,200 to 5,400 rpms before it shifts into second. The shift point will be lower when it goes into 3rd gear at WOT and is normal. Also tranny/tranny fluid temp has an impact on shift points (another reason why they went electronic later). If your TGP ever goes into 4th gear at WOT freak out now!!! The tranny cannot handle this and will die, al high-speed runs are hard (part throttle obviously) on the stock 4th gear setup. The TGP tranny from mid 1989 through end production is set to NOT shift into 4th at WOT, very early 1989s did, and failed quickly so GM took that function out (GM fixes something fast, unheard of!!).

 

Good luck, and nice to hear someone tweaking things proper, your tranny will appreciate your efforts.

 

Jeff M

Link to comment
Share on other sites

Good info, thanks.

 

But I thought the WOT shifts are determined by the govenor near the speed sensor, and the part throttle shifts are determined by the TV cable. Is this true?

 

So what should part throttle shifts be? Heres what happens...

 

roughly part (light) throttle:

 

1-2 at 14-18

2-3 at 24-27

 

Is this right, or is it shifting too soon? This is after pushing the button in and letting it slide in roughly 3-4 clicks from stock setting (push button, slide it all the way out, press the pedal to the floor, and let it adjust itself).

 

Otherwise it shifts great, clean and firm. Not too bad for my first trans rebuild.

 

Jason

Link to comment
Share on other sites

The governor indeed has an effect, but so does the TV cable and your concern I assume, is there is no complication between them. The gov is fine, nothing to do there (I do have one I have made custom for other reasons), the TV cable is the thing to use for adjustments, just like you are doing, so do it :) . As for the table of shift-points for minimum throttle, I took some time and did some digging and here you are:

 

MIN THROTTLE

1-2 shift

12-15 mph

 

2-3 shift

21-24 mph

 

3-4 shift

43-50

 

BUT, use the WOT/rpms setup as this is more critical then any min throttle/part throttle values, especially since these will fall into line/be what they are once the WOT/rpm values are set.

 

Jeff M

Link to comment
Share on other sites

I set the TV cable today...it shifts at about 5500 (according to the tach, so it's acutally like 5200-5300 RPM) at WOT. The min throttle shifts are right now too. I guess I was misinformed about the operation of the govenor/TV cable.

 

And I know what you mean about WOT in 4th. If you see one of these transmissions apart, you'll see why 4th isn't much of a power gear...it's got like only 1-2 clutch packs...as opposed to 5-6 for the rest of the gears. I can imagine what would happen in 4th if there was some power being put through it...ouch.

 

Jason

Link to comment
Share on other sites

In my tach at about 5600 it shifts at WOT.

 

but as far as I know my car is stock

 

but who knows.

15.00@90.02 in the 1/4

and have been clocked at 138MPH

 

so who knows maybe Im chipped and dont know it...

 

but right now my car is Running like ASS because of needing plugs and wires....and probly a good Run would help being the last time I went anywhere with it was the two flat tire incodent

 

Jeff with your CHip can I get governed at 145-150 maybe 155??

in OD that would not be to high maybe 48-4900 rpms

 

Just wondering.....

Link to comment
Share on other sites

  • 3 years later...

I know I just opened a REALLY OLD topic, but I thought I'd share the results of my own personal testing:

WOT and the tach works great, no need for TPS coordination, just know the tach is over by 200 to 400 rpms, so 5,200 rpms at the engine can look like 5,400 to 5,600 rpms on the gauge cluster tach. Since you know about adjusting and getting to that damn TV cable, adjusting it is not such an unknown. You want your WOT runs to shift into 2nd gear at about 5,400 rpms on the tach, lower is always better as this is a torque motor, and lower revs area easier on the engine AND the tranny, besides there is nothing to use/gain by revving too high. Push the TV cable button down (I use a long screw driver to reach that button), and make sure the button does indeed become depressed enough to release the cable, then push the cable in, to lower shift points (that is what worked on the last 2 TGPs I needed to adjust). Test the WOT shift points till you can get a nice low tach read of 5,200 to 5,400 rpms before it shifts into second. The shift point will be lower when it goes into 3rd gear at WOT and is normal. Also tranny/tranny fluid temp has an impact on shift points (another reason why they went electronic later). If your TGP ever goes into 4th gear at WOT freak out now!!! The tranny cannot handle this and will die, al high-speed runs are hard (part throttle obviously) on the stock 4th gear setup. The TGP tranny from mid 1989 through end production is set to NOT shift into 4th at WOT, very early 1989s did, and failed quickly so GM took that function out (GM fixes something fast, unheard of!!).

 

Good luck, and nice to hear someone tweaking things proper, your tranny will appreciate your efforts.

 

Jeff M

I tightened my TV cable a little bit and then I tok the TGP out for WOT testing with a scangauge and here are my results:

WOT 1-2 shift: ~4,800 RPM

WOT 2-3 shift: ~5,275 RPM

I didn't want to go past there.

I think this is pretty good and I wanted to keep my shiftpoints down, to be easier on the tranny with 12K on it. My only problem is that it shifts kinda hard. I KNOW that my dogbones and motor mounts are SHOT, because when the engine is running you can watch it shake quite a bit. I have also heard that the tranny check valve can cause harsh shifting. I am trying to get it to shift as smoothly as possible, so my question is:

Where is the tranny check valve located? I need to check it out and see if it should be replaced along with my motor mounts.

Also, what do you guys think about my shiftpoints? Do I need to change them at all from where they are currently?

Thanks

Link to comment
Share on other sites

If you mean the Vacuum Modulator, which affects the smoothness of non WOT shifts, then it is on the front of the trans just below the turbo. It should have a vacuum line going to it, with a check valve attached to vent boost.

You can buy adjustable modulators at parts stores, there are several threads about how to adjust them and such in the General, or Powertrain section.

Link to comment
Share on other sites

  • 2 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...