Shift points moved after Torque converter?

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brian_23456

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Apr 20, 2005

#1

• Apr 20, 2005

• #1

Well, i got a 2800 stall PI torque converter in this weekend and now when I am at WOT my car shifts into second REALLY late. So late that I am not going to floor it again until I get this figured out. I have a diablo delta chip that I still need to get programmed, will this solve my problem? Also I heard that a different valve body would do the trick.

 

streetstang03

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the dark side of the moon/home of the 1999, 2003,

Apr 21, 2005

#2

• Apr 21, 2005

• #2

you can always get s fully manual valve body and control the shift points yourself.

 

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brian_23456

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Apr 21, 2005

#3

• Apr 21, 2005

• #3

Yeah, i know.

 

B

brian_23456

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Apr 23, 2005

#4

• Apr 23, 2005

• #4

Anybody?

 

propellerhead

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Apr 23, 2005

#5

• Apr 23, 2005

• #5

Dump the chip for a handheld tuner so you can change shift points all day till you're happy with them.

 

Mike97gt

it doe snot

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the people's republic of massachusetts

Apr 23, 2005

#6

• Apr 23, 2005

• #6

brian_23456 said:

Well, i got a 2800 stall PI torque converter in this weekend and now when I am at WOT my car shifts into second REALLY late. So late that I am not going to floor it again until I get this figured out. I have a diablo delta chip that I still need to get programmed, will this solve my problem? Also I heard that a different valve body would do the trick.

Click to expand...

this is because the torue converter is much looser now.. . you need a shift kit too firm the shifts back up... and a programmer too change the shift points..

 

DBMSTNG

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Apr 23, 2005

#7

• Apr 23, 2005

• #7

there is a delay between when your computer tells the transmission to shift, and when it actually shifts. when you alter the car in a way that makes the rpm climb faster (IE: gears, tq convertor, supercharger), the engine will gain more rpm in that same time delay making it shift at a higher rpm if it shifts at all. changing the shift points lower and/or the J-mod will help.

 

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brian_23456

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Apr 23, 2005

#8

• Apr 23, 2005

• #8

Hey, tahnks for all the replies!
I think I may go with a valve body and programmer.

 

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brian_23456

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May 14, 2005

#9

• May 14, 2005

• #9

I put in a PA valve body and got the programmer. At WOT the car wont shift at the RPM I set the programmer at, it will hit the rev limiter. If I set it at 5200RPM, still hits rev limiter.
Also the PA VAlve body came with different 1-2 and 2-3 accumulator springs, With the Jmod dont you remove springs to get firm shifts?
Would like some help with this problem, kind of sucks.

 

Kurt2002

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May 14, 2005

#10

• May 14, 2005

• #10

brian 23456,, are you having lockup issues? When I installed mine converter my car would lockup in 2nd gear at around 4500rpm and unlockup, did the same thing in third.

 

B

brian_23456

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May 14, 2005

#11

• May 14, 2005

• #11

Yeah I have similar problems , not exactly the same though.
So do you know what is causing it?

 

nyuk98gt

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May 14, 2005

#12

• May 14, 2005

• #12

brian_23456:

Shifts are commanded by either mph or rpm, whichever target is hit first. If you are hitting the limiter, set the rpm target lower. As DBMSTNG said, the engine speed is climbing quicker and there is not enough time for the shift to complete from the time the command is issued. J-mod will work and a chip (SCT, imho) will let you fine tune things.

Kurt2002:

You have an SCT chip so tell your dealer about the shift problem and they will re-map the lock/unlock curves to eliminate the problem. If you have the cash, you can buy the ProRacer package and fix it yourself!

 

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brian_23456

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May 15, 2005

#13

• May 15, 2005

• #13

If I lowered the rev limiter, wouldn't I just hit it sooner (instead of shifting)?

 

Kurt2002

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May 15, 2005

#14

• May 15, 2005

• #14

I'm taking it today to get it fix, I'll let you know if they fix it or not

 

nyuk98gt

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May 15, 2005

#15

• May 15, 2005

• #15

brian_23456:

Don't lower the limiter, lower the commanded rpm shift point.

Example: Current shift point is 5000 rpm and the rev limiter is 6000 rpm. The shift does not have enough time to complete in the time between 5000 and 6000 rpm and the rev limiter is hit. Lower the shift point to 4800 rpm: this increases the interval from 1000 rpm to 1200 rpm and gives more time for the shift to complete.

Even with a "4800 rpm" (example only) shift point, you will have to make a run and observe exactly where the shift occurs.

*edit: Hit the 'reply' button too soon (*blush, blush*). Once you have the required interval figured out, you can then raise the rev limiter by the appropriate amount. As mentioned before, the J-mod will quicken the shifts and, most likely, eliminate the 'bouncing off the rev limiter' problem. This is the (preferred) first step, imho. *end of edit.

Chris

 

nyuk98gt

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May 15, 2005

#16

• May 15, 2005

• #16

Kurt2002 said:

I'm taking it today to get it fix, I'll let you know if they fix it or not

Click to expand...

Good luck. Looking forward to hearing that "it's all fixed up!!"

Chris

 

Kurt2002

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May 15, 2005

#17

• May 15, 2005

• #17

well it looks like it has to wait a couple of days, the tuner had to go out of town for some reason.

Looks like tuesday or wednesday.

 

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brian_23456

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May 15, 2005

#18

• May 15, 2005

• #18

Yeah, I think the lowest I've put my shifts point was 5100. 5700 I think was the factory setting. I'll try 4900 tomarrow.
With my valve body came 1-2 and 2-3 accumulator springs that actually made them stiffer to push up on. With the J-mod you take out springs, correct?
So, should I put the same accumulator spring setup as the J-mod and use my PA valve body?
Does that sound like a good idea or not?

 

nyuk98gt

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May 16, 2005

#19

• May 16, 2005

• #19

brian_23456:

The 2-3 accumulator spring comes out (there is only one and it is in the bottom).

For some applications, one of the 1-2 springs can be removed (I don't recall which one) but it makes the shift pretty hard. Some like the "single spring" 1-2 shift and others find it too hard for daily driving. FWIW, I just took out the 2-3 spring and all the shifts are quick and firm.

PA is a good company and they are familiar with the J-mod. I would just call them and ask if their valve body can be "improved" any further.

Chris

 

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brian_23456

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May 16, 2005

#20

• May 16, 2005

• #20

Yeah, I'll call them tomarrow and see what they have to say!