Add performance shift option to 98 4L60E trans
 

There was a way I came accross a long time ago, hope there are some people out there that may know.

There was a post about someone figuring out how to add a switch to his fbody that enabled the transmission to go between the Normal shift tables and the performace tables with a push button switch. (Like the low/haul mode) Any info about wiring please post up or PM me.

I know how to do it on a 99+ pcm I'm looking for it on a 98 PCM.

is there a difference? no j1-71 pin on your pcm?

http://www.hptuners.com/FORUM/showth...324#post128324
http://memimage.cardomain.com/member...35_86_full.jpg

does the 98 even have the performance switch or tables?

no the 98 does not have the switch table like the 99 pcm does, yes I have pin 71 available

well how does that work and what do i half to do to make it work on my 2000 ws6?im coures on this also?

just click on the link above and read the 1st 2 pages.
basically you just hook up a momentary switch between any old ground and pin J1-71 on the PCM. tapping the switch switches between normal and performance tables (which are never used until you enable and wire in the switch).

thing about it is that you gotta be able to tune the performance tables. a major part of that is enabling the switch in the tune. if they're not there, i have no idea what would happen if you hit a momentary ground switch on that pin.

with hptuners you can tune a couple different performance table parameters like shit points, line pressures, etc. i had it initially setup for holding each gear til it is wound out (ie, staying in 1st and not shifting into 4th at 30mph when i let off a little).

I did it a few months back and love it.
like said before, stock its turned off and shift tables are the same, so if you hit the buttob nothing will happen.
I have two switches, one for performance shift and on for full manual shift and a B&M Megashifter ratchet shifter.
the nice thing about it is you can go very conservative with your normal shift setup, and VERY aggresive with the performance shift settings......in performance mode I have all delays and torque management zeroed out, and pressures and shift points raised so it is down right brutal when it shifts :)

look on HPtuners web site, I think they have the needed pinouts for the 98, I know on newer computers its pinout 31 & 71

So, if you are in a parking lot, or cruising through your neighborhood going like 20mph. Usually if you let off the gas, it will shift into a higher gear and basically be idling as you are driving. With doing what you did, when will it actually shift?

I HATE that the car does that, it bothers the shit out of me. My car is so damn loud and when it shifts like that the drone is almost unbearable. If I pull the shifter down into 2 or 1, it will obviously be better, but I don't want to have to do that all the time.

with that setup, it would stay in each gear until you wound it out or dropped below a certain mph/rpm i picked out to shift into a lower gear.
i did it that way so if i was going to launch the car from a roll or let off the throttle for entering a corner, i wouldn't have to wait for a downshift when i hit the throttle again. even though i let off the throttle, it would be in the right gear.

you might as well just drop the shifter down into 2.

ok now back to my origional question, has anyone figured out how to do this with the 98 pcm? The pin 71 is available but there is no option in the trans switch mode.

hmm. i thought this was only for OBD1 cars and thats why GM dropped it after 1995? Then again i've heard of 96-97 LT1's being able to add it. not sure about LS1's though. i have it stock on my car. it was only installed on 1994-1995 Formulas and Trans Ams

Still Lookin for info.

How's the performance shift feature work with a shift kit?

excellent, I have mine setup with a civil tune for the street and down right brutal tune for racing. .....fully built a4 with transgo shift kit and 3,800 stall

Have you ever put a pressure gauge on your trans to see what happens when you do this? I almost think from reading this thread if you do not have the performance tables your trans might be in a max line pressure condition. IMO that is a bad thing and would not recommend it. What is the circuit of this pin you guys are talking about?

i believe all LT1 cars had it in the PCM. i guess it was a matter of the original owner actually paying GM to wire up the switch. My PCM had the performance table/s in it. I had it tuned to where i run it all the time. There was a small difference in feel, nothing spectacular.

nope, line pressure is about 1-2 % higher in performance shift mode.....the main difference is shift speed, rpm, and delay.....it is a separate table in the trans section.......it is the tow/haul option that you enable and setup.....then change to with the momentary switch.

Keepin alive

Personally I have no use for "non-performance" mode,
and I just set it up so it drives the way I like - econo
at low pedal (though I don't starve the line in order to
squeeze out that last MPG), and pedal-proportional
shiftpoints so it follows your foot all natural-like.

So ask yourself, is having "economy mode" worth any
work, or do you just want to tune it to suit?

Hey Jimmyblue, that's the beauty of having the mode options, you get the best of both worlds. My performance mode is setup VERY aggressive for the best performance, and my normal mode is set very conservative to give the most mpg possible...no give and, just like driving two different cars.

You can even go a step further now and run a dual tune computer that let's you have two different tunes for the engine, flip the switch, turn the key off, turn key back on and you have the alternate tune now...think of getting to the point with lean cruise, DFCO, optimized spark and tranny properties set just for the best mpg and then the other tune setup for performance only with no need for any economy because you only use the aggressive tune when you want it