Car: '98 Z24 Cavalier 2.4L w/4spd Auto
I was wondering if there is a mildly easy way to say force the transmission into 3rd or 4th, etc. without waiting got the transmission to do it by itself? Or a way to make it stay in a higher gear even with heavy throttle?
I suppose i want to make it like the "man-umatic" transmissions some cars come with now. I doubt this is easy, cheap, or even if it's possible. Why not ask though?
If it's all a matter of signals sent to the transmission via electronics, then any insight to what these signals are?
Other thoughts? I think my brain may be fried from finals, but i hope it's still an understandable question. Thanks!
Note: I'm wishing to avoid any modifications that can not be undone at a later time.
B&M shiftplus will make it shift harder and faster but the transmission shifts based upon need so no controlling it. you can limit how high of a gear it gets into by selecting it on the shifter but really the only thing you are getting out of that is preventing overdrive from kicking in. no real other benefit.
My car may run 18s, but I can do your taxes in 10 seconds flat.
JBO lube - they would never have enough in stock and we'd never see RodimusPrime again
why would you want to stay in a higher gear with heavy throttle?
HpTuners could do you well. I knw you can control several tables that the transmission uses. Like the speeds at which the trans shifts up or down while crusing, part throttle, and full throttle. Also the speed at which it shifts to help control overlaping of gears. You can control force motor current to give you firmer shifts. Lots of stuff to do. You can even turn torque management off to gain a lil power at the possible risk of your transmission.
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whiteboyz24 wrote:why would you want to stay in a higher gear with heavy throttle?
I mainly want to avoid having it kickdown when under constant throttle as it tends to do when i'm going up a hill. I'd rather have the option to let it roll the speed off instead. This is because i have no "need" to keep a constant MPH, and i know i can make it up the hill in 4th anyways (I have managed to get it to stay in 4th the whole way, but i'm not able to do it consitantly).
CheesyPackerFan wrote:HpTuners could do you well. I knw you can control several tables that the transmission uses. Like the speeds at which the trans shifts up or down while crusing, part throttle, and full throttle. Also the speed at which it shifts to help control overlaping of gears. You can control force motor current to give you firmer shifts. Lots of stuff to do. You can even turn torque management off to gain a lil power at the possible risk of your transmission.
I may have to look into this. However this is not something that can be changed on the fly via some controls is it? You'd have to reprogram it each time?
Thanks for the replies! Still looking into this...
If you are looking to shift gears "manually" you would basically have to build your own circuit, wait for Ron to finish his custom pcm, or buy one of the standalone aftermarket transmission controllers. I'm working on a method right now for a basic tap shift. I already have the logic worked out and have all the TTL components sitting in front of me. I just need a breadboard to test it.
As far as a cheap solution...Total invested so far: ~$6, and the only other parts I need right now are 4 momentary push buttons, a couple thermisters and a SPDT switch. Total shouldn't exceed $15.
What's the cost of a new transmission?
For power... I still prefer an automatic, with nitrous & blower... because I never have to let off the gas
But for "driving" I still like my stick. Swap the trans if you want to shift...
John Lenko wrote:What's the cost of a new transmission?
For power... I still prefer an automatic, with nitrous & blower... because I never have to let off the gas But for "driving" I still like my stick. Swap the trans if you want to shift...
Swaping the trans is NOT an option since that would be cost prohibative. I'm not sinking a lot of unnessecary money into this car since this is just something i'd "prefer" to have control over (and i didn't spend that much money on the car to begin with). I'm not looking to do this is try to get any faster (or even for going fast...)
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Whalesac, that sounds pretty interesting. I'd be interested in finding out more. Maybe i could help? Let me know what you have found. Thanks!
my 97 2.4 auto shifted when ever i told it , and i did nothing to it , if i held it in 1st it stayed in first
the 4t40e does not have the electronics to be paddle shift , unless you find a paddle shift that will tie into the shift lever at the trans
[quote=97cavie24ls(™)]my 97 2.4 auto shifted when ever i told it , and i did nothing to it , if i held it in 1st it stayed in first
the 4t40e does not have the electronics to be paddle shift , unless you find a paddle shift that will tie into the shift lever at the trans
It is obvious that you simply don't have a clue how GM electronically controlled transmissions work. The shift lever does nothing more than give the computer instructions on when to apply or release solenoids inside the transmission. It's not a direct link to the gears like a manual transmission. You have two solenoids that determine all 4 gears. Every GM automatic transmission has the capabilities to be "manually" shifted. You just have to know the components inside the transmission in order to do so. Or at the very least buy one of the several GM standalone trans controllers that already exist.
[quote=97cavie24ls(™)]my 97 2.4 auto shifted when ever i told it , and i did nothing to it , if i held it in 1st it stayed in first
Yes the car stays in 1st if you tell it to, but there is NO way i have currently to tell it to shift to 4th or 3rd, or even 2nd before it decides it wants to. This is my main goal in case i have not been clear.
schembo2000 wrote:http://tunersource.gmblogs.com/Racer-Tech/gm-sport-compact-performance-build-book/104742-enginehandbook_04racemodtrans.pdf
page 17.
Interesting. Does anyone know if the 4T40E is controlled via the same SHIFT LOGIC/Solenoid Control? The transmission listed isn't quite the same model so I'd like to double check.
DvBoard wrote:schembo2000 wrote:http://tunersource.gmblogs.com/Racer-Tech/gm-sport-compact-performance-build-book/104742-enginehandbook_04racemodtrans.pdf
page 17.
Interesting. Does anyone know if the 4T40E is controlled via the same SHIFT LOGIC/Solenoid Control? The transmission listed isn't quite the same model so I'd like to double check.
It uses two selenoids in the way the 4T65E does for gear selection, but the logic is different.
4t40e is
Gear..........Selenoid A (1-2)..........Selenoid B (2-3)
1...........................on..................................off
2...........................off..................................off
3...........................off..................................on
4...........................on..................................on
Quote:
4t40e is
Gear..........Selenoid A (1-2)..........Selenoid B (2-3)
1...........................on..................................off
2...........................off..................................off
3...........................off..................................on
4...........................on..................................on
Where is the solenoid that puts the tranny into reverse by holdding the planet gears?
Weebel wrote:Quote:
4t40e is
Gear..........Selenoid A (1-2)..........Selenoid B (2-3)
1...........................on..................................off
2...........................off..................................off
3...........................off..................................on
4...........................on..................................on
Where is the solenoid that puts the tranny into reverse by holdding the planet gears?
Honestly....I really don't know. I have looked through several 4t40e manuals and the Haynes, and none really explain reverse, neutral or park, except that the AB solenoid positions are the same as 1st gear (on/off).
What I plan to do for now though, is keep the J-body PCM controlling everything, except have a switch to change when I want to control the forward gearing (aka Put the car in "Drive" first, then flip the switch). I have a basic design to test first, then I will move on to building the pushbutton/tapshift circuit. Here are block diagrams for both...
BASIC SHIFT CIRCUIT
TAPSHIFT CIRCUIT
The same switching method in the "BASIC SHIFT CIRCUIT" of fliping one switch to change circuits would still be used here with the tapshift. The switch would be placed between the Op Amp outputs and the shift solenoids.
Also, I might add a couple high ohm 10W resistors to provide a load for the J-body PCM when switched to the "manual" shift circuit. Eventually, I would like to move on to PWM control of the torque converter solenoid too, but that certainly won't be for some time.
sorry to necro this thread, but did you ever get this working? does the pcm output 12v or ground? seems like in your circuit you have 12v on both sides of the solenoid ( zero across it).
its possible i've done it with a snapon scanner via the obdII port, i can also lock the torque converter in first. so i definitely say its possible
Its not how fast your car goes....its how much nerve the driver has to push it that fast.
so, just to get this right in my mind, to change gears, one would have to disengage the tcc solenoid, change the state of the 2 shift solenoids, and then re-engage the solenoid?
Weebel wrote:Quote:
4t40e is
Gear..........Selenoid A (1-2)..........Selenoid B (2-3)
1...........................on..................................off
2...........................off..................................off
3...........................off..................................on
4...........................on..................................on
Where is the solenoid that puts the tranny into reverse by holdding the planet gears?
There isn't one. I'm pretty sure that's controlled by the shift select cable. Just like and oldschool transmission. Think of it like this, while you have the range on your shifter, down on the transmission it's just Park -> Reverse -> Neutral -> Forward (rather than D321 which is done electronically)
DvBoard wrote:whiteboyz24 wrote:why would you want to stay in a higher gear with heavy throttle?
I mainly want to avoid having it kickdown when under constant throttle as it tends to do when i'm going up a hill. I'd rather have the option to let it roll the speed off instead. This is because i have no "need" to keep a constant MPH, and i know i can make it up the hill in 4th anyways (I have managed to get it to stay in 4th the whole way, but i'm not able to do it consitantly).
Now, this is where bad ideas come in. What speed are you going up the hill at? If you're hanging right around the normal shiftpoint (i believe 40-45mph) then you could expect it to shift back and forth on flat ground, let alone a hill where you need higher than normal throttle.
How long is the hill? You do realize that the shifting program in the controller for the auto trans is adaptive right? I.E, it learns how it's driven and will adjust shifting more towards that person. It should also eventually figure out that you're driving up a hill by various sensor inputs and decide that it needs to downshift. Which, is of course, the proper way to drive a car up a long steep hill. In fact some cars (and I highly doubt j-bodies are included in this) will actually learn when you're going down the other side of the hill and will downshift to help hold speed on the way down. And then there are some that will downshift and stay that way while going through a series of corners.
I think you are just running into the car's normal operation. It's doing this typically because it's been programmed to make up for the general population's lack of ability to drive properly. Also, it's probably deciding to downshift based on the idea that you'll get more MPG that way. Since emissions and mileage are a big thing that the government requires for them to even manufacture vehicles in the first place.
SHOoff (Tuner Bash Beer God) wrote:You do realize that the shifting program in the controller for the auto trans is adaptive right? I.E, it learns how it's driven and will adjust shifting more towards that person. It should also eventually figure out that you're driving up a hill by various sensor inputs and decide that it needs to downshift. Which, is of course, the proper way to drive a car up a long steep hill. In fact some cars (and I highly doubt j-bodies are included in this) will actually learn when you're going down the other side of the hill and will downshift to help hold speed on the way down. And then there are some that will downshift and stay that way while going through a series of corners.
I think you're giving our transmissions way too much credit. In my short foray in HPTuners, I had some experience with the shift tables. It wasn't so much adaptive, as completely dumb and predictable. This many MPH, at this much throttle? It will be in a specific gear. The thresholds between gears are well-defined. If a person wants their car to hold a gear longer and bog itself, then this is quite possible by reprogramming. It will just end up doing it every time whether they like it or not.
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Geeky wrote:I think you're giving our transmissions way too much credit. In my short foray in HPTuners, I had some experience with the shift tables. It wasn't so much adaptive, as completely dumb and predictable. This many MPH, at this much throttle? It will be in a specific gear. The thresholds between gears are well-defined. If a person wants their car to hold a gear longer and bog itself, then this is quite possible by reprogramming. It will just end up doing it every time whether they like it or not.
I'm pretty sure the program is adaptive. Wether HP tuners lets you change of that logic or not is a different issue. It's not something you should normally notice. The only time I noticed it was on one of my cars. I'd had the battery disconnected for a while so everything in the computer was lost. My little brother had drove it for me since I needed to take my 3400 Cav home. After parking the cav and getting in the other car and driving up the road I noticed that the transmission was slipping in between shifts. And not just a little slip. It seemed like a end of the rope kind of slip. But after about 100 miles or so it cleared up. It was just that the thing started to lean how he was driving the car. Since I drove more aggressive (by a lot) it got thrown off. HPtuners or not, it's in there. The only thing I can think of it being in there for though is for emissions and possibly to cut down warranty issues by not letting some/all trannies shift too hard.
Publikdstrbnce wrote:manual valve body and b&m ratchet shifter
And those are readily available for the 4t40 where?
Have you been able to find a solution yet?
I have a 93 Grand Am with the 3.1 I use on a circle track. I want to be able to downshift into 1st while braking into the corner and hold it through the corner, but most of the time it stays in second and bogs down outside the powerband.
Is there an override in the solenoids for full manual control for this? I don't need the driveability for roads as the car only sees a track in 1st and 2nd gears only.
Geeky wrote:SHOoff (Tuner Bash Beer God) wrote:You do realize that the shifting program in the controller for the auto trans is adaptive right? I.E, it learns how it's driven and will adjust shifting more towards that person. It should also eventually figure out that you're driving up a hill by various sensor inputs and decide that it needs to downshift. Which, is of course, the proper way to drive a car up a long steep hill. In fact some cars (and I highly doubt j-bodies are included in this) will actually learn when you're going down the other side of the hill and will downshift to help hold speed on the way down. And then there are some that will downshift and stay that way while going through a series of corners.
I think you're giving our transmissions way too much credit. In my short foray in HPTuners, I had some experience with the shift tables. It wasn't so much adaptive, as completely dumb and predictable. This many MPH, at this much throttle? It will be in a specific gear. The thresholds between gears are well-defined. If a person wants their car to hold a gear longer and bog itself, then this is quite possible by reprogramming. It will just end up doing it every time whether they like it or not.
No he is right, it is in fact adaptive. The PCM monitors shift times for each independant gear selection and adjusts line pressures and solenoid operation accordingly...
You have to think of it like this...In HPTuners we cannot adjust anything that makes the PCM swing from Rich to Lean and back again in closed loop...nor can we change how it determines STFT and LTFT's. Thats because the tables we mess with are the BASE operation tables the PCM works off of. Adaptives are an addition to those values. Same with the Transmission, we can adjust base pressure and FMC values, but beyond that everything still gets a final say from the adaptives before a command is sent by the PCM.
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