I can connect second gear starts to reduced torque multiplication but I cannot connect second gear starts to increased slippage inside the torque converter, or at least none of the technical articles I have read are describing it like that.That is what I am looking for, a technical description that says second gear starting increases slippage inside the torque converter (as you describe).
It is entirely a matter of the gear ratio to the road wheels. Nothing else happens in the transmission.
When the transmission is in first gear, the road wheels sill slip before the torque converter slips, because the gearing gives the road wheels more torque. Your wheels spin before the torque converter has a chance to slip.
When the transmission is in second gear and the car is not moving, the road wheels have less tendency of slipping because of the reduced torque. The slipping point of the torque converter is unchanged. But now, the torque converter will slip before the road wheels slip, because the slipping point of the wheels has changed. The wheels will not tend to spin.
It works. My last two vehicles had it. That’s why I want it.
What would be the indication that the torque converter is slipping? Again I ask if you can link me to any third party description of this converter slippage. We are big on getting technical theory of operation from 3 rd parties on this site.
If I am climbing a hill in “D” with my 3 speed auto and I downshift too “2nd” I can’t say what I experience could be called slippage. How would me moving to “2nd” while climbing the hill be any different than you selecting “2nd” in your driveway?
I think what you are calling “torque converter slippage” is really just the effect of less torque multiplication. Now if some internal valving change or solenoid change within the transmission is done I can get onboard, but we are speaking of a simple 1st gear lockout.
Gees guys, a torque converter always slips, except in TCC lockup, and that doesn’t happen until you reach a relaxed speed, above a certain speed,in top gear or in some cases in 3rd.
It is just easier to spin the wheels in 1st than it is in 2nd. 2nd gear does work better while driving off in snow. I had a '99 S-10 4 wheel drive, with the option of selecting 2nd gear and it was good in snow.
Buy a set of 4 winter tires and your problems will likely be solved. Buy winter tires that have ice/snow traction not snow tires which are sold under bargain prices.
On ice or extreme conditions many times Traction control is hinderance more than a help. That is why they include a defeat button. I think traction control is more for wet pavement and helps a bit in somewhat slippery conditions.
"What would be the indication that the torque converter is slipping? Again I ask if you can link me to any third party description of this converter slippage. We are big on getting technical theory of operation from 3 rd parties on this site.
If I am climbing a hill in “D” with my 3 speed auto and I downshift too “2nd” I can’t say what I experience could be called slippage. How would me moving to “2nd” while climbing the hill be any different than you selecting “2nd” in your driveway?
I think what you are calling “torque converter slippage” is really just the effect of less torque multiplication. Now if some internal valving change or solenoid change within the transmission is done I can get onboard, but we are speaking of a simple 1st gear lockout."
You can test this yourself, IF you have second gear start or a car with a 2 position. Go partway up a hill, then stop. Put the car in 2 or second gear start. Step on the gas, but not enough to move the car. The torque converter is slipping at this point. Otherwise, the engine would have to stop turning.
Or stop at a stop sign with any car. If the torque converter were not slipping at this point, the engine would have to stop turning to allow the car to stop.
The change in gear ratio is the entire effect. On ice, the change in ratio makes the slippage more likely to occur in the torque converter than at the wheels.
Let’s look at this mathematically.
Suppose the following are true:
-
The torque converter slips if it absorbs a torque of 1.0 X when the road wheels are not turning, measured at the input shaft of the torque converter.
-
The road wheels slip on the ice at a torque of 2.0 X, measured at the output shaft of the transmission.
-
The gear ratios are:
1st gear - 2.5:1
2nd gear - 1.6:1
3rd gear - 1:1
4th gear - 1:1.6
In first gear, the road wheels slip when the output shaft torque exceeds 2.0 X. Because the gear ratio is 2.5:1, the torque on the torque converter is only 0.8 X. Because 0.8 X is less than the needed 1.0 X, the torque converter does not slip.
In second gear, the torque converter slips when the input shaft torque exceeds 1.0 X. Because the gear ratio is 1.5:1, the torque on the road wheels is only 1.5 X. Because 1.5 X is less than the needed 2.0 X, the road wheels do not slip.
It is a matter of the weakest link in the chain slipping first. Changing gears moves the weak link.
Wow, some of you guys are really biased and not helpful at all.
All this guy wanted to know was if he could install a switch for second gear start. If yes, say yes, in no, say no. AND MOST IMPORTANT if you don’t know, please don’t respond. It’s annoying to read these threads and have 90% of the members just saying completely different things, eve after the OP said he didn’t want to use other methods. It is against the rules, and your getting really off-track.
I just have to ask.
What was your old car with 2nd gear start? I did not see it mentioned.
The way you get out of a slippery driveway is putting down torque correctly(may be solved by 2nd gear start), traction of tire(previous all-seasons may have done well on ice), and weight distribution of vehicle. Your Bonneville likely has a 3.8L which puts out a lot of torque and hence likely causes the slipping. What was your size of old motor?
Old car was a FWD 3.8 L 1995 Ford Windstar. It does not really have second gear start, but the “real” 2 position of the transmission gives the same effect by keeping the transmission in second. The weight distribution was worse than the Bonneville.
The vehicle before that was a RWD 1982 4.2 L Ford E150 Club Wagon. It had no trouble getting out of the driveway in the “real” 2 position. The weight distribution was good for RWD.
My vehicle before that was a RWD 1976 Olds Cutlass Supreme. It had no way to start in second (It had the S position that shifted between 1 and 2), and I spent a fortune on salt and sand to get it out of the driveway reliably.
A friend has an 1994 Olds Achieva with a 3.0 engine, FWD and the “fake” 2 position (shifts between 1 and 2), but no second gear start. We have to be careful to keep it out of the driveway in winter weather conditions.
Another friend has a 2002 Kia Rio Cinco, 3.0 L FWD with the “real” 2 position. It has no trouble getting out of the driveway.
Another friend has a 3.8 L Subaru Outback with FWD and the “real” 2 position. It has no trouble getting out of the driveway.
Another friend has a 3.8 L Ford Ranger with the “real” 2 postition and FWD. It has no trouble.
A Kia Sedona with the 6-speed transmission and FWD could not get out of the driveway, because the transmission would let it start in 1 or 2, but the ratio needed was 3, which the transmission would not shift into unless the car was moving.
A relative has a 1999 FWD Buick 3.8 with traction control, but no second gear start. He can get it out of the driveway with the traction control, but only after many attempts. Many times the brakes lock up, preventing the car from moving. He needs a running start to get out.
A colleague has a 2010 Kia Soul with 6 speed automatic transmission and FWD. It has the same problem the Sedona has.
A friend with a little 1989 FWD Plymouth Horizon with a 4-cylinder engine and the “fake” 2 position can not get out of the driveway.
A Hyundai Tiburon with the “fake” 2 position got stuck in the driveway. It had a switch for Power and Economy. Neither position helped.
A delivery truck with a stick shift got stuck in the driveway. Don’t know the details. A tow truck pulled it out from the street.
A 1985 Plymouth Voyager with RWD and the “fake” 2 position got stuck in the driveway.
A RWD Pontiac Firebird (year, drive, and engine unknown) with the “fake” 2 position slid trying to get up the driveway and ended up at right angles to the driveway. Since my car was trapped in by this car, I had to have a friend go buy me some sand to get it out with.
Note that all of the cars with “real” 2 positions can get out in 2, but not in D.
I am simply asking for a link from a transmission manufacture or remanufacture or from a car manufacture how this system is suppose to work. Like I posted all I find is a mention that the trans is locked out of first,I do not find any mention of any diversion of torque converter slippage like the OP claims. It seem he came up with his own theory of operation but all printed material on 2nd gear starts says it works simply because you do not have as much torque multiplication in 2nd as you do in first. If there is some kind of increased torque converter slippage I would think it would be described in some technical article somewhere.If the OP can’t find a link describing his understanding of what is happening just say so. I do find descriptions about second gear starts but no details about increased torque converter slippage. It stands to reason someone other than the OP has the viewpoint of increased converter slippage and would write something on it.
Just what is a “fake 2” position? I think it starts out in 1st and shifts up to 2nd and no higher.
And all that talk about converter slippage, well a converter always slips no matter what gear you are using. (except when the TCC locks up). And that dosen’t happen at start up.
“I do not find any mention of any diversion of torque converter slippage like the OP claims. It seem he came up with his own theory of operation but all printed material on 2nd gear starts says it works simply because you do not have as much torque multiplication in 2nd as you do in first.”
That is entirely how it works.
“If there is some kind of increased torque converter slippage I would think it would be described in some technical article somewhere.If the OP can’t find a link describing his understanding of what is happening just say so.”
You are missing the point. It doesn’t increase the torque converter slippage at all. You are imagining something that is not there.
It decreases road wheel slippage (by decreasing road wheel torque) to the point where the converter slips at a lower engine torque than the engine torque needed to make the road wheels slip.
Thus, the torque needed to make the road wheels slip never reaches the wheels, because the converter slips first.
This happens solely because the gear ratio is different. Nothing else happens.
How many times do I have to say this?
“It seem he came up with his own theory of operation”
No, Troubleshooter is just describing things in a slightly different way than you.
It’s not a radical new theory.
Maybe it’s not technically precise, but is this an open forum or a formal classroom?
As EllyEllis said a torque converter always slips.
It’s most obvious when the wheels aren’t turning because an IC engine has to idle (or does it?).
If 1st gear = 2.5:1 & 2nd gear = 1.6:1 then there’s only 64% as much torque at the wheels in 2nd gear as 1st,
assuming the torque converter behaves the same in each case.
This makes it easier to control torque at the wheel with the throttle.
Troubleshooter,
Now that your topic has been hijacked by thread terrorists, and executed on the internet, how about we get back to the beginning?
You said that you found an article that gives you directions on how to enable the second gear start feature on your car.
Have you tried this yet?
What question do you actually want us to answer for you?
If you can’t tell already, none of us here have followed the instructions the article you found (but have never provided to us to review -hint hint) to enable this feature on your car before, so NONE of us have any experience with this.
So we can’t even tell you if this is possible.
Chances are, you know way more about this than we do.
So I recommend one of two things:
Buy winter tires that are rated high for ice traction or install the switch, and see if it works.
And yes, you can test this feature anytime you want.
Just activate the button, and the car should start out in second gear.
The acceleration of the car should be entirely different than if you started out in first gear.
BC.
troubleshooter (OP) says:
"I read on one website that, because the Pontiac Bonneville was sold as more of a muscle car, they didn’t offer the SGS option, but that the computer still has the special connection pin for it. In other words, it was a marketing decision, not a matter of whether the transmission could handle it. They didn’t include a place on the instrument panel for the light because of this.
If SGS could be added, I was going to remove the idiot cell phone holder they provided (because nobody should be using a phone while driving), and put the switch and light there."
I agree with Bladecutter… it is obvious that no one in this forum can confirm or deny your claim, and you already seem to know about this subject better than anyone around here. I would suggest you try to locate this pin connector, and before investing in the switch and LED, simply jump it with a wire and see what happens.
by the way, your friend with the 2008 caprice… does he live in kuwait by any chance?
this very nice car is based on australia’s Holden Commodore. is coming soon as a police car:
http://www.chevroletcapriceppv.com/#home
it is being made available as a fleet car but apparently GM is thinking about making it available to the general public as well.
First off, you are wrong about tires. All-seasons are better than "regular" tires on ice, and snow tires are better than all-seasons, even on ice. They *could* make the difference. Personally I just use all-seasons, but in the worst weather I have had trouble. If I had to get somewhere I would get snow and ice tires.
Regarding traction control -- I have a 2000 Buick Regal, but the systems should be very similar. It retards the timing, and then if there is still spin it will shut the fuel off to 3 cylinders. The Caddys and cars with a supercharged engine could use the brakes to brake the wheels, but the system like on my Buick would not. Newer models have electronic throttle control, so they can electronically let up on the go pedal.
I've driven on very poor surfaces, as long as you are light on the throttle the traction control will prevent you from slicking up your surfaces. I've driven on ice, as well as on that snow that melts into ice with the slightest provocation. With the 3.8L if you are light on the throttle the wheels will naturally spin up to only about 3 or 4 MPH even if you are stuck, but after probably 1 turn of the front wheels, the traction control slows them down to about 1MPH (if that). A few times when i couldn't quite get up some hill (when I really could have used those snow tires), I actually could pop open my driver door and give a push with my foot, the traction control will get you going with the slightest bit of grip or momentum. HOWEVER, I am guessing like my Buick, your Pontiac probably has pretty wide tires. This will harm your traction quite a bit.
Finally.. on my previous GM vehicles that did not have traction control, I actually found due to the low end torque, plus a relative reluctance to rev, that I had an easier time controlling wheel speed in 1st gear than in second.
Oh finally.. they don't make a Subaru Outback that is FWD (front wheel drive), it would be AWD (All Wheel Drive). They also did not make a FWD Ranger, so that was likely 4WD (four wheel drive.) This of course would help traction considerably.
(Some people use AWD and 4WD interchangeably.. but, traditionally AWD referred to a system that can be used at all times, usually it runs power to 2 wheels until there is some slip and then distributes it to all 4. 4WD refers to systems that rigidly lock all 4 wheels together, so it cannot be used on dry pavement without damage (since the wheels turn at different speeds when cornering or turning.))
As for a second gear start... well, I don't know if there is a factory method. BUT.. get this. The electronically controlled automatics, the gear shift physically selects Park, Reverse, Neutral, or 3rd. Then a postiion sensor tells the computer if you are in 1, 2, 3, or D. The computer then picks the gear it wants with shift solenoid A and shift solenoid B. Wikipedia says "shift solenoid A" was renamed "1-2 Solenoid" for OBDII vehicles, and "shift solenoid B" renamed "2-3 Solenoid", and has this table:
1-2 Solenoid 2-3 Solenoid
1st Gear On On
2nd Gear Off On
3rd Gear Off Off
4th Gear On Off
So, I guess you could wire up some circuitry to force that combination, and the tranny will be in 2nd gear no matter what the computer wants. You might throw some codes though since the computer will be commanding 1st and the tranny staying in second.
(Bladecutter May 9)
“You said that you found an article that gives you directions on how to enable the second gear start feature on your car.
Have you tried this yet?”
The directions were for older models (1994-1998), and were written before my car was made. I wanted to make sure this still worked before damaging something, in case they changed something in that connector.
“What question do you actually want us to answer for you?”
Can it be done on this particular car?
“If you can’t tell already, none of us here have followed the instructions the article you found (but have never provided to us to review -hint hint) to enable this feature on your car before, so NONE of us have any experience with this.”
Google and you shall receive:
“So I recommend one of two things:
Buy winter tires that are rated high for ice traction or install the switch, and see if it works.”
I now have the tires. We will see if this really works come November. The wide wheel design here is a handicap.
“And yes, you can test this feature anytime you want.
Just activate the button, and the car should start out in second gear.
The acceleration of the car should be entirely different than if you started out in first gear.”
That’s how I knew I didn’t have a real 2 position.
Your tachometer also tells you. It moves suddenly when a shift happens. And mine shows a shift in the 2 position.
I’ll have to ask my friend again, but he said he has a FWD Ford Ranger. It’s a little pickup truck, not an SUV.
That Subaru was not an Outback. It was the smaller one they make that looks like an Outback (can’t remember the name right now).
My friend got his Caprice from a government auction, so maybe it was a fleet vehicle.
Troubleshooter:
Is there a reason this can’t more easily be resolved with a good set of winter/ice tires? Blizzaks or equivalent will certainly help you more than SCS.