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Old 02-05-2008, 08:42 PM   #11
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On my car... the lockup is actually part of the torque converter! It is available in top gear, at any throttle opening (and by design disconnects whenever you let off the throttle), and the same gearbox was used on the 3.0i V6 model

The clutches, on the other hand, aren't great (see bignissans.org.uk for a description of the gearbox and the problems it has when asked to handle a V6!). It was *very* advanced for its time... and therefore has its problems if pushed too hard.

I have just got another copy of the service manual, which includes full stripdown/rebuild instructions for the transmission. When I get time... I will see how easy it is to get to the lockup solenoid!

yi5hedr3 : My tyres are pumped up to 40PSI (that is daring with the sidewall pressure being 35PSI). It clearly made a difference from 28PSI... I can now coast down a multistorey carpark at work, and do about 5 floors before restarting the engine, prior to increasing the pressure, I could only coast about 1.5 floors before the car stopped.

My next tyres will be LRR with the highest sidewall pressure I can find. 35PSI is a joke!

P.S. I didn't get that manual transmission in the end, but am on the lookout for a FWD manual to fit to this car. Also wondering whether to get a 3kw motor fixed up to the car, and park in the sunlight (I worked out, I could collect enough power with 100W of solar panels to do twice my commute per day, so could end up paying v. little for petrol, using it only for acceleration, and then using the motor for most of the journey).
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Old 02-06-2008, 09:50 AM   #12
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I have a 4 speed auto in my Cavalier. If I'm watching the ScanGauge and see it's not coming out of the 20's relatively soon, I just let off the gas and lightly pump it. This gets me up into the 30's more quickly than just holding the accelerator down through the gears.It may not be as good as a manual might be,but I wouldn't say I have no control of the gears changing.
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Old 02-06-2008, 07:58 PM   #13
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My transmission is so old, the torque convertor is (as new) very slippy, and lock-up engages only at highway speeds. I just looked through the service manual - no way at all to change lock up (all hydraulic, the only solenoids are for preventing lockup occuring. I'm going to unplug that one so I can have lockup when cold etc

I have noted that, there is an electronic control box to replace the hydraulic control box (and I think the rest of the transmission is the same). I'm going to research this, in case I can get one for cheap from a scrapyard. If I did this, I would be able to control the lockup.

The way to control the lockup on the hydraulic box, is to engage it 'all the time' from the hydraulic viewpoint, but then, set the lockup-cancel solenoid to always be 'cancelling' it, unless you are pressing the lockup button (or switch which can be used when cruising on the highway). The other good thing is that the lockup would disengage when you stop the car anyway (it uses hydraulic pressure - if you tried to engage it at very low RPMs it would probably just shudder or slip).
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Old 02-07-2008, 03:13 AM   #14
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Yeah, I went with grill blocks and other mods to try and get my truck to warm up as quickly as possible, so it will engage TC lock as quick as possible. Right now it's about .5 miles or so from cold and before it engages I go about 5 MPH slower.

As far as around town I've tried various types of acceleration, the best seems to be to accelerate fairly quickly to 35ish and then be very light on the gas. Even though I can get the TC to lock at 42 or so with a light pedal (less torque) it's hard to maintain and there's always a redlight coming up soon anyway, so I found that sticking to 30-35 (about 5-10MPH below the 40MPH limit) I can pretty much maintain that speed and time the red lights, etc.

As for TC inefficincy, during hard acceleration it actually gives a boost to the torque to the wheels, as you said it's only really at low rpms or low torques when not TC engaged that it's really bad. That's why I accelerate fairly quickly (but not WOT) and then am very moderate. Nothing seems to help too much though....
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Old 02-29-2008, 04:53 AM   #15
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I thought that vehicles all mostly used electric to engage the TC clutch. One of the things I did when racing cars was install a toggle switch on the dashboard and directly wire it to the TC solenoid. That was on an older rear wheel drive GM car but still the same concept as many newer cars. By having it controllable manually this allowed me to engage it in any gear, for instance driving in slow traffic below 45 mph I could be in a lower gear and still engage the TCC. The down side of course is remembering to turn it off between shifting gears, and when stopping at a traffic light. If you leave it engaged while stopped then of course it will stall the engine. Leaving it engaged between shifts makes it shift much harsher.
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Old 02-29-2008, 06:23 AM   #16
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YOu could invest in an aftermarket Torque Converter with a lower stall speed. In the US Suncoast and others make them to your specs. Many Diesel owners here get a better TC just for that reason...slipping also causes tranny temps to rise which is a bad thing.
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Old 03-16-2008, 11:13 PM   #17
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Originally Posted by gto78 View Post
I thought that vehicles all mostly used electric to engage the TC clutch. One of the things I did when racing cars was install a toggle switch on the dashboard and directly wire it to the TC solenoid. That was on an older rear wheel drive GM car but still the same concept as many newer cars. By having it controllable manually this allowed me to engage it in any gear, for instance driving in slow traffic below 45 mph I could be in a lower gear and still engage the TCC. The down side of course is remembering to turn it off between shifting gears, and when stopping at a traffic light. If you leave it engaged while stopped then of course it will stall the engine. Leaving it engaged between shifts makes it shift much harsher.
I thought that too - however 'mostly' is the operative word .

My car has the lockup controlled by hydraulics - there is a 'lock up solenoid' which is electronically controlled. However, what this solenoid does is change a fluid path so it cannot enter overdrive.

It will only try to enter overdrive if doing just over 80km/h in overdrive. The lockup solenoid merely stops this happening.

One interesting thing is, if it is disconnected, it enters lock-up when cold, but an annoying thing is that it won't disengage lockup when the accelerator pedal is pressed.

I might install a switch to allow lockup when the engine is very cold, and then switch back to normal once warmed up to allow it to disengage when going down a hill in fuel-cut mode (since the engine then turns slower, allowing fuel cut with less engine braking). Obviously I coast down hills with the engine on (or off at 60kph or below) if I don't need to stop at the bottom, or slow down.
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Old 03-17-2008, 09:46 AM   #18
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Autos aren't that bad. Sure you can get a few more mpg's per gallon with a manual, but in your case, get a ScangaugeII and air up those tires to maximum sidewall specifications. You'll see a great improvement!!
The ScanGauge isn't compatible with my 1995 Civic EX.
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