|07-17-2012 11:27 AM|
FYI, here is a link to the adjustable time delay switch I purchased for $40 from Baker Electronix. It is probably cheaper to build one, but this is contained in a very small black box with a small control knob to adjust the length of the delay. You can specify the range of available delay when ordering.
Baker Electronix - Time Delay Modules
Can you put the time delay switch/circuit between the 4th gear switch and the TC solenoid so that the lockup doesn't occur immediately?
|07-08-2012 03:08 PM|
Sure I can do that.
Also, I have made some significant improvements in the circuit. BTW.
One of the things I noticed with this circuit is that the TCC will pretty much lock up as soon as you go ino 4th gear. And that's okay ..no problem...but it does create a sudden drop in rpm ..and I didn't like that.
My goal was to actuall wait 8 seconds after the transmission goes into 4th before TCC lock up...not just to prevent it from hunting. So I have modified the original cirucuit but..it requires soem minor chanes inside the transmission oil pan and it is more complex...but it work exactly the way I want it.
Use the original circuit as is, but if you find that you don't like the idea of it going into TCC lock at the same time as going into 4th, I will send you a new version of the circuit..but no doubt it is more complex.
I'll put a parts list together for the original.
BTW, a 1000 uf cap will probably give you closer to 8 or 10 seconds. But now the physical size of the cap are going to start getting big.
Unfortunately the resistor in the circuit has no significance contribution to the delay time constant. It's only there to prevent too much current going through the Transistor ad supply voltage to teh capacitor.
I will email you the more sophisticated circuit if you wish. Send me a private message.
|07-08-2012 02:51 PM|
I'd like a 10 second delay...any thoughts on capacitor size?
|07-08-2012 02:42 PM|
Larger capcitor. I think 880 uf is a standard avialble size, should give roughly 8 Seconds.
But the time constant will be a combination of the resistance of the relay coil (which you can't really change) and the capcitor.
If you use a different brand of relay you may get a different resistance ..but it should not be a huge difference.
You can also increase the capacitor value by putting capcitors in parallel.
Of course, you must keep in mind that capactors of these value are polarized. ..i,e there is a positive and a negative side..and you MUST put them in the correct polarity.
My circuit has now been working flawlessly for over a year.
|07-08-2012 01:55 PM|
|kikkegek||@ cadmanof50s: thanks man! how do you vary the time? bigger resistor or capacitator? maybe even make it variable?|
|07-08-2012 12:24 PM|
|08-12-2011 09:02 AM|
For sure, Overdriv.
Should be an attachment.
Let me know if you have any Q's about it.
|08-12-2011 09:00 AM|
|Overdriv||cadmanof50s, would you care to share the circuit you have made that fixes the cycling?|
|08-12-2011 12:14 AM|
John, as you so very astutely pointed out, the problem is that the turn on and turn off points of the vacuum switch are too close together. Unfortunately that can't be changed.
The circuit holds off applying voltage to the TCC after the vac switch closes again. This has the same effect as widening the vacuum switch turn off/turn on points. I'm just doing it electrically.
I was going to add a toggle switch as you did, but I'm too lazy of a driver. I wanted it all done by the gas pedal...:-)
BTW, I am happy to post a diagram of my set up ..if any one wishes to see it...just gotta figure out how to post a pic.
Thanks again, John.
|08-11-2011 11:20 PM|
I don't fully understand how the time delay solved the problem, but glad it works now.
On my 2004R I put both a time delay switch and an RPM switch in the circuit. The RPM switch allows the TCC lockup to only activate when RPMs exceed a set point, like 1700 rpm. And it unlocks the TCC when a lower set point is reached, like 1200 rpm. So in most driving situations the TCC lockups up between 45 and 50 mph and unlocks if speed drops below 40 mph.
So my circuit has 6 controls: brake switch, toggle switch, 4th gear switch, vacuum switch, rpm switch, and time delay. I haven't had to touch the toggle switch since putting in the rpm and time delay switches.
This past week I drove my 1939 Olds to the NSRA Nationals in Louisville and averaged 21 mpg on the interstate.
And, thanks for not correcting my useage of psi instead of inches Hg in my post. Should have caught that.
|08-11-2011 10:24 PM|
The circuit delay definitely solved the problem. The vacuum switch that I have is adjustable but the distance between off and on set points are fixed. You are right that is the issue...however since I can't make the on/off gap wider, a delay circuit effectively widens the turn on and turn off point (electrically) to the TCC.
I tested out the circuit tonight ..put about 60 miles on the car and it works great! I put a vac gauge in the car and found the point at which I want the lock to release. This was at about 6 in hg. Now when I want to unlock the TCC, I just push the gas a little more than required to maintain speed. At that point manifold vac drops briefly to about 5 in and then rebounds. At (or below) 6 in Hg point the vac switch opens and removes 12 volts from the TCC. When the Vac switch closes again (because vacuum rebounds), my circuit waits another 8 seconds before it lets 12 volts through to the transmission. The cycle issue is cured. Going up hills is a breeze: as soon as you lean into the gas pedal a little, the vac drops, the TCC unlocks and lets you finish the hill before re-engaging...
And now I have control over the TCC lock with just the gas pedal...no external switches to toggle, no touching the brake to unlock it, it doesn't jump into lock as soon as 4th is hit. I am actually very happy with the results.
|08-11-2011 07:31 PM|
I don't think time delay is your problem. Sounds more like the vacuum set points for ON and OFF are too close together. These are only made up numbers, but the vacuum switch should disconnect TCC (OFF) when vacuum hits some low value like 6-7 psi, and then not reconnect (ON) until vacuum reaches some higher value like 10-11 psi. This assumes normal vacuum under light load is in the 13-16 psi range.
There needs to be a significant gap between the ON and OFF triggers. If they are close together you will get cycling.
Which set point are you able to adjust? If its the turn ON point then it should be higher (like 10-11), not lower (like 6-7).
|08-11-2011 05:15 PM|
OK.. I fixed the problem.
For the life of me I could not find a Vacuum Delay module that will delay the vacuum like the GM 14020691 is supposed.
So I built a small electronic circuit that basically waits 8 seconds after the vacuum switch closes before it gives the TCC the 12 volts that it needs to lock.
What this does is allows the engine time to stabilize RPM and vacuum long enough after it unlocks..by preventing it from locking up with the rebound vacuum. It works great..although I have to wait 8 seconds after 4th gear is reached before TCC locks....I don't think that's a bad thing....it actually feels just about right....like I have a 5th gear.
I still need to figure out just what the right vacuum trigger point for unlocking the TCC...but the cycling is gone! I'm putting a vacuum gauge in the car tonight and taking it for a long drive to do some fine tuning.
|08-10-2011 09:23 PM|
I have mine switched for automatic fourth as well but I have the power to the solenoid switched so that I can turn it on only at higher speeds. If I didn't I would be driving around town between 50 and 35 and having it cycling.
It works for me. You can always give it a try.
|08-10-2011 06:05 PM|
I have mine connected so that it only comes on in 4th. So this typically happens at highway cruising speeds.
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