Sometime ago I installed a Painless Performance Products transmission lock-up harness in my 72 Skylark for the Art Carr-modified TH200-4R transmission. Everything works like it should, except.... the converter locks-up almost immediately after the trans shifts into OD. No problem at highway speeds but it causes the engine to lug at lower speeds around town. This condition is easily solved by leaving the gear selector in Drive around town, or installing a toggle switch to engage/disengage the lock-up manually, but I would rather have the lock-up work automatically as designed. According to the directions that came with the harness, its only necessary to install a GM #14020691 Vacuum Delay Valve (ACDelco 214-479 or Standard Motor Products DSV35 are equivalent) in the vacuum line to the converter vacuum switch to delay lock-up. One problem though: the GM, ACDelco and Standard part numbers are obsolete and, according to my internet search, are no longer available. Well, thats not exactly true: I was able to find the Standard part numbers listed on Amazon.com. Unfortunately, one of them is available for $75 and the other is listed for $9,999. Both are little expensive for a part that originally cost less than $20. Before I spend $75 on a delay valve Id like to find out from those of you who retrofitted an OD transmission and installed the appropriate vacuum delay valve: 1 - Did the vacuum delay valve work as promised? 2 - Did any of you use another part number delay valve that worked? Thanks for your help in advance.
This might be a little long but I have the same issue. I looked for this same part. However, I can't imagine how it can possibly work properly since the vacuum will already be high and the converter would still instantly engage. My car has the ATI vacuum lockup kit (link). It is not really satisfactory and I have it adjusted low enough it will fall into lockup unless you are pretty far into it to keep it from locking up. I've since connected it to ported vacuum and it will kick out while coasting, which is an improvement. This also has implications below. When I had it adjusted to a higher vacuum, it would in-out-in-out the torque converter until I either pulled it back to 3rd or applied enough throttle to cause it to stay out of the transition vacuum range. I looked for a window switch, one that would turn on at 2000 RPM and turn off at 1500 RPM but that's a hard item to source from what I can tell though it might be easy with something like an Arduino. As a computer guy, the Arduino appeals to me as an elegant solution but I have no experience with it don't know its capabilities. I have another solution I'm currently working on though slowly with my host of other issues. I bought a cheap delay timers (link) and set it to be a 7 second delay once 12V is applied to the circuit. My goal is to get 3 shifts (1-2, 2-3, 3-4) and then 7 seconds later, lockup torque converter. Hit the brakes, another 7 seconds until lockup. Allow it to coast, another 7 seconds until lockup. I originally wired this between the 12V interrupter for the brake disconnect. This was when I had to go back and figure out how the thing was wired. It seems there is 12V to the switch any time the ignition is on and the internal pressure switch only allows it to ground and that ground is through the vacuum switch. I have rewired my 7sec 12v delay switch to be ground instead of 12v+ but I have not reinstalled it as I will need to rewire (add some length) to get the unit in the proper orientation. The pricey solution that B&M sells (link) kicks out the lockup at adjustable speed and fits between the speedometer gear and the cable looks like a pretty solid choice but it is rather expensive without another person confirming it works as desired. I'd set mine to lockup at 48MPH and let it rip! That's about 1500 RPM when locked up which is acceptable when cruising. I'm hoping someone else might chime in with an elegant and robust solution but I think mine is inexpensive and well within most people's do-it-yourself realm.
I can't exactly help you guys with that particular set-up, but in my case, with CK Performance's kit, it came with a special 4th gear pressure switch. I just send 12v from the ignition and that's it. No vacuum or relays of any sort. Pressures in the valve body when shifted into OD dictate whether is locks up or not. I have zero issue with lugging of any sort. Works quite flawlessly. No issue when braking or downshifting. Not sure of my input at all helps. http://www.ckperformance.com/View/2004R-UNIVERSAL-LOCK-UP-KIT
The Arduino and associated shields are very capable. You can build your window switch easy enough and be able to adjust on the fly. I have migrated away from Microchip's PIC MCUs to using Arduino. Unfortunately sourcing one locally is more difficult now that Radio Shack is out. But yes assuming you have the intelligence of a 2nd grader for $30 you can have your cake and eat it too then make a pie and bake it too. :eek2: :3gears:
My kit has a 4th gear pressure switch and an additional vacuum switch. If I did nothing but wire the switch to the 12V, it shifts into 4th gear and immediately locks up. That's fine if I'm accelerating but in traffic with 3.73 gears, that tends to be on the cusp of having to slow back down and lug until it drops back to 3rd at 32MPH and 1000RPM. How does yours operate differently? There's a kit on MonoPrice (link) for $50 that looks promising. I wrote code for the first 10 years of my career. Still do some scripting. I can handle logic. My issue is figuring out how to get a tach or speedo signal into the Arduino. I considered trying to get a speedo alert and set that for the lockup trigger.
I am also running 3.73's. I can honestly say I have never had that issue. As soon as I hit 4th, and I release the throttle a bit, it locks up. As soon as it down shifts it unlocks. I never had it lock/unlock while crusing. I think I misunderstand your traffic example, in traffic I am in 1st or 2nd gear. In traffic at crusing speed it stays locked unless my speed slows and the trans automatically goes to 3rd or 2nd. But no lugging. Sorry not much help. You sure you don't have a 3rd gear pressure switch hooked up to 12v as well at the rear of the valve body? Did not mean to complicate, was just chiming in. My setup seems to work well for me.
I have two switches in series. One is the switch like you have. What RPM does your car shift into 4th and what RPM is it immediately after shifting? Then what RPM does it downshift at if slowing down? My answers are 2200 upshift into 4th but immediately locks up torque converter. It feels like it shifts twice quickly and lumbers along at about 1500 RPM unless I slow to 32MPH where it will drop out of lockup AND 4th gear back into 3rd. I have no lockup in 3rd at all. The second switch is a vacuum switch. If I drop enough vacuum during acceleration, my lockup with drop without down shifting unless I put my foot in it even more. With a tighter converter and less cam, I suspect the vacuum switch would work better. The problem is there is about a 300 RPM difference at that speed since it is below the converters stall speed and the cam causes a drop in vacuum. Mine works well enough but I want MORE, lots more. I want my 45 year old car to shift like a new Camaro. I want it to allow a bit of time in 4th before locking up. If I could determine speed, I could set a threshold for lockup/non-lockup where it would be much nicer to drive.
I'm running the B&M lockup control and really like it. I too purchased one of the little cheap delay boards but was planning to use it strictly for delay of re-lockup after I tap the brakes. The B&M controller allows you to pick the speed at which the converter is allowed to lockup. This allows you to avoid the trans hitting 4th then immediately going into lock up and lugging along. It is a bit pricy but buy once cry once. Installation of a generic cruise control brake switch allows you to easily unlock when the brakes are applied and the normally closed side go open and interrupts your lockup signal.
As guys are saying the b&m kit will do what you want... The TCI lockup kit has a vacuum switch that can be modified to make it adjustable so you can decide how any inches of vacuum is needed to lockup the converter... It almost sounds like you want a computer controlled trans though.
yeah a vaccum trans will never feel exactly the same as the computer trans in new camaro. the 200-4rs and 700r4s in 80s cars did about the same from the factory as what you guys are describing. speaking of new camaros a 6l80e or 90e would be awesome behind a buick engine though. my new truck has the 90e with the 6.0 it is a beast.
Hmm......next time I take it out, I will make a note of the upshift into 4th rpm, not sure but I think I am higher than 2200 rpm. We have the same rear ratio, maybe my tire height makes a difference, I seem to think coming off of 3rd, it is more in the 2500/2600 range, but I am always teasing with the secondaries and a heavy foot. I do however get that almost two shift feeling you mention. Once into 4th, and a second or two later as it locks when I release some throttle, otherwise it stays unlocked as I stay in the throttle. But I don't get the lug or lumber. When locked up, and I give it some part throttle, you can tell it is in OD, but it does not lug even at 1500, it picks up quick. Good luck with it, the B&M kit seems to be your answer. I am done throwing $ at it, lol. I have my TV cable routed through the firewall and hooked to the gas pedal rather than the carb, so maybe the geometry difference is what is giving me a different characteristic?
Yes, you an adjust the vacuum but with a looser converter and a bigger cam, it is very touchy to get the correct value. So touchy I've never gotten it to work satisfactorily for myself. I wind up in one of 2 positions, either it will hunt in-out-in-out or it will immediately lock as soon as it shifts to 4th. The vac switch is too sensitive for my tastes. If I could control my lockup via a logic program, I'd be much more inclined to love it. As is, the little delay board is my next iteration of adding drivability to my car.
Ah, you are pointing out the great divide many face. Integration. You can get an Arduino Uno and relay shield for ~$30. Yes more time is spent figuring out implementation and install. The Arduino has AtoD and digital GPIO pins. Good 'ol fashion voltage divider rule applies from your tach and/or speedo if you want to use analog. A time divided count would be used for a digital input. Many ways to crack this nut if you feel so inclined.
The problem with a mechanical vacuum switch, is you can adjust the trip point, but not the hysteresis. I finally went to solid state vacuum sensors, the transfer function allows ANY hysteresis needed (to avoid hunting). The mechanical switches may have very little. If you don't get into a programmable device, a CD4541 is a pretty useful timer. Bruce Roe
Attached is a more recent Arduino project. It is very similar to the PIC setup I used in my car to build my TCM and instrument cluster. In the picture this was a $50 kit (if I remember correctly). I do have a relay shield if I did want to actually install in my car to shift my 4L80e. To explain what is in the picture. There are 3 LEDs, each LED represents a input signal to a relay for each solenoid in my transmission (Solenoid 1 and 2 are red LEDs used for shifting gears 1-4) the yellow is a time delay input to the Torque Converter Clutch (TCC) solenoid. So, if this were a video my finger is on the Upshift button pressing down, you would see the LED sequence correctly to shift the transmission, Once in 4th there is a timed delay (I made a count down on the LCD display to show when the TCC solenoid were to engage. (Yellow LED on). For kicks I ran an analog temperature readout and displayed it as well. The other button is for down shifting. At any point I could use any or multiple inputs to make things "automatic" like a traditional transmission. :TU: This second picture is of a relay shield on top of another Arduino I have (you see the pins only because I did not press the two boards together. A shield is designed to be fully mated to an Arduino to minimize wiring so you don't have a mess like shown in my first picture. Effectively the only wires you would see are those required for power, sensors, and transmission (all external wires unlike my birds nest above).
Even with my 2005 Chevy truck I found the lockup would engage at times that I did not want it to... So I had the guy who custom tuned my truck set it up so when I press the tow/haul button the lockup unlocked and when I turned it back off the computer controls the lockup again. On my old cars with 200R4 trans I use a toggle switch AND the vacuum switch as well as the brake switch because after having my fuel injected truck stall out at about 70 MPH when I hit the brakes (because the lockup was engaged on a toggle switch with no brake switch)... It is very dangerous to drive without a brake switch.... And remember the lockup is designed to have 12 V all the time and the switching is to be done on the grounding side of the circuit. Many people use the switches on the 12 V side, but I have read that can lead to premature damage to the solenoid.
Off topic I know - :shock: Not sure how that could be true or substantiated. There would need to be more to the story. GM trans are designed to have positive applied all the time and ground triggers the solenoid, but severing all positive by switch and maintaining a constant ground would work with the same reliability.:beer
Who knows if it is true, but why not do the same as GM designed and switch the ground not the positive... They must have had a reason to do it. It is the same amount of work either way, just most people do not know how GM did it. BTW thanks for sharing your latest gadgetry... I hope to use the 4L80E controller you built me soon, its been on the shelf for years now. I show it off to my friends all the time, its a cool piece!
I have a 700 in my RIVI , tried the vacume TCI switch, same issue. lugging around town. I realized i dont give a crap about lock up around town, it will make no differance in gas mpg in my big ole boat. The only time lockup is useful is on the freeway in fourth gear. So I just used one of them small alarm push button switch. That way it works only when I want it to. Because , no matter what you do , it will never work to your sastifaction 100% of the time. With any of the nifty after market gadgetry gizmo stuff out there.
This is exactly true, it is only needed when going fast... And up hills it is nice to be able to shut it off so its doesn't lug... extra 200 RPM helps keep the engine happy up hills I find. Just remember to always use a brake switch so that if you hit the brakes hard your engine will not stall out...
