KC95SC400

iTrader: (3)

Answering questions. Again, this applies to my 95, I can't speak for other years. I would think that everything is the same for at least 95 and under SC400's. 96 and up obdII cars are likely a different ball game altogether.

Driver's side, on the side of the trans case directly after the bellhousing.

I don't see any reason why you couldn't put a switch on it, I've even thought about doing it myself.

No, I don't think you could wire it to the ECT/PWR switch. There is 12volts going to the switch anytime the ignition is on. Turning the switch to PWR mode sends the 12 volts to the ECU pin 18 and to the indicator light in the cluster. Wiring the solenoid to the switch would allow 12volts to go to the cluster light, the ECU pin 18, the ECU pin 13 (for solenoid 4) and to the solenoid itself which is normally controlled with pulse width modulation. Good chance of frying something.

I do remember reading somewhere that the SC300 stayed with a mostly manually controlled trans until 97 or 98.

I find it interesting that the 2jzgte trans has 5 solenoids. Seems redundent to have the accumulator bleed off solenoid when the ECU has full contorl over line pressure anyway.

I have access to TIS but definately feel free to post stuff here for the benefit of others.

Yes. Same goes for tq clutch lock up, trac control, abs ect. I don't have the cruise hooked up on my car but I'd bet it would be fine as well.

I do understand the concern...but I think the a340x is a different animal. The only purpose of the no 4 solenoid is to bleed off line pressure during a shift for a smooth shift and to prevent squat. Think about this for a second, what happens when any transmission shifts smoothly......it's slipping. The smoother any given trans shifts, the more it's slipping. As far as preventing vehicle squat, the solenoid is causing enough slip to reduce power to the wheels to keep the car level on take off for a luxury, not sporty feel.

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Now on my car I have been running quite a while, including 70+ track runs, with about twice the stock power on the trans and haven't had any problems other than bouncing off the rev limiter during the 1-2 shift at WOT. Also keep in mind that I have .525 inch of shim in both the 1-2 and 2-3 accumulators. AND...I have adjusted the main pressure regulator to up line pressure. I'm still considering adding MORE shims. It definately shifts firmer but could be better.

So, someone with a stock car would probably not see as much of a difference as I have by disabling the solenoid. But, it has made quite a difference. Even with twice stock power and a 2800rpm dragon, I still felt like the car was a bit weak on take off and when downshifting. Now, the car squats like freakin crazy, it actually feels like a high powered sports car.

To go over a few things again. Unplugging the od speed sensor will not hurt anything but it WILL make the overdrive light on the dash blink and there will be a trans code, 67. Cutting the solenoid wire WILL NOT make the overdrive light flash but there will be a trans code in memory, 46. Benefits. You will have more power off the line and when downshifting due to the fact that the ECU is not making the trans slip to REDUCE power. All shifts will be firmer during all driving conditions.

KC

t42gs3

Use the 12v signal from the ECT/PWR switch to energize a single pole double throw relay(SPDT). This will disconnect the tranny wire when the PWR switch is on, and reconnect the tranny wire when the switch is off.

KC95SC400

iTrader: (3)

Awesome idea! Very smart.

Has anyone tried unplugging the od speed sensor yet? I'm very curious to hear what difference is felt on a otherwise stock, or slightly modded car.

KC

ScottURnot

iTrader: (33)

Wow KC, this sounds like it may have some promise to the SCguys. Cutting edge stuff, I got to see how this turns out.

818sc400

hey im willing to try this. kc can you pls take a picture of where its located. my trans slips pretty bad into 2nd. will i need any tools etc.?

KC95SC400

iTrader: (3)

I wouldn't be able to take a pic until at least Monday but it's easy to find. Attatched is a pic that will help. No tools needed, just unplug it and make sure the loose wire won't hit anything hot.

I'm not sure this will help you much if your trans is slipping, but it shouldn't hurt any.

KC

818sc400

it only slips if i floor it from a dead stop. if im jus driving normal or spirited it doesnt slip at all. but ya pm me the pic or post it all ill give it a try

OneSickSC

so no one know if this trick will work in the 96+ sc4's?

KC95SC400

iTrader: (3)

So, has anyone tried it yet? I'm real curious to know...........


Check post 21 for the attatched PFD, it's easy to find and unplug the sensor. I don't know for sure that it's the same on a 97 though.

I don't know, I'll have to look into it for you. I'm pretty sure it's the same trans until 98 but not 100%. Do you know which trans you have? If you look at the sticker that's on the driver's side door area, it will say what trans you have.

KC

LiCelsior

iTrader: (32)

wonder if it works on LS400s....

OneSickSC

ok cool lmk....i checked my door it didnt say wat tranny i had.....any other ways to find out?......

KC95SC400

iTrader: (3)

The sticker should be on the door, same sticker that has the vin and the color / trim code info. It will say A/T ****/*****.

I'll check what it says on TIS. I'm kind of interested if a 97 tranny would work in my car anyway.

KC

OneSickSC

that sticker isnt onmy car maybe previous owner took it off......well i did that trick to my car....dont know if its mind over matter but i feel a BIG TQ difference......car squats and actually wiggles from a dead stop lol.....

sc-driver

iTrader: (7)

I am really tempted to try this but will I get a check engine light or is it only the O/D light? (If I just disconnect the wire)

Thanks

SC400TT

iTrader: (4)

KC, this is some cool stuff!! I am excited that you are paving new ground to find both economical and definitive mods to the auto tranny to improve performance. I look forward to your progress.

I will experiment with some of this as well. I will have somewhat of a different challenge though. Since my tranny has been modded by BL, I will get the specific changes in detail that they made, and since I am no longer using the stock tranny ecu, but the PCS tranny ECU, I am curious how far we can go with managing shifts electronically. I discussed this with PCS on a cursory level, but once I get the car back next week, it will be ready for connecting both ECU's and tuning them to optimum performance. I do know that I can control and manage shifts based upon a combination of engine load, rpm's and boost. But, i do not yet know all of the details and how granular we can go. I do know that I should be able to fine tune shifting with this combination. Plus, with adding e-shift, that wil also add a whole new dynamic to the SC.

I do know that the weakest link seems to be with the second gear sprag with these trannmissions, so, I am working on tuning to protect that during hard driving and shifting.

I hope my comments are not hijacking your thread here. My purpose is to emmulate what you're doing as much as I can with my modifications and to see what positive and negative effects I end up with.

I do know that the line pressure has been increased and the spring rate has been stiffened as well. It will be interesting to see how much difference will be noticeable between the two transmissions, especially since both yours and mine have the Dragon TQ convertor.

Ryan