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09-24-08, 04:36 AM
#31
It's not in your head. I thought it was my imagination till I found out what the RM says about the solenoid. Even with my power level, the car never really felt fast off the line, now it squats like crazy. I can devistate the tires on a 2 to 1 downshift from a 20mph roll, kind of scary really. Anyway, it actually feels like a high powered sports car now. Also note that this difference was not noticed after shimming the accumulators.
09-24-08, 04:39 AM
#32
I did find out that the 97 has an a341e vs the a340e in my car. Also, the a341e has 7 solenoids! It does have the same solenoid labled "accumulator control" or something. I assume that since the 96+ is obd2 it will set a check engine light with either unplugging the sensor or cutting the wire.
OneSickSC, any light on?
KC
09-24-08, 04:48 AM
#33
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
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
I am also very interested in the trans controllers...PCS, Suprastick, ect.
My biggest problem right now is bouncing off the rev limiter before shifting to 2nd at WOT. I've been playing around the last couple of days and I'm pretty sure my tires aren't spinning, although it's still possible. But, I think either the trans is going out or the ECM is just not fast enough to control the trans with the rpms rising MUCH faster than stock. Heck, I attempted to manual shift the car at the 1/4 mile track and did a worse job than the ECU.
I really don't think it's the transmission. The only problem is WOT 1 -2 upshift. Downshifting at WOT to 2nd has no problems. If 2nd was screwed I would think it would slip hardcore on a WOT downshift since that is likely where the most torque is put on the gear.
I'm going to use my MAFTPro to monitor the no 2 solenoid to see if it comes on before or after I'm on the limiter. The solenoids are 1 on 2 off for first and 1 on 2 on for second, so I should be able to get an idea of what's going on.
KC
09-24-08, 05:07 AM
#34
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Interesting enough, I had the same problem on a Boost logic built auto in a Boosted SC300 I used to own. About 50% of the time it would bounce off the rev limiter instead of shifting. I think sometimes it was spinning that caused it.
09-24-08, 06:20 AM
#35
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09-24-08, 07:26 AM
#37
No, your not hijacking at all, this is all good stuff to know. I have to wonder if you'll end up with a GM tranny at some point with your power goals.
I am also very interested in the trans controllers...PCS, Suprastick, ect.
My biggest problem right now is bouncing off the rev limiter before shifting to 2nd at WOT. I've been playing around the last couple of days and I'm pretty sure my tires aren't spinning, although it's still possible. But, I think either the trans is going out or the ECM is just not fast enough to control the trans with the rpms rising MUCH faster than stock. Heck, I attempted to manual shift the car at the 1/4 mile track and did a worse job than the ECU.
I really don't think it's the transmission. The only problem is WOT 1 -2 upshift. Downshifting at WOT to 2nd has no problems. If 2nd was screwed I would think it would slip hardcore on a WOT downshift since that is likely where the most torque is put on the gear.
I'm going to use my MAFTPro to monitor the no 2 solenoid to see if it comes on before or after I'm on the limiter. The solenoids are 1 on 2 off for first and 1 on 2 on for second, so I should be able to get an idea of what's going on.
KC
I am also very interested in the trans controllers...PCS, Suprastick, ect.
My biggest problem right now is bouncing off the rev limiter before shifting to 2nd at WOT. I've been playing around the last couple of days and I'm pretty sure my tires aren't spinning, although it's still possible. But, I think either the trans is going out or the ECM is just not fast enough to control the trans with the rpms rising MUCH faster than stock. Heck, I attempted to manual shift the car at the 1/4 mile track and did a worse job than the ECU.
I really don't think it's the transmission. The only problem is WOT 1 -2 upshift. Downshifting at WOT to 2nd has no problems. If 2nd was screwed I would think it would slip hardcore on a WOT downshift since that is likely where the most torque is put on the gear.
I'm going to use my MAFTPro to monitor the no 2 solenoid to see if it comes on before or after I'm on the limiter. The solenoids are 1 on 2 off for first and 1 on 2 on for second, so I should be able to get an idea of what's going on.
KC
I do remember PCS telling me that the transmission would shift much quicker by leaving the shifter in Drive (4th) and letting the PCS control it. Manually shifting it would be much more delayed. E-shift will also be interesting...I think it is all in the tuning...
Ryan
09-24-08, 01:55 PM
#38
KC, I did some checking, and I did find out that the ECU for the tranny is integrated into the main ECU. I also determined that the shift speed and the force is indeeed managed by the stock ECU, and that no matter what you do, save changing out the ECU with a stand alone for the engine and the auto tranny, you will be very limited with your success in changing the shift speed and shift points. The only way to change it totally, and manage it so it shifts the way one would want, ie; shift soft slowly with regular driving, and powerfully and quickly with WOT, is to change out the whole ECU. I beleive you may have tapped the potential with what you already have accomplished, KC. Just a heads up...
Ryan
Ryan
09-24-08, 10:05 PM
#40
OK guys, this is going to be a long post so be prepared.
First off, LS guys, sensor should be the same and be located in the same place as in the pic on post 21.
As far as OBDII cars, I'd be surprised if the check engine light doesn't come on for you no matter which way you do it. But, the affect should be the same.
If anyone wants to know the no 4 solenoid's ECU pin location, PM me your email and vehicle info.
OneSickSC, any update on codes? You should get that O2 fixed btw. Long story but I figured out only having one good sensor will cause all kinds of trouble, missing / bad front sensor anyway.
Probably not unless you have REALLY long double jointed arms. LOL.
Read the posts and ye shall find the answer.
PM me your email and I'll send you PFD's as soon as I can. I bet its the same ECU pin as my 95 but I'd rather check and be sure than just assume.
It's encouraging to hear that a built auto had the problem. I really don't think I'm spinning the tires but I have not yet had someone verify this for me, one way or the other.
But why does it shift faster with the TCU is the question? The ECU makes the trans slip by bleeding off pressure using the no 4 solenoid. In theory, as far as I know, this is the ONLY control the ECU has over trans slippage. I'm fairly sure the actual shift solenoids are either on or off, nothing inbetween. I could be wrong though, the voltage to the solenoids may be variable. I am willing to bet that the PCS or any other TCU doesn't use the no 4 solenoid, at least not when a firm shift is desired / programmed in to the unit.
I somewhat agree with this. I don't think the ECU needs to be totally eliminated with an aftermarket unit though. The stock ECU could be used with a seperate TCU to make it shift. There might still be some timing retard issues and such with the factory ECU in place, but I've read that most shift controllers elimate that problem as well.
-------------------------------------------------------------------------
Ok, did some testing tonight. I'm a bit discouraged by the results though.
For 1st gear the no 1 shift solenoid is on and the no 2 is off. For second, the no 1 stays on and the no 2 kicks on. I used the MAFTPro to monitor / log the voltage being sent to the no 2 shift solenoid so I could see when the no 2 comes on compared to when the car actually shifts.
Unfortunetly, the solenoid is being turned on by the ECU BEFORE the eninge is bouncing on the limiter. The ECU is sending voltage to the solenoid at around 6200rpm, the engine is THEN bouncing around between 6500rpm and 6300rpm or so. I was hoping that I wouldn't see the solenoid come on until after the engine was on the limiter. Then I would know, for sure, that the ECU was the problem. I also noticed that on a couple of normal 1 - 2 shifts, the solenoid would get voltage and a significant amount of time would pass before the RPM's would drop.
This leaves me with only a few other things that could be happening.
1. My tires are spinning. It honestly wouldn't surprise me but I really don't think so.
2. The solenoids (no 2 at least) are slow to react, or for some reason fluid is just not being routed fast enough. I meant to bring my DVOM home with me so I could check the resistance on them but I forgot it at work.
3. Maybe the ECU is still screwing with me despite the disconnected no 4 solenoid.
4. The trans is slipping. I might be in denial but I just really don't think it is. Looking at the operation schematic of the trans has only helped convice me the trans is ok. Would take a while to explain why.
Any other ideas, or, ways to test please share.
------------------------------------------------------------------------------
TCU's, there's a few available. From simple to complex.
There's the PCS unit...Top of the line. Was going to post a link but website appears to be down.
The IPT unit....http://www.importperformancetrans.co...ddUVQz00n8SQdG
The AWShifting unit......http://awshifting.com/controller.htm
The Suprastick......http://www.latentsolutions.com/suprastickuv.html
Probably more.
I'm considering either the Suprastick or the AWShifting units. They will do what I want and are both reasonably priced. The Suprastick is more an actual TCU, the AWShifting unit is much simpler allowing switched control from full auto (controlled by the factory ECU) and full manual control. The Suprastick is much closer to the PCS unit in it's ability.
Even if a controller doesn't really fix the problem, I could at least try shifting it earlier to see if it helps.
Any input from anyone would be great!
KC
First off, LS guys, sensor should be the same and be located in the same place as in the pic on post 21.
As far as OBDII cars, I'd be surprised if the check engine light doesn't come on for you no matter which way you do it. But, the affect should be the same.
If anyone wants to know the no 4 solenoid's ECU pin location, PM me your email and vehicle info.
OneSickSC, any update on codes? You should get that O2 fixed btw. Long story but I figured out only having one good sensor will cause all kinds of trouble, missing / bad front sensor anyway.
Originally Posted by JonSC4
Can you guys get to this sensor from the top of the engine bay? I don't have a jack right now so I can't get under the car
Originally Posted by sc-driver
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)
Originally Posted by twizted
I'm going to do this, get some pics of exactly where the 4th solenoid is if you can guys. Ill be able to tell you before and after affects from stock to high boost in January....
Yesterday 04:55 PM
Yesterday 04:55 PM
Originally Posted by ScottURnot
Interesting enough, I had the same problem on a Boost logic built auto in a Boosted SC300 I used to own. About 50% of the time it would bounce off the rev limiter instead of shifting. I think sometimes it was spinning that caused it.
Originally Posted by SC400TT
It may not be the trans that is causing the problem with the rev limiter bounce...perhaps it is the ECU because the transmission system is designed to slip, as you have stated several times, KC. The slip is for the smooth shifting, so, perhaps there is much more control from the stock tranny controller then we may realize. I will discuss this with PCS as well, because I believe that is one of the major benefits of the PCS, to speed up shifts only when needed, based upon proper tuning of the application.
I do remember PCS telling me that the transmission would shift much quicker by leaving the shifter in Drive (4th) and letting the PCS control it. Manually shifting it would be much more delayed. E-shift will also be interesting...I think it is all in the tuning...
I do remember PCS telling me that the transmission would shift much quicker by leaving the shifter in Drive (4th) and letting the PCS control it. Manually shifting it would be much more delayed. E-shift will also be interesting...I think it is all in the tuning...
Originally Posted by SC400TT
KC, I did some checking, and I did find out that the ECU for the tranny is integrated into the main ECU. I also determined that the shift speed and the force is indeeed managed by the stock ECU, and that no matter what you do, save changing out the ECU with a stand alone for the engine and the auto tranny, you will be very limited with your success in changing the shift speed and shift points. The only way to change it totally, and manage it so it shifts the way one would want, ie; shift soft slowly with regular driving, and powerfully and quickly with WOT, is to change out the whole ECU. I beleive you may have tapped the potential with what you already have accomplished, KC. Just a heads up...
-------------------------------------------------------------------------
Ok, did some testing tonight. I'm a bit discouraged by the results though.
For 1st gear the no 1 shift solenoid is on and the no 2 is off. For second, the no 1 stays on and the no 2 kicks on. I used the MAFTPro to monitor / log the voltage being sent to the no 2 shift solenoid so I could see when the no 2 comes on compared to when the car actually shifts.
Unfortunetly, the solenoid is being turned on by the ECU BEFORE the eninge is bouncing on the limiter. The ECU is sending voltage to the solenoid at around 6200rpm, the engine is THEN bouncing around between 6500rpm and 6300rpm or so. I was hoping that I wouldn't see the solenoid come on until after the engine was on the limiter. Then I would know, for sure, that the ECU was the problem. I also noticed that on a couple of normal 1 - 2 shifts, the solenoid would get voltage and a significant amount of time would pass before the RPM's would drop.
This leaves me with only a few other things that could be happening.
1. My tires are spinning. It honestly wouldn't surprise me but I really don't think so.
2. The solenoids (no 2 at least) are slow to react, or for some reason fluid is just not being routed fast enough. I meant to bring my DVOM home with me so I could check the resistance on them but I forgot it at work.
3. Maybe the ECU is still screwing with me despite the disconnected no 4 solenoid.
4. The trans is slipping. I might be in denial but I just really don't think it is. Looking at the operation schematic of the trans has only helped convice me the trans is ok. Would take a while to explain why.
Any other ideas, or, ways to test please share.
------------------------------------------------------------------------------
TCU's, there's a few available. From simple to complex.
There's the PCS unit...Top of the line. Was going to post a link but website appears to be down.
The IPT unit....http://www.importperformancetrans.co...ddUVQz00n8SQdG
The AWShifting unit......http://awshifting.com/controller.htm
The Suprastick......http://www.latentsolutions.com/suprastickuv.html
Probably more.
I'm considering either the Suprastick or the AWShifting units. They will do what I want and are both reasonably priced. The Suprastick is more an actual TCU, the AWShifting unit is much simpler allowing switched control from full auto (controlled by the factory ECU) and full manual control. The Suprastick is much closer to the PCS unit in it's ability.
Even if a controller doesn't really fix the problem, I could at least try shifting it earlier to see if it helps.
Any input from anyone would be great!
KC
09-25-08, 05:49 AM
#43
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ok here goes.....96+ sc4......did the sensor trick.....from a dead stop i feel a BIG difference....but from like a 20 roll the car just powers through the gear an does not down shift into first like it did wit the sensor plugged in....also from a 50 roll at WOT the car down shifts but **** at around 5k no matter if i have the ect in power or normal.....so i think from a roll it effects the car in a bad way.....i could me wrong....can someone explain if they know.......i didnt get my codes ran yet i'm gonna get them ran today.....
09-25-08, 07:56 AM
#44
ok here goes.....96+ sc4......did the sensor trick.....from a dead stop i feel a BIG difference....but from like a 20 roll the car just powers through the gear an does not down shift into first like it did wit the sensor plugged in....also from a 50 roll at WOT the car down shifts but **** at around 5k no matter if i have the ect in power or normal.....so i think from a roll it effects the car in a bad way.....i could me wrong....can someone explain if they know.......i didnt get my codes ran yet i'm gonna get them ran today.....
I've had people tell me that this cable does not have anything to do with downshifting, just pressure, but I'm not convinced. When I had my car on the dyno, the only way we could keep the trans from downshifting to second from third was to completely remove the cable from the throttle body. With the cable connected, it would downshift every time. With the cable disconnected, it didn't downshift once.
KC
09-25-08, 09:37 AM
#45
OneSickSC, also make sure you unplugged the sensor by the bellhousing and not the one on the rear of the tranny.
The one in the rear, on the tailshaft, is the no 2 speed sensor and could definately cause shift issues if unplugged.
KC
The one in the rear, on the tailshaft, is the no 2 speed sensor and could definately cause shift issues if unplugged.
KC
