rewiring 6l80 to get control of tcc and line pressure

[parish8]

issues are too low of actual line pressure with the hptuners tables having no effect and issues with the tcc lock up and no hptuners tables to fix that yet either. i didn't feel like waiting for hptuners to come up with a fix although i am sure they will eventualy.

there are several pins in the trans conector that do nothing. i took the ground side of the tcc noid to one of these pins. i should be able to ground that pin and get lock up when i want. for starters i will try locking it right after it shifts into 3rd while racing the local 1/8th mile. not sure of the control circuit i will use. i am thinking a spring loaded switch that will latch it on and a tap of the brakes to shut it off. then i can use it on the highway too when i want since the tripple disks have issues with lock up below 70mph.

2nd part of was to work on the line pressure. i only see 80psi at the top of 3rd and 4th. tranny slips when the power is turned up. i am told 80psi is too low but messing with the pressure tables in hptuners has no effect on actual line pressure. in order to get more line pressure i need to lower the current going thru the line pressure noid. for that to work i believe i will need to add resistance inline with the grounded side of the noid. to do that i had to cut that side of the noid and bring both leads out. for now i just have them shorted together. not sure if i will wire in a control circuit or just wire in a resistor and up the pressure a certain amount all the time. i am not an electronic expert but i am thinking i will need a resistor that has a low value and high current rating. if i knew the value of the resistor it could have been added internaly and not need any wires leaving the tranny.

next project is to get some factory pins to put in the tranny conector and start playing with them. see what effect i can have with the mods. there are lots of pics here >> http://www.neufamily.org/images/g8gallery/index.htm#41

http://www.neufamily.org/images/g8gallery/images/IMG_3164.jpg

[Andy@SquashPerformance]

Interesting.... Subscribed...

[STL_G8GT]

Is the lack of adjustability on actual line pressure an issue for all g8s or just ones breaking the 500hp mark. Basically... how global of an issue is this, and what are the effects?

[parish8]

i only have had problems when i really pushed it. 600+rwhp on a mustang dyno. i saw it happen twice on the dyno. both times the line pressure was around 80psi. after talking to some tranny guys that seems low. 150-250 sounds to be a more common range for a high hp car. i plan on the car harder and harder so i want to get that line pressure up.

for most this wont be an issue and like i said above hptuners will come up with a fix eventualy.

[norm8332]

Interesting. Are you worried about seals etc if you manually raise the pressure?

[parish8]

Are you worried about seals etc if you manually raise the pressure?

yes i am. that is why i need to experament a little and see if i can just bring up the low part without pushing the high part up. there are times when the pressure is over 300psi now. it seems like the highest pressures now are part throttle 1st and 2nd gear. might wire in a hobbs switch and only have it boost the line pressure only when the boost is over 6psi. that would be easy to do.

[G8GT721]

so are you going to try different resistors until you find one that works or use a rheostat
Have you talked to the guys from INTENSE racing, they were 700+wheel in their TT G8

[parish8]

so are you going to try different resistors until you find one that works or use a rheostat
Have you talked to the guys from INTENSE racing, they were 700+wheel in their TT G8

i am going to start with a resistor.

i havent talked to intense but i do know they killed their tranny. i have talked to circle D and when i told them about the low line pressure he said that explained some of what they were seeing on their built trannys.

i think my tranny is hurt right now. it is doing some wierd things. i figure now is a good time to experiment a little.

[STL_G8GT]

Mind boggling here... isn't this trans in a couple other platforms for GM? Why is it such a mystery in the G8. I know we talk about the weight of the car being an issue, but how have the other platforms addressed the issues around line pressure - or have they?

[parish8]

Mind boggling here... isn't this trans in a couple other platforms for GM? Why is it such a mystery in the G8. I know we talk about the weight of the car being an issue, but how have the other platforms addressed the issues around line pressure - or have they?

i dont think anyone has it really figured out but some are getting by at least for awhile. with some internal mods you can get farthur. more clutches and steels, better clutches and steels. circle D told me they rework some oil pasages to try and get more oil where they think they need more oil.

it may still slip with more pressure, time will tell.

[Patrick G]

Good stuff Jim. Again, you're blazing the trail and paving the way for others. I will be checking on your progress often.

[irnwkrkev]

In the July issue of GM High Tech Performance there is an article on a procharger supercharged G8. It is making 600rwhp and 500rwtq and had the trans updated by Level-10. They installed a Vigilante 2,800rpm stall by Precision Industries due to the tuners suggestion. The tuner is Matt from Tune Time Performance. I wonder what type of handle they have on triple disc converters?

[parish8]

In the July issue of GM High Tech Performance there is an article on a procharger supercharged G8. It is making 600rwhp and 500rwtq and had the trans updated by Level-10. They installed a Vigilante 2,800rpm stall by Precision Industries due to the tuners suggestion. The tuner is Matt from Tune Time Performance. I wonder what type of handle they have on triple disc converters?

i do not think there is a single person running a tripple disk of any kind that is able to use it under 70mph or at wot. i would love to hear from someone that has it figured out but i do not think the tables we need are there yet.

i am curious to find out how the tcm reacts to my overides. the line pressure thing will likely be ok since i plan on just adding a few ohms of resistance but the tcc one might upset it a little. i am hoping for a code only, limp mode would suck.

i needed to change my tranny oil anyways so it's not the end of the world if it doesn't work. if you can't tell i like to fiddle with things and a lot of stuff i try doesn't work.

[parish8]

whew, i got to thinking(worrying) about the tranny going into limp mode so i had to go try it. i just stabed a wire into the conector since i dont have the proper pins for it yet. fired up the car with the back wheels up. put it in m3, got the speed up, grounded the tcc noid. it locked up for about 5 sec then set a code and went into limp mode.

i reset the codes and then tried it with an 8ohm resistor. it locked up and never set a code. resistor got warm and it is a 20watt. next i tried 2 of them in parallel so 4ohms and 40watts. still worked, no codes, wasn't getting warm but i only tried it for 30sec or so. i dont know the pressure it is giving at that setting. i want to find the least resistance i can run without setting a code. less resistance is more pressure. the resistance across the noid was 4 ohms.

i will probably want to heat sink the resistors just to be on the safe side, i may want to use this method of lock up for hours at a time rolling down the road.

this is fun.

[G8GT721]

Will the resistor be permanent or be on switch to control/force lock up

Sent from my Droid using Tapatalk

[parish8]

i will ground the tcc noid thru the resistor when i want it to lock up. i am not sure what kind of control i will use, might be a latching relay(controled by a switch) that releases when the brakes are applied. hell, i might even be able to use the stock computer to get that latching relay to latch. hmmm... :-)

soo, wire from noid, thru factory conector, into car, thru resistor, thru some sort of control circuit that grounds it when i want lock up.

[GeoffA]

This is interesting... Subscribed

[irnwkrkev]

Congrats on your first step to success! I'll be following this thread closely.

[parish8]

i tried some resistors inline with the line pressure noid and they had some effect. at idle in park i see 60psi, sperarate the leads so full pressure took it to 380psi. 4ohms was still 60psi, 8ohms barely above 60psi, 16ohms took it to 180psi.

things were a little wierd. my 20watt resistors were getting hot fast and not giving consistant pressures. i will need to get some larger resistors, i see some metal 100watt units for around $5 each. i only got a code when i unhooked the leads completly and it went to 380psi. there are a couple more things i want to do before wiring it up for good. i want to run it down the highway and hit the lock up for a few miles so see if it sets any codes. i also want to see if i can get the tcm to close the latching relay.

i think i can get this to work like stock. program it with hptuners when to come on. below 50mph, wot, whatever i want.

[edmanet]

i do not think there is a single person running a tripple disk of any kind that is able to use it under 70mph or at wot. i would love to hear from someone that has it figured out but i do not think the tables we need are there yet.

i am curious to find out how the tcm reacts to my overides. the line pressure thing will likely be ok since i plan on just adding a few ohms of resistance but the tcc one might upset it a little. i am hoping for a code only, limp mode would suck.

i needed to change my tranny oil anyways so it's not the end of the world if it doesn't work. if you can't tell i like to fiddle with things and a lot of stuff i try doesn't work.

Through the grapevine I have heard that they turn off the lockup until 80mph on any triple disc they install.

[parish8]

Through the grapevine I have heard that they turn off the lockup until 80mph on any triple disc they install.

that along with not being able to lock it at wot pretty much ruin the whole idea of a tripple disk. i hope for this to take care of both issues.

looks like i will be waiting on the 100watt resistors for a week or so. wont be much progress till they show up.

[parish8]

it took me awhile to get back to this.

tonight i hooked up some resistors and a relay on a switch. when i flip the switch it puts a 100watt 15ohm resistor inline with the pcs1 ground side and i see a 40psi jump in actual line pressure. at the same time when i flip that switch it grounds the lock up pcs thru a 100watt 2 ohm resistor. without the resistor the tcm would go into instant limp mode when i grounded the lockup pcs.

flip the switch and see extra line pressure and instant solid lock up. first test is down the highway. get up to 60mph and flip the switch, tranny locks up and rpms drop, soo far so good. about 4 miles later tranny sets a code and starts doing wierd things. one of the codes were tcc locked on. grrr. not looking good. looks like we need a software solution for this one.

next test is wot. i tried locking mid 3rd gear at minimum boost. worked well. turned the boost up and up to 10psi and it was still working well. no slip. i tried to get it to shift while locked but no luck with that one. it might work but will at least require some shift mph and rpm settings.

before i mess with it much more i am going to hit up the track and see what locking it in just 3rd does for my mph and et. if i dont get a decent improvement then i might not even mess with it any more. i use all of third at the track so it will be a good test.

[Patrick G]

Jim, I think you'll most likely find that the lightest, most efficient converter that you don't have to lock under WOT will make you ET the fastest. Torque converters have come a long way in efficiencies compared to the crappy ones we used to have to lock-up in our Grand National days. If your converter is not a single disc 258mm converter, that should be your next mod. That's what I'm going to put in mine.

[parish8]

do we know for sure that a single disc 258mm converter will lock up down the highway like normal? it can handle the slip that the computer wants to see?

i hear what you are saying and you are probabbly right but i really liked being able to lock up my 4l80. i see my current issues as a software problem. if the software was there to control the converter then i am not convinced of the single disk advantage.

[Patrick G]

I know for a fact that the Yank SS 3200, SS 3600 (both 245mm single disk converters) and the SC 3000 (258mm single disk) all lock up exactly like stock on the highway. The SC series converter is what you want for a turbo car.

[Circle-D]

it took me awhile to get back to this.

tonight i hooked up some resistors and a relay on a switch. when i flip the switch it puts a 100watt 15ohm resistor inline with the pcs1 ground side and i see a 40psi jump in actual line pressure. at the same time when i flip that switch it grounds the lock up pcs thru a 100watt 2 ohm resistor. without the resistor the tcm would go into instant limp mode when i grounded the lockup pcs.

flip the switch and see extra line pressure and instant solid lock up. first test is down the highway. get up to 60mph and flip the switch, tranny locks up and rpms drop, soo far so good. about 4 miles later tranny sets a code and starts doing wierd things. one of the codes were tcc locked on. grrr. not looking good. looks like we need a software solution for this one.

next test is wot. i tried locking mid 3rd gear at minimum boost. worked well. turned the boost up and up to 10psi and it was still working well. no slip. i tried to get it to shift while locked but no luck with that one. it might work but will at least require some shift mph and rpm settings.

before i mess with it much more i am going to hit up the track and see what locking it in just 3rd does for my mph and et. if i dont get a decent improvement then i might not even mess with it any more. i use all of third at the track so it will be a good test.

Very interesting stuff, great job. Sounds like the trans/converter is capable but the computer is still trying to control things. Just an FYI I have cut open a few OE converters, 300mm style single disk and the clutch was completely gone. These were in heavy trucks, but it looks like this slipping might even take a toll on the OE. So hopefully the tables will be opened up in the software soon.

Chris

[parish8]

good news. when i tried locking down the highway before i just fliped the switch. i tried it again this time by programing it to lock and then fliping the switch. no codes and it stays locked now.

not a giant deal but it will be nice for road trips when i cant go 70mph.

my tranny is messed up anyway so i thought i would try shifting thru the shift. didn't really work but my tranny can barely get thru a shift without trying new things.

[G8-4-Speed]

Just wanted to bring this back to the top since it is good stuff!!! I am looking to try and do the resistor mod for the line pressure bump if HPT doesn't come up with a fix for the line pressure table soon:thumbsup:.

[G8-4-Speed]

http://www.electronicsurplus.com/Item/152836/

Going to give this a try.........

[neuralfraud]

Hi.

Very interesting subject. Back in "the day" the th200-4r's you could lock them up by putting a paperclip into the odb connector, most people installed a toggle switch and on a stock turbo regal it was good for 2 tenths as it would force lockup in 2ndgear as opposed to at 45+mph in 3rd gear only. This resulted in some extra heat buildup but most people installed external coolers.

How is the lockup solenoid different in this case? The OP is running into issues where there is an AWFUL large amount of current going through these circuits. Did GM not build in any part of the system a way to intentionally control lockup like they did in the ODB-1 equipped cars of the 80s?

[parish8]

hp tuners just released some new tables that appear to give full control of the lock up functions. as far as i know there still isn't any line pressure control that works with hptuners.

that being said the lock up problems at part throttle should be all gone. wot lock up with high hp will likely need more line pressure and i dont think you can get that with programing right now.

[neuralfraud]

Amazing what happens during the evolution of a thread ;)

Can you fill me in perhaps (unless it's already been answered? (I just did a search for "tcc" to find this thread)) on why a lot of members seem to favor non-lockup settings? would seem to me that as long as you're making good power, not locking the converter would be a waste.

[parish8]

there are a few arguments against.

one is to get a converter that can handle high hp you have to go with a multi disk unit. it ends up weighing more and costing more.

another is not being able to control the line pressure. there are settings but they seem to do nothing. at wot actual measured line pressure was getting down near 100psi and that seems to be too low for the converter to not slip. i am talking 600+rwhp.

another is the 6l80e isn't the most hashed out tranny. the gear spacing is kinda close and to get any real benifit of locking it you would need to lock it thru at least one and maybe 2 shifts. i broke an input shaft on a 4l80e doing that. i think the harsh shift would break something and that the softening of the shift from the looser converter helps the tranny to live.

people claim the newer converters are very efficient but i still belive that there is a lot to be gained by locking the converter if you dare to try it. i got a tripple disk mainly so i could lock it at wot on the dyno. yeah, it's just for braging rights to show a big number but i like big numbers.