The Shop Truck

[folkenheath]

So I can't find any minimum delay setting in the software either. I measured my shifts and it was .58 seconds from the call to shift and .37 seconds to actually make the shift once it starts. However, if you look at the actual gear ratios it takes .18 seconds to from when the ratio starts to change to when it is full changed ratios.

Here is an NA pass with my regal. Except you can see the launch caused my foot to let off the throttle a tad, I learned quick to correct that one.

I may make a youtube video showing people how to do this.

The blue line is the "gear ratio" math channel that calculates the trans ratio. With my trans brake it lets the input shaft turn some on the brake which means the ratio is infinite with the output speed locked, but you can see the ratio come in and then you can see the gear changes happen pretty fast, and if you hover on them you can see them go from 2.48 to 1.48 then to 1. This line will be off in 4th gear as the OD planetary is in front of the turbine shaft, but I don't use 4th at the strip anyway except sometimes at the shutdown area.

The peach colored line is the converter slip math channel. You can see it peaks during the transbrake, then it peaks again during the gear changes and it drops to its lowest point at max RPM right before the gear change.

The rest of the lines are standard Holley channels with a 4L80E. RPM, TPS, gear, input shaft speed, speed, line(trans) temp.

You can also see the TC Clutch output I created so I can lock it immediately whenever I want, on a timer, at a certain speed, etc. I use speed.



Here is a nitrous pass where I lock the converter....it looks like a 4th gear but its not as you can see.



Here are those two math channels. I may make a youtube video on how to do this...



The converter slip is easy, just

((RPM/Input Shaft Speed)*100)-100

The Gear Ratio channel depends on what you have your stuff set at in the Holley software such as Tire diameter and axle gear, it has to match or it will be wrong.

This is the equation I derived...

(Input Shaft Speed x 3.14159 x TireOD)/(Speed x Axle Gear x 1056)

Once you do that you can see if the gear ratio is a quick change like mine on the 1-2 and 2-3, or if its drawn out or not a flat line. I have zero filtering on those lines. If the 1-2 and 2-3 looks crisp. Then look at the converter, IMO it should get to 10% or less at high RPM, mine drops down to under 3% before the 1-2 gear change and about 6% before the 2-3 gear change. You can also see my converter lockup at 135 MPH wasn't holding the full power on that run or it should go to zero slip, even though it was still dropping the slip quite a bit in high gear. The slip is less in lower gears because the converter basically has more leverage so it's easier for it in lower gears.

Hope this helps you diagnose...

 

[r3dd0g]

Thanks @folkenheath, I'll try to set that up, it looks like useful information.
I have sent my datalogs and tunes to GearStar and they're looking at it. Their initial response is to just work around the long shifts by moving the WOT RPM shift points out of the way like you mentioned. I gave them 3 sets of datalogs, one from my last 1/4 mile pass at Firebird where everything worked properly, one with the 1-2-3 shift, and one with the 1-2-3-2-3 shift.
They talked to Yank and if anything they think my torque converter is too tight, not too loose. The tech I talked to was digging into it more and I'm still waiting to hear back from him.
I'm thinking the softer launches could be from me holding the brake harder and not letting off quickly enough. I'll be honest, when I launch it I don't even think about my brake foot, I just let go of the button and it goes. The reason I don't trigger the nitrous and 2 step with the brake pedal is because it takes .3-.4 seconds for the light to go off after I let off the pedal. When I compared my best launch (1.42 60') with my last launch that should have been quicker with the 3200 RPM leave the brake light was on for an extra .03 seconds, so that could have been the issue. I will likely be adding a trans brake to fix this issue.

 

[folkenheath]

Thanks @folkenheath, I'll try to set that up, it looks like useful information.

For what you are dealing with I consider it vital information. It will tell you definitively if your clutches are slipping or your converter is not holding at high RPM.

The great thing about the Dominator is it records everything, so you can go back and add those math channels and then insert them into your trans graph in the data log config and see everything from those passes.

It may be the shift is slow but the clutches are holding good once complete, that can be fixed in the valve body without removing the trans either by eliminating accumulators or enlarging the orifices. I have zero accumulators. Or maybe your trans is fine, you'll know.

I also log trans pressure too, I use a 500 psi sensor in the case. So I can see that too but I hid it because the graph was busy enough for this illustration.

I have sent my datalogs and tunes to GearStar and they're looking at it. Their initial response is to just work around the long shifts by moving the WOT RPM shift points out of the way like you mentioned. I gave them 3 sets of datalogs, one from my last 1/4 mile pass at Firebird where everything worked properly, one with the 1-2-3 shift, and one with the 1-2-3-2-3 shift.
They talked to Yank and if anything they think my torque converter is too tight, not too loose. The tech I talked to was digging into it more and I'm still waiting to hear back from him.
I'm thinking the softer launches could be from me holding the brake harder and not letting off quickly enough. I'll be honest, when I launch it I don't even think about my brake foot, I just let go of the button and it goes. The reason I don't trigger the nitrous and 2 step with the brake pedal is because it takes .3-.4 seconds for the light to go off after I let off the pedal. When I compared my best launch (1.42 60') with my last launch that should have been quicker with the 3200 RPM leave the brake light was on for an extra .03 seconds, so that could have been the issue. I will likely be adding a trans brake to fix this issue.

If you continue to launch from the foot brake I would log brake pressure with a sensor, that will tell you. The brake switch shuts off only when the brake pedal is all the way back, whether there is pressure on it or not.

I am a dealer for ATD, "Hipsters Brake". Their billet 4L80 brake is full manual and would require a race shifter and shift solenoid.

I used a brake from Jakes Performance that still allows automatic shifting with the ECU, I built the trans myself over 15 years ago before the Hipsters brake existed, I really should give it a refresh.

 

[r3dd0g]

Gearstar actually got back to me right after I posted. Their only comment was that when it shifted right the trans line temp was 170 and when it didn't shift right it was 130-140. The difference between AZ and Michigan .
It doesn't seem like they're seeing anything to be concerned with. There isn't a test and tune session until the 19th, so I have plenty of time to prepare. I'll likely move the RPM based shifts out of the way and use MPH/TPS based shifting like you suggested. But before I do that I need to get a new driveshaft. It shook last time I was at Firebird and I'll be going even faster now with full boost and nitrous. It shook enough that it contacted my crossmember (1/2" clearance), but it didn't damage the driveshaft so I just assumed it would be OK doing the 1/8th mile stuff.
The next event I'm scheduled for is the Kingman Street drags on Route 66, but I think we're going to bail on that one. We are going to Duct Tape Drags the following weekend though. I'll probably only make a few passes, but I'm planning on entering the burnout competition for that one, so I definitely need the driveshaft sorted before then.

 

[r3dd0g]

I just got off the phone with GearStar again, they mentioned that I should have a pressure sensor as well, I told them about your advanced tables and they were intrigued. He's going to try to do some math manually to see trans slip.
Apparently it does lower trans pressure based on line temps, but at 130 it was only reducing it by 1% so he didn't think that would have caused the issue we were seeing. It's not converter slip, so either everything is working fine, or the clutches are slipping. When I pull the pan to do the trans brake, I'll be able to see if there's a ton of clutch material. They recommended the Rossler kit.

 

[Babaganoosh]

Hope to see you at Firebird for the Duct Tape Drags! Following along, really interested in these logs you have and trying to soak in the info.

 

[folkenheath]

Gearstar actually got back to me right after I posted. Their only comment was that when it shifted right the trans line temp was 170 and when it didn't shift right it was 130-140. The difference between AZ and Michigan .

It should shift fine at 130 or 170, or even 100 or 220.

I just got off the phone with GearStar again, they mentioned that I should have a pressure sensor as well, I told them about your advanced tables and they were intrigued. He's going to try to do some math manually to see trans slip.

Apparently it does lower trans pressure based on line temps, but at 130 it was only reducing it by 1% so he didn't think that would have caused the issue we were seeing. It's not converter slip, so either everything is working fine, or the clutches are slipping.

You could of had my math channels in your data log already and not be waiting for his math. PM me your global file and data log, and data log config file if you modified it, I'll put it in for you and send it back, it will take me like 2 minutes. Besides, he isn't going to do the math for every data point like the data log math channel will. You need to know it's working the whole run not just one or two data points.

When I pull the pan to do the trans brake, I'll be able to see if there's a ton of clutch material. They recommended the Rossler kit.

Most TH400 or 4L80E trans brakes require drilling a bleed hole in the direct drum and different springs. Did gearstar already do that to prep for a transbrake? If not it likely needs to be done depending on the brake. That's not a valve body only thing. Trans has to come out and the pump, OD planets, forward hub and direct drum need to be removed, back to the center support basically. Hopefully that's already done.

 

[r3dd0g]

It should shift fine at 130 or 170, or even 100 or 220.

He looked at it more and said the same thing.

You could of had my math channels in your data log already and not be waiting for his math. PM me your global file and data log, and data log config file if you modified it, I'll put it in for you and send it back, it will take me like 2 minutes. Besides, he isn't going to do the math for every data point like the data log math channel will. You need to know it's working the whole run not just one or two data points.

I didn't think you could retroactively add it to an existing datalog. I had planned on adding that before the next trip down the strip, but if you are willing to do it for me DM me your e-mail address so I can send it to you.

Most TH400 or 4L80E trans brakes require drilling a bleed hole in the direct drum and different springs. Did gearstar already do that to prep for a transbrake? If not it likely needs to be done depending on the brake. That's not a valve body only thing. Trans has to come out and the pump, OD planets, forward hub and direct drum need to be removed, back to the center support basically. Hopefully that's already done.

I'm good with any of that, but they stated that the Rossler unit they recommended didn't require any additional modifications. They have 2 on the shelf, if I can't get one direct from Rossler they are going to send me one of theirs so I can get it installed before the 19th.
Also, I sent them some pictures of the truck and they want to use it on their social media, so that's cool. Maybe I can get a sponsorship, lol.

 

[folkenheath]

I didn't think you could retroactively add it to an existing datalog. I had planned on adding that before the next trip down the strip, but if you are willing to do it for me DM me your e-mail address so I can send it to you.

Yeah you don't have to wait for the next trip down the strip, the Dominator records everything every log, and you can add math to old logs. I sent a PM.

I'm good with any of that, but they stated that the Rossler unit they recommended didn't require any additional modifications. They have 2 on the shelf, if I can't get one direct from Rossler they are going to send me one of theirs so I can get it installed before the 19th.
Also, I sent them some pictures of the truck and they want to use it on their social media, so that's cool. Maybe I can get a sponsorship, lol.

Nice!

 

[ashman]

A lot of this stuff is over my head, but I'm enjoying learning by watching.

 

[r3dd0g]

A lot of this stuff is over my head, but I'm enjoying learning by watching.

That is why I'm trying to keep this conversation here on my thread rather than hiding it in a DM with Heath or whoever. It's hard to find this info, so I'm trying to keep this public. I make mistakes and learn from them and post them here, if everyone else did that, I could learn from their mistakes .

Heath, I forgot to mention that I have a full Reid case and bellhousing, so it likely has all the modifications done to it straight from the factory.