Displaying Torque Converter 'Slip' with the PowerLogger

[Nigel]

It is a 2 pulse per speedo cable revolution? Maybe it could be used to calculate and display drive shaft rpm directly. The the only correction would be for the speedometer gearing which is easy to determine. It may be a nice if room existed to add the feature. Trying to figure out exactly how to determine the correction factor is like going on an Easter egg hunt. At the end of the day I think the calculated numbers should match what Dave experimentally determined, even though they are close now they should agree. I guess the other option to help nail it down would be if you could pull out the factors that the ECM uses to calculate the MPH. Knowing the exact tire height and any other assumptions to dial in the correction factor may get it right on.

P.S. - The MAFT Pro is still a killer piece of gear, I am using in Translator VE mode, and it makes it real nice to integrate the alky injection. I needed more fuel and had an old Caspers 7th shooter(old school, many cringe at the thought) from the 90s sitting around so I tried it out, and also able to use the VE map to integrate that. I have had a lot of fun with the MAFT Pro, well worth the purchase. Thanks for the great products.

 

[Pronto]

I'm bringing this thread back. I'm having a strange issue with the CS% readings. I have 28" tires with the corrected gear. My mph is correct on the speedometer and PLC. I put in the numbers suggested for the 28" tire in the correction factor window. On my old logs with my old combo I see about 2% slippage at the end of the run which is about correct since I was locking the converter. On new logs with the new combo the slip at the end of the track says 68% which of course is way off. From online calculators it should be about 12%. The interesting thing is if I switch from an old log to a new one the CS% will briefly read about 12% then goes back to the high readings. I've set up the PLC (version 2.6) on 2 laptops. The .ini files are the same. The CS% is the same on both and both show early logs correctly but new logs incorrect. I have never tried the CS feature until I read this thread today. One difference I know is the new trans does not have the electrical connection since it's a nlu. Could that be the issue? Any suggestions?

 

[TurboBob]

the converter slip takes into account the current gear, if the gear switches are not correct, then the calculation will not be correct.

you just have to fake it out in the CS factor settings.

Bob

 

[Pronto]

That's what I was thinking. I'll mess with the factors and see what happens.

 

[Pronto]

OK, I changed the correction factor in 4th gear to the same as third and got exactly 12%. With the logs of the nlu, 3 and 4th gear is indicated in the Data page. With the lock up trans, third gear is only checked.

 

[BobbyBuick]

what would b 2nd and third gear numbers for a 400 turbo with 28" tires

 

[stevek]

I tried this on my PL but like another member my numbers came up negative, i didn't see any post on how it was corrected . let me know thanks, here is pic of my Pl

 

[dank GN]

What numbers would I put in for a th400 with 28" tires

 

[LIVE4RDO]

Subscribed

 

[Nigel]

For the guys with the 400s, what is your speedometer gears? Also, unless you have a gear switch to the ECM, you want to load only the 3rd gear factor in all slots.

 

[dank GN]

For the guys with the 400s, what is your speedometer gears? Also, unless you have a gear switch to the ECM, you want to load only the 3rd gear factor in all slots.

I actully switched to a electrionic pickup that I have wired into a speedometer calibrater that converts it to the right frequency that the Ecm needs

 

[Nigel]

If the speedometer input is accurate for a 28" tire, I would use 46.4 * (26/28) since the power logger is setup based on stock tire height. If the speedometer signal is not correct then you will have to figure a correction factor based on that. If you have no gear switch input to the power logger then only the second gear factor input will work, so you only need the second gear factor entered and it will when in third.

 

[TurboBob]

the actual tire size and rear end are not part of the slip calc, since it uses the speedo input which is actually driveshaft speed. but to make it all correct there are a couple things to set.

if you have a sample log or 2 I can look at (cruise, and WOT) we should be able to figure it out.

 

[dank GN]

the actual tire size and rear end are not part of the slip calc, since it uses the speedo input which is actually driveshaft speed. but to make it all correct there are a couple things to set.

if you have a sample log or 2 I can look at (cruise, and WOT) we should be able to figure it out.

Here is a quick log

 

[TurboBob]

i need to compare to a log with 3rd gear cruising at very light throttles, slight accel, steady speed and slight decel. what do you know about the speedo gear tooth counts in your trans?

Bob

 

[Sleeper-6]

Just thinking out loud here. I should be able to verify the converter slip numbers are spot on for my car by cruising with the converter manually locked up. If everything is good I should show 0% slip when locked, right?

 

[dank GN]

Just thinking out loud here. I should be able to verify the converter slip numbers are spot on for my car by cruising with the converter manually locked up. If everything is good I should show 0% slip when locked, right?

Yes if you locked the converter and the clutch in the converter is good it should show 0 slippage .

 

[Nigel]

TurboDave used a lockup to determine correction factors, so yes you should see zero slip with a locked convertor unless it slips.

The ECM reads a 2 pulse signal, then converts to mph. If you modify the two pulse signal, then you have to correct it back as if you had the stock 2 pulse signal going to the ecm.