Just what it says.. got 500 miles on new motor and MC twin disk... warmed the tires up and did a few 2-4 gear pulls.. in the logs it looks like it has rpm jumps... is that my clutch slipping?? pull5 is 2-4 gear. Pull 6 is warming up tires rolling to about 45mph in 2nd and pulling till top of 4th gear. I then let off a little and shifted to 5 for a short pull to see if the clutch would brake loose.. i dont think it did.. i just dont under stand the rpm spikes..

95 6speed 383 total E. air flow 305 heads, cam, all the bolt ons, f1a 14psi, fmic,ETC... old set up on stock heads same cam it made 633 rwhp.. dont know what it makes yet (700-740whp).. clutch is good to 1200fwhp.. tires are M/T et streets..(not tire spin)

http://www.2shared.com/file/3tpOH6dO...rmuptires.html

http://www.2shared.com/file/TH6evflv/pull6.html

 

Both those files downloaded as .exe files. They are not Datamaster .uni files, even though the second one is labeled as a .uni

 

how do i get them to .uni files?

 

A standard DataMaster file is a .uni file. Those look like something else. The second one shows up as a ".uni" on the FTP site, but when I downloaded both of them, they were saved as .exe files. I don't think anyone will want to run an unknown .exe file.

You can also use the "export engine data" function to export the file as a .csv file, which can be opened with Excel.

 

Your file share site is tricky, had to use the download button near bottom of screen to download your files. The top of screen download button(s) sends .exe files to install the sharing site program.. Are you using RPM or RPM16 to view engine speed. RPM is an old display spec that only used one byte (8 bits) from the PCM and displays/logs in 50 RPM increments. RPM16 displays in 1 RPM increments it uses all 2 bytes (16 bits) sent from PCM so its a lot smoother and accurate. At what record numbers do you think slippage occurs, I did not see anything real obvious.. Do you have skip shift wire disconnected, ref the DTC 84 in logs ??

 

im not sure about the rpm and the rpm16.. how do i tell? I down loaded the latest version of tts data master and just starting logging (still waiting for my reg. code from AKM cables).

im not by my tunnig computer right now, but i think it really started jumping around 4000-4500ish and up.

yes i just got the car running again and i didnt put the skip shift jumper back in.. I was going to shut it off in the tune (if you can).. Does that hurt anything that it is not hooked up??

 

You can also see my inj duty cyl. jumping around bad...??? looks like it follows the rpms and the timing goes up at the end of the pulls in each gear when im pulling timming for more boost not adding timing...

the only thing i changed with this tune is pulled 2 deg. of timing and raised fuel psi up to 68psi no vac.(afr is dead on for me 11-11.5).
thanks for the help!!

 

It's not clutch slip.

What brand opti do you have? These logs look similar to mine though I never figured it out, I went to a Megasquirt and now my rpm logs are way smoother.

Your timing and injector pulse are changing based on RPM since it's going into different cells which is normal, but I do not think the spikes are abnormal.

I used a few different opti's and they all show irregular RPM lines but some show more than others, now I have an MSD billet opti and it also showed irregular.

I just compared my oem PCM logs on car to OEM PCM using an electric motor on the opti tests I did in the past. The electric motor spinning the opti logs are completely smooth, the running engine WOT logs are jerky like yours.

My megasquirt logs of electric motor are also completely smooth, the on car logging is mostly smooth, with a little bit of the spikes that you see, but only 25-75rpm at the most, yours and my stock PCM logs show about 400rpm worth of spikes.

Right now I'm running the Megasquirt off only the low res signal and it may be ignorning or smoothing some of the spikes which could be due to slop in the cam chain, or engine vibration, something causing the opti to jitter.

There is also a Timing Error % in megasquirt that shows the rpm signal vs calculated signal (calculates when it thinks the signal should hit based on rpm), and shows the percent difference. This number bounces around a bit, I wonder if it's the opti jitter causing that.

Then my final thought is how can spark timing be accurate with all of this jitter in the signal! Maybe it's not a steady accurate signal and maybe that's what adds to a bit of spark knock and reduction in timing as the result (I mean, how can it be that accurate if it's driven off of the cam?)

 

wow good info!

I run GM opti's.

Do you know y it is adding a timing after around 4500 rpm and not taking away.. I have the tune pulling timing as rpm and boost go up... is that also a glitch.

and how so i see if i have it on rpm or rpm16?

 

The stock PCM adds timing to whatever you input as RPM climbs for some reason, so you have to take more out than you need to compensate. And, the IAT will not affect your Timing number, it only affects injector pulsewidth (proven in my 2 bar post).

Not sure about the rpm vs rpm16, but I know one is high and one is low res, or at least I think. Never tried to change the graph to other than default but you could probably graph it in excel using the data export if the RPM16 is an option.