mega jolt v4 tach out to rpm input race capture pro

azz1266 · Post by **azz1266** » Mon Apr 14, 2014 8:42 pm

Im trying to use the signal from my v4 megajolt tach out to the rpm input of the rc pro.

I recieve a signal but its not matching the one on the megajolt config screen.

any ideas how i can get this to match? It shows the rpm 200 less the the config screen?

ta

azz

azz1266 · Post by **azz1266** » Wed Apr 16, 2014 5:00 pm

Anyone?

I want to avoid buying the coilx pcb as I have the feed there already from the megajolt ecu?

Ta

azz

Post by **brentp** » Tue Apr 29, 2014 9:19 pm

Hi,

Thank you for the response. I think you have your RCP configured correctly with the clock divider; there might be an issue with RPM calibration inside of RCP. Let us investigate and get back with you!

-Brent

azz1266 · Post by **azz1266** » Tue Apr 29, 2014 9:21 pm

Thanks brent,

im sure its just something silly!

Azz

azz1266 · Post by **azz1266** » Tue May 06, 2014 9:59 pm

I have an update for you guys.

Had a couple more goes at getting the rpm signal to work properly and I have solved the issue!

Firstly I had a dirty cable connection going into the rcp unit which made the signal intermittent.

Secondly the rpm settings are as follows,

for the correct rpm signal from a megajolt v4 tach out pin, using a 36 toothed trigger wheel on a 4 cyclinder engine the clock divider needs to be 128 and the pulse input per ignition event needs to be 2! NOT 36 as expected.

unsure why but these settings work for my 1.3 polo gt

now to crack utilising the oem temp sensors without any calibration data!

I will pop a picture up when ive finished the wiring of my install

azz

Post by **brentp** » Tue May 06, 2014 10:02 pm

Thank you for the update! How close is the RPM between Megajolt and RaceCapture on your system?

azz1266 · Post by **azz1266** » Tue May 06, 2014 10:07 pm

Pretty close,

im going to do data logs on both tomorrow,
Is the megajolts data log set at 1hz as I tried to compare logs and I had more data points on the rcp.

what time stamp does the megajolt data log capture also, just trying to marry up the 2 of them for an easy comparison

azz

Post by **brentp** » Tue May 06, 2014 10:09 pm

You can use the time column in the log file for comparison. Also, you can do a casual test by simply holding RPM and monitor both apps simultaneously

azz1266 · Post by **azz1266** » Tue May 06, 2014 10:10 pm

By the way When I mean pretty close, I mean they look exactly the same

azz

azz1266 · Post by **azz1266** » Tue May 06, 2014 10:14 pm

Ideally I want to compare both bits of data to confirm they are the same,

I know the gps records seconds from midnight but im not sure what time stamp format the megajolt software is in?

azz

Post by **brentp** » Tue May 06, 2014 10:16 pm

IIRC the MJ software records current time.

azz1266 · Post by **azz1266** » Tue May 06, 2014 10:34 pm

mine differs from the normal time?

please see attached screen shot

azz

Post by **brentp** » Tue May 06, 2014 10:42 pm

Which log file is this? Could you just attach the actual log file data instead of a screen shot?

azz1266 · Post by **azz1266** » Tue May 06, 2014 10:48 pm

Im not on my laptop now (on the tablet)

Will have a play with it tomorrow and attach the log file tomorrow evening.

Azz