Contour Enthusiasts Group Archives Forums Modifications Forced Induction Proper data logging

I just received an Xcal2 from ADC. Keith wants me to datalog various info, short term fuel trim, long term fuel trim...etc. Does anyone know what would constitute good data? Is there a specific way to drive so he has all necessary info. At this point with just a base tune, i really do not feel comfortable taking it anywhere near redline.

Oh yeah...it is turbo'd, t-28 kit.

Adam

do a pull with constant throttle in both open and closed loop modes. 3rd gear pull is good speed limit permitting...

so by highway pull, are you saying, pick 3rd and slowly wind it all the way out??

personally, when i need to data log i always use a good 3rd gear highway pull. i usually do it with 3 other people though lol. we get all mission impossible/james bond style and send one person to an on ramp before the one i will be driving up, send one person about 1/2 mile ahead (just before the next on ramp) and one other person in the car with me to hold the laptop. short shift 1st and 2nd on the on ramp and let it rip WOT all the way through third.

~Andrew

Find an out of the way street. Sit in neutral turn on the datalogger and rev the engine up in about 750 rpm increments. Should be about 6 reference points. This will show how to tune your idle and cruise. Then do a quick run through 1st and 2nd up to about 5k. If you have room get third. Turn off datalogger. You will be stunned how fast it will ramp up to 5k.

Thank you guys for the input, I really appreciate it.

One clarifying question before I go out to "play". When taking the "quick" run through 1,2,3 taking the RPMs up to 5000, what type of throttle should I be using? Wide open? Steady acceleration? If less than WOT, what percentage is suggested?

Adam

You need to do both. At idle, at light cruise in 3rd gear, and then a 3rd gear pull from a lower rpm.
During your light cruise datalog runs, pick rpms that are easy, such as 2000, 2500, 3000, 4000 rpm so that you have several runs that represent different airflows and thottlepositions.
Then the full throttle run from say 1500 all the way to redline in 3rd gear will show how the fuel system is metering in WOT mode.
The cruise runs will show how your O2 sensors are working along with your MAF and of course the fuel trims will help determine how closely the tune is matched.