Datalogging 2nd gear pull?

[1Cor10:23]

Hi all,

I know it's been said that best data is typically a 3rd gear pull but for those that want to respect the speed limit as best as they can, how off would a 2nd gear pull be?

[Lytheum]

3rd or 4th gear gives you a lot more data to look at because they take longer to run out. You'll get the same data, but a smaller sample size.

[Luckrider]

Note, you can't just do the run at lower throttle to get more data because it needs to be a WOT pull.

[1Cor10:23]

Originally Posted by Luckrider

Note, you can't just do the run at lower throttle to get more data because it needs to be a WOT pull.

Yes of course, haha. That much, I get.

[jamesm]

you'll want to do runs in 3rd gear, so that the ramp rate allows sufficient time to gather data, especially with lower sampling rates (anything less than 16-18hz). i have to do my pulls in 4th for high boost now because it just spins all the way through 3rd, so i know what you mean about high speed being a bad thing. it gets hairy sometimes .

also i believe you're na, but for anyone with FI you'll want to remember to turn traction control off before the pulls. it will close the throttle and ruin your run.

[Luckrider]

Originally Posted by jamesm

you'll want to do runs in 3rd gear, so that the ramp rate allows sufficient time to gather data, especially with lower sampling rates (anything less than 16-18hz). i have to do my pulls in 4th for high boost now because it just spins all the way through 3rd, so i know what you mean about high speed being a bad thing. it gets hairy sometimes .

also i believe you're na, but for anyone with FI you'll want to remember to turn traction control off before the pulls. it will close the throttle and ruin your run.

You need more grip too though. My 245/40R17s would probably do you nicely.

[Sportsguy83]

Originally Posted by Luckrider

You need more grip too though. My 245/40R17s would probably do you nicely.

LOL... 265's Michelin PSS are not enough already...

Any other tire with noticeably more grip= unsafe for street/rain conditions.

[jamesm]

Originally Posted by Luckrider

You need more grip too though. My 245/40R17s would probably do you nicely.

yeah it's pretty hopeless. we have the same problems on the cars with stickier rubber, just to a lesser degree. The only hope for traction (without killing power) with any reasonable street tire at high boost is custom map based traction control. it also has the happy side effect of cool noises.

[xjohnx]

Originally Posted by jamesm

you'll want to do runs in 3rd gear, so that the ramp rate allows sufficient time to gather data, especially with lower sampling rates (anything less than 16-18hz). i have to do my pulls in 4th for high boost now because it just spins all the way through 3rd, so i know what you mean about high speed being a bad thing. it gets hairy sometimes .

also i believe you're na, but for anyone with FI you'll want to remember to turn traction control off before the pulls. it will close the throttle and ruin your run.

I've found that I'm able to get sampling rates of up to 16hz by cutting back on the parameters that are logged when using my new laptop from work (HP ProBook). What kind of rates have you been seeing?

[jamesm]

Originally Posted by xjohnx

I've found that I'm able to get sampling rates of up to 16hz by cutting back on the parameters that are logged when using my new laptop from work (HP ProBook). What kind of rates have you been seeing?

anywhere from 16-32hz with the new windows laptop (cheap acer from best buy). depends upon not only the number of channels, but which channels you are sampling. some channels cost you nothing at all, where others cost 2-3hz by themselves. i think it's the obd channels that slow it down, but i'm not really sure. i know logging the ecutek-specific stuff is fast (custom map results, sd stuff and what not).

[steve99]

Originally Posted by jamesm

anywhere from 16-32hz with the new windows laptop (cheap acer from best buy). depends upon not only the number of channels, but which channels you are sampling. some channels cost you nothing at all, where others cost 2-3hz by themselves. i think it's the obd channels that slow it down, but i'm not really sure. i know logging the ecutek-specific stuff is fast (custom map results, sd stuff and what not).

found the same with Tactrix logging

Reading direct RAM address = fast 20Hz or so
Reading OBD parameters = slow

[1Cor10:23]

So I did the 3rd gear pull and wow, my IAM was screwed up , and this was on vpower 91 (1.5 gallon remaining - immediately topped up with 94 E10) - started at .57 and slowly went up to .86 at end of drive.

I've documented my issues here on this thread if any of you would like to chime in, would greatly appreciate it!