Data Loggers vs. PDR times

RUQWIKR · 05-20-2018, 02:34 PM

Spent yesterday on the short techinical configuration at Motorsports Ranch - Cresson (MSR-Cresson, Texas). It's 1.3 miles long with a lot of elevation change. They run it always CCW as they do the 3.1. The 1.7 can be run both directions.

Anyways, I just put Harry's Laptimer on my iPhone to compare to the PDR plus I borrowed an AIM Solo yesterday. Both the AIM and the iPhone were in the dead center of the car. The AIM and Harry's were very close, all within 0.07. However, the PDR would vary widely session to session.

Laptimes were ~64 to ~70 seconds depending on traffic with 20 minute sessions. One session, most of the laps were between +/-0.25 of each other but there would be a flyer of a second faster to two seconds slower. Another session, all were within +/-0.25. Another session, all times were over a second different both slower and faster, etc.

Is the GPS link or execution all over the map with the PDR as Harry's and AIM seemed a lot more consistent to each other.

I'm looking at getting an AIM or is there one you guys would recommend?

Thanks. Dave

JeromeS13 · 05-21-2018, 03:20 AM

From my experience, the PDR lap times were within .01 second of the track's AMB transponder, if marked at the correct start/finish loop.

trackjunkie61 · 05-27-2018, 07:52 AM

I have an Aim Solo DL for sale if anyone is interested. Includes mount and extra long CAN harness.

Destroyer_1LE · 06-09-2018, 11:19 PM

I compare the times between the tracks transponders and PDR after every track and and the largest differences Ive noticed between the two is about -+ 0.01 but most the time its dead on.

Also make sure to make the mark the Start/ finishline on the real start/ finishline if you don't the times will be skewed due to mixing two lap times and over doing in sections just to cross the finish line faster (happens all the time at my local K1 Speed Anaheim the lap timer in the ground is mid corner. if you can to set a fast lap time you can blow through the corner and blow into the wall and drop second or more off your time)

mr965 · 06-10-2018, 02:20 PM

PDR is accurate except for the indicated speed. I believe it operates off the speedometer which is not optimal.

05-20-2018, 02:34 PM	#1
RUQWIKR Drives: 1LEs Join Date: May 2009 Location: DFW - Texas Posts: 1,319	Data Loggers vs. PDR times Spent yesterday on the short techinical configuration at Motorsports Ranch - Cresson (MSR-Cresson, Texas). It's 1.3 miles long with a lot of elevation change. They run it always CCW as they do the 3.1. The 1.7 can be run both directions. Anyways, I just put Harry's Laptimer on my iPhone to compare to the PDR plus I borrowed an AIM Solo yesterday. Both the AIM and the iPhone were in the dead center of the car. The AIM and Harry's were very close, all within 0.07. However, the PDR would vary widely session to session. Laptimes were ~64 to ~70 seconds depending on traffic with 20 minute sessions. One session, most of the laps were between +/-0.25 of each other but there would be a flyer of a second faster to two seconds slower. Another session, all were within +/-0.25. Another session, all times were over a second different both slower and faster, etc. Is the GPS link or execution all over the map with the PDR as Harry's and AIM seemed a lot more consistent to each other. I'm looking at getting an AIM or is there one you guys would recommend? Thanks. Dave

05-21-2018, 03:20 AM	#2
JeromeS13 Drives: 2017 1SS/1LE Join Date: Sep 2016 Location: FL Panhandle Posts: 1,559	From my experience, the PDR lap times were within .01 second of the track's AMB transponder, if marked at the correct start/finish loop.

05-27-2018, 07:52 AM	#3
trackjunkie61 Drives: 2017 1LE Join Date: Dec 2016 Location: Gulf Coast Posts: 26	I have an Aim Solo DL for sale if anyone is interested. Includes mount and extra long CAN harness.

06-09-2018, 11:19 PM	#4
Destroyer_1LE Drives: 2017 Camaro 1LE Join Date: May 2016 Location: La Palma, California Posts: 95	I compare the times between the tracks transponders and PDR after every track and and the largest differences Ive noticed between the two is about -+ 0.01 but most the time its dead on. Also make sure to make the mark the Start/ finishline on the real start/ finishline if you don't the times will be skewed due to mixing two lap times and over doing in sections just to cross the finish line faster (happens all the time at my local K1 Speed Anaheim the lap timer in the ground is mid corner. if you can to set a fast lap time you can blow through the corner and blow into the wall and drop second or more off your time)

06-10-2018, 02:20 PM	#5
mr965 Drives: ///M3 Join Date: Nov 2016 Location: west coast Posts: 439	PDR is accurate except for the indicated speed. I believe it operates off the speedometer which is not optimal.

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