Aim Solo DL Datalogger

[CSG Mike]

This is the unit that we've been using to log in our BRZ.

MSRP is $699 for the Solo DL, which can read the following off of OBD2:

- Engine Coolant Temp
- Throttle position
- Pedal position
- Brake pressure
- Steering angle
- Individual wheel speed sensors
- Engine Oil temperature

It logs other things as well (Vehicle speed, GPS speed, 3d accelerometer, etc.), but we find that these are the metrics that most people find important.

Please PM me if you're interested in a unit, we'll be receiving a large shipment in the next 10 days or so, and we want to move them fast

http://aimsports.com/products/solo/

The Solo DL suction cupped do our windshield, showing 4 readings:

- Manifold air pressure
- Barometric air pressure
- Intake air temperature
- Ambient air temperature

[CSG Mike]

Here is an example of Solo DL Data Analysis

So a brief explanation of what is going on here

Top graph = throttle position
2nd graph = Front left wheel speed
3rd graph = Front right wheel speed
4th graph = Rear left wheel speed
5th graph = Rear right wheel speed
6th graph = steering angle (negative = left, positive = right)

Blue/purple thin boxes - compare the left and right wheels, and you can see momentary lockups under braking. Decreasing wheel speeds mean I'm braking the car, and the little sudden dips are the wheels on the verge of locking up, but recovering before they actually do. The wheel speed would go to 0 if it actually locked up. This is shown to demonstrate the accuracy of the equipment we are using, and validity of this test.

Red box #1 - under acceleration and turning, notice the wheel speed differences between the rear left and rear right wheels. The rear left wheel is the "inner" wheel in this case, and you can see spikes where it speeds up, and then slows back down as I modulate the throttle. With a mechanical LSD, I would be able to give the car more throttle without the rear wheels going at different speeds or spinning altogether. Spikes on the left rear wheel here indicate that the inside wheel is spinning, rather than gripping. The inside wheel travels a lesser distance than the outer wheel, and should be travelling at a lower speed, not a higher speed.

Red box #2 - Notice the dips and peaks of the rear right wheel, compared to the rear left wheel. The spikes up and down are a result of throttle modulation, but I am unable to put down any power, because when I do get on the throttle, I'm spinning the inside (rear right) wheel instead of accelerating.

Red box #4 - Note the spikes in the rear left wheel. Same thing; I'm modulating the throttle (top graph) to accommodate the car's inability to put all the power down. If the inside rear wheel were not slipping, I'd be able to corner faster, and put down more power.

Red box # - I manage to spin BOTH wheels for once, and need to countersteer....


TL;DR: mechanical LSDs help you power out of corners, and corner faster, regardless of power output levels (note that all the times where I cannot power out are at partial throttle) and driving experience.

[CSG Mike]

Comparing two different laps:

[7thgear]

it is also quite viable for Autocross


here is a deconstruction of a recent event between myself and another driver.

Originally Posted by 7thgear

Update:

My basic analysis based on what I see in the graphs along the length of the run


1. * General comment : Frankie's tires are no less grippier than mine. Peak G's barely vary and at times his are greater than mine.

2. My launch is substantially better, I get the car hooked up at a higher RPM (not shown in this graph, 5500rpm vs Frankies 4000) and carry that speed all the way to the first braking point.

3. We brake almost same amount, except that he peaks and feathers off, while I roll on to the brake, however our time spent braking is identical! And because of this I carry more speed through the initial corner. More on this later.

4. The next part is interesting, even though I am part throttle because I carried more speed I feather myway through the next section at an overall higher speed before coming to the braking point for the tight S

5. again we brake for an almost identical amount of time, with Frankie peaking harder and feather off while I feather the brakes into the turn. We decelerate at an even pace but I carry a bit more speed through it AND, if you look at the initial map, my line is simply tighter.

perhaps this can be attributed to a gentler brake deeper into the corner (so more front tire grip) and more confidence in the car completing the turn

6. Next part is interesting, Frankie goes WOT but he's still in 2nd gear while I shifted into 1st during my braking for the S. So even though I am feathering the throttle I am putting down more power, until I go WOT and accelerate much harder before we start turning right.

7. during this turn our stats are very similar, with the exception of a higher peak speed while Frankie has higher peak Gs, if you look on the GPS map you can tell he took a much more even circle while I did an egg shape hoping for a straighter line into the two-cone box

8. Going through the two-cone box we're doing pretty much the same thing. Not sure for Frankie but the reason there is brake pressure there is because the VCS, even though its turned off, still turns on to help the torsen do its thing... the two-cone box was pretty grainy so maybe that's why

9. in the long sweeper we see that Frankie ultimately attacks it harder and WOT 100% through it and is rewarded by a higher entry speed. I was much more conservative but at the crucial point I keep my foot partially on the gas which had me end up carrying more speed overall through the entire turn.

10. as you can see, the fact that Frankie let off completely resulted in him engine braking much sooner than me, this is reflected in both the G-load and Speed graphs.

11. I bleed off the extra speed by braking harder during the little straight before the hairpin, Frankie, in retrospect, having bled off all that speed, could have probably not bothered to brake at all until right before the hair pint

12. the hairpin is we start to diverge completely. As you can see, I braked harder and shorter to settle the car and my steering input was SMOOTHER yet QUICKER

13. as per the GPS map, this results in Frankie taking a much longer way around the hairpin pylon, and the end result is Frankie simply having to take a longer route through the slalom, hitting his turns at a much different rythem, turning before the pylon where as I was turning at the pylon

14. as I mentioned before, GRIP isn't a problem, we're hitting the same G-Loads, however as I am more consistent in this section with my throttle, I have much less speed variance going through it

15. the "BOX", Frankie goes nuts here and his throttle is ON/OFF/ON/OFF, while I maintain a near uniform steering and throttle input

16. the entrance to the exit is executed better by Frankie. I decided to take a tighter line but felt no grip in my tires, partly because I've had it setup to almost eliminate oversteer so I just casually turned and semi-coasted past the beam while Frankie rocketed into it like the boss that he is.

in the end, however, I was 1.9 seconds faster.

So two main things to draw from this

I still have room to be more aggressive and Frankie has a bit more training to do with his right foot.

But I think ultimately what won this for me was A. Better launch B. Overall smoothness with part-throttle to limit speed loss. C. nailing the hairpin entry, transition and exit.

http://www.casc.on.ca/forums/showthread.php?t=30177

[dradernh]

Originally Posted by 7thgear

here is a deconstruction of a recent event between myself and another driver.

Is the x-axis distance in your overlay graph?

[7thgear]

Originally Posted by dradernh

Is the x-axis distance in your overlay graph?

correct


I find this lends itself much better to micro analysis between runs/drivers... as it's more important for me to know what I'm doing rather than when.

[dradernh]

Originally Posted by 7thgear

I find this lends itself much better to micro analysis between runs/drivers... as it's more important for me to know what I'm doing rather than when.

For track data, distance on the x-axis is what's needed for that same reason.

[Sleepless]

List of all ECU/OBDII values available: http://www.aim-sportline.com/downloa...12_103_eng.pdf

[celica73]

No Mac software, so no good for me.

[CSG Mike]

Originally Posted by celica73

No Mac software, so no good for me.

Bootcamp/VMware!

[Sccabrz192]

Mike,

What type of datafile does it output? is there an option to export as a .CSV?

[whataboutbob]

In. Will send a PM.

[RehabJeff86]

@WoOosOn and @ddeflyer please buy one!!!! lol

[whataboutbob]

On the list!