Recommendations for performance meters / dagaloggers?

[WDB748372]

@gsxr I've been entertaining the idea of getting a performance meter recently to try on a stock, tuned, and supercharged W210 E55 along with the E60.
Are there any devices you'd suggest? I've been looking at a Dragy for $180:

 

[gsxr]

@gsxr I've been entertaining the idea of getting a performance meter recently to try on a stock, tuned, and supercharged W210 E55 along with the E60.
Are there any devices you'd suggest? I've been looking at a Dragy.

@WDB748372 - that is a great question. I started using a RaceTechnology AP-22 meter nearly 20 years ago, at the time it was a pretty good solution, although it had no GPS capability. Around 2011, I upgraded to the AX-22 meter for ~$350. The AX-22 has an external GPS antenna, and also an input to log engine RPM from the tach (cool stuff, if you need that, may not work on a 210 though). I found the AX-22 was within about 1-2% of dragstrip timing lights which was adequate for my needs.

Both of these old RaceTech units are relatively obsolete by modern standards. I'd like to upgrade to something newer and more accurate that relies more on high-res GPS positioning, and less on internal G-force meters. I haven't looked into Dragy yet. These are the units I had been considering, although I have not seriously investigated any of them yet. I believe @Beater400E has the Racebox Mini-S.

Racebox Mini-S ($250):​

Mini S | RaceBox

www.racebox.pro

​

Racebox ($350):​

RaceBox

www.racebox.pro

​

Vbox Performance Box ($350):​

Performance Box - Lap Timer, Speedometer, Accelerometer

GPS based performance meter that allows you to measure G-forces, speed, lap & split times, 0-60, braking distance and many more.

www.vboxmotorsport.co.uk

​

Vbox Performance Box Touch ($860 !!):​

Performance Box Touch

Calibrated Precision Performance Meter & Lap Timer with Easy to Use Color Touchscreen

www.vboxmotorsport.co.uk

Make sure the meter is capable of measuring between any 2 selected speeds, and that it doesn't have "fixed" speeds only. I.e., I want to test from 0-100, and also 0-130, etc because 0-60 times are often useless due to traction issues on the street. The AP-22 and AX-22 both had a datalog output function, the AX-22 captures far more data (100Hz, IIRC?) for detailed analysis if desired. I want a newer unit with similar capability. It doesn't appear that RaceTechnology still manufactures anything similar to the AX-22, Racebox, or Vbox... they primarily have multi-thousand-dollar racing/industrial dataloggers, which are awesome, but far beyond my price range.

 

[WDB748372]

Thanks for the valuable info as always!

Make sure the meter is capable of measuring between any 2 selected speeds

This was going to be a follow up question. I was sold on the Dragy unit due to it's accuracy and easy to use interface but couldn't tell if it was capable of measuring between any two speeds. That was a huge drawback. There looks to be some default metrics only.

The Racebox Mini-S does exactly just that although a bit more pricer. @Beater400E would love to hear your experience with it.

 

[Beater400E]

I've been happy with the Mini-S so far. Admittedly, I have not spent a ton of time exploring all its features, and I have not taken it to the track to compare accuracy between an NHRA timing system and the Racebox.

I can say that the Mini-S appears to be ruggedly built, and the fact that it does not need to be constantly paired to my phone to capture data is a big plus.

I've never had another performance meter, so I can't tell you how it compares with any others. I do know that one key thing to look at is how many GPS pings per second a device us capable of. The Mini-S is capable of 25Hz, which basically means it should be accurate to within 0.04 seconds on your leave. That makes it one of the most accurate meters on the market, and that, along with the affordable price is why I chose it.

 

[gsxr]

I poked around the Dragy website a bit and was not impressed. No user manual that I could find, and the FAQ's are useless. They imply you may be able to define any two speeds for timing, but don't explicitly state this other than "custom measurements". I get the impression this is more of a social media tool intended to upload directly from the required-phone to Bookface/Instatweet/Tickytok/Gram. Not what I'm looking for, but I guess every user's needs may be different.

Racebox does allow selecting any 2 speeds and supports "rolling start" as well - not sure if Dragy supports that. I'm on the fence about a unit that requires a phone/tablet to function though, which is the difference between the Mini and larger/standalone Racebox. Hmmm. I like the PerformanceBox Touch, but ooof, that pricetag.

I'll need to check into Racebox/PerformanceBox software and data export capability. I like the data available from the old AX-22 and want to retain that type of functionality. I think both have this but I'd want to verify before purchase (or, use their X-day free trial, if available - Racebox is 14 days, didn't see a free trial / money-back on PerformanceBox).

 

[Beater400E]

I'm on the fence about a unit that requires a phone/tablet to function though, which is the difference between the Mini and larger/standalone Racebox.

I'm sure you're aware of this, but I figured I'd call it out explicitly. The Mini-S does not have a screen, and does require linking to a phone or tablet to configure, and to read back recorded telemetry, but a phone or tablet is not required to capture and record data. It can record as a standalone device, and then you can pair with your mobile device after you're done racing to review your results. Might not make much of a difference to most, but for some who are worried about needing to bring their mobile device on track, it's worth clarifying.

 

[gsxr]

I'm sure you're aware of this, but I figured I'd call it out explicitly. The Mini-S does not have a screen, and does require linking to a phone or tablet to configure, and to read back recorded telemetry, but a phone or tablet is not required to capture and record data. It can record as a standalone device, and then you can pair with your mobile device after you're done racing to review your results. Might not make much of a difference to most, but for some who are worried about needing to bring their mobile device on track, it's worth clarifying.

Yes - good clarification! I also need to verify that the recorded data is easily accessible on a Windows PC. I don't process data on a portable device. It's likely saved in a CSV format which can be opened in Excel, similar to the AX-22.

 

[Beater400E]

Yes - good clarification! I also need to verify that the recorded data is easily accessible on a Windows PC. I don't process data on a portable device. It's likely saved in a CSV format which can be opened in Excel, similar to the AX-22.

"Easily" will depend on your tolerance for jumping through hoops.

When you record a session, you can save the session from your mobile device, at which point it will upload to your cloud account. You can then access your cloud account by logging in to your account on the Racebox website. From there, you can download your session data in a number of different formats, including csv.

I just tested it and was able to download the csv and open it on my pc just fine.

 

[gsxr]

"Easily" will depend on your tolerance for jumping through hoops.

When you record a session, you can save the session from your mobile device, at which point it will upload to your cloud account. You can then access your cloud account by logging in to your account on the Racebox website. From there, you can download your session data in a number of different formats, including csv.

I just tested it and was able to download the csv and open it on my pc just fine.

Awesome - thanks for confirming! Could you share a sample CSV, if available?

I guess it would be simpler to have a unit that records to SD card, but that requires bumping to any of the options above the Mini (i.e., $350+)...

 

[Beater400E]

Could you share a sample CSV, if available?

Sure thing. When you log in to your online account you can pull up any sessions you've sent to your account.



Keep in mind there are countless configurations and settings, so what you see here is not the limit of what is offered. This "session" was me walking around my house for 20 seconds.

Once you've chosen a session to review, you can click in the top right to download session data. You'll be given a few file type options:



You'll then have a few different options for the type of data you want to download:





Here's a sample of the actual data for this session's Telemetry Overlay, in CSV format:

 

[WDB748372]

it does not need to be constantly paired to my phone to capture data is a big plus.

Appreciate your input. Didn't know but that is also huge plus too. So far this looks great and worth the difference compared to the Dragy. I'll do some more digging on this unit. Thank you again.

I get the impression this is more of a social media tool intended to upload directly from the required-phone to Bookface/Instatweet/Tickytok/Gram.

That's honestly how I came across it. A YouTuber was using it in parallel during his 1/4 run and I was impressed how accurate it was given the price point.

Racebox does allow selecting any 2 speeds and supports "rolling start" as well - not sure if Dragy supports that.

That's great to know as well. Again a more applicable case where I would want to use it and not have to hit 130mph every single time to get some sort of metric like the Dragy.

 

[gsxr]

That's honestly how I came across it. A YouTuber was using it in parallel during his 1/4 run and I was impressed how accurate it was given the price point.

Correct - any good unit that receives high-resolution GPS signals (i.e., 10Hz or better), should be able to provide very accurate data. The difference then becomes the UX/UI, and features available from the hardware and/or software, i.e. rolling start capability, selectable start/end points, battery life, external antenna capability, etc.

That's great to know as well. Again a more applicable case where I would want to use it and not have to hit 130mph every single time to get some sort of metric like the Dragy.

Exactly. We want more of a true datalogging solution, that also shows some commonly desired metrics like 0-60, 0-100, 1/4 mile, etc. The AX-22 software is not user friendly but it has all data in 100Hz (0.01-second) increments.



As a side note: When measuring performance, I've found that low-speed measurements such as 0-60 are not particularly useful. There is far too much variability at the launch, based on traction on public roads with street tire compounds. Wheelspin can cause times to be several tenths of a second slower, and can be as much as 1-2 seconds with severe spin and ASR/ESP intervention. Best case, spend some time at a dragstrip with a sticky surface and (if possible) drag radials where there will be zero wheelspin. This will give you the best numbers, for given atmospheric conditions, which can vary substantially day to day. It also will show the peak G forces at launch which is cool to see on cars that launch hard.

For street testing, data to 100, 130, or higher is more indicative of true performance as it minimizes the effect of wheelspin at the start. Or better yet, compare data from 20-100, 30-100, 30-130, between vehicles. That should eliminate the launch-wheelspin variance. For each test date/vehicle combination, also note the fuel load, weather conditions (temp and barometric pressure are the main variables), and vehicle setup - tires, anything that isn't stock which may add or remove weight, etc etc. A near-empty fuel tank will be ~20 gallons lighter vs full tank on a 500E, which translates into nearly a 150-pound difference.

 

[WDB748372]

As a side note: When measuring performance, I've found that low-speed measurements such as 0-60 are not particularly useful. There is far too much variability at the launch, based on traction on public roads with street tire compounds. Wheelspin can cause times to be several tenths of a second slower, and can be as much as 1-2 seconds with severe spin and ASR/ESP intervention.

First thing came to mind for me was 0-60. That's a great point though, it would be more accurate for me to do a rolling start. Will keep weight in mind too.