Well, after reading through the 100-300kph and 60-130mph performance threads, I am now persuaded by Jean, Toby and others that dyno-ing the car is a waste of time - too many variables, too much opportunity to massage the numbers, insufficent standardization, too much hocus pocus! So in this context, I was wondering about the forum's views and experience with different performance computers.

From the net it is hard to find any scientific validation data on these devices. Issues like data integrety, reproducibility, accuracy and the like seem important, as does impact of cost on the aformentioned.

The AX22, Driftbox and now the PerformanceBox are no doubt in many members hands. The PerformanceBox on paper looks interesting to me as I like most I suspect, wouldn't need the slew meter (drift angle) which is the only function of the bigger brother DriftBox not onboard, and because of its price at 295 GB pounds (about US$600). At this price two or three dyno runs and you've paid for it!

Does anyone have views or experiences to share about their performance computer? I figured I might get one or other before any engine upgrade to do before and after measurements, rather than spend the money on a dyno.

Thanks for your thoughts......

Malcolm.

 

Hi Malcolm, great idea

I love the functionality and user friendliness of the Performance Box. All but two of our PClub members who use datalogging devices have them on board. They take no space and are not cumbersome. They have great fun comparing data between each other.

However, from my observations, long/lateral Gs measurements on the PBox are not very reliable, I have witnessed this several times and the numbers thrown by the device were wrong. Two days ago I was checking the data of one of the members right after our race, he has a GT3 with -3.0 degrees of front camber and stock suspension, running on Sport Cups.

His data shows a couple of places with lateral 1.45Gs. At those same spots, I see 1.3Gs and another member with a race prepared 996GT2 (-5 degrees of camber) sees 1.35 Gs on AX22, but we are both faster in that sector. Obviously the Ax22 might be wrong and not the PBox, however when comparing to a 997GT3 cup car, we saw 1.55Gs on slicks on Motec. Based on this and analysis of several other acceleration tests, I am inclined to think that the accelerometers are more accurate/conservative in general on the AX22. To most people that does not make any difference, but for some of us who put a lot of work on fine tuning suspension and racing lines based on these measurements (and sector timing obviously), this is very important.

For the occasional street usage and fun measuring acceleration runs on the track, the Pbox is a very capable tool. There are some newer devices out there BTW that look wonderful and are extremely capable, I would broaden my search.

 

Here is an interesting comparison of the sub $1000 units from Car and Driver.
The G-Tech Pro RR and the AX-22 look the best in this report - really a "drag strip" comparison with no test on lateral G's). The PerformanceBox was not included in the test.
http://www.caranddriver.com/features...ature/(page)/1
Here's another (but probably sponsored) comparison of the G-Tech Pro RR and the PerformanceBox.
http://www.performancebox.co.uk/down...CHvPB_Test.pdf

 

Mal,

My business partner uses a Traqmate. www.traqmte .com They have had MANY issues with it down here - but have stood by him and sent a new unit (x2 or 3) a new Antenna (x2) and have worked with the issues to make it right - so from my side they stand by their product - (which is rare in this day!!!) Maybe worth looking at?

Not sure if it will give you the data points you are looking for - but he is techno geek and loves it...

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Simon.