Saw this on the big book of faces. Apparently it's some sort of device that bolts to one of your wheels and gives you a power output reading at the wheel.
https://www.magicmotorsport.com/car-dyno-dynoroad/
I vaguely remember seeing something similar about 5 years ago, but don't know anything about that either. Does know anything (or have any guesses) as to how this is supposed to work?
Well, if you've got weight and acceleration you can back into HP.
Looks like this is doing that but probably getting wheel rpm as well, and maybe getting phone gps for accurately translating rpm to speed.
I remember a few units about 5 years ago that went between your trans and driveshaft, and measured torque/strain I think.
Robbie (Forum Supporter) said:Well, if you've got weight and acceleration you can back into HP.
Looks like this is doing that but probably getting wheel rpm as well, and maybe getting phone gps for accurately translating rpm to speed.
I remember a few units about 5 years ago that went between your trans and driveshaft, and measured torque/strain I think.
Yes, it's the same principle as "virtual dyno", which is software that can take a data log of vehicle speed/RPM and compute a dyno chart from it. The biggest challenge to using it is finding a road on which you can do 30-120 mph pulls that's flat, empty of traffic, and doesn't garner official attention. That's as a tuning tool -- getting a dyno chart that's useful for comparing to a different car is (IMHO) basically impossible because there's no practical way to get the aero drag numbers accurately enough.
I believe AEM made the strain gauge that went between the transmission and the driveshaft -- very cool product, but required lots of expensive custom bits to adapt it to your car and only worked on RWD thus cutting out a huge percentage of their market.
I suppose that raises the question - what makes this worth $1800 vs something like Virtual Dyno, which is basically free?
In reply to boxedfox (Forum Supporter) :
Seems to me that you should be able to do just as well with an obd2 feed and a nice gps.
The obd2 gives you rpm (and probably lambda - which would be a huge improvement over this guy). With a good GPS you'd have what you need.
In fact, the obd2 version could also probably do the same rpm pull in the same car in 2 different gears and use the difference to estimate aero drag.
Robbie (Forum Supporter) said:In reply to boxedfox (Forum Supporter) :
Seems to me that you should be able to do just as well with an obd2 feed and a nice gps.
The obd2 gives you rpm (and probably lambda - which would be a huge improvement over this guy). With a good GPS you'd have what you need.
In fact, the obd2 version could also probably do the same rpm pull in the same car in 2 different gears and use the difference to estimate aero drag.
Back in college we had to use OBD2 data to calculate power/dyno as well as do coast-down testing to estimate aero drag. We did it on a 'flat' road, but with GPS you could do elevation changes as well.
I'm not at all understanding what the product in the OP is providing. I'd laugh if it was a $$$ battery that lit up an LED, and all of the actual math was done via OBD/phone GPS data.
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