Just got an email yesterday that these are back in stock...I ordered one yesterday to see what they are like. Im tired of paying 75-100 bucks each time for a dyno session after doing mods ETC ETC. Even if this isnt as accurate as a "Shop Dyno" (they claim to be VERY close, a few %) i still will have a relative baseline to use for everyting else down the road.

<a href="http://www.charm.net/~mchaney/homedyno/dynokit.htm" target="_blank">http://www.charm.net/~mchaney/homedyno/dynokit.htm</a>


Actually look prettys cool!! anyone have any thought to the set up? Its all physics really, the more accurate your data entry the more accurate the results i suppose? <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

 

I have one. Alan C also has one and tested it against a real dyno. The road dyno was shy 5hp... close enough for a base line.

I got mine for that reason alone. Before and after mods, and tuning. You pay for it for 1 dyno session. You MUST have the 100& accurate info for it to work right. Barometer readings can change it 15hp either way. Temp, drag, all that needs to be right. Also, do 2 runs on flat road, 2nd gear. 1 run one way, the second the other. I tend to use the same spot for all my runs as well, although I tried 3 diffrent areas and was off by 2hp, so perhaps it does not matter.

Enjoy!

 

Great, thanks for the info! Odds are i may take it out to the local test and tune at "The Strip" a few times here in vegas. That way i know the road surface is fairly consistant, flat and should be able to get accurate readings each time...IF, i can find a good source for portable weather info that includes a baro reading.

 

This is very interesting.

I have wanted to make an accelerometer (like Gtech) that would do some of the same things, but I never thought of using RPM as the input. I would still use the accelerometer approach(It could do more things), but this is definitely a cool idea.
They make you put in the drag coefficient, this could be a tricky thing..


JIM

 

Tony -

Don't forget about the G-Tech Pro!

<a href="http://www.gtechpro.com/" target="_blank">web page</a>

It's about the most fun you can have doing self tests for $139... HP, 0-60 E.T., 1/4 mile E.T., 1/4 mile Speed, currently delivered horsepower during acceleration, 60-0 braking, Lateral G-Force, Longitudinal G-Force. It's about the size of a radar detector, plugs in to your cig lighter and "all" you do is input the cars weight.

 

The reason i like that ROAD DYNO is that you can print out the results in a graph form and you can make successive runs and keep the previous data.

The drag coefficient is published in the owners manual i think along with gear ratios and i THINK frontal area. Gaawwwd i sound like ED : )

As for the weight i go down to my local landscape place and drive on their scales. I stood on them and the showed a spot on 180lbs...pretty darn accurate for the size of them!

 

I've talked to two 928 owners that said they couldn't get the Road Dyno unit to record runs consistently. There was always a problem with getting a good signal for the engine RPMs. There are two similar devices available. One of those is OnTrack, which also uses a pickup on an ignition wire. The other is Dyno Plus, and that one uses an accelerometer, like a G-Tech does, instead of attaching it to an ignition wire. The information on those two units is at:
<a href="http://www.microsmith.co.uk/perf.htm" target="_blank">http://www.microsmith.co.uk/perf.htm</a>
<a href="http://www.ontrackdigital.com/" target="_blank">http://www.ontrackdigital.com/</a>

 

hmmm, i like that DYNO PLUS device. I wonder why they would have trouble with the ignition signal. Every "shop" DYNO ive run or smog check, i have never encountered a "pick up" problem. I guess i will find out!

thanks for the links.

 

I've never had or heard of a 928 really having problems getting a signal on a dyno or something like that either. Both of the guys I was talking about have spent a lot of time on a dyno with their cars and never had a problem there. It was just with the Road Dyno. Maybe it was just a quirky Road Dyno unit, since it was the same unit used on both cars. Let us know how yours works out.