I bought a Pocket Dyno from pdyno.com. It’s a pretty cool little device that is essentially a poor-mans dyno. The model I got cost just under $50.00 It is a small accelerometer with Palm OS interface and software that will calculate several parameters. There are several models available. I got the mini lite version. The next version up is basically the same, but will store data on your palm device, and then you can export it to a spreadsheet.

You just enter the weight of your car, calibrate the device and you are ready. The 0-60 measures your 0-60 time, then estimates the ¼ mile time, speed and max hp. This way, you can have fun testing without having to risk a fat ticket. You can set it to do your actual ¼ mile time if you want to. I don’t know how accurate it is, but I think it will yield useful data for comparison purposes.

I have a 2003 mc with 16’s and runflats. No other performance mods.

I guestimated the weight of my car with driver at 2750lbs. 2524 unladen weight from the mini brochure + 220 for me, the driver + a few extra lbs to round the number off. I will probably go the county landfill and use their scale get the actual weight of the car + driver.

I ran some baseline runs, then switched the stock air filter with a drop in foam filter. In the future I plan to test a pipercross filter, and rogue exhaust system which I already have but have not installed yet, then the pipercross and rouge together.

I made a total of 12 runs with each setup. 4 runs shifting at 4k rpm, 4 shifting at 5krpm and 4 runs shifting at 6krpm. The table below shows the average of the 4 runs.

0-30 30-50 0-60 1/4 time 1/4 speed hp
Stock 4k 5.03 5.55 14.30 19.33 69.82 74.67
Foam 4k 4.69 5.23 13.39 18.90 71.46 80.33
Stock 5k 4.36 4.68 12.23 18.36 73.51 87.33
Foam 5k 4.37 4.75 12.36 18.42 73.27 86.33
Stock 6k 3.68 4.13 10.64 17.51 77.08 101.00
Foam 6k 3.77 4.08 10.17 17.36 77.72 103.33



The foam filter shows some gains in the lower and upper range, but a loss in the mid range. I don’t know why.

Has anyone else played with one of these devices?

Andy


_________________


It's time to motor. MC CR/B

 

Andy, that is some great data. Thanks for doing the experiment
rather than just saying it really improved everything.

This is the kind of thing we need more of in the performance
world. people measuring their improvements and posting
the results.

Thank you. A very good demonstration of what you got
from your intake mod.

 

If you get a chnace, could you try that again with different grades of gas?

THAT would sure be a great set of data.

 

Can you try it again but with your key cut in half?

--
Cheese

 

I must be reading the chart wrong, does it say that your 0-60 times are 14.30 for the slowest run and only 10.17 for the fastest run? What am I missing, it's early and I am still half blind.....

 

>> does it say that your 0-60 times are 14.30 for the slowest run and only 10.17 for the fastest run?

I think that's what it says also.

What numbers were you expecting? Bigger or smaller.

I have no idea what "normal" numbers are for this thing.

 

>>I must be reading the chart wrong, does it say that your 0-60 times are 14.30 for the slowest run and only 10.17 for the fastest run? What am I missing, it's early and I am still half blind.....

The shift point moves from 4K to 6K. If you shift at 4K you are missing most of the power so you get a 14.3 0-60. Even 6K would be considered a short shift.

 

Yes, you are reading the numbers right. The reason I choose the different shift points was to try to establish some consistent runs. Sometime in the future I will go ahead and shift at redline and see what the results are.

The other thing I wonder about is if the chip takes some time to get used to the different mods. I drove the car about 5 miles at varying speeds before logging the data.

Once again, these numbers are useful to measure the effects of different mods, and at 50 bucks, a nice tool.

I did a few runs where I shifted over 6k and got 0-60 runs of 9.02 and 9.3.

None of these runs were very aggressive off the line.

Andy

 

Did you buy it used? The cheapest, the mini lite, is still $99. If not where did you get it?
-Chris

 

So Andy,

If I get what you are saying. When I read that the S can be 0-60 in (depending where you reaad it...) 6.9 to 7.4 seconds that means a very aggressive run, fast start, highest shift points.

The runs that you got are not the full potential of the car.

Am I close, damn I feel dense today

David

 

>>So Andy,
>>
>>If I get what you are saying. When I read that the S can be 0-60 in (depending where you reaad it...) 6.9 to 7.4 seconds that means a very aggressive run, fast start, highest shift points.
>>
>>The runs that you got are not the full potential of the car.
>>
>>Am I close, damn I feel dense today
>>
>>David
if i didnt read wrong.
i think he has a mini cooper, not S?

 

>>So Andy,
>>
>>If I get what you are saying. When I read that the S can be 0-60 in (depending where you reaad it...) 6.9 to 7.4 seconds that means a very aggressive run, fast start, highest shift points.
>>
>>The runs that you got are not the full potential of the car.
>>
>>Am I close, damn I feel dense today
>>
>>David

David, You are right, I was not trying to get the full potential out of the car, and erichui is right, I don't have an s. The reason for the short shift numbers is to try to measure gains under more normal driving conditions.

Most of us do not shift at redline all of the time. A 4k shift is probably common in easy moroting, a 5 k shift crossing traffic etc, and maybe a 6k shift entering the freeway or passing.

I will try to get the most out of the car sometime down the road, but my purposes for these tests is to measure gains under everyday driving conditions.

Andy

_________________


It's time to motor. MC CR/B

 

>>Did you buy it used? The cheapest, the mini lite, is still $99. If not where did you get it?
>>-Chris

I got it new for 49.95. They had an introductory deal earlier this month. Ask them about it, and see if they will extend the offer. $99 is still not a bad deal considering the cost of a dyno run.

Andy