0-60 times in wet

Anonymous · January 10, 2007, 19:45

HAve you got the programme as just a .cab file or equiv so I can install it direct from my ppc (don't have a windoze pc you see).

If so I'll give it a whirl on my axim x51 win 5.0.

spit · January 10, 2007, 23:14

Beta version of GPS speedo, it works!!! Excellent. I am in awe of you programmey people. Nicely done.

My times were crap, but thats me (wet), Manchester rain (the wettest), pulling out from a layby and 2 gearshifts s:cry: :cry: s:cry:

Get those excuses in early s:lol: :lol: s:lol: 6.314 secs

Ties in nicely with the times me and Mike got under similar drowned rat conditions using his accelero-do-dah which IIRC was 6.64, or 6.46?

muffdan · January 10, 2007, 23:30

cool, I was getting around 6.3 in the dry earlier. I don't have a dyno read out for my car though so I don't know if the time is accurate or not. Any volunteers who have stock cars to try it? We can compare to stock 0-60 times then. BTW, anyone tried a 0-100 yet? Not on a public road of course s:)

s:)

Anonymous · January 10, 2007, 23:41

6.3 in the dry?!

were you trying to as fast as possible?

muffdan · January 10, 2007, 23:55

yeah, I was pretty much nailing it. My speedo was reading 90 odd before the GPS read 60. The speed of the GPS is only updated once a second (regardless of baud rate), the speed is an averaged over I don't know how long. I think these parameters will vary between GPS devices too. So in order to hit the 60mph 'stop timer' trigger you have to average 60 over a second (or whatever the averaging duration is).

My next task is to ignore the speed calculated and reported by the GPS device and do the maths myself from the latitude and longitude. I can remove the averaging that is happening which will bring the times down.

Anonymous · January 10, 2007, 23:57

Nice work Dan,

Just tried out my Muff'ometer (all praise to dan)

1st two runs I got 7.6 seconds - dry, clutch drop from 3k with not the greatest starts and abit of back end wobble.

These seemed pretty accurate - I also timed with a chrono stop watch using my speedo to a calibrated 60mph and got 7.8sec.

My final run - 6.7 sec. Seems very quick to me but it was a good getaway with minimal wheel spin and no wobble.

SUGGESTIONS:

1/ The speed readout and running timer - it would be better if these were in a big bold font so you can easily read them.
2/ How about standing 1/4miles, presumably that would be possible.
3/ A permenantly stored log of say your last 10runs and your best so far.
4/ What would be ultimate would be a graph of speed against time - that way you could see if you made a bum gear change or bad start etc etc - although I appreciate this could be tricky to programme (not that I know)

thanks for the work
s:D

s:D

Anonymous · January 10, 2007, 23:59

BTW I had to pretty much hit the limiter in second to get it to register a time.

IIRC 2nd gear tops out not much above 60 anyway.

Anonymous · January 11, 2007, 00:00

just supprises me?!

the time you ran, i would expect abit lower than that especially if the tyres were warmed up, reason i say this is because TTET is 5.9?! but youve got the SP downpipe and the exhaust?!

so surely your can must be under achieving?! strange! now me thinks is your car set up on correct psi?!

Anonymous · January 11, 2007, 00:04

Just had this image of dozens of roadsters across the country steaming down dualcarriagways and empty industrial estates and fiddling with PDA's.

s:D

s:D

enid_b · January 11, 2007, 00:08

Quote from: "spit"Beta version of GPS speedo, it works!!! Excellent. I am in awe of you programmey people. Nicely done.

My times were crap, but thats me (wet), Manchester rain (the wettest), pulling out from a layby and 2 gearshifts s:cry: :cry: s:cry:

Get those excuses in early s:lol: :lol: s:lol: 6.314 secs

Ties in nicely with the times me and Mike got under similar drowned rat conditions using his accelero-do-dah which IIRC was 6.64, or 6.46?

if u want some one to hold it for u *ahem ooo-err missus, then gimme a shout. we could do my stock NA one too for comparison.

E

muffdan · January 11, 2007, 00:15

Quote from: "bossman23780"just supprises me?!

the time you ran, i would expect abit lower than that especially if the tyres were warmed up, reason i say this is because TTET is 5.9?! but youve got the SP downpipe and the exhaust?!

so surely your can must be under achieving?! strange! now me thinks is your car set up on correct psi?!

Yeah, if you were to ask me if the reading was slow, or the car was slow, I would hedge my bets on the reading being slow. My car feels sub 6 sec on the dash. Performing multiple runs will give better results, and I'm sure different GPS devices will calculate this speed differently (there is no standard way to calculate this, it is down to the hardware manufactures as far as I can tell).

I'm researching calculating accurate speeds from latitude/longitudes and it is a pretty complex business, prone to rounding errors (more errornous based on the car's heading) and the altidude of the car, so it might take me a while to get it working accurately. Once this is in the timings should be MUCH more accurate.

Anonymous · January 11, 2007, 00:19

kool s8)

s8)

keep practising mate! s:lol: :lol: s:lol: s:wink: :wink: s:wink:

shame though that they never built an in car timer!

muffdan · January 11, 2007, 00:19

Quote from: "simonp"Nice work Dan,

SUGGESTIONS:

1/ The speed readout and running timer - it would be better if these were in a big bold font so you can easily read them.
2/ How about standing 1/4miles, presumably that would be possible.
3/ A permenantly stored log of say your last 10runs and your best so far.
4/ What would be ultimate would be a graph of speed against time - that way you could see if you made a bum gear change or bad start etc etc - although I appreciate this could be tricky to programme (not that I know)

s:D s:D

All sound good, thanks for the feedback. I'll change to a tabbed window system and add distance runs to one of the tabs. Graphs are more work but no problem to add. Ultimately I want to be creating torque.power plots too. I think I might have a product I could actually sell if it did that!

Anonymous · January 11, 2007, 00:30

Nice one Dan - If those guys can market their product for £10 or whatever I'm sure you could!

We'll all expect it free of course! s:P

s:P

Anonymous · January 11, 2007, 00:32

Quote from: "muffdan"I would hedge my bets on the reading being slow.

You mean I could have done it even faster than 6.7 - Awesome! s:D

s:D
I'm going to bed a happy man..

Anonymous · January 11, 2007, 00:36

Quote from: "simonp"Nice one Dan - If those guys can market their product for £10 or whatever I'm sure you could!

We'll all expect it free of course! s:P s:P

FREE!! s:shock: :shock: s:shock:

FIRST DIBS ON IT s:twisted: :twisted: s:twisted:

northernalex · January 11, 2007, 12:32

youd make a fortune just on ebay!

Good work mate!!

Anonymous · January 11, 2007, 18:49

My Boss's new car Cayman S has the sportspack which has a time on the dash to record time's which is way cool. I keep telling him his car is to slow that why I have to get the Stage II.

kanujunkie · January 11, 2007, 20:24

just been out and given it a test drive, i love my muffometer s:D

s:D

only critisism i'd say i that the figures are too small to read and the reset buttons could also do with being a bit bigger, as for the times, well i'm thinking it could be a bit over optimistic, road was damp, i couldn't get good traction and the wheels were spinning a bit, other times i got varied but i saw a 5.25, a 6.4 and 7.2 plus a couple of other 6.somethings. The boost spiked at 7psi so still nowhere near top boost, the run in the photo had very minimul wheelspin though.

really simple to use software apart from that Dan, damn nice effort s:D

s:D

thanks

muffdan · January 11, 2007, 20:53

already working on version 2; has bigger buttons, manual stop as well as manual start, large red bold font for the speed, saves comm/baud settings and whatever else I add tonight/tomorrow s:)

s:)

Will try and improve accuracy too, but having worked on this project, GPS devices weren't designed to time 0..60 runs!

Anonymous · January 11, 2007, 20:57

Accuracy is only an issue when comparing cars. Provided the inter run variability is minimal it would be a very useful tool for monitoring the effect of mods on a cars straight line performance.

I may try it with and without my unichip running for example.

kanujunkie · January 11, 2007, 21:21

Quote from: "muffdan"GPS devices weren't designed to time 0..60 runs!

its not the GPS system upstairs, thats damn quick, its the fact that were useing commercial grade GPS down here, its rubbish and doesn't update quick enough, IIRC every 1/10th sec approx or once very 760yrds approx at 60mph approx, not good s:(

s:(

northernalex · January 11, 2007, 21:50

Quote from: "kanujunkie"
Quote from: "muffdan"GPS devices weren't designed to time 0..60 runs!

its not the GPS system upstairs, thats damn quick, its the fact that were useing commercial grade GPS down here, its rubbish and doesn't update quick enough, IIRC every 1/10th sec approx or once very 760yrds approx at 60mph approx, not good s:( s:(

if you have all the data points for location vs time you can work out speed, acceration and 0-60 using a graphical program and a spline (easyplot for example). If the software could save a distancevs time .csv file it would be easy to mathematically work all this out.

Pain to program though??

kanujunkie · January 11, 2007, 21:59

s:shock: :shock: s:shock: what you say in english s:shock: :shock: s:shock:

muffdan · January 11, 2007, 22:02

the GPS devices we are using (they will vary) are only required to communicate at 4800 baud, although you can connect faster if the device supports it. Mine, succeeds at connecting at all baud rates, but the NMEA strings streamed over the comm still only seem to come in at 4800 s:(

s:(

Other people with better (more expensive) receivers might get better results. The flashing '_' you see after the 'mph' is a sign that I have received new positional and speed data from the device. For me, at 4800 baud that is about once a second.

My plan is to use the positional data and to create an acceleration line at these known time intervals. I can then approximate when the car pulled off, and when the car hit 60, but the gear change we have to do just over 60 into 3rd is going to play a part, smoothing off the acceleration curve. Hopefully the accuracy then will be in the region of a few tenths. Performing multiple runs and using an average (which I'm also adding) should give a very good indication of actual performance.

I'll try implementing this over the weekend, testing is pretty tricky as I'm sure you can imagine and requires popping into the car every 15 minutes to do a few runs!

People look at me odd when I tear it out of a layby, fly past them and pull into the next layby half a mile up the road!