Number Crunching GM's Performance Update

[Bogie]

Originally Posted by lorennerol

Does the shareware give you any sort of 'accuracy of fit' info? What you really need is a better data set... Is it possible to get more data points from the dashhawk?

The polynomial fits the data as perfect as the resolution of the data. Here is the plot. The red line is the poly plot. Dots are the trap data. Y axis is feet. X axis is time.

[RedHeaded RedLine]

Originally Posted by Bogie

For the run above, here is a polynomial fit. p(t) is position (trap distance) and t is elapsed time.That said, I also differentiated the polynomial, yielding a velocity profile. I ran some time numbers and came up with a 0 to 60 mph of about 4.9 seconds. Again, I can't say that is the reality of the run. All I can say is a vehicle with a position and velocity profile reflected in the polynomial will hit all the position and velocity trap numbers on the ticket, and hit 60 mph at 4.9 seconds.

You make my hair hurt. -J

[LeadSled1]

I'm wondering if your time to shift (500ms) is too long. The no lift shift is a window of 200ms to complete the shift. By going at the max window over two shifts you have 400ms of shifting, 1/10th additional loss of time to get to 60mph.

I would think the GM engineers would have some safety fluff time built in to the window to protect the engine from the spark kicking back in prematurely.


Just a thought.

[Forcefedsc2]

Any word on when this performance mod would be available? Cost? I just got my '08 Sky and I'm enjoying it, but a little more power couldn't hurt anything

[mbeardsley]

So would the 30 hp gain effectively increase our top end speed as well?

I would think that it would have at least some effect.
Bogie, care to get your calculator back out again...?

[lostcause]

Originally Posted by mbeardsley

So would the 30 hp gain effectively increase our top end speed as well?

I would think that it would have at least some effect.
Bogie, care to get your calculator back out again...?

It would be cool if it did but have you actually taken your car all the way to the top speed? I've tried once or twice but the car isn't very aerodynamic and every time I hit 125-130 it started getting a little squirrelly.

[RedHeaded RedLine]

Originally Posted by lostcause

It would be cool if it did but have you actually taken your car all the way to the top speed? I've tried once or twice but the car isn't very aerodynamic and every time I hit 125-130 it started getting a little squirrelly.

I have been a passenger at 128, felt fine from the right side. He said it felt stable, not awd stable, but certainly crusiable if on an interstate. -J

[mbeardsley]

Well, we'll be bringing it up pretty high this weekend on Texas Motor Speedway, but I was really just interested in the computations.

I've actually never gotten a car over 130 anyway, but I'd still like to know what it COULD do.

[RedHeaded RedLine]

Originally Posted by mbeardsley

Well, we'll be bringing it up pretty high this weekend on Texas Motor Speedway, but I was really just interested in the computations. I've actually never gotten a car over 130 anyway, but I'd still like to know what it COULD do.

I was a passenger at 145, if I closed my eyes I would have never guessed it was that fast.
In the right car, right driver, right circumstances, it is good. -J

[Bogie]

Taking a wag at it, I would say a 30hp increase will probably give us 5 to 10 mph on the top end...probably closer to 5.

Edit:

Here are the numbers (WHP vs mph):

230 : 149
240 : 151
250 : 153
260 : 155
270 : 157

If your current WHP is between 230 and 240, a 30 HP improvement will increase your top speed by 6 mph.


And for geewhiz, I ran 'em to 500:

300 : 163
400 : 179
500 : 193

Assumptions:
Density: 1.2 kg/m3
Drag Coefficient: 0.42
Drag Area: 2.3 square meters (I previously used 2.7 but after additional analysis conclude 2.3 is better).

[OLDMX4]

Any word on this release date and the final price?

I want it, if it's not too Pricey

[enkymion]

What happened to this?

[mbeardsley]

Latest word is that the project has been (unfortunately) cancelled.

It seems that GM has bigger problems to deal with right now.

I'm disappointed, but I'm not surprised.

(it sounded too good to be true anyway)

[enkymion]

Yeah. I just discovered it in another thread not too long ago. Terribly unfortunate. Oh well.

[rmt]

Originally Posted by OKC08SKYR/L

Would you happen to have a link to this GM upgrade or at least more details?

I would like to know this as well