[DCD]

To all the mathmaticians and technically minded folks out there...need a bit of help.
Does anyone know how you can calculate an approximate top speed from these 4 parameters;

Weight of vehicle;
Power of vehicle;
Cd and
Frontal area.

Appreciate any help

 

[SteveC]

Hi Dino,

That is the sort of question we ask you !!

sorry mate no Idea

 

[MikeR33]

There's a shareware program on the web called CarTest, I have used it and it was within 1 tenth of a second and 2mph on my 1/4 mile time/speed. It does do top speed also but I haven't tested that to be able to compare the accuracy (yet)

 

[wsurfa]

Car Test program

I've also used this for my old GT4 and it was quite accurate for 0-60 etc. After my ban I was a bit reluctant to test the top speed accuracy ;-)

You can find it at http://home.earthlink.net/~patglenn/ct.html

Remember it's shareware so do pay up if you're going to use it properly. The only problems I remember with it were that it did over play wheelspin - but then it was based on US cars not really used to active torque split etc

cheers

Iain

PS anyone used one of those Race Technology meters ? Looks like a good low cost toy?

 

[DCD]

Thanks for the replies!

Had a go with that program...pretty damn cool! The thing is that I only have the 4 parameters I listed on my first message...and the prog requires a lot more.

Still searching...

 

[Hugh Keir]

Dino,

I have the calculations at home, but am working in the USA just now and don't have them with me.

I raised this topic in January; thread http://www.gtr.co.uk/forum/upload/showthread.php?s=&threadid=1106 you were one of the significant contributors, but no one was able to come up with the frontal area.

Do you now know the correct frontal area?

Cheers

Hugh

 

[Fuggles]

It would be good if somoene stuck this on their laptop and brought it along to the next Dyno day. Just a matter of putting the figures in as we go.

Unfortunately I don't have a laptop. Any volunteers?

John

 

[MikeR33]

I'll borrow one from work and bring it along.

 

[DCD]

Hi Hugh...the actual calculations I'm doing are for a scale model my brother has built for his dissertation in aerodynamics. Looks like we sorted it out

Cheers guys

 

[Fuggles]

Top speeds @ Dyno Day

Mike is bringing a lap-top to the next Dyno Day so we can do theoretical top speeds as well.

Still missing a few bits of information if anyone can help;
Frontal area for R32, R33 and R34
CD for R34

Thanks
John

 

[DCD]

John,

If you click the link that Hugh posted in this thread you will see a post I made with all the R34 Cd values(with the different spoiler settings).

 

[Fuggles]

Dino,

Much appreciated. Now all I need is frontal areas!

Thanks
John

 

[DCD]

Tough one

 

[Fuggles]

I'm almost contemplating taking a picture of my car, front on, and overlaying a matrix. Counting up the squares and working out from there. Oh joy!

 

[DCD]

If you downloaded the program wsurfa posted the link for, there is all the data you could ever need for an R33 GTR in the database. Unfortunately nothing for the R34....better start counting