superocho

I just wanted to let you know, abou this website:

http://www.yawpower.com/tqvshp.html

"Buger" posted this in another thread. The above articles within the webpage he posted talks about HP, torque, acceleration in a very nice and clear fashion -- giving lots of insightful understandings about should I worry abou HP, torque, etc. The guy is focused on the rotaries, but the infroomation he gives is of course generic and based on physics -- its well written so you don't have to be a physics major or math expert to understand it....

superocho

I just made some calculations using the formulas from the above webpage (yawpower...).

I have an RX8 on order and am excited about it, based on my driving experience with it, it was great.

Below is a reporting of the "rate of acceleration" in G's (multiples of the gravity constant), in both 1st and 2nd gear, for several cars:

(below stats on got from their websites)

Honda Civic LX: 110 torque, 2474 lbs curb weight, 1st gear=3.462:1, 2nd gear=1.870:1, final drive=4.070:1

BMW 330Ci: 214 torque, 3285 lbs, 1st = 4.21, 2nd = 2.49, final = 2.93.

RX8: 159 torque, 3000 lbs, 1st = 3.760, 2nd = 2.269, final = 4.444

G35: 270 torque, 3450 lbs, 1st = 3.794, 2nd = 2.324, final = 3.536

350Z: 274 torque, 3247 lbs (touring), 1st = 3.794, 2nd = 2.324, final = 3.536


Car 1st 2nd
--------------------------------

Honda 0.63G 0.33G
BMW 0.80G 0.47G
RX8 0.70G 0.53G
G35 1.05G 0.64G
350Z 1.13G 0.69G

......RX8 is still cool for me!

superocho

oooops, G35 was the coupe model, i.e. G35C.

superocho

And the above data is "peak power", meaing the G's vary according to the RPM, so in reality I should show you a graph per car, but that's a lot of computation for me now. Any MS Excel geeks can give it a try...

Buger

Hi Superocho,

I think what you were trying to compute was G's at peak torque not peak power.

I did a similar thing a couple of months ago in the below post:

https://www.rx8club.com/showthread.p...5770#post75770

but we seem to have come up with different #s. Are you sure you are computing things correctly?

Brian

superocho

The formula I used was the one at the bottom of the webpage:

http://www.yawpower.com/tqvshp.html

We used different numbers. For one, I assumed 1-ft radius wheels. You did 18" which is more accurate, my fault for being lazy. I used that same size for all makes. I think G/8/Z all have 18" inches, so the relative numbers are correct but not the absolute. You also used more weight than me. I used the posted vehicle weight, no drivers etc. Somehow these approximations balance out but I guess sway towards one side.

I had not seem you post before -- looks great! If I get a chance (or you ), I'll try to use your Mr. Yaw's formulas to make a graph for all relevant graphs, like yours, and use correct wheel sizes.

Thanks!

syntrix

Took me a while to read through all this today, but here's a few things that might help:

1. Run Flat tires - they usually weigh in the range of ~60lbs a piece, that will affect a dyno run. Mini Cooper S is an example, each rim/tire weight about 60lbs.


2. DBW Throttle - Simply use an obdii tool to read the % that the throttle is open. That was a potential concern each time. I have two different obdii tools, and hopefully I can read that value if I buy an RX8.

3. Stability/traction control (name?) - is there a switch to turn it off? If it's kicking in because of a speed difference between the two rear wheels, it's probably kicking in and applying brakes?

Just a few rants off the top of my head, sorry for not knowing the car that well yet. I've been tuning for a LONG time, and I've only gone as far as sitting in the RX8. I love it, and I'm stripping the 03 GTI down to stock tonight, and going for a test drive tomorrow

zoom44

1. the car does not have run flats

2. good thought someone else did suggest that but to my knowledge no one had done it.

3.yes, there is a switch, it can be used to completely disable the traction/stability control systems and runs were done with it off.

edit:oops! hello and welcome!

mikeb

this thread is way off original course

8_wannabe

This thread used to be about what BOOSTD 7 was going to do to address the power issue (and hopefully the mpg issue which still looms huge to many of us.) Since the thread has been hijacked so badly, I wonder if we can get back on topic. Any update on this, Boost? The Oct deadline is coming up soon and I'm still holding onto my paperwork. I appreciate any inroads you can make on our collective behalf with Mazda.

Sputnik

Since this continues to go off topic, I'll close it for now. BoostD can still post his updates, and we'll open it back up when appropriate.

---jps