Had the unique opportunity to do some skidpad testing today. Something I never thought I'd have the chance to do but turns out a local business has a 150ft diameter skidpad on site. Some of the local SCCA guys are friends w/ the owner and secured some time on the pad for us. I was extremely happy w/ the results of the testing, I ended up w/ a best result of just over 1 lateral g (1.001 I think) I was running on fairly worn Azenis w/ Zeal B2 susp. It's kinda nice being able to say that I've tested my car at 1 lateral g and it was definitely an experience, still feeling a bit dizzy

If you ever have a chance to do this type of testing, do it! It was a great environment to try little changes w/ your setup. I was able to dial out quite a bit of my cars understeer just playing w/ tire pressure and my susp. settings.

Also let a few of the more experienced members drive the R and I think they really enjoyed it Only bad thing is they had better runs than me

One of the other members snapped a few pics of my car (thanks Matt). Only have access to one right now, I'll try to post more later.

 

Corner like a viper y0!

 

Sounds very cool. I've wanted to do that, but as you said, never had a place to do it. How exactly do they measure the maximum g-force achieved?

 

nice for a FWD car

 

Not sure of the exact calculation but they use the diameter of the skidpad and the time it takes you to get around it to arrive at your lateral g.

 

Nice. We did that last year as part of a fun auto-x day... it is a great experience.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sscguy &raquo;</TD></TR><TR><TD CLASS="quote">Sounds very cool. I've wanted to do that, but as you said, never had a place to do it. How exactly do they measure the maximum g-force achieved?</TD></TR></TABLE>

It's centripetal acceleration, which is v^2/r. You can find v with 2pi*r/time = v. Acceleration of gravity is 9.8 m/s^2, so #442's lateral acceleration was 9.089 m/s^2.

 

Is there then a unit conversion to "g's"? Physics and I just plain don't get along.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sscguy &raquo;</TD></TR><TR><TD CLASS="quote">Is there then a unit conversion to "g's"? Physics and I just plain don't get along.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Stumpy &raquo;</TD></TR><TR><TD CLASS="quote"> so #442's lateral acceleration was 9.089 m/s^2. </TD></TR></TABLE>

Actually ... 9.8098 m/s^2 = 1.001 G

 

Another pic, for some reason it uploads weird



Link w/ conversion: http://www.iroczone.com/calcs/chassis.htm

My run radius was 75ft and my time was 9.5xx sec.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sscguy &raquo;</TD></TR><TR><TD CLASS="quote">Is there then a unit conversion to "g's"? Physics and I just plain don't get along.</TD></TR></TABLE>

1g = 9.8 m/s^2

 

Ah, thanks. I'm an idiot, and really should've known that.

&lt;---Adam: took three years of physics in high school, two semesters worth in college, maintained a solid C- average overall

 

Was that at Payne Engineering?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">Actually ... 9.8098 m/s^2 = 1.001 G </TD></TR></TABLE>

I guess I was dyslexic when I read the calculator.

 

Thats awesome. Better than most $100,000+ supercars....
I cant tell from the pic. Do you have a rollbar installed?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jond &raquo;</TD></TR><TR><TD CLASS="quote">Thats awesome. Better than most $100,000+ supercars....
I cant tell from the pic. Do you have a rollbar installed?


</TD></TR></TABLE>

It does look like he has one in there.

 

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jond &raquo;</TD></TR><TR><TD CLASS="quote">Do you have a rollbar installed?</TD></TR></TABLE>

Yup.

Chris, good stuff man

 

Hey Dude,

So what settings you end up going with?
Height f/R
Camber?
Preload?
alignment F/R?
damper setting?

Or is it top secret :D

 

awesome! Whats the stock R rated at for lateral g's?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris1091 &raquo;</TD></TR><TR><TD CLASS="quote">Was that at Payne Engineering?
</TD></TR></TABLE>

yes

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jond &raquo;</TD></TR><TR><TD CLASS="quote">I cant tell from the pic. Do you have a rollbar installed?</TD></TR></TABLE>

and yes.

Thanks for calling me and telling me about this, Chris.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RTW DC2 &raquo;</TD></TR><TR><TD CLASS="quote">awesome! Whats the stock R rated at for lateral g's?</TD></TR></TABLE>
.93

Just for comparison, according to motor trend, the 2001 Ferrari 360 Modena does .90
http://64.233.167.104/search?q...hl=en

A 2000 Porsche 911 Turbo does .96
http://64.233.167.104/search?q...hl=en

 

Nice I hope I get to do that one day with my.

 

To answer a few questions yes I do have an autopower 4pt. rollbar.

As far as settings on the car, I need an alignment so no alignment settings yet. I don't know exactly where the height/preload is set on my coilovers I ended up going w/ damper setting of 3F & 6R and cold tire pressures of 45psi F and 34psi R.

 

you're ready for nascar