hard, very hard. i don't know that anyone here has even tried that. i seem to recall that in the last sport compact car ultimate street car challenge, only one or two of the cars pulle 1g lateral.

 

I think you need more tire meat for 1g than the stock body can provide for. Even with the tightest configuration you gotta have sufficient contact to the ground to handle all the lateral force.

jason

 

OK, I really don't want to come off all snotty... but 1.11 latg's for a Jetta? Out-turning the late gen Z06? Out-turning an STi? A Jetta out-turning pretty much 99% of the cars on the road, right off of the showroom floor. NFW. Where can I see some documentation about this? I've been looking for specs on the VW website, but they must not be excited about a 1.11 latg because they sure aren't bragging about it.


jason

 

Ain't no Jetta pulling that. The Noble M12 can just barely do 1g, as well as the special edition Z06.

http://www.europeancarweb.com/projec...0311ec_projvw/

"...and the skidpad performance skyrocketed from 0.77g to 0.88g. "

I say BS until you reference an article.

Can you imagine the abount of rubber you will need on a car that top heavy? You need a LOW center and gravity and some meat on your shoes.

 

...and for those interested in some stock cars skidpad just to see a range:

http://www-cs-students.stanford.edu/.../handling.html

Notice the stock Forester out handling the Jetta! LOL

 

forgive my stupid question, but what exactly is a skid pad? and how do they measure it?

</hijack>

~SGD

 

okay, here are the skidpad results from the most recent SCC USCC (Ultimate Street Car Challenge):

1. Ultima GTR 1.133g
2. Dodge Viper 1.097g
3. Toyota Supra 1.076
4. Mitsubishi Eclipse 1.071g
5. Nissan Skyline 1.063g
6. Nissan 350z 1.063
7. Audi S4 1.031g
8. Mitsubishi Eclipse 1.018
9. Toyota Supra 0.945g

the #9 Toyota Supra was the only car in the test that wasn't wearing either Hoosier near slicks, or other serious R comound race rubber.

anyone who thinks that a stock VW Jetta can pull almost as many lateral G's as an Ultima GTR or a heavily modified viper knows precisely squat about suspension and grip. i don't think that there is a car available for under $150k that will pull 1g on the skidpad showroom stock, and even then it might need race tires.

 

Yeah... Jettas don't pull 1.11g. Anyways, how to make an Impreza pull 1g. First off, skidpad results are a bit misleading. The way skidpad results are produced is pretty simple. A car is driven around a 300 foot radius and the "laps" are timed. Then, some calculations are performed to measure lateral acceleration. That number is then divided by gravitational acceleration. In other words, if your car generates 1g on the skidpad, then the sideways force of the car trying to go in a straight line is the same as the force of gravity.

So what's misleading? A couple things. First, the number is entirely dependent on vehicle weight, and of course tires. Okay, tires are probably more important. So first thing you need are race tires like Hoosiers. Then, cut the weight on your car down as far as possible. With a full interior strip and pulling stuff like A/C and whatnot you can get an Impreza down to 2200-2300 pounds.

As for suspension, you have to be pretty hardcore. REALLY stiff rates, big sway bars, the works. Not for streetable cars. It can be done though. Anyways, skidpad results are misleading somewhat. A car with great skidpad numbers isn't always going to turn faster laptimes than a car with just a "good" skidpad number. Furthermore, getting a higher skidpad number requires tons and tons of driver skill, and it's not necessarily skills that make you a faster driver. You havce to setup a car to either be perfectly neutral for the exact turn of a skidpad, or make it tailhappy and basically drift it around the skidpad. Both methods can pull big numbers, but guess which one makes a faster race car? Anyways, enough of my digression. Basically, just remember 2 things when it comes to handling mods- tires give you ultimate grip, and suspension tuning just sets the bias between oversteer and understeer. Make your mods to change that bias to your preference.

 

Stock Vettes do .97, 1.01 with better tires according to goodyear. Stock Z06 does 1.0 on skid pad. My buddies did 1.1something on racing slicks and a bit of tuning to the suspension. How sweet would it be if a stock car could pull 1.11 though? I would want it.

 

A skidpad is a smallish circle track (which is truly a circle). You drive around and record the laterl g-forces at the breaking point of the cars grip on the road. Calculating in all relevant factors gives a normalized "lateral-g" rating.

jason