Skidpad performance

[Doubt_Incarnate]

Anyone know where i can find a site that lists skidpad numbers for various makes and modles? or maybe even know what a 86 cavaleir rs convertabile pulls?

I might be pumping up my suv's suspension and i want to see how it compares, the v8 model explorer with the upgrades from explorerexpress.com pulls a .82g's wich is pretty close to what a lot of smaller sportier cars are doing.

[mfewtrail]

You'll probably only find that info from an old magazine where that particular car was road tested or reviewed.

[RebelGT]

the Beretta GTU was .88g's so figure the cavalier probally a tad bit worse, and say .84 or so.

[Mach10]

SUV...
Skidpad...
Performance?!?


lol...

you're joking, right?


I keed, I keed...

Skidpad numbers are useless anyway. Heavily dependant on tires, and basically a measure of the spring stiffness. Skid pad takes the numbers after the suspension has been fully loaded. Doesn't say anything about the car's handling (which is expressed in dynamic ranges).

The REAL metric for cornering performance is lateral transfer. Slalom numbers.

Car & Driver

Skidpad +/- .3g

'86 Fiero (.84g stock on original tires, .86g on more modern rubber)
'94 Ford Mustang GT (.86g)
'95 Lamborghini Diablo VT (.87g)
'93 Lotus Esprit Turbo (.86g)
'94 Mitsubishi 3000 GT VR-4 (.86g)
'94 Mitsubishi Eclipse GSX (.86g)
'93 Acura NSX (.87g)
'95 BMW M3 (.87g)
'97 BMW Z3 2.8 (.87g)
'96 BMW 740i (.82g)
'95 Porsche Carerra 4 (.85g)
'97 Mercedes SLK230 Kompressor (.83g)
'95 Pontiac Firebird Formula (.85g)
'88 Toyota MR2 Supercharged (.80g)



Slalom +/- .5 mph

'86 Fiero (63.9 mph)
'92 Dodge Viper (62.7 mph)
'93 Ferrari 348 (62.8 mph)
'93 Porsche 968 (63.3 mph)
'89 Porsche Carerra 4 (63.3 mph)
'95 BMW M3 (62.8 mph)
'97 BMW Z3 2.8 (61.4 mph)
'94 Nissan 300ZX Twin Turbo (63.0 mph)
'94 Mitsubishi Eclipse GSX (63.6 mph)
'94 Mitsubishi 3000 GT VR-4 (63.7 mph)
'93 Acura NSX (62.3 mph)
'94 Chevrolet Corvette (62.6 mph)

You can make an SUV pull a .92G on the 'pad and still come out with a 40mph slalom.

[RebelGT]

slalom numbers have more of a human variable involved in them though, so its still hard to tell, ecspecially if the tests were done by different people.

[Mach10]

To some extent, but I still say it's more of a metric of what the car's capable of versus a skidpad. I'd say that a slalom is as much an indicator as 0-60 and 1/4 times. There's just as much of a driver element.

Skidpad just tells you how much body roll you get on stock trim. When you hit the skidpad, all you've done is load the outside suspension. To crank up skidpad numbers, you could REMOVE the shocks and add insanely stiff springs and still get respectable numbers.

The suspension in cars isn't designed to adapt to continuous load like that. If it were, the wheels would be hinged and cantilevered so the wheels would camber into the curve.

Hell, just putting larger tires on the outside will give you insane skidpad numbers (*cough*nascar*cough*)

How many corners have you hit that tested prolonged lateral adhesion? Ok, the occasional cloverleaf maybe, but the fastest line through one of those isn't to bull your way through it at adhesion limit.

[RebelGT]

How many corners have you hit that tested prolonged lateral adhesion? Ok, the occasional cloverleaf maybe, but the fastest line through one of those isn't to bull your way through it at adhesion limit.

lots, a lot of the race tracks I've been on have a carousel, or sweeping turn. But also, cloverleafs/jughandles are a big part of daily life, well mine anyway, so that is important to me as well.

[Doubt_Incarnate]

I'll admit it isnt a race car, but i just got it back from the shop (full set of ball joints) and its pretty damn sporty. makes moms 96 olds bravada feel like a wallowing pig, and her car makes dads '99 century feel about as responsive as a cube of jell-o.

[Mach10]

Your entrance and exit to the corner are more important than your adhesion at the apex. Bulldozing the car through the corner won't get you around the track faster.

A car that's "lighter on it's feet" with an excellent lateral transfer will begin the corner wide, brake late and cut through the inside to get a straight line through the apex, and whip the nose hard into the turn.

The instantaneous Gs of this kind of manouver will be considerably higher than a skidpad rating. On my lowly G-tech at the autoX I was cutting instant .92Gs on an almost bone stock 86 Fiero suspension with street tires although my best on a skid was maybe 83-86 (gtech will recall average and peak, not what was going on in the longer turns, and it's hard to concentrate on cones and a little red LED display )

Maybe I shouldn't imply that the Skidpad is a useless number, because it isn't. All I'm trying to say (and probably failing miserably ) is that it doesn't give you even half of the story.

[Doubt_Incarnate]

granted. all i wanted was numbers for comparison. thanks for info tho. i dont think i'll be lowering the "F-word" just getting a meatier sway bar and new poly bushings. since its got over 130K miles maybe i'll get around to new shox to. i took it for drive when i picke it up, i can rip through the same turns my 99 trans am did at about 5mph less and the tires arent crying yet.

[Mach10]

You'll have to forgive me. I have a LOT of anger regarding pickups and SUVs just based on my experiences in my area.

I'll be honest. I'm a fish out of water in a bigger truck. It doesn't feel right, the big springs and soft suspension dampen the road-feel, and the body roll is so excessive that I can barely tell which way I'm travelling, let alone how much I'm rotating. I found that the tires on my friend's trucks didn't complain much before letting go, and that they'd start to slip long before they let go completely (and start howling something fierce.)

I'm not trying to pick on you, but I hear a lot of people say that their XX truck is more stable on the road than their YY car. And honestly? Its like I pass two or three of them in the ditch daily.

It seems to me as if the long wheelbase of the trucks make them feel more stable, but they sure as shit don't act so friendly when they run into trouble. It's tempting to go grab one and toss it around on an autocross course and figure it out for myself.... Because I can't account for it. I mean, we all complain that drivers are retarded where we each live... But this is ridiculous.

It's been a worse year than normal. Mild temperatures during the day, freezes at night, the high-ways are skating rinks. Iv'e seen (and this is an official count, BTW) 19 SUVs, 12 trucks, 2 Minivans, and 1 station wagon in the ditches between my home and my work this year. Of those, 6 of the SUVs were roll-overs, 3 trucks were rollovers. The minivans and wagon were simple ditch pigs.

the worst by far was the one who wiped out on the highway overpass near my place. A green SUV lost it, hit the median and flipped over. I'm not 100% sure of what happened next, as I got there just after, but it seems like the front passenger was ejected. Right into the path of an oncoming semi. We all sat there for 1.5hrs until the cops and EMS got there. We were being directed through the slalom-course of car parts, and each of us had to drive through what looked like a deer splash on the road. Of the three ambulances that left the scene loaded (of 4 that got there), two had lights on, and the other left real slow-like.

I couldn't drive for the rest of the day, my hands were shaking so bad.

Personally, I don't give a shit if people think that the vehicle is more stable, and that they then get over-confident, and I don't care if it's an illusion, that the SUV/Truck chassis really is more unstable. The end result is the same: Needless waste of human life and/or rising insurance premiums from the increased claims.

Do what you like to your vehicle. But drive it responsibly. People can make claim that suspension upgrades etc make a car more safe on the road. But shit, if I can keep my car in a straight line with a blowout, what does that have to do with the suspension? And what possible excuse do the rest of these clowns have? I have driven EVERY day this winter, either to work or the Fiancee. My little dodge-colt with 13" pizza-cutter wheels goes pretty slow in 10" of driving snow. But I haven't gotten stuck, I haven't put it in the ditch, and I haven't rear-ended anyone yet.

Auuughh... Sorry, I'm in a bad mood just thinking about that accident.

[Doubt_Incarnate]

no offense takin, 99% of the time im real easy about anything.

I understand that some people can become over confident and risk themselves and others in stituations that they shouldn't have been in. Most the time that boils down to the drivers fault, they can slow down or properly maintain their vehicle, usualy a combo of the 2 is the perfered choice.

I like my vehicles. most of the time i dont put them in situtations where i'm going to lose them. sometimes by myself on the back roads, i let them stretch their legs and challenge their foot work. improving the suspension on an suv or any car for that matter is like adding control, which in turn adds to safety in the hands of an alert and moderately skilled driver.

[EspanolaGuitarista]

I'm really pissed off at SUV drivers too...

More mass means drive slower not faster. I was in my 'Retta and had an SUV on my bumper. I went into a banked on-ramp going 80 and exiting around 100. The idiot tried to follow me. I could have swore I heard something. I'm not sure if he wiped out, but yeah, complete over-confidence. The first thing you do when you get an SUV is put a stiff set of Rancho shocks or an equivalent. Then upgrade those sway bars. Make sure your tires are inflated. With a truck that heavy it is critical. Looked like deer carcass? Ewww! Unless your really into offroading there is no need to have anything fancy like a swaybar disconnect. I don't suggest lowering springs since these trucks need full suspension travel to work properly.

[Mach10]

That's the thing that pisses me off. Everyone says "Yeah, they were just driving too fast."

Well, if they lost control, they obviously were.


Here's the kicker: In winnipeg, we have some of the crappiest driving conditions known to man. Yet everyone drives like a spastic nutjob.

So why is it that I almost never see the cars in the ditch as compared to the trucks? The cars are driving just as quickly, and just as stupid.

There is something terribly wrong with the way the trucks are handling themselves... Am I the only person that can see this?

[Doubt_Incarnate]

trucks do have inherent "flaws" that cause them not to do as well as cars. unfortunately, there is little to do about it since its a consequense of design. farmer joe would love to use a car to haul hay,if it was capablr if getting in and out of feilds, if it could tow, if it had tires enough to support the weight. i'd love to use a car for everything since they are way more fun to drive, but i cant fit a tv in there, at least not a cool tv. and it wont tow a trailer. or a washer, dryer, boat, couch, matress, etc...

Being tall makes them more suseptable to cross winds, higher center of gravity, and being heavier requires bigger sway bars (what manufature is going to spend the $$$ to put the right sizes bars on 100,000 cars?), but it still boils down to over confidence of the driver. driving a suv or a truck means being more careful, you have an average 4500lbs vehical, not designed to take turns like a f-bdy, not going to stop like a f-body. one reason you didnt see as many cars in ditches is most people with fwd or rwd cars slowed way down, like a smart person, not being so confident of their cars ability.

in the winter of '04 we got plenty of snow, and all i had to drive was my '99 trans am. i never made it over 30mph, and at times, never used the gas pedal.