I’m trying to make my car oversteer, by running 245/40/16’s in the front, and 205’s in the rear.
I’m assuming that if I have wider tires in the front, it will cause oversteer, and if I have wider tires in the back, it’ll cause understeer.
(I know that the staggared tire size topic has been discussed before, but I didn’t really find what I wanted to know.)
Has anyone tried running 245’s in the front? (I’m know I’d need longer lug nut studs, plus spacers, plus I’d need to do alot of cutting, and welding, to make room under the wheel well to fit 245’s.)
I know that sticker tires are also imparative–but aside from that, I’m assuming that since the weight distribution of our G2’s are not 50/50, and since they are FWD only, then it does not seem to make entire sense to me, that ALL 4 tires are the same size. Also, FWD race cars are running staggared tire sizes.
I think the only case where ALL 4 tires should be the same size, is on an AWD mid-engine car with 50/50 weight distribution. Given that the initial torque distribution on the differential is even.
(Other than that, tire sizes is a matter of economics.)
Not that I know of.
(I know where you stand Ben–against the staggared tire sizing. I’ve read your stuff. You did bring up some good points, but it didn’t seem to incorporate the reasons why FWD race cars used staggared tire sizing.)
With a FWD car, when taking a hard turn and accelerating simultaneously, the front outside tire in the turn, is being stressed by the car’s shifted weight, plus the turn, plus acceleration.
I also read that a tire can only have 100% traction. When you begin to turn, brake or accelrate, or add load to the tire, you begin to divide the 100% of traction. So WHY not have wider front tires?
(Plus, wider front tires, would result in less wheel spin, and faster acceleration when drag racing.)
“…using tire stagger to tune oversteer and understeer is dumb. Lets say you have a car with 215’s all the way around and it understeers. Then you put 205’s back there and it is neutral or oversteers. know what you did? Killed the end that was working.”
But to begin with, FWD rear tires are NOT tracking very well. Plus I am NOT reducing the amount of rear tire traction, but I am increasing the front tire traction, with 245’s. Also, since there is more weight in the front, and power is put down with the front tires, it seems logical to have wider/stickier front tires.
Also you wrote:
“I hate to tell you but “any transfer of load from one tire of a pair to the other reduces the total tractive capacity of the pair” is true of any car with any drivetrain config, FWD, RWD, AWD, 4WD, and even 1 tyre fryer. If it werent then lowering the weight of your car wouldnt make it handle better. And last time I checked a lighter car handles better (all other things ==) than a heavier one.”
This makes sense to a degree, but upon accelerating on a turn, depending on which set of tires is putting down power, will have an effect on whether the car will track through the turn with oversteer, or plow off the road with understeer.
For example, if a RWD car punches the throttle on a turn, the nose will point inward, and rear end will slide. With a FWD car, the nose won’t point inward, and the rear would stay on the same plane as the front. Right?
do what you want man. I’m not getting into this again. And read some chassis dynamics books. “How to make your car handle,” “Tune to win” and “competition car suspension” are some good ones.
Alright, this is all I am going to say: Why not put the bigass/sticky tires all the way around. then tune your suspension to use all the grip. That seems a hell of a lot more logical to me.
Since weight distribution is not the same, and power output on the front and rear wheels are not the same, then the tire sizing should be modified accordingly.
For instance, look at your suspension. Are the spring rates for front and rear the same? Look at Eibach, Tien, Ground Control etc… They all have different spring rates corrosponding to weight distribution.
It seems too cut and dried, to run all 4 same sized tires on both front and rear, when there is alot of tangible evidence indicating otherwise. I.e., CTR race cars, ITR race cars, Celica, and RSX race cars, etc…etc…
Multi million dollar race teams are staggering their tire sizes, and their FWD cars have no different general drivetrain layout as our G2’s.
I don’t really think there is a such thing as a neutral car, unless you’re driving in a straight line. In a turn, a car either understeers or oversteers–but is not neutral. Plus the tendancy for ALL FWD cars is to understeer.
Also, my car understeers, and I’d rather have it oversteer, and when turning too much, I’d just back off of the turn, instead of getting off of the gas.
Does anyone experience this problem? I’m sure it’s common for all FWD cars–pushing a FWD car around a turn at 80 to 90 mph, will result in understeer.
Suspension/wheels/tires:
Racing Hart C8’s 16"
Perrelli Super Sport P7000 fronts 205/45/16
BF Goodrich Euro T/A rear 205/40/16
Tockico HP Blue shocks (F and R)
Custom shock compression bottom-out dampeners
MaxSpeed Ajd. Racing coil overs w/ 2" drop
(450 lbs front, 350 lbs rear)
Drop Zone front camber kit
rear washer camber adjustment
Professional laser ailignment
Misc:
Weight reduction: power steering unit, 3rd brake light, rear wiper unit, some interior parts, and more.
Engine:
LSvtec: Pr3-4 head, AEM cam gears, Type R .25 over pistons, rebuilt B18a block, 8.5 lbs ACT flywheel, intake, exhaust, cat, B16 IM, B16 bored/ polished TB… (there’s more. I’m just too lazy to list it. Plus I don’t think listing it is crucial.)
Okay right off the bat… have you ever thought about how the back tires might be stickier than the front? Try getting the same tire on all 4 corners next time.
Get rid of the blues and get a Koni Yellows or Tokico Illuminas.
What are your alignment specs?
You’re getting way ahead of yourself here with the staggered tire sizes
so, wait. You have front stiff springs on cheap coilovers and stock swaybars and you want to do the mAd k00L tYrE StaGgEr cause some jdm road racers do it?
IMO the only time someone would need it is when A) they need to heat up the tires in the same, short, amount of time (prepared autox cars, the EP folks sometimes do it). The smaller back tires heat up with less work than the big fronts, and since the front tires are more used, well, you get the idea. Or B) you are already transferring the max at the rear (lifting a freakin tire, which you OBVIOUSLY are NOT) and you NEED more rotation.
I’m telling you, read some chassis/suspension dynamics books.
if you want a loose rear end/ a car that understeers, get a big ass roll bar in the back, much stiffer springs in back, and less negative camber in back than in front.
Actually the BFG tires are not as sticky as the perrelli’s. I’ve swaped them back and forth many times, and found the Perrellis to be stickier on the front.
Thanks guys for replying! I was waiting for counter arguments to the point I was trying to make. I’ll get you my ailignment specs in a bit.