future RS

with a significant change to the wheel base but both equal in front and rear what would be the changes to expect?

turn in? turning radius? oversteer/ understeer?

im looking for both negative and positive info for this.

so far from what i have gathered it may negativly effect my turn in/radius.. but im not positive on this.

also how would it effect the camber curves of the car?


anyone on here have any good links to some reading? i searched but couldn't find much...

dawicka2

Negative effects include increased hatin-*** responses from fellow motorists and jealous rx7club members, + wheel bearing wear (although with a -1 and -18 (overall) in the rear, i havent felt or heard anything with mine). You also have to come up with a widebody set up to flush them as well.

Positive=Ballerness.

panda is gonna look nuts with those wheels.

..........The whole suspension geometry is designed around the wheel offset. In somewhat simplistic terms, once the suspension designer decides what kind of wheel bearing/hub assembly they will use, the offset is calculated to spread the load that the wheel supports evenly across the wheel bearing. The load is not only the weight of the car, but also cornering loads. As was mentioned by others, too little offset will shift the load to the outside of the wheel bearing, and too much offset will shift the load to the inside of the wheel bearing, causing premature failure. But bearing loading/wear is only one of many variables that are affected by offset. Castor is the angle through the suspension kingpin bearings. These are the bearings that the wheel/tire turns on when you move the wheel left or right. The angle through the kingpins (Castor) is designed to end up on the ground in the middle of the tire's contact patch. If you move the offset very far this scrub radius will be adversly affected. This will make steering more difficult, and less responsive because you won't be using all of the tire's contact patch to steer with. The length of steering components like A arms also depend on wheel offset, so that camber changes as the wheel/tire moves up and down rotate around the center of the wheel/tire. All of these features of suspension design rely on where the centerline of the wheel/tire is. So moving that point very far will not only adversly affect wheel bearing life, but wear on other suspension components as well. I have read that you can get away with + or - 5mm from the factory designed offset before you start to cause damage and adversly affect the handling of your car.
......taken from an sti forum. Personally.....i have seen no adverse effects on mycar or anyone i know's car, though.

john ny

future RS

haha thanks dawicka.

yeah i was reading up on the scrub radius of the car and such. and wheel bearing effects as well.

what sort of turning response did you feel after getting the lower offset wheels? a positive increase or a decrease?

jjwalker

I think what you are refering to is track width, not wheel base. Wheel base is the distance between the centerline of the front wheel and the centerline of the rear wheel.

Sorry, i am just nitpicking.

dawicka2

I would say "if i had to pick one or the other" Turning radius has increased slightly, nothing significant inhibiting street driving though. I do not track this car. It is set up to be a daily, clean reliable vehicle and the current offset has inspired me to go much more agressive after i paint this thing next month.

If negative offset was so bad..... the juiceh's and such would not jeopradize all the time they have in their 7 for a "look".

a Wider track for the most part directly relates to a better handling vehicle if suspension is designed for it. But again on the other hand bla bla bla......

Cut the **** out of your quarters, fit widebody, mount wheels.

Post pictures.

Looking forward to this one.

john ny

future RS

Thanks yeah I was referring to track stance.

And thanks dewicka

classicauto

iTrader: (3)

Personally, you'll see much more of a difference in handling moving to a better compound tire, or more contact patch then you will running a typical width, slightly further apart.

R-compounds on a 9" rim will whip the snot out of a 10" street tire mounted a couple inches further from the body.

I've personalyl never driven a car with AS MUCH negative offset as what yours will have, but compound will make a much more noticeable difference. I've found too much negative offset in the front does affect turn in though, but it was more of "different then what I'm used to" feel, didn't drive it enough to really say if its worse or better.

jjwalker

Not totally true. A larger contact patch increases the likelyhood of hydroplaning when it rains.

To the OP, what is your ultimate goal here? You may be able to do something that is more cost effective AND yield better results.

sub9lulu

iTrader: (7)

ib to fit his wheels under his fenders not looking mexiflush

Juiceh

iTrader: (4)

Buy a new set of wheel bearings and send them to 300below.com. Even if you haven't messed with the castor angles much its still probably a good idea. I think the wider wheels will be putting more stress on the bearings even with a proper offset and a castor angle centered on the contact patch.

j9fd3s

iTrader: (3)

assuming the wheel stays the same offset, spacers change the scrub radius in the front

and the track width will slightly change the handling, it basically changes the lever arm of the suspension. if you change front and rear differently it will slightly tune the balance of the car.

i know this explanation isnt the best, its an odd concept.

if you're on the street its not a big deal

KhanArtisT

iTrader: (2)

Increasing track width (not wheelbase) = REDUCING the total amount of lateral (side/side) weight transfer. Negative effects include increased stress on wheel bearings and increased positive scrub radius (more "kickback" on uneven surfaces from steering).

You probably didn't find any info because there is no such thing as widening wheel base

future RS

thanks lol i do realize that now. it was late and i was extremely tired as i am now...


i appreciate the responses guys.

this is not a street car. and if it is driven on the street it will not be for any extended periods or very often.

this is going to be a track car/look ridiculously good car(personal taste).

what i am most worried about is the steering response and turn radius of the car.

and the wheel bearings are being looked into. as for the positive scrub radius the car will be driven on more even surfaces.

and as far as likeley hood of hydroplaning i do realize that but this is not some highway cruiser and i also live in one of the dryer states so lucky me.

thanks for the site juiceh ill have to take a look at that.

classicauto

iTrader: (3)

Track. Car.

WingsofWar

adjustable tie rods & tie rod ends have greater impact on turn in and turn radius. Id think fitting those "overkill" negative offset staggerd wheels is going warrant you some understeer but probably some awesome stability and traction. Like everyone says your major concern that you need to address is your wheel bearing stress issue. But using those wheels for the track? oh man good luck dialing in the proper settings, sounds like there might be way more involved getting those wheels used to their full potential.

future RS

thanks. i was expecting the increase in stability but also with the scrub radius but im not too worried about that.

and i will be looking into the wheel bearings.

and the dialing in the suspension is the fun part LOL

wvumtnbkr

You will only get an increase in stability if you have the front track wider than the rear. The opposite would also be true. If your rear end was wider, it will cause the car to be "twitchy".

Most of the people that run wide bodies is not for the increase in track width, but so the larger contact patch of oversized wheels and tires will fit. To put it in a simpler way, they want wider tires to increase mechanical grip. In order to put wider tires under the car, they have to go "out".

I do not think that just taking the smae size tires and pushing them out further would do anything good for the handling of the car.

As stated previously, the lever ratios of all of the suspension go right out the window. I would think you would have to change your dampers and springs as well.

Generally, I am going to say... Not a good idea!