Help! I want bigger tires for my VX

[don moore]

i went to good year and asked for some prices ..the guy asked what i had I told him ...lol as usual he said A WHAT??.. well i said i wanted 285s for it ..he said he couldnt do that ..it suppose to have 265s ..i left.. ill og to a place that wants me happy.

[pbkid]

since I am not as high as some people on this site (no pun intended dub)

good one lisa....

[sloop]

My Question being some what of a Tire expert my self is ( not trying to cause a arguement just need to understand as tires I know, Mechanics not so much) in theory all you are doing is adding weight! and not a whole lot compared to if you had 250 lb passanger that rode to work with you everyday,if that was the case would it not be suggested to upgrade your brakes then? I think the bigger issue would be with rolling resistance and the stress on the CV and other components more so then brakes that are used infrequntly. Like I said Just wondering myself I Am Not a Mechanic.

[mdwyer]

My Question being some what of a Tire expert my self is ( not trying to cause a arguement just need to understand as tires I know, Mechanics not so much) in theory all you are doing is adding weight! and not a whole lot compared to if you had 250 lb passanger that rode to work with you everyday....

I'm not an engineer, either. Not a mechanical one, at least. But I believe the problem is not so much the added weight added so much as where it is and what you're doing with it. Weight on the wheels is 'unsprung weight', which impacts handling.

[sloop]

so this is why you would require larger brakes? Cars are not designed around the Tire it's the other way around and you can buy cars with Larger tires and rims yet the brake package remains the same (I'm just alittle confused!) and thats nothing new for me(LOL)

[sloop]

Also by larger brakes you are actually adding more unsprung weight unless your brakes are mounted inboard,really the unsprung weight should only deteriate the ride so you would lose alittle of the sport car feel and have more of a What I call soft feel. I have had many types of tires mounted on my VX and the biggest issue I have found is (ride) and it depends on the type A/T M/T or Performance ( cornering) never braking it always feels the same and I have never had brake issues.

[Ldub]

I think this all to be a moot point in any event, since there are exactly zero aftermarket "big brake kits" to be had...

I believe you'll find the same number of multi piston calipers available.

The hot tickee seems to be:

Drilled, or drilled/slotted rotors

Stainless braid brake lines

OEM pads

That's my theory & I'm stickin' to it...

[4X4 UFO]

I believe that the need for larger brakes is based on the larger diameter of the tires more than the weight. You're dealing with more torque (at the same road speed) applied by the road under braking (as long as you have traction) with larger diameter tires. Having said that, the handling decrease you get with really large tires will usually moderate your speed. I believe the stock brakes in good condition will take care of anything you need them to, unless you're racing........

Randy

[Riff Raff]

'unsprung weight'

Excellent "link". Unsprung weight (aka unsprung mass) has nothing to do with tire diameter, only pure mass of weight that is "suspended" in rotating motion.

For example-- take two identical size/brand tires like the Grabber AT2, but which have different individual weight.

TIRE A: Grabber AT2 in P275/65R18, C-Load Range (6-Ply) (32" O.D./44 lbs).
TIRE B: Grabber AT2 in LT275/65R18, E-Load Range (10-Ply) (32" O.D./54 lbs).

Now, using equal pushing force-- shove each tire down the street and let it freely roll on its own merit until it finally peter's-out, wobbles, and falls over. Measure the distance traveled by each tire. You will discover, the heavier TIRE B rolled further due to its combined "suspended" (unsprung) momentum, centrifical force and perpetual motion that kept the tire rolling further. Simply put, it takes more braking effort to stop a heavier tire than a lightweight tire.

When auto manufacturer's design and engineer their vehicles, the OEM brakes are perfectly adequate to stop the OEM tires (and vehicle) within a recommended safe stopping distance set by the automotive industry. There is a window of allowable variance that aftermarket tires may be heavier than the OEM tires and still allow braking distance to be within safe margins.

The tire industry and US-DOT has determined this safe allowable variance of additional aftermarket tire weight to be 10 lbs over OEM tire weight on any given vehicle. This will still allow the vehicle to safely stop within the prescribed stopping distance for that type of vehicle.

Thus; for us VX'ers, since our OEM tires weighed only 34 lbs each, the maximum allowable variance for a heavier aftermarket tire is 44 lbs (10 lbs over OEM). I like to think of excess tire weight as "tire fat", in which case the tire industry & US-DOT allows us to have 40 lbs (10 lbs x 4 tires) of extra "tire fat" per vehicle and still be able to safely stop within a prescribed safe stopping distance.

Of note, most VX's are wrecked/totaled because they rear-ended the car in front of them because they simply couldn't stop in time using the unmodified OEM factory brakes in a safe distance due to very excessive "tire fat" (extremely heavy tires). During an emergency panic stop in conjested traffic, the small OEM factory VX brakes will say (if they could talk)-- "You want me to stop these big humungous meats??? Sorry; not today, ain't happening!!!" That's why I always harp on people to please, please, please allow an extra cushion of space between the car in front of you when running extremely heavy tires greater than the recommended 44 lbs maximum per tire weight on the VX!!! That's why I like www.TireRack.com as they list individual tire weight on their "spec" chart and is the very first place I check when people ask me about various tires. Riff

[sloop]

Excellent "link". Unsprung weight (aka unsprung mass) has nothing to do with tire diameter, only pure mass of weight that is "suspended" in rotating motion.

For example-- take two identical size/brand tires like the Grabber AT2, but which have different individual weight.

TIRE A: Grabber AT2 in P275/65R18, C-Load Range (6-Ply) (32" O.D./44 lbs).
TIRE B: Grabber AT2 in LT275/65R18, E-Load Range (10-Ply) (32" O.D./54 lbs).

Now, using equal pushing force-- shove each tire down the street and let it freely roll on its own merit until it finally peter's-out, wobbles, and falls over. Measure the distance traveled by each tire. You will discover, the heavier TIRE B rolled further due to its combined "suspended" (unsprung) momentum, centrifical force and perpetual motion that kept the tire rolling further. Simply put, it takes more braking effort to stop a heavier tire than a lightweight tire.

When auto manufacturer's design and engineer their vehicles, the OEM brakes are perfectly adequate to stop the OEM tires (and vehicle) within a recommended safe stopping distance set by the automotive industry. There is a window of allowable variance that aftermarket tires may be heavier than the OEM tires and still allow braking distance to be within safe margins.

The tire industry and US-DOT has determined this safe allowable variance of additional aftermarket tire weight to be 10 lbs over OEM tire weight on any given vehicle. This will still allow the vehicle to safely stop within the prescribed stopping distance for that type of vehicle.

Thus; for us VX'ers, since our OEM tires weighed only 34 lbs each, the maximum allowable variance for a heavier aftermarket tire is 44 lbs (10 lbs over OEM). I like to think of excess tire weight as "tire fat", in which case the tire industry & US-DOT allows us to have 40 lbs (10 lbs x 4 tires) of extra "tire fat" per vehicle and still be able to safely stop within a prescribed safe stopping distance.

Of note, most VX's are wrecked/totaled because they rear-ended the car in front of them because they simply couldn't stop in time using the unmodified OEM factory brakes in a safe distance due to very excessive "tire fat" (extremely heavy tires). During an emergency panic stop in conjested traffic, the small OEM factory VX brakes will say (if they could talk)-- "You want me to stop these big humungous meats??? Sorry; not today, ain't happening!!!" That's why I always harp on people to please, please, please allow an extra cushion of space between the car in front of you when running extremely heavy tires greater than the recommended 44 lbs maximum per tire weight on the VX!!! That's why I like www.TireRack.com as they list individual tire weight on their "spec" chart and is the very first place I check when people ask me about various tires. Riff

Well put on my next tire test I will do a little experiment to test this, we have a skid path at the Texas proving grounds. I will try to use 4 sets with different weights and use the exact same wheels for all

[pbkid]

Of note, most VX's are wrecked/totaled because they rear-ended the car in front of them because they simply couldn't stop in time using the unmodified OEM factory brakes in a safe distance due to very excessive "tire fat" (extremely heavy tires).

ok buddy... im gonna have to play devils advocate on this one...
2 things-

1. where did you get the information that most wrecked VX's have oversized tires on them, and how do you know that the tires were the cause of the accident?
2. there are MANY more influences on the road that are far more important than tire size. if everyone drove exactly the same and perfectly safe (ie: never looked away from the road, never drove drowsy, etc) then yes, theoretically tire size would effect car accidents. but in that case, personally i would take my integra over the VX any day. its stopping distance is significantly less than the VX.
so, what im trying to say is that stupid drivers who dont pay attention, or dont drive correctly is what causes accidents, not tires. (i guess its a similar argument to that of gun control eh? )

in fact, i consider myself a MUCH safer driver with my huge tires than 90% of the drivers on the road. because of 2 things- i DO pay attention to the road all the time, and consistently try to not be distracted. and second, but MUCH more importantly, i have NO quams with diving my VX into the median doing 90mph because i know that my huge tires are gonna be able to handle the ruts and dips.

[pbkid]

sorry to pick on you riff. nothing personal, i just had a long day.

and i view it a little differently than you.

and, yes, i have driven my car through the median more than 5 times to make sure i dont get rear ended by the idiot behind me that isnt watching where he is going.
yup, and he has definately rear ended the guy i was following, which should of been my rear end instead of his...

[Riff Raff]

Jack--- No harm, no foul. I hope you have a better day tomorrow my friend.

[Triathlete]

I would have to say EXCESSIVE SPEED has probably been responsible for the biggest amount of VX accidents where the VXer was at fault.

[Golfindoc]

Ashley, welcome from Gig Harbor!
Listen to the group for answers to any questions. RiffRaff is a local guy and Has given me some good advice already. I bought my 2000 a couple of months ago. Have fun with your VX!
golfindoc (Alan)