All Terrain Tires?

[Ben_]

Hey Fellas,

I've been lurking around for a while now and I finally decided what mod I want to do to my little blue yaris. I'm at about 42k miles on the stock Potenza re92 which worked just GREAT for my first auto-X event ever last month . As you can imagine with almost 45k its getting time to replace them soon.

I want to fit 215-75-15 BFG A-T T/A tires on my stock steelies and have some fun with the car off highway. I am wondering how close these tires are to fitting inside the wheel wells in stock form and what will be needed to make them fit. Suspension lift? Remove quarter panels and bumper and fab a 'brush gaurd' bumper to replace the plastic one? Body lift? Wait a second this is a unibody car that wont work. Well you probably get the idea.

Chime in if you have tips. Second to driving down to the tire store and actually trying to bold one up I'm not sure how to approach this.

[CTScott]

You are pretty limited on off road tires without lifting the front suspension and modifying the front fenders. For tires that will work without modification, rally gravel or snow tires, or just aggressive snow tires are your best bet.

On Crashy I run Maxxis Bighorn 15" ATV Tires on stock steelies, but I also have a 4" custom suspension lift and no front fenders:

[Ben_]

What does your 4" suspension kit look like? What parts did you replace to achieve that?

What suspension components are available? Coil-overs are available, but how much lift can be achieved with them before the stock suspension geometry becomes ineffective?
How much lift can I get from longer springs or a spring spacer without changing shocks?

How can i measure where the interference points are with the new 75mm tall tires and the inner fender and fender 'flares'?
Stock diameter is 24.5"
BFG A/T 215/75/15 is 27.7"
BFG A/T 195/75/14 is 25.5"

If removal of the fenders and front and rear bumpers makes it fit I would do that.

[Thirty-Nine]

Well, you're going to be nearly four inches in diameter larger then stock with a 215/75/15—that's a giant leap. I doubt you could fit them in the fenders. Also keep in mind your gearing will take a huge hit meaning both fuel economy and power are going to be affected.

Case in point, I have a '95 Suzuki Sidekick. It came with 205/75/15 tires stock. I added 235/75/15 tires, which is only 1.7 inches larger in diameter. Even with 5.13:1 gearing, performance isn't as good. I mean, the little thing only has 95 horsepower—only about 10 fewer than the Yaris.

The 195/75/14 would be a much better choice (only 1.78 inches larger in diameter). You still may have rubbing issues.

[CTScott]

^ Those are all good points. I forgot also that with the 26" high x 10" wide tires I am using that I still needed a 1" wheels spacer, as the extra diameter and width mean that you start rubbing on the back of the wheel well when the wheel is turned.

For my 4" suspension lift in the front I created 1/4" steel plates that extend the strut mounting points up by 4". Longer strut assemblies, airbags, or coilovers could be used, but they would all cost a lot more than the pieces of steel did. I also had to extend the strut supports and did so by cutting them and welding a piece of thick walled pipe to add the extension to them.

For the rear, I simply used a set of Firestone spring helpers (about $100 for the set), which are adjustable airbags that you shove inside of the rear springs.

On thing though is that even with the aggressive tires, you will still have traction issues. When I am plowing it is never an issue as my plow weighs about 200 lbs and I engineered the plow frame to translate the dead weight of the plow and the weight of the snow being pushed into downward force on the front tires. When I have the plow off in the warm months and am using her around the yard (and screw around in the woods) I have gotten her stuck a few times. A locking differential would be the solution, but thus far I haven't found a kit that will work with such a tiny differential. A limited slip diff would probably do just fine, but it would end up tearing up my lawn, so I would rather have a normal diff that I can lock on demand.

[Ben_]

Ok so maybe I can go for this angle

Firestone spring helpers for front and rear $200

195/75/14 BFG AT $520 from tirerack.com

Kosei K1 TS Grey 14" 9.3lbs $476 from tirerack.com

Wheel spacers

Edit: remove unnecessary body panels


hit the trail

[CTScott]

Originally Posted by Ben_

Ok so maybe I can go for this angle

Firestone spring helpers for front and rear $200

195/75/14 BFG AT $520 from tirerack.com

Kosei K1 TS Grey 14" 9.3lbs $476 from tirerack.com

Wheel spacers

Edit: remove unnecessary body panels


hit the trail

The firestone helpers are only for the rear. The fronts have struts inside of the springs, so there is no space for them.

The BFGs look like a good choice at 25.5" high x 7.7" wide

[Exiwolfman]

so u want to make ur Yaris something like this...this is on the tire size u want looks cool :P

standard.jpg

[Ben_]

How about universal coil spring spacers for the front?

[Ben_]

Hit the nail on the head, exiwolfman. Is that a Golf? Looks SWEEEEEEET!

[CTScott]

Originally Posted by Ben_

How about universal coil spring spacers for the front?

Spring spacers might work, but with them on the front struts the springs would not have any compression range, so the front would be rigid. That VW looks like it is running rally suspension. MCA Suspension makes a setup that would work on the Yaris, but I wouldn't even want to know what it costs.

[Exiwolfman]

Originally Posted by CTScott

Spring spacers might work, but with them on the front struts the springs would not have any compression range, so the front would be rigid. That VW looks like it is running rally suspension. MCA Suspension makes a setup that would work on the Yaris, but I wouldn't even want to know what it costs.

i think spring spacers should work...had a set on my jeep Tj on the front to level it 1 inch u could use isolators (however u spell that lol) coil spacers worth a try

[Exiwolfman]

Originally Posted by Ben_

Hit the nail on the head, exiwolfman. Is that a Golf? Looks SWEEEEEEET!

Golf Syncro 4X4 ...love that set up

[Ben_]

what springs are available for stock front shocks?

[CTScott]

Originally Posted by Ben_

what springs are available for stock front shocks?

I wasn't able to find anything off-the-shelf that would raise the front, other than air bags, which are very expensive and I don't believe are rated for the abuse that they would see off road.

[Ben_]

So the only option is serious modification of the front suspension to fit larger tires. Its possible it would work with 14" wheels and minor modification but I'm not willing to fund that project.

All season tires are gonna have to do.

I took the Yaris off highway today for about 20 miles down a dirt road. It has enough power to haul up steep gravel/slippery hills and enough clearance in stock form to make it over most obstacles on the trail. I only scraped bottom a few times. The traction control was very helpful for getting through mud and soft dirt it made it possible to get more traction than without traction control. Now all I need are some WRX stickers for extra horsepower :D

[CTScott]

Originally Posted by Ben_

So the only option is serious modification of the front suspension to fit larger tires. Its possible it would work with 14" wheels and minor modification but I'm not willing to fund that project.

All season tires are gonna have to do.

I took the Yaris off highway today for about 20 miles down a dirt road. It has enough power to haul up steep gravel/slippery hills and enough clearance in stock form to make it over most obstacles on the trail. I only scraped bottom a few times. The traction control was very helpful for getting through mud and soft dirt it made it possible to get more traction than without traction control. Now all I need are some WRX stickers for extra horsepower :D

I should really build up a few of my kits, as it seems like there is more and more interest in off roading.

Traction control would definitely help with where I have had issues. I have an extra ABS ECU/Pump assembly and have been thinking of rigging it up to Crashy where I can fire it as needed, as opposed to adding all of the rest of the components necessary to have traction control.

[Thirty-Nine]

Originally Posted by CTScott

I should really build up a few of my kits, as it seems like there is more and more interest in off roading.

That'd be cool. I'd think it wouldn't be too hard to fab up a spacer lift, no?