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View Full Version : 285/70R17 on 2.5inch lift



cis911
11-20-2011, 10:03 AM
HEAR ME OUT FOR A SEC.



my set up; rough country 2in spacers front with rustys leveling spacer

rough country rear spacer



NOTE TO EVERYONE: i dont care how much trimming chopping i do to my XK. i dont care about the inner front plastic linner.



now with that said. i want to see everyones opinions on the following





Rims UNIQUE 297 17x8 WITH 0 OFFSET

Tires 285/70R17(32.71") mud tires doesnt matter wich ones right now

WHEEL SPACERS: Rough Country 1.5inch Wheel spacers.



here is what i figured out so far. The front of my xk doesnt really allow my tire to stuff up into the wheel well due to the ifs. so i know it wont rub when "flexing" now turning with those rims and spacers and trimming of the pinch weld, bottom corner of front bumper and molding or even getting rid of that stupid plastic liner do you guys think i should be fine?

strokeZ
11-20-2011, 10:19 AM
Sounds like you have this thought out. I think however no matter what you do in the front you will run into issues with the rear pushing forward under heavy articulation. Chop away if you dare and let us know if it works out!

cis911
11-20-2011, 10:21 AM
yeah i had put a lot of thinking behind this lol. my wife thinks im crazy.

Sal-XK
11-20-2011, 10:21 AM
Just go a head and chop all that crap out of there man. If you take your time deciding on how to do it or what line to draw you can make it look good.

http://www.theultimatejeep.com/showthread.php/685-Front-Bumper-Mod?p=6932&viewfull=1#post6932

https://theultimatejeep.com/images/imported/2010/06/100_4029JPG-1.jpg
(http://www.theultimatejeep.com/showthread.php/685-Front-Bumper-Mod?p=6932&viewfull=1#post6932)

Matt
11-20-2011, 10:22 AM
I'm sure you mean 0 OFFSET not backspace. An 8" wide wheel with 0 offset has 4.5" backspace. Absolutely NO reason to run wheel spacers with them.

So get rid if the spacers, get out your grinder and give it a shot.... probably going to need to relocate the firewall a bit so I hope you can weld...

cis911
11-20-2011, 10:23 AM
Hell yeah sal im going to chop up my front bumper like yours

Sal-XK
11-20-2011, 10:37 AM
That size tire he's talking about is little less then 33" correct. If that is the case I don't see him having that many issues like hitting the firewall or the rear pushing into the doors but it will be close with just a 2" lift. The guy who ran 35" on his 2" lift had some issues of course. He had trim the rear because he pushed into his doors back there but he wasn't hitting the firewall I believe. If he's willing to trim all the crap out of the way 33" seem like they would fit. I think he might have to pull the rear heat lines out of the way like one of the other members did.

cis911
11-20-2011, 10:48 AM
32.71 inches is the overall diameter for 285/70r17

Sal-XK
11-20-2011, 10:50 AM
Hell yeah sal im going to chop up my front bumper like yours

I really like the way mine turned out. It made it look lie a whole different Jeep and much more improved off road as well. The best part was it's free!

Sal-XK
11-20-2011, 10:55 AM
32.71 inches is the overall diameter for 285/70r17

You'll have some work to do up front I'm sure. Make sure you check those rear heat lines. One guy loosened them and pulled them in a tied them up underneath the Jeep. If you put the longer moroe road leveler shocks out back they will give you the extra height needed in the rear that might alleviate some of the issues you'll have in the rear.

Sal-XK
11-20-2011, 11:04 AM
The only way you can run 285's is with a 4" lift.

This is the answer you got on the other forum LMAO no offence to the dude but it takes more then reading all threads to give advice on modding our Jeeps but the guy can search like nobody else :) I guess there's not to many members over there left that are modding there Jeeps.

strokeZ
11-20-2011, 11:05 AM
I push the rears into the doors with the 4" lift....I am willing to bet its the lift design though. I would love to try 35's! Also remember that not all 285/70/17's are created equal. They are all close, but lug style and sidewall can effect if the tire rubs or not.

Come to think of it the AEV Iceland Commander runs 39's with the 4" Superlift but they did have to modify the rear doors to get the required clearance. Man that would be something - 39's! I am willing to bet that if I can get the newly modified rear arms I could fit 35's with little issue so in that light 285's might just work on a ~2" lift.

Sal-XK
11-20-2011, 11:13 AM
I push the rears into the doors with the 4" lift....could be the lift though. I would love to try 35's! Also remember that not all 285/70/17's are created equal. They are all close, but lug style and sidewall can effect if the tire rubs or not.

The guy who ran 35"s had to carve away like 2" out of body to stop from rubbing. The stock setup pushes forward even sitting level with the 2" lift. I'm surprised SL didn't address this with there lift. Not sure how to correct this but maybe adding a link bar to the rear or something maybe. I know the axle need an adjustable track bar because it pushes out as well sitting level.

strokeZ
11-20-2011, 11:20 AM
Yeah its a classic issue with the SL - they did re design the rear arms to not push forward. Trialbyfire was looking into if we can just buy those. My only issue now with going with larger tires is that the engine will be pushing even more than it does now to get them to roll.

Sal-XK
11-20-2011, 11:27 AM
Yeah its a classic issue with the SL - they did re design the rear arms to not push forward. Trialbyfire was looking into if we can just buy those. My only issue now with going with larger tires is that the engine will be pushing even more than it does now to get them to roll.

Ya without gears available I think 33"s might be our max a little bigger if you don't need to drive it 40 miles to work and back everyday.

Just to clarify on my previous posts about these fitting. My impression of the OP was he's willing to go at his XK with saw an trim all the crap off of it. These tires in no way will fit if your keeping your wheel wells not addressing the heat lines and such. The only way these tires will fit a 2" lift is with a insane amount of cutting things up. There's a thread on the other forum where there all saying this is insane but there all keeping there XK stock just adding lifts. A lift isn't enough with this size but chopping the front bumper and probably needing to just get rid of the wheel well and doing the pinch weld mod they should fit. But by that analogy any tire size will fit just depends on how much of your Jeep your willing to cut away :)

strokeZ
11-20-2011, 11:34 AM
That is my impression of the OP's suggested mod as well.

Holaday07 4.7
11-20-2011, 12:53 PM
He may just want to add some Extended bump stops in back. My 32s rub bad on the back at full flex, so I would assume the 33s would be rough

Sal-XK
11-20-2011, 01:12 PM
He may just want to add some Extended bump stops in back. My 32s rub bad on the back at full flex, so I would assume the 33s would be rough

Do you have your sway bar disconnected? Even before I got my extra lift in the back I wasn't rubbing but I trimmed the wheel well in the rear when I put my lift on.

Holaday07 4.7
11-20-2011, 01:37 PM
Do you have your sway bar disconnected? Even before I got my extra lift in the back I wasn't rubbing but I trimmed the wheel well in the rear when I put my lift on.

They are connected. Tore all the rivets off the front of the rear fenders. Could just be mine though

Matt
11-20-2011, 01:42 PM
An 8" wide wheel with 5-5.5" backspace will help. I said what I did because width is just as important as diameter. Every 1/2" further out the tire sits, that's 1/2" closer to the firewall than before.... its gonna be close, that's for sure.

07JeepXK
11-20-2011, 06:56 PM
Sal can you post close up pics of your front bumper mod? I think once I get my rear ac/heater lines deleted this week im going to have some fun with my front bumper. I want it identical to yours. What did you use to cut the bumper?

Sal-XK
11-20-2011, 07:06 PM
Sal can you post close up pics of your front bumper mod? I think once I get my rear ac/heater lines deleted this week im going to have some fun with my front bumper. I want it identical to yours. What did you use to cut the bumper?

(http://www.theultimatejeep.com/showthread.php/685-Front-Bumper-Mod?p=6932&viewfull=1#post6932)This is where most my pics are HERE (http://www.theultimatejeep.com/showthread.php/685-Front-Bumper-Mod?p=6932&viewfull=1#post6932) Just basically used a jig and rotor saw and a razor blade to clean up the edges. I wish I could delete my rear AC lines but I use them especially when I sleep back there in the cold I use the heat. And every time I think I can loose my third row my jeep is used to transport 7 people :(

07JeepXK
11-21-2011, 07:11 AM
Thanks! Im hoping this weekend to do the bumper mod and paint my rocker pannels that are rusting from off roading.

Omelet
11-23-2011, 09:10 PM
Ok first off I know I have a WK and not an XK and I know that clearances are more stringent! Besides folding over the pinch weld and smashing the piss out of it, have you thought about using a longer bump stop to limit you up travel? Once you clear the rear of the well out, your fender while stuffing the tire will be your next concern. In the rear you can fold the lip of the fender and extend your bump stops to keep your tire from rubbing at full stuff. I know you guys have these crazy ac lines that we don't so I am not sure how those come into play. I just thought I would through some ideas out there, because I have done similar things to mine :D

Also, maybe I am thinking of the wrong XK, but the white one with a 2" lift that I know about had 34s (285/75 R17) I thought?

Sal-XK
11-24-2011, 08:41 AM
Bump stops will work I agree but they will limit the amount of flex you have. Ideally I guess hack off as much as you can then use bump stops to stop you from hitting.

The_War_Wagon
11-27-2011, 05:52 AM
Since I have no CLUE what the "285" in tire size means (nor what the "245" in my current tire size means!), can anyone who speaks American, tell me if 31x10x17's will run without rubbing or modification, with a 2" lift? If not, I'll drop to a 30x9.

BTW... the last metric thing I owned AND understood, was a S&W 1006. "Litres" are for measuring Mountain Dew, and 20 degrees Celcius in Europe still looks to me like they're freezing their ass off!

Your daily AMERICAN rant - over & out.

https://theultimatejeep.com/images/imported/2011/11/RonaldusMagnus1-1.jpg

Matt
11-27-2011, 05:59 AM
285 = the width in mm. 25.4mm per inch mean that 285/25.4= 11.22" wide.

245 mm wide = 9.64" wide

The middle number (70 in a 285/70/17) is called the aspect ratio. In laymens terms, this tells you how tall the sidewall is as a percentage of the width.

70 = 70%
70% of 285 is (about) 200. So the sidewall height is 200mm (or 200/25.4 = 7.8")

Then to figure out the diameter of the tire, you just add up sidewall+wheel size+sidewall = 7.8"+17"+7.8" = 32.6"

In conclusion, the standard translation for a 285/70/17 is 32.6x11.22

.... want to know a really EASY shortcut?

Matt
11-27-2011, 06:05 AM
Shortcut:

I've combined all of the steps in that previous example for a quick and easy way to calculate the tire height of metric tires (its just algebra, nothing fancy).

For tire sizes: AAA/BB/CC here's what you do. Plug it into a calculator exactly like this:

AAA x BB / 1270 + CC = Diameter

Example: 285/70/17
285 x 70 / 1270 + 17 = 32.7 (in my previous post i used a lot of rounding, so it was a lower calculation due to all of the fractions being dropped off)

For someone who isn't familiar with standard order of mathematical operations, this is what your calculator is doing:
(285 x 70 / 1270) + 17

cico7
11-28-2011, 11:35 AM
For someone who isn't familiar with standard order of mathematical operations, this is what your calculator is doing:
(285 x 70 / 1270) + 17
Please .............Excuse.......... My ...............Dear.... Aunt......... Sally
Parentheses / Exponents / Multiplication / Division / Addition / Subtraction

criket
11-29-2011, 05:46 PM
HAHA, I haven't heard that Please Excuse thing since high school.

AJeepZJ
12-05-2011, 08:18 AM
Since I have no CLUE what the "285" in tire size means (nor what the "245" in my current tire size means!)]

There is also a thread that I created - which also have the same information that Matt contributed to HERE (http://www.theultimatejeep.com/showthread.php/1153-Tire-Sizes-Descriptions-Conversions-and-Chart)... Scroll down and you will see a conversion outline.

hoaxci5
12-05-2011, 02:27 PM
A nice little tool for helping convert and see a comparison between two tire sizes
http://www.miata.net/garage/tirecalc.html

cis911
03-23-2012, 05:16 PM
everything sounds good. and i just found out that ROCKYROAD has 2in wheel spacer wich would be better than 1.5in in this case.

Matt
03-23-2012, 05:31 PM
ill add a tire size converter to the offset/backspacing converter I made for you guys

07JeepXK
03-23-2012, 07:58 PM
Sal is now running 285/70's on his XK with a 2 inch spacer lift

cis911
03-24-2012, 05:15 AM
pictures are needed

criket
03-24-2012, 05:20 AM
pictures are needed

Sal's build thread in the Garage area.