Trouble with lift + tire selection.

[Viper45]

I'm a little hesitant to start my own thread on this topic, because I think I need to continue to do more research... but I feel like I'm starting to hit a wall in my quest to find the lift and tire size that fit my needs/budget. It doesn't help I'm stuck in ND working nights, so I can't call or drive by any local shops to ask questions in person. Aaaand it's starting to drive me crazy when I look at the P rated tires I still have. Anyways, here it goes, hopefully I don't ramble on too much.

Anyways... if it isn't apparent by now, this is the first lift I've ever installed and the biggest problem I'm running into is that I cannot figure out how I go about comparing the on/off road ride quality characteristics of each lift combination against the price/durability for each item without actually riding in a 4Runner setup with that suspension. For instance, going from the P to a C/E load rated tire alone is going to effect how the 4Runner drives. Add in stiffer front/rear coils with better shocks and now everything is different. Don't get me wrong though, I get it, the ride with any option below I choose will be stiffer, I just don't want to end up driving a rock.

So I have a 2013 TE w/ KDSS, I live in CO and drive to ND regularly. When home we go camping and run trails as much as my schedule allows and in the winter are ALWAYS up in Summit Co snowboarding. My goal is for a 2-3" lift (without sag in the rear with people and gear) so that I can fit 33's (285/70/17 so really 32.71" new), with minor trimming/heat forming; which IIRC I think Intruder has done. Tires will be either BFG AT's or GY Duratrac's which ever I can find a better deal on. To be honest though, I haven't done a great deal of research in the tire fitment dept, just what I've seen as I've been looking at suspensions. So if it ends up being that 285/70/17's are too much work or cutting I'll be going for 265/75/17's until I get a few more miles on it; I just don't feel right cutting this truck up yet.

On to the suspension, if I've interrupted the lifts most of you guys are using correctly, some of the more reasonable options I have are the following:
1)5100's on OEM coils (then add coils & UCA's later as needs change).
2)FJ coils + 5100's.
3)OME 884/895E & 90010/60004
4)Toytec Ultimate
5)Icon Stage 1
+
1)LR UCA
2)Total Chaos UCA

How I have these laid out in my head is:
1)Cheapest option and reliable, awesome for leveling or lift alone if not geared down heavily.
2/3/4)I'm thinking these three, all with the LR UCA, would be the best bang for the money. (Assuming durability on all three hold up, how many miles do you typically get out of these suspensions before you start to see sagging and shocks needing rebuilt, 40-50k??
5)Icon stage 1 + LR UCA would be a better ride at highway speeds because of the digressive valving in the shocks (Is this right??) I cannot find the link now, but I thought I read progressive valving = better over bumps while moving slow and digressive valving = better while moving faster; not to mention (again possible misconception here too) Icon's can be rebuilt easier.

I'm not going to say budget is not a factor, but I'd much rather it be the deciding factor once I've finalized what I'll require with my specs based on my needs. Otherwise I'd just overkill the shit out of it and run an Icon Stage 6 and call it done, but I'm pretty such the wife wouldn't be happy with that decision.

 

[Alex T4R]

The lift you listed are all great, I think you will find in your search that the bilestein has good reputation and cheapest option. The OEM kit is good, but I heard that it heavy for heavy load otherwise your suspension will be bouncy. The guys that put heavy bumpers use OEM. Toyotec is good reasonable kit all around. Icon is great on road and offroad, that what I have Icon with MT long travel kit. You also did not mention anything about Radflow kit, which is good kit too. As far as tires size with 285/70/17 you will have to move the fender lining forward, and it is only 3 bolts, Harper7 has a great write up on it and maybe would have to do a Body Mount chop in the long run, depends on specs you will get with the suspension. I can tell you this, I know you mention you do not feel right about cutting the truck, but if you get 265s I think you will upgrade to 285s later, I know some people who did, which in the long run you will spend more money. Just look at 5th gen Built threads and see what the guys running, that how I picked my chooses. Budget was a factor for me too, so that why I wanted to do it right from the first time and I learned my lesson when I had my 4th gen I installed spacers and got some tires which I regretted my choice later.
Good luck with your chooses and happy modding.

 

[mgrande]

What kind of wheeling do you do and how often?

 

[dwc]

What kind of wheeling do you do and how often?

x2

You've done your research so it's really up to you. In my case, mild wheeling once a year if I'm lucky. So, the 5100s and stock coils are more than enough for me.

 

[Viper45]

Awesome guys, thanks for the comments.

What kind of wheeling do you do and how often?

Hard to give an honest estimate I guess, I currently work very ****ty hours. During the last two years, we went out 1-2 times a month, but this year I've yet to make it out since I was covering for a buddy and picked up his shifts while he had a kid and moved... so it's kind of hard to say what will happen next year. Could be more or less.

As far as the what kind of wheeling, just know that everything prior was done in my stock (plus BFG MT KM2) 2003 Taco, so I tried to keep our camping and trail running to stuff I knew it could handle. Trails I can remember off the top of my head are Slaughterhouse Gultch, Webster Pass, Georgia Pass, Santa Fe Peak, Medano Pass, and Mt Baldy; so fairly easy to moderate I guess. I guess for the 4R, it'll depend on the new capabilities of the upgrades, but I plan continuing to pick trails that don't necessarily push it's limits, but I would like to increase trail difficulty and range of the outings a bit more.
__________________________________________________________________________________________________________________________________

So I guess it might help if I list the other plans I have for my 4R that will impact this. I'm not planning on replacing the front/rear bumpers at this time, maybe later if they get banged up, but I'll cross that bridge if/when I get there.

Currently installed:
-Gobi Stealth + Ladder = 70# + ~30# (Ladder weight not listed)
To-do-list:
-Bud Built, Regular Bump out Sliders = 110#
-Bud Built, Diff Skid = 20# (Weight not listed)
-Bud Built or RCI Metal 5/4 piece (under body skids) = ~200-250#

Total increase in weight = 100+110+20+250 = 480# ~= round up to 500# for lights etc... (aaand maybe twinkies)

Now if I'm on the stock tires/suspension (with skids/rack/sliders) and I take my wife and 2 others out camping, before we even load up with gear I've used more than 1/2 of the 825# Vehicle capacity weight. Basically meaning, bad idea... Which makes sense why so many of you upgrade the tires so quickly, I mean it's almost a requirement for any similar mods like this.

So, if I understand this right, I'll only gain the increased load limit if the (new c/d/e) tire is inflated past 35psi; but I'm not sure if that only works when comparing P/P tires or works for P/C/D/E... Anyone know??

I also don't know how the load index rating translates to usable vehicle capacity weight. For instance the stock Dunlop Load index number is 113, which means it can support 2535#; however, since it's on a light truck, it's actually 9% less than that so really that 2535# is now ~2306#. But how does that 2306# equate to the 825# vehicle capacity weight??

Hopefully you all can understand me wanting this information... I guess that it's part of me wanting to challenge myself to learn something new and the correct way to apply it; while also being confident with the mods I've made.

 

[Jeremy556]

With your planned skid plates, a lift, and 33ish inch tires, you shouldn't have much trouble with 7 rated trails.

As far as tires, do a search for the "LT Tires Need More Pressure" thread. If you keep your OEM tires, they will certainly be the limiting factor as far as trails go. With stock size LT tires, you should be running around 44psi for street pressure, or 38psi for a LT285/70/17.

Load capacity for tires are de-rated by 9% when P metric tires are used on trucks. LT tires are not re-rated.

 

[Viper45]

Yeah I didn't think I would have much trouble; I guess I'm just trying to come up with the new numbers for load limits that these lift kits create. Partly because I'm curious, and partly because I think it helps me understand the how the whole system works.

I've got another tab open and will check that thread out now, not sure how I missed it in searches I've done. (edit) Actually, I'll save my questions until I fully read and digest the thread you mentioned (/edit)

Load capacity for tires are de-rated by 9% when P metric tires are used on trucks. LT tires are not re-rated.

Might have been how I worded it, but I understood that part; thanks for making sure though!

 

[Viper45]

With stock size LT tires, you should be running around 44psi for street pressure, or 38psi for a LT285/70/17.

That thread helped this make perfect sense, thanks.

Now for a few questions regarding max loads. For the sake of this example lets leave out lifts and the fact that adding more than the recommended 825# to the stock coils will make the rear deflect more than I want, thus creating issues when the wheel wells are fully stuffed. I'm more or less just curious if you can take a weighted average of the difference between the two ratings for quick reference, like below. Is this correct, or am I over simplifying it?

Max Loads @ Max PSI for Load rating
Stock Dunlops @ 35psi = P265/70R17 113S; (2535# * .91 = 2306.85#)
Goodyear Duratrac @ 50psi = LT265/70R17C 112Q; 2469# or 1.070290656% greater than stock.
BFG AT KO @ 80psi = LT285/70R17E 121Q; 3195# or 1.385005527% greater than stock.

Vehicle Capacity Weight
Stock Dunlops = 825#
Goodyear Duratrac = (825# * 1.070290656 = 882.9897913#)
BFG AT KO = (825# * 1.385005527 = 1142.63#)

I ask, because I'm curious about how the sum of all of the parts (once I figure them out) end up working together.

 

[Jeremy556]

Lots of things are going to go into the max load of a vehicle besides just spring rate and tire load capacity.

 

[Viper45]

Looking at my options, I have 3. Stock, taller and skinnier, taller and fatter. All three come with pro's and con's, but this post isn't planning on focusing on that aspect. I want to discuss the tire and it's relationship with the speedometer/odometer in regards to it's diameter & circumference.

Based on this recommendation (bottom of the page), I've been using the 1010.com tire calc(<-URL has the 3 sizes below already).
Speed Variance
265/70R17 = n/a
255/75R17 = 1.41%
285/70R17 = 3.37%

This speed variance will not only show up on the speedometer (which I can deal with), but also the odometer. While I overestimated the percentage on the upper end of the spectrum in this post earlier tonight (by not checking to see if those sizes tires were available), the lower end of the spectrum still holds true @ ~4%. Correcting for my estimation error yields:

(@ 3.37% speedo difference)
2000 * 1.0337 = 2067.4
2080 - 2000 = 67.4
67.4 * .25 = $16.85

200,000 - 13500 (current mileage) = 186,500
186,500 / 2000 = 93.25

$16.85 * 93.25 = $1571.26

To me that's a alot of money I could save for other mods, while also not having to put up with the headache of having to remember to correct all of the data I gather. I've been searching the 5th gens section, but I cannot find anyone that has tried, or cared enough, to correct it. Have any of you installed something like this?

--------------------------------------------------------------------------
Also, off-topic, but I like to challenge myself to figure out the formulas used and this problem is causing me a bit of grief. I am attempting to cross reference the data on the 1010 link above but am coming up with a(few) errors. For simplicity, here on out 1010 is in black, my hand calcs are in red.

Diameter, I used: (2 * (section width * (aspect ratio * 0.01)) / 25.4) + rim diameter
265/70R17 = 31.61, 31.61
255/75R17 = 32.06, 32.06
285/70R17 = 32.71, 32.71

Circumference = Diameter * pi, I used pi out to 5 decimals = 3.14159
265/70R17 = 99.29, 99.31
255/75R17 = 100.72 , 100.72
285/70R17 = 102.76, 102.76

Pretty close so far, but after this I start losing how they find their numbers, but maybe I'm not interpreting correctly (most likely). I started by using 63360 (inches per mile), revs per mile, and circumference. I think we should be able to deduce that:

63360 = (revs per mile) * Circ; or
63360 / Circ = (revs per miles)

Rev/mile, using above I get:
265/70R17 = 658.10, 638.00
255/75R17 = 648.80, 629.07
285/70R17 = 635.92, 616.58

Inches in a mile, Using the above formula again with rev/mile and circumference I get:
265/70R17 = 65342.749"
255/75R17 = 65347.136"
285/70R17 = 65347.139"

Here's what I don't understand though, we know there are not 65347 inches in a mile, so what am I missing that give me a 3% discrepancy (across all sizes) in my calculation? Secondly, a quick check of the Stock Bridgestone load table shows that they have 657 rotation per mile. I'm obviously wrong, and my only guess is that is has something to do with tire deflecting/deforming where it contacts the road, due to and an average assumed load.
----------------
Eddie - @ your response that got deleted... and mine that answered that.

TLDR ver = subtracting an average off the tread depth from the tire creates a problem; the new diameter does not equal the published information from the manufacturer or from 1010's calcs. Leading me to believe that I'm missing something.

*edit* Oh yeah, part of my post that got deleted... I know some of you may think this is a pointless endeavor, but I think it's a better use of my time than watching TV for 12 hours straight during my shifts that are problem free.

 

[eddiebx]

....
----------------
Eddie - @ your response that got deleted... and mine that answered that.

TLDR ver = subtracting an average off the tread depth from the tire creates a problem; the new diameter does not equal the published information from the manufacturer or from 1010's calcs. Leading me to believe that I'm missing something.

*edit* Oh yeah, part of my post that got deleted... I know some of you may think this is a pointless endeavor, but I think it's a better use of my time than watching TV for 12 hours straight during my shifts that are problem free.

Hmm yeah I see what you mean...well I'm certainly stumped but also curious to know the reason. Have you thought about emailing a tire manufacturer?

Off topic, do you monitor a TV channel's broadcast signal to make sure the programs are playing as scheduled? I used to do that about a million years ago when Sony Flexicarts were all the rage, lol.

 

[Viper45]

Nah, I do directional work in the oilfield. I monitor surveying equipment that I'm running down hole. The hardware pumps up realtime data that the drillers and geologist use to keep us in zone. I'm officially a MWD operator, measurement while drilling, but most refer to us as "movie watching dudes".

 

[proquip]

I think the variance you're referring to (rev/mile) has to do with the fact that the tires are not exactly round when loaded riding down the highway due to the rubber's elasticity. While the static circumference of the tire is what you've calculated, there is distortion rotating at speed under significant load.

Hope that helps. In the end, better to go by the manufacturer's rev/mile calculation as it takes into account dynamic loads.

 

[thebwlife]

Nah, I do directional work in the oilfield. I monitor surveying equipment that I'm running down hole. The hardware pumps up realtime data that the drillers and geologist use to keep us in zone. I'm officially a MWD operator, measurement while drilling, but most refer to us as "movie watching dudes".

I work in completion and production ops.

 

[canadiansr5]

Looking at my options, I have 3. Stock, taller and skinnier, taller and fatter. All three come with pro's and con's, but this post isn't planning on focusing on that aspect. I want to discuss the tire and it's relationship with the speedometer/odometer in regards to it's diameter & circumference.

Based on this recommendation (bottom of the page), I've been using the 1010.com tire calc(<-URL has the 3 sizes below already).
Speed Variance
265/70R17 = n/a
255/75R17 = 1.41%
285/70R17 = 3.37%

This speed variance will not only show up on the speedometer (which I can deal with), but also the odometer. While I overestimated the percentage on the upper end of the spectrum in this post earlier tonight (by not checking to see if those sizes tires were available), the lower end of the spectrum still holds true @ ~4%. Correcting for my estimation error yields:

(@ 3.37% speedo difference)
2000 * 1.0337 = 2067.4
2080 - 2000 = 67.4
67.4 * .25 = $16.85

200,000 - 13500 (current mileage) = 186,500
186,500 / 2000 = 93.25

$16.85 * 93.25 = $1571.26

To me that's a alot of money I could save for other mods, while also not having to put up with the headache of having to remember to correct all of the data I gather. I've been searching the 5th gens section, but I cannot find anyone that has tried, or cared enough, to correct it. Have any of you installed something like this?

--------------------------------------------------------------------------
Also, off-topic, but I like to challenge myself to figure out the formulas used and this problem is causing me a bit of grief. I am attempting to cross reference the data on the 1010 link above but am coming up with a(few) errors. For simplicity, here on out 1010 is in black, my hand calcs are in red.

Diameter, I used: (2 * (section width * (aspect ratio * 0.01)) / 25.4) + rim diameter
265/70R17 = 31.61, 31.61
255/75R17 = 32.06, 32.06
285/70R17 = 32.71, 32.71

Circumference = Diameter * pi, I used pi out to 5 decimals = 3.14159
265/70R17 = 99.29, 99.31
255/75R17 = 100.72 , 100.72
285/70R17 = 102.76, 102.76

Pretty close so far, but after this I start losing how they find their numbers, but maybe I'm not interpreting correctly (most likely). I started by using 63360 (inches per mile), revs per mile, and circumference. I think we should be able to deduce that:

63360 = (revs per mile) * Circ; or
63360 / Circ = (revs per miles)

Rev/mile, using above I get:
265/70R17 = 658.10, 638.00
255/75R17 = 648.80, 629.07
285/70R17 = 635.92, 616.58

Inches in a mile, Using the above formula again with rev/mile and circumference I get:
265/70R17 = 65342.749"
255/75R17 = 65347.136"
285/70R17 = 65347.139"

Here's what I don't understand though, we know there are not 65347 inches in a mile, so what am I missing that give me a 3% discrepancy (across all sizes) in my calculation? Secondly, a quick check of the Stock Bridgestone load table shows that they have 657 rotation per mile. I'm obviously wrong, and my only guess is that is has something to do with tire deflecting/deforming where it contacts the road, due to and an average assumed load.
----------------
Eddie - @ your response that got deleted... and mine that answered that.

TLDR ver = subtracting an average off the tread depth from the tire creates a problem; the new diameter does not equal the published information from the manufacturer or from 1010's calcs. Leading me to believe that I'm missing something.

*edit* Oh yeah, part of my post that got deleted... I know some of you may think this is a pointless endeavor, but I think it's a better use of my time than watching TV for 12 hours straight during my shifts that are problem free.

all i see is black and red....im on a night shift too and you are clearly far more productive than i have been.....

good on ya. :rockon:

 

[eddiebx]

Nah, I do directional work in the oilfield. I monitor surveying equipment that I'm running down hole. The hardware pumps up realtime data that the drillers and geologist use to keep us in zone. I'm officially a MWD operator, measurement while drilling, but most refer to us as "movie watching dudes".

How do you stay awake if nothing breaks, lolol.

So I was searching this a bit on google and I read something that might make sense (at least to the lay person like me). Someone had mentioned that what you need to do to get an accurate rolling diameter is to measure the tire while it is loaded down on the ground. So basically measure from the center of the hub directly down to the center of the contact patch on the ground; take this value and times it by two for the diameter. Then plug it back in and maybe the numbers would be closer to manufacturer's specs rev/mile?

Seems reason since our hand calculated rev/mile keep coming out lower than manufacturer spec, which indicates they are using a smaller circumference I think.

 

[1engineer]

How do you stay awake if nothing breaks, lolol.

So I was searching this a bit on google and I read something that might make sense (at least to the lay person like me). Someone had mentioned that what you need to do to get an accurate rolling diameter is to measure the tire while it is loaded down on the ground. So basically measure from the center of the hub directly down to the center of the contact patch on the ground; take this value and times it by two for the diameter. Then plug it back in and maybe the numbers would be closer to manufacturer's specs rev/mile?

Seems reason since our hand calculated rev/mile keep coming out lower than manufacturer spec, which indicates they are using a smaller circumference I think.

There are two things that will screw up any calculation:
1. Inaccurate measurements
2. Inaccurate data collection

In the case of passenger vehicles like the 4Runner, both are true in respect to tire size and speed. You are only going to get close and not exact because the tire size is not always the tire size and the speedometer can be off by 2% legally.

Tires all have a nominal size and most, even though they are the same published size, are not in reality the same.

The speedometer makes it even worse as there are actual rules and regulations that state the accuracy of this gauge. Plus or minus 2% apparently is no big deal so getting something exact is going to be tough.

 

[eddiebx]

There are two things that will screw up any calculation:
1. Inaccurate measurements
2. Inaccurate data collection

In the case of passenger vehicles like the 4Runner, both are true in respect to tire size and speed. You are only going to get close and not exact because the tire size is not always the tire size and the speedometer can be off by 2% legally.

Tires all have a nominal size and most, even though they are the same published size, are not in reality the same.

The speedometer makes it even worse as there are actual rules and regulations that state the accuracy of this gauge. Plus or minus 2% apparently is no big deal so getting something exact is going to be tough.

Hmm...how do you explain where the missing rev/mile goes (when compared between hand calculations of a perfect circle and manufacturer spec). ie. hand calculated 265/70/17 = 638 rev/mi, while most tire manufacturers spec are ~657 rev/mi. Does it make sense that it is due to the deflection when the weight of the vehicle is sitting on the tire causing the diameter to shrink, so to speak?

Inquiring minds want to know this useless information.

 

[proquip]

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=203

While this explanation from Tirerack is pretty simplistic, the point is the same, a lot is going on when the tire is loaded rolling down the highway at 60mph, factors that are not considered when you calculate rev/mile when using the tire specs.

 

[1engineer]

Hmm...how do you explain where the missing rev/mile goes (when compared between hand calculations of a perfect circle and manufacturer spec). ie. hand calculated 265/70/17 = 638 rev/mi, while most tire manufacturers spec are ~657 rev/mi. Does it make sense that it is due to the deflection when the weight of the vehicle is sitting on the tire causing the diameter to shrink, so to speak?

Inquiring minds want to know this useless information.

The term you are looking for is "static loaded radius." Look that up and you will be further down your journey's path. Unfortunately as soon as you fill up with gas and your family gets in, that number changes.