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I am running  215/60/16 on my TC and the ride is better the handling and shifting performance is the same and the Speedometer error is 2 mph .  I consider it a very nice improvement on the TC

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8 hours ago, Fifty150 said:

The bigger the tire, the wider the turn radius.  35" tires really messed up my truck's turn radius.  I can't make u-turns anywhere in The City.

 

Its too early in the morning for math. I would think that the turn radius would stay the same unless something else occurred to move the actual position of the tire or for some reason you couldn't turn the wheel full on or something. Something other than just the diameter of the wheel would have to change. Not trying to argue with you or even say that you're wrong, just that I work right now as a CAD operator and the geometry of the statement caught my interest. I'm weird like that.

 

I think possibly with your truck that the offset may have changed to get those bigger tires to fit or just simply it never COULD make those u-turns before either.

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With a lift kit, the truck has wider wheels with different backspacing, taller and wider tires, a different scrub radius under the tire.....but full lock steering is the same because the kit is engineered to allow for turning without rubbing.  

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1 hour ago, Fifty150 said:

With a lift kit, the truck has wider wheels with different backspacing, taller and wider tires, a different scrub radius under the tire.....but full lock steering is the same because the kit is engineered to allow for turning without rubbing.  

 

Sure, this indicates a change in the position of the center axis of the tire. That is what would have to occur to change the turning radius. Changes to the width or height of the tires, in and of itself, would not.

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1 hour ago, OLDSCHOOLFOOL said:

 

Sure, this indicates a change in the position of the center axis of the tire. That is what would have to occur to change the turning radius. Changes to the width or height of the tires, in and of itself, would not.

 

 

I'm glad that you bring an informed point of view.  It all makes as lot more sense.  Big wheel.  Small wheel.  Equal turning.  After all, they're both just as round.

 

That tire size effect on turn radius has been hotly debated for years.  Online.  In real life.  Almost as controversial as motor oil.  A lot of people insist that size of the tire has nothing to do with turn radius.  Yet, everyone with a lift and bigger tires will tell you that their turn radius circle got bigger.  It's just like with motor oil.....you just keep doing what you're doing.  Because no matter what anyone else says, when I drive the car, it's a larger turn radius circle and those u-turns aren't possible anymore.  

 

We could also touch on whether bigger tires get better mileage.......another hot topic.

 

I was beginning to wonder if it's just perception.  Sort of like driving a cab over axle truck.  When you are sitting over the front axle, it feels like the truck is making tighter turns and turning on a dime.  People also have perceptions of the cabover design being unsafe, since you're right up front with nothing protecting you.  Despite the evidence that with conventional trucks, the engine gets pushed through the firewall, and that will kill the driver, not protect the driver.  

Edited by Fifty150

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Asked about turn radius as larger tires [especially if wider] "may" rub on body => need to limit steering.

As for winter [BTW; 'furries' in tonights forecast] tires, the 'driver'is just as important. Had a case when I worked as security guard: saturday heavy

snowfall and only my Vibe and an suv in parking lot. End of shift and other driver went out to go home while I 'filled-in' night guard.  suv driver came back inside after 20-25 min, said was stuck and would leave car and walk to road to get bus or taxi.  I went out, SLOWLY wiggled my out of the lot and went home. Next morning suv was still there so went over to look - it was a Lexus AWD with top-of-line (new) snow tires.  My FWD vibe had low-cost Goodyear snow tires.

Snow tires are mandatory by certain dates in Quebec & Ontario, chains are optional but rarely used now-a-days (wouldn't fit on the Vibe anyhow - I tried). In old days of Bias-ply tires chains were necessary quite often.  I doubt the T-C (gen2) has enough clearance for them.

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Often times, driving skill is the equalizer.  AWD is not 4WD.  People often are not able to differentiate between the 2.  

 

Don't you guys who live in a snow climate carry things like shovels?  And I am assuming that since the guy lives in a snow zone, he should know a few tricks.

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People who "know" do carry shovels, traction plates/mats, abrasives, etc.  Highly recommended by the CAA/AAA !

Personally, also carry emergency blankets, flares, small survival kit (long trips only), as well as regular stuff.

But as an old radio commentator used to say " if Common Sense were truly common, the world would be a far better place!"

Perhaps we can also blame the car adverts for implying that "technology" is everything??

Edited by Gideon
add info

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Shovels, sleeping bag, and a SET of CHAINS!

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So long as the wheel offset remains the same, wider tires shouldn't affect steering at all  -  The center of both the wide and narrow tires are both in the same place, geometrically  -  Track width hasn't changed at all.  Changing the wheel offset can widen the track and that messes up steering.  When you steer, the inside tire turns sharper than the outside tire and that difference is set to be correct for the track width the vehicle was designed with.  When you change the track width by even a small amount, you would need to change that ratio of how much tighter the inside wheel turns than the outside one, but there is no way to do that  -  It's a built in parameter

 

If you take a pick-up truck where the wheel offset has been changed by a bunch and turn the wheels all the way to one side and then try to push it when it's sitting on level ground, you will learn a couple things.  First, it's really hard to get it to move at all . . . . you've gotta push it really hard.  Second, since you're pushing it and the engine isn't running, you will actually be able to hear and feel the front tires scrubbing on the pavement.  This is because the steering geometry is all messed up and you are actually sliding the tires sideways.  that kills your gas mileage and it doesn't make your tires last very long either

 

Don

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Tires are on wheels.  Wheels have different widths, offset, and backspacing.  Allow those measurements factor in with tire size to effect your driveability.   

 

Same offset on a wider wheel means change in backspace.  If you are installing an aftermarket wheel, check for the scrub radius.  This is what will effect the contact patch of your tire on the pavement.   

 

Any good tire shop will be able to measure and do the math so that you don't buy something that doesn't fit and can't turn.  

 

Nothing worse than to spend $$$XXX, then your tires rub into the wheel well, the inside of your wheel is hitting suspension components, and you cannot turn steering to full lock.  Most shops will not give you a refund.  You picked out the wheels and tires.  They can't take the merchandise back for restocking.

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My worry is this: wider and/or taller tires need more space in the wheel wells - this MAY limit the maximum steering angle that can be used.  Result - wider turn radius.

Ideally, I'd like to increase ground clearance by 1-1 1/2" to ensure clearing higher-than-normal curbs, and for the rough paths at some campgrounds (save wear/tear/dents on underbody).

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3 hours ago, Gideon said:

My worry is this: wider and/or taller tires need more space in the wheel wells - this MAY limit the maximum steering angle that can be used.  Result - wider turn radius.

Ideally, I'd like to increase ground clearance by 1-1 1/2" to ensure clearing higher-than-normal curbs, and for the rough paths at some campgrounds (save wear/tear/dents on underbody).

 

 

Calculate the new wheel and tire combination that you are thinking of using.  Verify fitment with a tape measure.  jrm223 is using 215/65R16 on OEM wheels.  OEM wheels and OEM tire width, with a higher sidewall, gave a little taller tire with the same scrub radius.    His gain in height is minimal, but he is using a tire with a more aggressive tread pattern.  

 

wheel size.jpg

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11 hours ago, Gideon said:

My worry is this: wider and/or taller tires need more space in the wheel wells - this MAY limit the maximum steering angle that can be used.  Result - wider turn radius.

Ideally, I'd like to increase ground clearance by 1-1 1/2" to ensure clearing higher-than-normal curbs, and for the rough paths at some campgrounds (save wear/tear/dents on underbody).

I have studied this to death over the past year and have concluded that 215/65R16 (27") is the largest diameter tire that will go under the front without modification. Change the width or move the wheel out and you are almost certain to rub. The real limitation is directly in front and behind the wheel, not above it. Lifting may provide a little bit more clearance but I suspect in front and behind the tire, it will probably be minimal. I was trying to see if I could get a 235/60R16 on the front and with the added width it was a no go. I certainly would like to be proven wrong.

 

What size tire are you thinking about precisely?

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I can say that my 215/65R16's on stock wheels has not affected turning at all, at least not that I ever noticed. Granted, I never did before/after turn radius measurements; but I have never heard any rubbing while turning, so the slightly larger diameter of the tires is not causing problems in the wheel wells of the van.

 

Fifty150, you had asked about getting stuck. With the OEM tires, I did get stuck in my own yard at my project house here in Texas. That was a couple years ago when it was raining almost every day for a month, but I only got stuck the very last day (when I was leaving, of course) after being there for a week. That was also a slightly lower spot in the yard than I had been parking in most of the week, but I had also parked right there to unload when I first got to the house. So far, the Generals have not gotten stuck, even when the grassy ground between my gravel driveway and garage is 3" of muddy soup. One of these days, I'll have more gravel brought in since the previous owner did not fill in that area - she just parked on the driveway, instead.

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6 hours ago, OLDSCHOOLFOOL said:

Lifting may provide a little bit more clearance but I suspect in front and behind the tire, it will probably be minimal. 

You will need an aggressive lift. Trucks are lifted from 6" - 12".  So that the wheel well is above the center line of the tire.  The entire suspension is re-engineered for the larger wheel and tire.  Even the drive shaft is extended.  The differentials are regeared.  Computer is reprogrammed for proper shifting and speedometer & odometer readings.  

 

Not impossible. You could do all the R&D, then recuperate the cost by selling the system you developed.  Or get even more creative.  Mount a Transit Connect body onto a 4WD Ranger chassis.  Replace the motor with a 302.  Just day dreaming.  

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On 10/20/2018 at 3:04 PM, Fifty150 said:

 

 

I'm glad that you bring an informed point of view.  It all makes as lot more sense.  Big wheel.  Small wheel.  Equal turning.  After all, they're both just as round.

 

That tire size effect on turn radius has been hotly debated for years.  Online.  In real life.  Almost as controversial as motor oil.  A lot of people insist that size of the tire has nothing to do with turn radius.  Yet, everyone with a lift and bigger tires will tell you that their turn radius circle got bigger.  It's just like with motor oil.....you just keep doing what you're doing.  Because no matter what anyone else says, when I drive the car, it's a larger turn radius circle and those u-turns aren't possible anymore.  

 

We could also touch on whether bigger tires get better mileage.......another hot topic.

 

I was beginning to wonder if it's just perception.  Sort of like driving a cab over axle truck.  When you are sitting over the front axle, it feels like the truck is making tighter turns and turning on a dime.  People also have perceptions of the cabover design being unsafe, since you're right up front with nothing protecting you.  Despite the evidence that with conventional trucks, the engine gets pushed through the firewall, and that will kill the driver, not protect the driver.  

My experience with gearing changes is with motorcycles on the race track, but it applies to tire diameter changes.  Assuming you aren't getting into wheel slip, frictional losses, and all kinds of other stuff that gum up the calculations.  I put lower gearing on a Triumph TT600 that I had back in the early zeros.  Stock, it would run out of steam on a long straight as well as have somewhat anemic acceleration from the low end.  It was a 600 cc motorcycle, so running out of steam is all relative, and once you got into the power band, it ran like a scalded cat.  With lowered gearing (bigger rear sprocket), it ran higher rpm, which gave it better performance at the low end, and ironically, gave it a better top end as well.  It was in the power band a little better at the top with the gearing change.  No apparent change in fuel mileage on the street, either.  Once I got into full on racing, and not just track days, gearing was set up to run out of revs at the end of the fastest part of the fastest track I was likely to run on, and it was a dedicated race bike, so I wouldn't know what kinds of effects the gearing had on it anywhere on a public road.

 

All things are never equal, and what I learned on the bike may be completely wrong for anything else.  I bring it up because it shows that what seems like the logical conclusion isn't always correct.

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THANKS GUYS for all the help.

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On 10/24/2018 at 8:51 AM, WillMartin said:

 

I put lower gearing on a Triumph TT600 that I had back in the early zeros. 

 

 

 

Regearing is something that racers and off-road guys have been doing for decades.  Guys used to drive to the track, change out the gears in the rear differential, race, change back to street gearing, then drive home.  Not as simple as it sounds, but it was done.  Most people with lift kits will swear that regearing makes all the difference in the world.  Some people with stock wheel & tire, will regear so that they can have more low lend torque for towing.  

 

Simply not an option with Transit Connect's front wheel drive.  

 

And apparently, there isn't a product on the market for remapping fuel trim, changing shift points, or changing the tire size to read correctly on the speedometer.  With my old tech cars of yesteryear, SCT made awesome handheld programmers for Ford vehicles.  I currently have an extra SCT Livewire not paired to any vehicle.  But nobody is writing custom tunes for Transit Connect.  So I'll just save it, and hope it will still work and be compatible if I buy another Mustang.  Maybe hope & pray, that as a joke, a custom tuner will want to write a tune for Transit Connect, then e-mail to me as a gift.

Related image

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As you have said many times ,at least here in the states most of the TC's are commercial that kills the performance parts demand.  With the trans the PCM adapts the shift points , so if you clear the shift point memory you can change the transmission shift points to match your driving style.

I think Ford wound most of the power out of this engine.

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On 10/20/2018 at 1:01 AM, G B L said:

I am running  215/60/16 on my TC and the ride is better the handling and shifting performance is the same and the Speedometer error is 2 mph .  I consider it a very nice improvement on the TC

What make and model of tire? My oem contacs ok but kind of harsh on pave patch roads..yours any better?

Edited by Willygee

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