Sooooo, everyone understands the weight of larger tires isn't the real issue right???

[TxNessie84]

So if I understand you correctly then this is the look I should go for to improve my 0-60 time.

 

[CoronaRaptor]

So if I understand you correctly then this is the look I should go for to improve my 0-60 time.

View attachment 332750

Nothing will help a dodge, the ball joints will still break off and the axles will snap before it reaches the finish line.

 

[TwizzleStix]

The diameter/circumference, gear ratios, weight, etc. of everything rotating between the engine and the tires has an impact on acceleration. Thought this was a given. Guess not...

Oh, it was a given about 30 years ago because most people buying any sort of performance vehicle had basic physics knowledge and knew the specs of the vehicle of interest. It was called “common sense” usually beginning in early grade school as cause and effect and action vs reaction. The Ed system today only teaches racism and socialism, so any semblance of actual knowledge is long gone.

 

[TwizzleStix]

So if I understand you correctly then this is the look I should go for to improve my 0-60 time.

View attachment 332750

Yeah that’s what the fiat crowd does do they can do burnouts.

Actually, if the tires got infinite traction, then the gearing would run out at around 60ft and it would never reach 1/4 mile as it blew up at 70ft.

 

[CoronaRaptor]

Oh, it was a given about 30 years ago because most people buying any sort of performance vehicle had basic physics knowledge and knew the specs of the vehicle of interest. It was called “common sense” usually beginning in early grade school as cause and effect and action vs reaction. The Ed system today only teaches racism and socialism, so any semblance of actual knowledge is long gone.

I think we touched a nerve, ha ha! Tell us how you really feel, lol.

 

[PlainJane]

The problem with your analysis is it does not take into account we have GEARS!
I would agree that there is some loss when not in direct drive, but that's another discussion.

 

[DINOZR]

correct, but having seen a few threads where people were worried/comparing tire weights it seemed to me that many were not actually aware of the over all gear ratio change. That is why I didn't give an explanation in the original post, if I had a bunch of "yea I understand" responses then I was going to just let it die.

My perception is that almost everyone understands the gearing issue. Yes, in a perfect world the 37s would have slightly lower (numerically higher) ring and pinion gear sets. But the difference in RPMs is so minimal with the same gear set that they don't get steeper gears for 37s. OK. Not perfect, but very livable. So gearing is water under the bridge. It's done. Nobody is regearing for the transition from 35s to 37s on a Raptor unless they just have money oozing out their ears.

So if we take that as a given: We understand the gearing issue but we are not regearing for going to 37s. Then is there anything we can affect when moving to 37s? Tire and wheel weight. Is it a large effect? IDK. Not as large as gears. But if you're replacing tires anyway, might was well optimize what you're buying (since you are indeed buying tires and are not buying gears).

 

[SurfRaptor]

A tire is a "reverse lever". A tire/wheel is driven from the center (at least in automobile applications). It is the exact opposite of getting a longer ratchet to get more leverage on a bolt. Imagine if the bolt was spinning the ratchet, the longer ratchet would have less torque at the end.

lets say we have an engine that makes 500 ftlbs of torque, with a transmission first gear ratio of 3:1 and a rear differential of 4:1

500 ftlbs into trans gets you 1500 out
1500 into the differential gets you 6000 ftlbs applied to the axle shaft.
now apply that to different tire/wheels
32" (has a 16" radius) would get that 6000 ftlbs down to the glorious number of 375 ftlbs applied to the ground
33 would be 363.6363
35 would be 342.857
37 would be 324.32

Now if we regear the differential to 4.2 we get 6300 ftlbs applied to the axle shaft.
which with 37's would give you 340.54 ftlbs to the ground. basically matching 35's

This is why people regear after getting bigger tires, they lost a bunch of torque and want it back. Think jeep going from 31's to 37's. it is also why you have to go to bigger axles if you make such a large change, factory jeep axles can't handle the amount of torque going from 3:73's to 5:30's

This ^^^^^ but in addition keep in mind what you gain on low end you lose at the top end with higher gears. Factory Wrangler axles are Dana 30's on the front (44 rear combo) unless its a Rubicon model and then they are Dana 44's all around. The axles are never changed in the JKU world, for the most part. They are able to withstand the punishment. I guess you could say the guys going to 5:30's would maybe swap the axles but most people stay with 4.56 or 4.88. 5's are a huge difference in MPG and driving on the highways for a stock 3.8L engine with only 202hp - 260-285hp depending on model and torque around the same range is a nightmare.

"weight of the tire" isn't the real issue when it comes to winning at a drag race yes, but it still takes more power to get it rolling of the start line, so it is a factor. Weight of the tire really comes into play when off-roading since it can cause more parts to break/bend and wear down faster. Ball joints, tie rods and drag link being the biggest issues for jeeps and the dreaded death wobble.

PS Wheels not rims lol

 

[TwizzleStix]

My perception is that almost everyone understands the gearing issue…

Yeah, I’m quite sure your perception is incorrect in reality. They may “understand” that the acceleration and likely fuel mileage will be less, but I don’t believe that “everyone” even has a real knowledge-based clue as to the total list of effects. However, I also believe they since they don’t how much they don’t know that they don’t care. When something fails or otherwise doesn’t perform as they think it should, they tend to blame the failed pert/piece rather than the root cause.

What’s the idiots name that blames Ford for his steering failures?

 

[DINOZR]

Yeah, I’m quite sure your perception is incorrect in reality. They may “understand” that the acceleration and likely fuel mileage will be less, but I don’t believe that “everyone” even has a real knowledge-based clue as to the total list of effects. However, I also believe they since they don’t how much they don’t know that they don’t care. When something fails or otherwise doesn’t perform as they think it should, they tend to blame the failed pert/piece rather than the root cause.

What’s the idiots name that blames Ford for his steering failures?

Well it wouldn't be the first time I've been incorrect.

This isn't black and white. Of course not *everyone* *fully understands* *every facet* of gearing. I'm certainly not sure I do. But my point remains: OP is concerned that people are ignoring gearing and only worried about rotating mass. People are not, generally, ignoring it. They have simply moved past it and are focusing their efforts on things that are more readily changed. Are they unwise to do so? You can argue that. But most people who have the tire weight discussion *here on this forum* are not ignoring the effects of gearing.