Drifting, hellaflush, slammed, tire stretch blog/bash thread.

[vex]

I can't tell from how you drew the friction, does it have a direction? If it has a direction you need to apply either a torque or a force to the tire to dictate the impulse of motion (or the force enough to cancel out the 'amount' of friction acting on the tire to keep it from moving). If the tire is static (which would be easier) you have drawn the FBD correctly.

[Rotary no Densetsu]

Niggas jelly of my mad stretch dawg.



The car is hideous. I can for once understand why he's running retarded negative camber in the rear though, since it's a Front-wheel drive drift car. Less contact patch, no grip, etc etc etc.

That stretch on the front though, that is so stupid, I'm sorry.

But this guy has daily driven this car like that for years. I don't know how he hasn't killed himself, but yeah. I dunno, my mind was blown when I first saw it.

[mazpower]

That poor Celica is the most hideous pile of shit I've laid eyes on. And front wheel drive drift car? That's an oxymoron.

[Rotary no Densetsu]

Originally Posted by mazpower

That poor Celica is the most hideous pile of shit I've laid eyes on. And front wheel drive drift car? That's an oxymoron.

Yeah, it is. Funny enough though, he slides that thing better than your average drifter.

[RotorDad]

There is no excuse for that car being in that condition. The owner should never touch a car again.

[scotty305]

You know who else slides better than your average drifter?

http://www.motoiq.com/magazine_artic...t-machine.aspx

The second photo on the page shows tires that appear to be properly sized. I suspect they have tried quite a few setups, at that level of sponsorship I wouldn't be surprised if they receive literally pallets of tires in the size(s) they request.


I'm not a drifter myself, and I generally disagree with the 'hella flush' style. That said, anyone who dislikes drifting should still go check out a Formula D event if you're able to. The paired elimination rounds after the drivers have qualified are a pretty entertaining display of car control and big horsepower. The cars aren't as cool a ALMS, but the track is set up in a way that makes it a really good spectator event (even compared to roadracing or NASCAR).

[Rotary no Densetsu]

Difference is, that's a front-wheel drive Celica, versus Foust's rear-wheel drive car with three times the horsepower, not to mention Kawashima (the guy that owns the Celica) isn't a pro. Not defending the looks or stretch, I'm just saying, totally not fair to compare the two.

Only certain guys, even at a pro level, have a selection like that, ie. All the Falken guys. Double stacker full of tools and tires.

At any rate. There are still a lot of "herrafrush" cars in Formula D. Tanner's car is set up like that, because he didn't build it. He just drives it, that's it. Same goes for 90% of the other Formula D drivers.

[sofaking]

Vex,

Okay, I can see how I misinterpreted the MoS thing. The point about not being at max load wasn't as much a reference of the fact that it determines the whole criteria, but that it plays a role in the original engineering specifications. When I say that it's not at its maximum rating on an average vehicle I'm just saying that if it isn't at it's maximum load then changing the load (large assumption here) might have some wiggle room. <-I know there's no way you'll concede to that point.

I had to read the gun reference a couple times to pick up the point you were making there, still not 100% sure I understand what you're saying about the non-firing round. (I'm not a gun person, I stay away from them.)

I did understand the brake master reference. That's an excellent reference for anyone that has driven with a leaking brake master. I could definitely see how the two correlate. That's your best argument yet for real world relation IMO. (this was the thing I was trying to do previously with coffee and baseball bat references, it's hit and miss sometimes with metaphors)

Your reply of "Not really" is the point I've been trying to make the whole time. If you didn't see ANY validity in what I said you would've answered "No", but you did see some truth in what I'm saying. You don't agree with it as being safe by engineering standards, but obviously have to accept that the possibility that it will hold is true. I am willing to more directly concede. My only point this whole time was to get acknowledgement that it's possible it's safe (from a standard of holding for the life of the tire). I'm not saying it is, I agreed with your statements of material sciences from the get-go and agree that there will be deformation on the tire. All I've argued is that it's possible that it will hold and get you safely from point A to point B for the life of the tread. I understand your stance of safety and agree that there is definitely a possibility that it could fail as well based on using it outside of its designed specifications.

For the vulcanized rubber, where am I looking this up and what types of numbers am I looking for?


And as for the VIP Celica... that thing is awful. Also, there's no way I'd be willing to stretch a tire that far. I am definitely not arguing for what that guy is doing. That shit is wrong on so many levels.

[vex]

Please quote my previous response as it makes things easier to keep track of.

Originally Posted by sofaking

Vex,

Okay, I can see how I misinterpreted the MoS thing. The point about not being at max load wasn't as much a reference of the fact that it determines the whole criteria, but that it plays a role in the original engineering specifications. When I say that it's not at its maximum rating on an average vehicle I'm just saying that if it isn't at it's maximum load then changing the load (large assumption here) might have some wiggle room. <-I know there's no way you'll concede to that point.

Honestly there's too much variability to say for certain. For a regular all terrain tire it very well may have enough 'room' to work in a stretched application as their made with different constraints in mind where as high performance tires with high speed ratings may not (lean manufacturing; basically means that the FoS gets closer to 1).

I had to read the gun reference a couple times to pick up the point you were making there, still not 100% sure I understand what you're saying about the non-firing round. (I'm not a gun person, I stay away from them.)

That's fine. It's the same as the master cylinder analogy.

I did understand the brake master reference. That's an excellent reference for anyone that has driven with a leaking brake master. I could definitely see how the two correlate. That's your best argument yet for real world relation IMO. (this was the thing I was trying to do previously with coffee and baseball bat references, it's hit and miss sometimes with metaphors)

Your reply of "Not really" is the point I've been trying to make the whole time. If you didn't see ANY validity in what I said you would've answered "No", but you did see some truth in what I'm saying. You don't agree with it as being safe by engineering standards, but obviously have to accept that the possibility that it will hold is true. I am willing to more directly concede. My only point this whole time was to get acknowledgement that it's possible it's safe (from a standard of holding for the life of the tire). I'm not saying it is, I agreed with your statements of material sciences from the get-go and agree that there will be deformation on the tire. All I've argued is that it's possible that it will hold and get you safely from point A to point B for the life of the tread. I understand your stance of safety and agree that there is definitely a possibility that it could fail as well based on using it outside of its designed specifications.

Not to be a dick, but that's a contradiction. Safety does not include taking a chance where it can be eliminated. Sure you could get to point A to point B, but will you make it every time with a stretched tire? It's the same issue with the leaking MC. How often can you make that trip with the cylinder like that? Once? Twice? Forty? It's a gambit at best.

For the vulcanized rubber, where am I looking this up and what types of numbers am I looking for?

Check the Matweb website, I found this one, but if you want to use a different rubber feel free to find it:
http://www.matweb.com/search/DataShe...ff3f5da&ckck=1

We want the mechanical properties.

[sofaking]

Originally Posted by vex

Not to be a dick, but that's a contradiction. Safety does not include taking a chance where it can be eliminated. Sure you could get to point A to point B, but will you make it every time with a stretched tire? It's the same issue with the leaking MC. How often can you make that trip with the cylinder like that? Once? Twice? Forty? It's a gambit at best.

I agree. The more things that are outside of design the higher the risk. I would agree risk goes up with tire stretching. In your opinion would you think that it is more dangerous to blow out a stretched tire than a blowout for any other reason? If so, why? Obviously this is a reference to driving within the laws of the road you're traveling on, not assuming some sweet jdm drift battle on the mountain with a bunch of morons trying to get youtube footage with thier friends in the car.

Originally Posted by vex

Check the Matweb website, I found this one, but if you want to use a different rubber feel free to find it:
http://www.matweb.com/search/DataShe...ff3f5da&ckck=1

We want the mechanical properties.

I also found this one (and a couple others of different particle mesh size) but no mechanical properties are listed.
http://www.matweb.com/search/DataShe...0718874&ckck=1

I didn't see a way to post it here that would be easy to read so I separated the fields using astrix..

Mechanical Properties *** Metric ***** English ***** Comments
Hardness, Shore A ****** 30.0 - 100 *** 30.0 - 100 *** Depends on compounding
Hardness, Shore D ****** 30.0 - 45.0 *** 30.0 - 45.0 ** Depends on compounding
Tensile Strength, Ultimate * 28.0 MPa **** 4060 psi **** Compounded Tire
Elongation at Break ****** 100 - 800 % ** 100 - 800 %
100% Modulus ********** 0.00150 GPa ** 0.218 ksi
Shear Modulus ********** 0.000500 GPa * 0.0725 ksi

Would you mind explaining what the "elongation at break" field means? It seems at a glance that it would mean that it can stretch 1-8x its length before breaking... that seems like a HUGE range.

[vex]

Thanks for quoting.

Originally Posted by sofaking

I agree. The more things that are outside of design the higher the risk. I would agree risk goes up with tire stretching. In your opinion would you think that it is more dangerous to blow out a stretched tire than a blowout for any other reason? If so, why?

Yes. As the tire is already stressed outside of spec; damage to the wheel is more than likely to result (not to be confused with the tire). Normal blow out allows for material sacrifice to save the wheel. This is of course dependent upon the amount of stretch on the tire. The closer the stretch is to stock spec the more material will be available to sacrifice in maintaining the wheel.

Obviously this is a reference to driving within the laws of the road you're traveling on, not assuming some sweet jdm drift battle on the mountain with a bunch of morons trying to get youtube footage with thier friends in the car.

I also found this one (and a couple others of different particle mesh size) but no mechanical properties are listed.
http://www.matweb.com/search/DataShe...0718874&ckck=1

I didn't see a way to post it here that would be easy to read so I separated the fields using astrix..


Would you mind explaining what the "elongation at break" field means? It seems at a glance that it would mean that it can stretch 1-8x its length before breaking... that seems like a HUGE range.

Elongation at break is the elongation of the material at catastrophic failure during a tensile test. During material testing they install a test piece similar in design to these:

Elongation is the final distance (if given in percentage the final distance divided by the original) the sample is able to make it. This is not the same as failure (encroachment into plastic region of deformation).

[sofaking]

With Rotary's point Tanner's car has a NASCAR V8 under the hood. That thing has so much torque he has to jam the widest tires he can on it to have a possibility of control, not to mention the whole "purpose built race car" thing.

Look at the guys like Mad Mike Whiddett, or Matt Powers if you want to see the "style" stuff. The guys in there with big sponsors that don't wrench on thier own cars aren't the guys that everyone shows up to watch. The guys we want to see and are cheering for are the guys with blood sweat and tears into thier car. The sport would fail if it weren't for the little guys that are still about style in my opinion. The whole sport is based on style, cars like Sam Hubinette's Dodge Challenger look like sore thumbs. If you spend NO time working on style and everything on engineering the best car in a series based on style no one will root for you. Sure he's a good driver, but I can see a car like at the dealership. Big MEH, not interesting to look at, watch, and doesn't draw you in. At least Tanner's car is widebody and some cool engineering went into converting it to RWD. It's not all about the tire stretch, it's just one of many factors of style.

[Rotary no Densetsu]

Sam's car is kinda ugly yeah, but he's cool as fuck.

So I forgive him.

[josh18_2k]

im no expert here, but is it really the rubber thats going to fail?
i would expect failure either from the bead unseating or bands in the sidewall breaking. thats kinda the point of the bands, to hold the rubber together...

this whole 'preoperties or rubber' argument seems pretty pointless considering theres much more than that to a tire.

[vex]

Originally Posted by josh18_2k

im no expert here, but is it really the rubber thats going to fail?
i would expect failure either from the bead unseating or bands in the sidewall breaking. thats kinda the point of the bands, to hold the rubber together...

this whole 'preoperties or rubber' argument seems pretty pointless considering theres much more than that to a tire.

Unfortunately there isn't anyone to my knowledge that would be able to engage in those mathematics out of the box. Hence why I'm taking it piece by piece. Understanding FBD's, application of appropriate formula, etc, before getting into something like this:

http://resources.metapress.com/pdf-p...4&size=largest