: Sidewall stiffness



Luna.
03-10-06, 03:03 PM
I've been reviewing a lot of tire threads on this board, but I can't seem to find many threads that talk about sidewall stiffness.

What tire on the market, not considering a run-flat, is generally regarded as having the stiffest sidewall? The Falken Azenis RT615?

Dreamin
03-10-06, 05:29 PM
Manage your ride stiffness with springs and shocks (i.e. FG2's and GC coilovers)... not tire sidewalls.

But to answer your question Michelin PS2 are pretty stiff... but still not as stiff as the stock RF's. I've never tried the Falkens.

RobzBLKV
03-10-06, 05:47 PM
Falkin's are supposed to be pretty stiff, but I have no experience. I switched from Bridgestone Re750s to PS2s once, and I thought the Bridgestone's side walls were significantly stiffer. The SO3s are stiffer yet.

But I don't think it matters much on this car. Nothing will be as stiff as the oem tires were (at least I doubt it), but the car feels a ton better with decent tires on it.

Luna.
03-10-06, 10:09 PM
Manage your ride stiffness with springs and shocks (i.e. FG2's and GC coilovers)... not tire sidewalls.


Totally agree. The sway bar kit is coming...:)

Further, I anticipate the FG2s in my near future. Hey--a group buy for FG2s could be a serious one!!!

However, tire sidewall stiffness plays a role in my mind. I experienced the exact same problem in my '97 Z28 Camaro that was cured when I went to a stiffer sidewall. As much as I loathe the run-craps for tire wear, they were superb in terms of handling...

DILLIGAF
03-10-06, 10:25 PM
I have the falkins,they are a very stiff sidewall tire.No track days here,just beating on the tires.I can't tell a difference in cornering.The falkins stick better in the cold than the runcraps.Mounting the tires is tough due to the sidewall stiffness,just as bad as the runcraps.You can not roll these suckers on their sidewalls.I'm going to buy a couple more because the rears are smoking fast.I have wanted to do smokey burnouts with this car and just couldn't with the runcraps.With the falkins=no problems

Luna.
03-10-06, 10:27 PM
How do the Falkens do in terms of tread wear? Are they expected to last as long as the run-craps?

DILLIGAF
03-10-06, 10:48 PM
How do the Falkens do in terms of tread wear? Are they expected to last as long as the run-craps?
To tell you the truth,I don't care,160 a piece.I had some trouble with my dealer balancing the tires,I went to a tire shop that specializes in rims and tires=bling bling crap.They sell falkins and hadn't seen the 615s yet,they loved them.They were pissed they didn't have them in the showroom.My first set of runcraps lasted 15000 miles,second set 9000 miles.Falkins are the real deal,I always buy the name brand shit and decided to try these tires for a change.I will buy more,and more,and more at 160 apiece.If I get 5000 miles out of them i'm pumped,I went 5000 miles on the runcraps on the wear bars sliding all over the fn road.No brainer,falkins good rubber to beat on.I can get three of these tires for one runcrap and I can't tell a difference in handeling.Only difference,wheelhop 85% gone and way better ride.Sorry for the long post:alchi:

thebigjimsho
03-12-06, 03:27 AM
Manage your ride stiffness with springs and shocks (i.e. FG2's and GC coilovers)... not tire sidewalls.

But to answer your question Michelin PS2 are pretty stiff... but still not as stiff as the stock RF's. I've never tried the Falkens.I need to disagree, or clarify, on this topic.

The problem is, when enhancing handling, one usually increases stiffness. Whther it's springs, shocks, sway bars, wider wheels, it's usually to get max handling. Just like some sway bar endlinks are snapping, there is increased stress on these components.

I found that on my SHO once I installed Koni struts, Eibach springs, wider wheels, bigger sway bars and poly-eurethaned every bushing I had, I was: 1)Snapping endlinks like crazy, and 2)Putting more stress on the tires. Havin a stiffer sidewall at this point was important. With all that stiffening, a soft sidewall made the SHO feel very squidgy, much more so than when the car was stock.

I think that, with our taut stock suspension, adding FG2s and bigger sway bars will increase the need for keeping stiff sidewalls, more than a stock suspension would need. Add the fact that we have an undertired, 3850 lb sedan, tuned with runflats, means that sidewall stiffness is pretty crucial. With less flex throughout, all that energy will buckle under soft sidewalls.

Kind of like the theory, a chain is only as strong as its weakest link.

Dreamin
03-12-06, 03:55 PM
...very valid points...

My point to Luna was... dont change tires and ignore the suspension... you'll only get a harsh ride - and that's it (perhaps better turn in response - but you can manage that with alignment). Sidewall stiffness is maybe 2% of the handling equation... I dont think the "softness" in ride Luna is unhappy with (he's posted a few times about it) is his tires... i think he'd be happier with more suspension.

Also i am assuming "within the same class of tire"... (i.e. within "max performance" tires). Obviously the GS-DS3 sidewall is softer than the stock RF sidewall, but within the 'max perf' non-RF class for tire... between GS-DS3, S03, PS2, the sidewall stiffness will vary maybe a few percentage points... again most bang for the buck is suspension upgrades.

FWIW, my GS-DS3's dont feel 'squishy' to me... and i'm running 500/550lbs springs, and just installed the hotchkis bars.

Of course if you're running all-season tires... you want to get better rubber on before suspension.

Luna.
03-12-06, 04:07 PM
My point to Luna was... dont change tires and ignore the suspension... you'll only get a harsh ride - and that's it (perhaps better turn in response - but you can manage that with alignment). Sidewall stiffness is maybe 2% of the handling equation... I dont think the "softness" in ride Luna is unhappy with (he's posted a few times about it) is his tires... i think he'd be happier with more suspension.


I would never presume to debate you animalistic handling gurus... :)

All I can say is that with all things equal (no suspension upgrades), I can easily feel the difference between the GSD3s vs. the stock run-craps. That turned me onto sidewall stiffness. I had a similar issue with my '97 Z28 Camaro.

The GSD3s are definitely great tires. I have always just liked a ride that is firm as hell, probably much firmer than most anyone would prefer. As such, the mods are incoming... :)

ace996
03-12-06, 06:29 PM
...very valid points...

My point to Luna was... dont change tires and ignore the suspension... you'll only get a harsh ride - and that's it (perhaps better turn in response - but you can manage that with alignment). Sidewall stiffness is maybe 2% of the handling equation... I dont think the "softness" in ride Luna is unhappy with (he's posted a few times about it) is his tires... i think he'd be happier with more suspension.

Also i am assuming "within the same class of tire"... (i.e. within "max performance" tires). Obviously the GS-DS3 sidewall is softer than the stock RF sidewall, but within the 'max perf' non-RF class for tire... between GS-DS3, S03, PS2, the sidewall stiffness will vary maybe a few percentage points... again most bang for the buck is suspension upgrades.

FWIW, my GS-DS3's dont feel 'squishy' to me... and i'm running 500/550lbs springs, and just installed the hotchkis bars.

Of course if you're running all-season tires... you want to get better rubber on before suspension.

All good points, and I usually agree with the majority of what you post...but I disagree on the sidewall issue. I'm not looking to be arguementative, just add a different perspective. As with any stock vehicle that is designed and spec'd with runflats, the V very much needs a stiff sidewall. This is a result of the matched stock suspension parts and weight of the vehicle.

First, I'll address the weight. Taking a realistic weight of 4000lbs, as it sits on the road, the stock sized tires having that stiffness is mandatory. Rolling the V through twisties places a great deal of stress on the tire's sidewall. The runflats are quite adept at handling the rolled-weight and resisting roll-over. The sidewalls also help resist the rim from making contact with the road when a bump or pothole is encountered. If there was a wider tire mounted, with more load-carrying air inside it, perhaps the need for wooden-sidewalls would be redundant. As far as I recall, I don't remember hearing anyone ever blistering a tire or bending a rim with the runflats...

Second, the suspension can be seen as many parts...with the tire being a very important component. The bushings, the springs, the shocks, the roll-bars all contribute to the measured "spring-rate" at the hub. When a tire is added to this equation, the sidewall stiffness is an integral component that can change the overall "wheel-rate" quite significantly...to the point of the vehicle "feeling" as if it had more done to it than just a tire swap. Without a doubt, the F1EMTs add quite a bit of "wheel-rate" that would need to be addressed if one were to spec a different tire. To keep the same "wheel-rate", one would need to increase the "spring-rate".
This Saturday, I just re-mounted my stock F1s and retired the Kumho ASXs that were my winter tires. The "feel" of the F1s are more immediate, with much sharper turn-in, and a measurable resistance to the "roll" that I was experiencing with the Kumhos. It feels as if I did add stiffening springs, and the handling is much improved.

Now if someone was just driving on the street, not autoxing or tracking their car, the difference would not be "huge" but more of a polished "softening" of the characteristics of the vehicle. But when I switched between the "stock" tires of my Spyder to the Falken Azenis 215s, the additional sidewall stiffness was a major change and I actually needed to soften my shocks to keep the same compliance...they made that much of a difference.

For most, it won't be a big deal. For some, its the difference between loving the handling characteristics of a car or getting put to sleep by it. The tire is the one component of the vehicle that interacts with the road. I've always believed it to be the most important part, as even a basic switch to R-compound tires will allow a vehicle to outhandle one with substantial suspension upgrades.

As Dreamin said, within the top-tier of MaxPerformance tires the differences are very small and it would take a very discerning driver to be able to tell the difference between them. Sidewall stiffness is probably the most discernable feature, though.

-ace

trukk
03-13-06, 01:20 PM
I would never presume to debate you animalistic handling gurus... :)

All I can say is that with all things equal (no suspension upgrades), I can easily feel the difference between the GSD3s vs. the stock run-craps. That turned me onto sidewall stiffness. I had a similar issue with my '97 Z28 Camaro.

The GSD3s are definitely great tires. I have always just liked a ride that is firm as hell, probably much firmer than most anyone would prefer. As such, the mods are incoming... :)

For what it's worth, I agree %100 with your post Luna.

I went from the F1 EMT's to the F1 GSD-3's (albeit I did go to 275/40's out back). I could tell a definate difference. I expect half of it may be the larger tire size, but the other, is most certainly the sidewall stiffness. The stock EMT's are really an amazing tire. If the rear-end set up on our cars wasn't so FUBAR'd, I think these tires would get a much better rep.

I also like my ride firm as hell. I plan on updating my suspension at one point. It may or may not be this summer, depending on how the 'early apodpters' do with the new products. I currently have FG2, and would like to couple that with stiffer springs (I'm hoping the GC product is the answer). Perhaps addding stiffer sway bars in the process. I'd like the car a bit lower (perhaps 3/4"), and would prefer to stay with the 275's in the back ( I'm enjoying having a bit of oversteer.)

Anyway, great thread. ACE, Dreamin, WW et al, please keep us in the loop on your suspension mods :D

-Chris

Luna.
03-13-06, 01:52 PM
For what it's worth, I agree %100 with your post Luna.

Thanks!! :worship: :)


If the rear-end set up on our cars wasn't so FUBAR'd, I think these tires would get a much better rep.

And if they lasted more than ~10k miles...and weren't so stinkingly expensive... :)


Anyway, great thread. ACE, Dreamin, WW et al, please keep us in the loop on your suspension mods :D
-Chris

:yeah:

I anticipate that I will get the Hotchkis bars installed before I change out the tires, so I will be able to get an idea of how much those will help...

Luna.
03-14-06, 03:30 PM
To tell you the truth,I don't care,160 a piece.I had some trouble with my dealer balancing the tires,I went to a tire shop that specializes in rims and tires=bling bling crap.They sell falkins and hadn't seen the 615s yet,they loved them.They were pissed they didn't have them in the showroom.My first set of runcraps lasted 15000 miles,second set 9000 miles.Falkins are the real deal,I always buy the name brand shit and decided to try these tires for a change.I will buy more,and more,and more at 160 apiece.If I get 5000 miles out of them i'm pumped,I went 5000 miles on the runcraps on the wear bars sliding all over the fn road.No brainer,falkins good rubber to beat on.I can get three of these tires for one runcrap and I can't tell a difference in handeling.Only difference,wheelhop 85% gone and way better ride.Sorry for the long post:alchi:

Where are you getting the Falken Azenis RT615 for $160 a piece? Please let me know. :)

Dreamin
03-16-06, 12:59 AM
http://www.edgeracing.com/tires/2554018/

Luna.
03-16-06, 12:38 PM
http://www.edgeracing.com/tires/2554018/

Nice Dreamy!!! :worship: