Discussion in 'Fiesta ST Autocross' started by Mister_Mino, Jan 6, 2015.
Care to expand on why? I'm still debating on the ZII* and the RE-71R.
I'm a big fan of buzz & hype and it has both, lol! Also, Bridgestone offers contingency where Dunlop doesn't. Chances are small at a podium but I can put go faster stickers on my car...
Yeah I've been reading a lot about them on the SCCA forums. Just wish Bridgestones made them in 225/45-16 then it would be a no brainer.
For me it is as simple as available sizes...I do not want to run a 225 on a 7" wheel. I have autocrossed on street tires for enough years to know what I prefer. We will know more after Spring Nationals in Lincoln, but I believe I will have the 205/45/16s on at the Championship in September. The Rival-S may have addressed the lack of grip on OPR covered concrete, and I do like the RS3s, so I am not completely convinced just yet.
The 215/45 16 Rival S is tempting too.
Note that with both on 7" wide wheels, the 205/50 Bridgestone and 225/45 Z2*S are within 0.1" in width. In other words, the Bridgestone runs WIDE for it's size
Top is the Z2*S, bottom is the RE71R
With RE71Rs running wide I'm wondering about how well 215/45/17s will work. I know folks had issues with the Rivals in that size (though we did not with the ZIIs).
And wow, those Rival S sizes. Maybe the 245?
I am glad we have people running some other combinations...hoping this year we will really start to figure out the optimal set up(s)
If the RE71R is running that wide, I make pick up a set of those in the 205 as well just to have as an option.
The Rival S is getting tempting as well and could be fast.
But I'm not one to follow hype....look at how similar the Z2 and 71R look to each other.
I am the Stock Suspension set up guinea pig. Lol
Yeah you were bone stock just with kooks as tires correct?
Tires change so rapidly and they are all "good" in their own ways, it more comes down to what you're comfortable with. My driving is going to hurt way more than a bad "good" tire, lol.
Well I look at it this way....more options for tires makes more competition which could in turn make every tire better.
Yes. I do hope to test swapping wheels and tires with a driver here who has an aftermarket (I don't know which) fsb and single adjustable konis. We will be doing so to test tires, but I am also curious how much time I might be able to pick up, if any.
I may just have to cave and buy another set of 16's so I can have the RE-71R's and the Rival S for Spring Nationals.
You know I think the bottom is the dunlop...I say that because there is a "tread" connected to the center groove...similar to the ones in this picture. But the design is so close.
Edit: I had to remove some of the tables as they did not copy and paste well. I bold the section width (1st number) and tread width (2nd number). Rim width tested is the number prior to the section width.
Interesting that the sect width and tread width are listed as larger for the 195/55R16 on a 6" rim @ 8.4"/7" than the 205/50R16 using a 6.5" @ 8.4"/6.6". I gotta wonder if that is a typo. The 205/45R16 looks to be too short with our gearing to me.
86V SL200 A A1168 lbs. 51 psi 8/32" 21 lbs.5.5-7.5" 6.5" 8.4" 7" 23.1" 901 JP
87V SL200 A A1201 lbs. 51 psi 8/32" 22 lbs.5.5-7" 6" 7.9" 7.2" 24.4" 853 JP
87W XL200 A A1201 lbs. 8/32" 22 lbs.6.5-7.5" 7" 8.1" 23.2" 897 Country of Origin "JP" = JAPANJP
87V SL200 A A1201 lbs. 51 psi 8/32" 21 lbs.5.5-7.5" 6.5" 8.4" 6.6" 24.1" 865 JP
89W SL200 A A1279 lbs. 51 psi 9/32" 23 lbs.7-0" 7.5" 8.9" 8.5" 23.9" 873 JP
87W SL200 A A1201 lbs. 51 psi 8.8/32" 22 lbs.7-8" 7" 8.4" 7.9" 24.6" 843 KR
The measured rim widths above are different but the Dunlop should be wider even on the same rim from my experience. I have both tires mounted so I stacked the full set side by side (the easiest way I have found to see the difference as it starts to magnify when times by 4).
The difference visually...
My rough measurement says around 1.5" for the set in favor of the Z2*
Ed, any chance you could please do the same with a set when you get the 16" RE71R with the Dunlop side by side?
Goes to show that even tires of the same design do not compare apples to apples to different sizes. The 45, being a "smaller" tire is listed as a pound heavier than the 50. Why? lol
I'm willing to guess that the size stamped on the side is just as liberal as the tread wear ratings, what ever they feel like putting on there.
Stamped sizes aside and actual tread width aside, I think the RE-71Rs will be faster against the Star Spec. Just a hunch though...
Trevor, I am sure the extra 3mph would be missed on a handful of courses, but I don't think the 225 is the best for me. I'll be glad to see results from the Rival-S, as the 215/45/16 may be perfect for me.
I'll get more pictures soon.
Note for section width, rim width is CRITICAL in it. And both Dunlop and Bridgestone are essentially playing a bit of game here . Per TR, a 0.5" change in rim width results in a roughly 0.2" change in section width. So for the RE71R numbers, ADD 0.2" to section width (since they list on a 6.5" rim) while for Dunlop SUBTRACT 0.2" (since they list on 7.5" rim) to get the 7.0" rim numbers.
Do that, and it matches very closely to what I measured (i.e. works out to 8.6" for the 205/50R15 or 205/50R16 on the RE71R, 8.7" for the 225/45R16 on the Z2SS)
No picture yet (still uploading), but I took a picture this morning of the 4 205/50R15s stacked next to the 4 205/50R16s when I dropped all 8 off for balancing. All 8 are on 7.0" rims and inflated to 40 PSI. The 16s are BARELY wider than the 15s, but it is less than 0.1" per tire.
Good catch on the tread pattern pictures...stand corrected, top tire is the RE71R and bottom is the Z2SS.
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