Discussion in 'Fiesta ST Autocross' started by Mister_Mino, Jan 6, 2015.
I love the way you look at tires as a tool and not as a solution.
**Stacked Set of 4** - Difference between 215/45R16 Rival S (left) vs 215/45R17 RE71R (right)
I've been poking my finger nail into both as well. At 40'ish degrees, the RE71R definitely feels softer. As temp increases to the 70'ish degree range, for me, the tires are difficult to tell apart.
Figure on about that stack height difference for a set of 4, but with the RE71R taller, for the 205/50R16 RE71R.
In other words, pretty close for all
Really makes you wonder how companies measure the width as the 225/215/205s are all almost exactly the same! Seems almost as messed up as the 200tw "rating"
I was aware it varied between manufacturers and even between models of tire for the same manufacturer. However, Ed's and my information is definitely interesting with regard to the 205/50R16 and 215/45R17 RE71R. It seems the 205 is wider than the 215 even though the 215 should be wider on the same width rim. I wonder if the 205/45R17 is wider than the 215/45R17 too
I hoped the new Z2 SS wouldn't do this....but the blue is back
Most tires due this from heat. Tires exposed to the sun often do. Minerals can also cause it. Check out Google and all the off road guys mentioning it after they go mudding.
Yeah, I wouldn't worry about it.
Interesting, as I don't think my Z2SS are doing the blue-ing much. I'll try and remember to look more closely this weekend.
Note : remove those Sparco centercaps while racing. They'll get hot and start melting. Ask me how I know
Thanks for the heads up on the center caps Ed! I wonder if the centering rings are going to be a concern too?
You can get aluminum center rings. The plastic will melt. Pretty cheap from many online places. I would use a thin film of anti-seize on the ring, just be careful not to get it anywhere else (brakes etc...).
I'll update the results thread when they're posted, but additional RE71 data point from today's NWR event: They handle cold (low 40s for first runs) about as well as the Dunlop, which is good, and they handled two drivers really well. They got warm enough to where I would have sprayed them, if they had been Dunlops, but they felt fine.
The tire -- a 215/45/17 -- seemed to like less pressure rather than more. The fastest runs and best feel came when the tire was showing a bit of rollover wear.
Was about to note, I went ahead and got a set of the centering rings in aluminum. No issues so far with them.
Tire testing yesterday at a PCA event at Marina (concrete, known as a decent grip but pushy site) : 215/45R16 Rival S in the morning, 205/50R16 RE71R in the afternoon.
Ended up about 5 tenths faster on the RE71R (on a 38 second course). I also suspect my setup was "closer" on the RE71R than Rival S, and the Rival S would benefit more from additional heat cycle/scrub. Feel like I was pretty close on RE71R pressures (ended up at 35F/40R), wish I had tried a few PSI less in front on the Rival S (36F/40R)
Interestingly, the Rival S had a lot less wheelspin powering thru/out of sweeping turns DESPITE being the shorter tire. Not sure if that was indicative of more longitudinal grip OR less lateral grip (i.e. the RE71R had enough extra lateral grip that it was unloading the inside front tire more).
Hollis described the RE71R as "Z2SS + Moar" and Rival S as "R1R + Moar". I'd agree with that. The Rival S felt a bit vague but you know it'll stick (which is a lot like the R1R on a ST Civic was like), while the RE71R felt a bit easier to "feel" what it was doing. Wear looked pretty reasonable on both tires.
So as the conclusion (for now) : as the car and this driver sits the RE71Rs seem a little better matched. Both tires are very good, which means it'll probably come down to setup and preference. This isn't a bad problem to have
Des : let's test some more on Friday at Crows
Ed, I am torn between the two tires and sizes you tested. Seems like the bulky shoulder of the Rival-S would wear better than the RE-71 but that does depend on the sidewalls of each brand. Also, I liked reading you likes the feel of the RE-71R even with the large sidewalls.
I appreciate you sharing that info and your suggestions.
I am aware of the aluminum centering rings but have never had a problem with the ones that Tire Rack has provided in recent years. They seem to handle heat really well. I never had an issue on the FoST even with the Hawk pads catching fire at the Solo Trials last Fall. I would be surprised if the FiST can generate more heat than the FoST. My OZ center caps look good as new too from the FoST and the rings, while stuck nicely to the rim, show no damage or deformity. It is likely more an issue of the Sparco rims not having center caps that are heat friendly.
Never had an issue with them sticking with the BRZ, FoST or FiST but I did have that experience years ago with the ones provided from Tire Rack that I was using on my Genesis Coupe.
I should have asked Ed, "Did you need to get aluminum centering rings due to problems with the those included by Tire Rack?"
I did the aluminum rings pre-emptively. ST Civic experience (no E-diff there, but TINY rotors = lotsa heat into the hub/wheel) is why.
Also ran aluminum ones on the Genesis Coupe with 18" RPF1s. Machined the 19" Rays so no rings needed (Nissan 66.3 out to Hyundai 67.1).
Thanks for the clarification Ed. It is good to know actual problem vs being proactive.
I did melt the sparco center rings at Laguna seca last year when I did a track day with stock equipment besides wheels and tires. But the plastic center rings held up, and I definitely got those suckers very hot as smoke was the pouring out after my first session, after that I did cool down laps in the parking lot to cool the brakes. I think if they can be melted it would have happened at LS.
Ha, I forgot to remove mine once, too. A single session at Streets of Willow melted one up front. Since I have two sets of Sparco wheels, I have plenty of spares -- I don't need any of them. Hit me up if you want some.
Thanks, I'm good. Due to the tire testing plus wheels being on clearance (i.e. cheap), I have 10 of the White 16x7 Sparco wheels right now. 4 centercaps melted on the backside, immediate took the other 6 out of the wheels.
Ironically the melted ones still look OK from the front and seem to hold in the wheels ok. But not pressing my luck
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