225/45/15 BFG g-Force Rival
04-16-2013, 01:05 PM
#102
BFG Rival first impressions on track
We had the chance to run the 225/45/15 Rival on Buttonwillow 13CW last Sunday. Car was our 95R street project car. Xida 700/400, 15x9's, 140whp, 2550# (with passengers all day). Ambient was 75~85° with track surface temps of 93~106°. We have run this car with RS3's on several different tracks and weather conditions. Very familiar with min corner speeds, braking points and overall feel of the RS3 on 13CW in particular. No A/B testing done against the RS3's Sunday but some impressions stood out.
Lateral grip
SOTP, the Rival seems to generate about the same peak lateral grip as the RS3. The difference was that the Rival would still generate useful grip when well past optimum slip angle. More like a race tire than the RS3 which prefers small slip angle and loses grip more rapidly with large slip angles. This made the Rival easier to drive and allowed a few "toss and catch" entries into double apex turns that were a touch faster than the slight lift the RS3 required in the same spot. This ability to generate useful grip at large slip angles made them feel more like race tires than any other feature.
Steering
Response and feedback were, like the RS3, very good when the tire was lightly loaded as it would be entering a turn at full throttle. The noticeable difference was under straight line or heavy trail braking where the Rival communicated available grip and slip angle much better than the RS3. The RS3's can get a little numb under heavy trail braking. So unloaded they steered about the same. Transfer weight onto the nose and the Rivals talked more. Overall I would rate the steering response and feedback as very good.
Braking
This is where the Rival is significantly different than the RS3. The RS3 has earned a reputation as a tire with braking that does not quite match is stellar lateral grip. The Rival had noticeable better braking grip and feedback compared to the RS3. Of note is the RS3's characteristic of requiring the driver to transfer weight onto the nose more carefully while the same car/driver on Rivals could reach peak line pressure much sooner without locking.
Temp range
Since we were not conducting A/B testing that day, data collected was minimal. Peak temps were only in the low 170's even after a full session. We did see that the Rivals lap times stayed consistent even after several laps at full speed. This is rare for a street tire. Most street tires have slightly heavier casings and more tread mass than a race tire so they tend to not shed heat as well as a race tire. This typically manifests as the street tire being fastest on it's first hot lap. While there was some drop off late in the session it was less than .6s on a 2:05 course. This is excellent for a full tread tire. The indication here is that the tire sheds excess heat very well, possibly better than most other tires in this category. My guess is that autocrossers with a co-driver will fare better than solo drivers on this tire. We did not run the tire in the morning while it was still cold so I can't comment on cold performance. We ended up with about 35psi hot which compares to 29~34 psi we usually run with R compound tires.
Overall, the RS3 feels like a really fast street tire, having a narrower range of optimum slip angle and weaker braking than a true R compound. The Rival in contrast, felt quite a bit like an NT01 (R compound) with about 5 heat cycles on them. An educated guess is that the 225/45 Rival would be less than 1s slower than a 225/45 NT01 on a ~2:00 road course, everything else being qual. That is just astonishing to this driver. A 200 treadwear (grain of salt) that can nearly keep up with medium compound race tires for a full track session.
Lateral grip
SOTP, the Rival seems to generate about the same peak lateral grip as the RS3. The difference was that the Rival would still generate useful grip when well past optimum slip angle. More like a race tire than the RS3 which prefers small slip angle and loses grip more rapidly with large slip angles. This made the Rival easier to drive and allowed a few "toss and catch" entries into double apex turns that were a touch faster than the slight lift the RS3 required in the same spot. This ability to generate useful grip at large slip angles made them feel more like race tires than any other feature.
Steering
Response and feedback were, like the RS3, very good when the tire was lightly loaded as it would be entering a turn at full throttle. The noticeable difference was under straight line or heavy trail braking where the Rival communicated available grip and slip angle much better than the RS3. The RS3's can get a little numb under heavy trail braking. So unloaded they steered about the same. Transfer weight onto the nose and the Rivals talked more. Overall I would rate the steering response and feedback as very good.
Braking
This is where the Rival is significantly different than the RS3. The RS3 has earned a reputation as a tire with braking that does not quite match is stellar lateral grip. The Rival had noticeable better braking grip and feedback compared to the RS3. Of note is the RS3's characteristic of requiring the driver to transfer weight onto the nose more carefully while the same car/driver on Rivals could reach peak line pressure much sooner without locking.
Temp range
Since we were not conducting A/B testing that day, data collected was minimal. Peak temps were only in the low 170's even after a full session. We did see that the Rivals lap times stayed consistent even after several laps at full speed. This is rare for a street tire. Most street tires have slightly heavier casings and more tread mass than a race tire so they tend to not shed heat as well as a race tire. This typically manifests as the street tire being fastest on it's first hot lap. While there was some drop off late in the session it was less than .6s on a 2:05 course. This is excellent for a full tread tire. The indication here is that the tire sheds excess heat very well, possibly better than most other tires in this category. My guess is that autocrossers with a co-driver will fare better than solo drivers on this tire. We did not run the tire in the morning while it was still cold so I can't comment on cold performance. We ended up with about 35psi hot which compares to 29~34 psi we usually run with R compound tires.
Overall, the RS3 feels like a really fast street tire, having a narrower range of optimum slip angle and weaker braking than a true R compound. The Rival in contrast, felt quite a bit like an NT01 (R compound) with about 5 heat cycles on them. An educated guess is that the 225/45 Rival would be less than 1s slower than a 225/45 NT01 on a ~2:00 road course, everything else being qual. That is just astonishing to this driver. A 200 treadwear (grain of salt) that can nearly keep up with medium compound race tires for a full track session.
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04-16-2013, 02:22 PM
#104
No matter how fast street tires get, NASA rules still favor Hoosiers. No other 3pt mod is worth as much gain as the jump from NT01's to R6's. My opinion? R6's should be 15pt tires, and A6's 18 pts. That is how many points it would take in aero, weight or suspension to match the gain. Of course, that ain't happening so everyone will still run Hoosiers when it counts.
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04-16-2013, 02:27 PM
#105
Overall, the RS3 feels like a really fast street tire, having a narrower range of optimum slip angle and weaker braking than a true R compound. The Rival in contrast, felt quite a bit like an NT01 (R compound) with about 5 heat cycles on them. An educated guess is that the 225/45 Rival would be less than 1s slower than a 225/45 NT01 on a ~2:00 road course, everything else being qual. That is just astonishing to this driver. A 200 treadwear (grain of salt) that can nearly keep up with medium compound race tires for a full track session.
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04-16-2013, 02:40 PM
#106
Blasphemy
BUT the BFG R1 is faster than the R6, and the R1S is faster than the A6.
How could you possibly suggest that the Hoosier be the same points as the BFGs, or MORE.
I tend to agree, the rules favor R-compounds (and Hoosiers specifically) which unfortunately means if you want to be truly competitive you have to run Hoosiers. For those that cannot afford to pay for A6s they are at a competitive disadvantage. Which has been the case in club racing for ever and ever. PT and TT was supposed to change that, at least in theory...
The PT tire rules also tend to favor light-weight cars but anywho, I digress
BUT the BFG R1 is faster than the R6, and the R1S is faster than the A6.
How could you possibly suggest that the Hoosier be the same points as the BFGs, or MORE.
I tend to agree, the rules favor R-compounds (and Hoosiers specifically) which unfortunately means if you want to be truly competitive you have to run Hoosiers. For those that cannot afford to pay for A6s they are at a competitive disadvantage. Which has been the case in club racing for ever and ever. PT and TT was supposed to change that, at least in theory...
The PT tire rules also tend to favor light-weight cars but anywho, I digress
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04-16-2013, 03:56 PM
#107
I am stoked about having two seriously quick tires available for the 200+TW street tire category. We should be running a set of 225/45/15 in the new 200TW RS3's and Rivals in June at our chump race.
Initial reviews is that they wear well, but who knows how they start to drop off once starting to get worn. At TWS, the Star Spec seems to be a 12-14 hour tire, RS3 seems to be a little less at 10-12 hour. Hopefully it will fall in the range of the Star Spec, but we shall see.
Initial reviews is that they wear well, but who knows how they start to drop off once starting to get worn. At TWS, the Star Spec seems to be a 12-14 hour tire, RS3 seems to be a little less at 10-12 hour. Hopefully it will fall in the range of the Star Spec, but we shall see.
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04-21-2013, 07:10 PM
#108
Raced on them today.
I really liked them.
I have been about 2~3 seconds behind some of my friends with a 15x8 and a 205 re-11
I closed the gap today. 3 tenths of a second behind someone in my class (I came in 2nd) and ~. 7 tenths behind another guy with a turbo miata in a different class. (although i'm sure a lot of it was going to a 15x9 and a 225). Looking at the event as a whole event only about 5 or 6 cars were not in reach.
I cant wait to see what they will do when i get new endlinks and play with the camber.
currently
1.8 front
1.6 rear.
crappy cell pic.
I really liked them.
I have been about 2~3 seconds behind some of my friends with a 15x8 and a 205 re-11
I closed the gap today. 3 tenths of a second behind someone in my class (I came in 2nd) and ~. 7 tenths behind another guy with a turbo miata in a different class. (although i'm sure a lot of it was going to a 15x9 and a 225). Looking at the event as a whole event only about 5 or 6 cars were not in reach.
I cant wait to see what they will do when i get new endlinks and play with the camber.
currently
1.8 front
1.6 rear.
crappy cell pic.
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04-22-2013, 09:47 PM
#109
Emilio's post is pretty much exactly what the local STS hotshoe said about it (but in regards to the Direzza Z2), especially the comments about the tire liking big amounts of slip angle.
I think that the Z2s still have the potential to be quicker than the Rivals; however, good ******* luck getting that one perfect lap. When my R-S3s are toast, I'm looking forward to picking up some Rivals.
Thanks, Emilio.
I think that the Z2s still have the potential to be quicker than the Rivals; however, good ******* luck getting that one perfect lap. When my R-S3s are toast, I'm looking forward to picking up some Rivals.
Thanks, Emilio.
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Can't wait!
04-25-2013, 06:40 PM
#111
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We had them on the camber challenged lemons e30. Great tires, you can definitely recover easier with these compared to rs3 if you upset the car. I didn't hear as much squealing as was talked about by everyone else. Maybe that is because it was pretty cold the whole weekend, I think the high was 55F, it was snowing a little on Friday and Saturday.
Developed this tread splice on one of the tires but it didn't seem to affect it. From what I've read BFG says not to worry about it.
Developed this tread splice on one of the tires but it didn't seem to affect it. From what I've read BFG says not to worry about it.
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