Stock Tires or Pilot Super Sport? Which to burn up?
 

I'm going to the track in a few months, Thunderhill and Laguna Seca. I'm buying Pilot Super Sports for the street as the original tires have worn through, but I have an extra set of stock wheels with the Primacys on them. Which should I burn up at the track? This'll be my 4th-6th track days. I'm actually tempted to AB them.

Never mind. I realized that I don't want track brake dust ruining my normal rims. I'll run the Primacys at the track. Lower grip just means lower speeds and more chances to learn. Then I can put slicks on when they're worn through.

I am sorry nobody else responded to this sooner

My advice given you are new to driving on track....run the stock tires...they are cheaper and have less grip which is a good thing while you are learning

I will advise better brake pads..I race in norcal and the stock brakes in my FRS (measured at 7mm last week) fade stupid fast... Especially with traction control on...why it works very well it cooks the brakes far too fast....

If I am driving "hard" I can get maybe 3 laps (7 min) before the fade forces me to drop pace....

Just kill off the OEM tires first. Believe it or not, the peak sustained Gs between the OEM primacy and MPSS are the same, so your apex speeds won't be significantly different between the two. I have datalogs to prove it.

Please don't jump to slicks from OEM/MPSS tires. Huge mistake.

I find the G's claim hard to believe. The car currently goes significantly faster in a turn without slipping in the rear and is far less tail happy on power. Why do you say no to slicks?

As for pads, I'm definitely going to get a set. Stock will absolutely not cut it, I'm beyond sure. People seem focused on Project Mu and Carbotech. I've talked to a couple vendors but haven't committed. I'd really prefer an endurance compound, I'm thinking. Maybe we can get PFC to bring the 06 or 08 pads to the twins?

I don't how to respond to that. I don't make stuff up. I'm a man of science and I've learned (particularly when it comes to forums) to only believe hard, solid, OBJECTIVE data. Butt dynos mean nothing.

I'm using the internal accelerometer on an AiM solo DL, which was calibrated and logging at a rate of 50Hz. Stock OEM primacy and MPSS both can hold sustained 0.9Gs and will start to break away at 1.0G on a stock setup. BFG Rivals will hold 1.1Gs and start to break away 1.2Gs. That is objective data. I'm rounding data up to the nearest tenth, so perhaps there could be a .05G difference between the 2, but it's not the huge difference you think it would be. If you have any objective data to share that would contradict my logs, I'm all ears. Otherwise, I don't buy into any subjective 'feel' data. I'm not the only one to have found that the OEM primacys grip better than we all would expect. I was surprised with the results myself. However, data doesn't lie. Subjectively, while the peak sustained Gs are the same, I did feel that the MPSS tires were more controllable upon breakaway than OEM primacy. Maybe that's what you were feeling.

Rookie mistake. If you're only interested going as fast as you can and you're out there to win a DE, sure. However it will hide your mistakes and you won't learn how to drive a car at the limit properly. EVERY single guy I've seen who jumps to slicks/semi-slicks before learning how to properly drive at the limits of a good street tire or even an DOT R compound is ultimately SLOWER than someone properly driving on a street tire. Happens EVERY time. Those guys never progress and are always stupid slow. Plus, they waste of ton of money on tires that only last 3 track days. I honestly only know of one guy that use real slicks at a DE. Semi-slicks like hankook z215 or Hoosier R6 I see more of. Your next tire should be something like an RS3 or BFG Rival (1.1-1.2G). Those tires grip plenty. NT01 (1.2-1.3G) would be the next up, followed by an R6 (1.4-1.5G).

I've been happy with project mu club racers. I actually like them better than the PFC08 I use on my Porsche. I like the initial bite on the Pmu CR better. Different braking systems and tires, though, so it's not apples to apples.

Okay.....#1 DO NOT FALL INTO THE MOD TRAP

want to know the single best way to go faster.................improve the DRIVER.... For about your 1st several track days you do not need any mods at all....maybe brake pads...thats it...then slowly mod the car as your ability exceeds the car

go to track days with quality instruction....you will improve by leaps and bounds, however I am concerned with your attitude about slicks....will the peak grip be higher...YES much higher....are slicks harder to control for novice drivers due to their lack of "communication" (think sound)...YES....street tires give you much more feedback, other than just steering wheel (front tires) and butt (rear tires)...the howling is helpful too....one thing the stock tires to is HOWL

The most I can get out of the stock tires is maybe 1.2g....my racer on slicks hits peaks of over 1.8g with sustained 1.5-6

the morale of the story is this....don't be in such a hurry to have the best track car possible then learn how to drive it.....that is a recipe for disaster....typically a wrecked car..... I learned SO much more driving Miata's than my much more powerful Porsche

Are RS3's loud enough for a beginner, with progressive enough sliding, or should I look at something else? My primacy's are starting to wear but I can't even drive them at the limit as is stock.

My ideal tire would be something that grips more than the primacys, but I can hear at the limit of adhesion, and that breaks away more progressively than the primacy's. Maybe I'm a little optimistic

I thought slicks would actually last longer on the track, being made for it and all. Clearly I'm not about going the fastest since I'm saying I'll use the stock tires on the track right now, and everything else is stock. With tires and pads, you have to buy them anyway, so there ya go.

As for MPSS = Primacy, I'm struggling with that still. Magazine test after magazine test have shown them faster. As for the butt dyno, cornering at speeds I've felt the end let go have led to nothing but grip on the MPSS. They turn in faster. They even grab rocks off the ground and throw them into the underside of the car. Perhaps you need to look at other parameters? Perhaps something was flawed in your methodology? Magazine tests have put the skidpad numbers for the OEM tires at about .9G. I'd hazard an intelligent guestimate of .95g on the MPSS. Can that be felt? Sure seems it to me. .05G. What does that feel like? Me weighing about 10lbs more. I'd feel that. My car having almost 150lbs more force pushing sideways on the tires.

More importantly, steady state G is not the only measure of a tire.

As far as data goes, the closest test I can find is:
http://www.caranddriver.com/comparis...va-ad08-page-8
and
http://www.caranddriver.com/comparis...-sport-page-10
and
http://www.edmunds.com/car-reviews/t...rack-test.html

That compares advan 08 to MPSS and then primacies to wider advan 08.

But in the end, I'm not here for the fastest track time. You guys might be. I'm here for fun. I want the car that feels the best. I want the car that makes me smile most. Track times? Well, that's cool and all, but not matter what I do, I will always be slow. I WILL ALWAYS BE SLOW. I want to have fun driving the car around the track. I'm no Parnelli Jones and, I'm guessing, neither are you guys. I don't care about being the fastest. I don't care if the tires cover up my mistakes. Hell, that sounds like a good deal to me. If they're covering my mistakes, I can have more fun with less chance of going off. I mean, did I somewhere say that I wanted the fastest track car possible? I think I specifically said I was choosing what I thought was the slower tire.

That said, in the real world, the MPSS are damn sticky. As for on the track, well, on the 550i, they got slippery darn quick, but that car weighed 4000lbs, and even though it had a lot more tire to take the heat, I doubt the FR-S can mistreat them so much.

And in the end, MPSS cost less than the stock tires. What? Yup.

No way. You're thinking brake pads. The stickier the tire, the quicker it wears out.

I'll give you my testing conditions and allow you to find confounding variables. In return, I'll decontruct your butt dyno:

1) same driver, 5 years of track experience, advance level driving.
2) same car with no confounding interval modifications
2) Numbers obtained with fresh tires OEM tires and MPSS tires with no heat cycling. I also have test numbers that are stable even after a couple of heat cycles. Excessive heat cycling is not a confounding factor here.
3) tires sizes OEM on OEM wheels. I am not using wider tires or wider wheels on MPSS
4) ambient temps were similar
5) dry track
6) test done on track with tires heated up to temperature.
7) objective testing equipment in working condition.

Let's take a look at your test and potential confounding variables:

1) placebo effect: Your data is completely subjective and is subject to the placebo effect. No different than the guy that just got a new intake or exhaust for his car, and thinks the car FLIES now. Then he dynoes the car and it makes 1-2 extra HP, some times less HP than stock. All within margin of error.
2) Confidence: somewhat along the lines of placebo, but since you are a novice driver, the more stable characteristics of the MPSS tire on breakaway and the placebo effect give you more confidence through the corners and the feeling of a higher apex speed. However, the oem tires could have carried the same apex speed if you had more confidence in them.
3) Did you do your butt dyno testing on the track with the tires warmed up? Testing on the street won't tell you anything since the tires won't be up to temperature. It's certainly possible that the MPSS grip better than OEM when the tires are cold.
4) Are your MPSS tires OEM 215 size? Are the wheels they are mounted on OEM width?
5) Were your OEM tires heat cycled out? How many track days and sessions on them vs MPSS when you did your test?

Motortrend did a test that proved the OEM tires were pretty good. They swapped to Bridgestone S04 tires with wider aftermarket wheels and were only 0.2 seconds faster on a 1:33 course. 0.2 seconds faster on wider wheels and tires is NOT an impressive difference.

[ame]http://youtu.be/FSqWD5BSeoY[/ame]

I'm not saying the OEM primacy and MPSS are identical. They do have different characteristics and the MPSS probably grip a little more, but the difference is SMALL.

Here is a 2:15 run I did on MPSS at thunderhill:
[ame="http://www.youtube.com/watch?v=eI08YWtfX3w&list=UUL-Rm-7D8xHVNA8Al7KmZtQ&feature=share&index=5"]2:15 lap time at Thunderhill in a Subaru BRZ - YouTube[/ame]

Thanks for sharing the data! Does your data show anything about longitudinal grip or the ability for a tire to multitask, i.e. braking or being able to get on the throttle sooner on exit?

RS3 or BFG rivals would be a good choice. However, if you are daily driving, they will not last as long and will not perform well in the rain, so keep that in mind. Otherwise, MPSS. Last longer and are cheaper than OEM. Grip isn't much better, but breakaway seems to be a bit more progressive. Other option is RE-11.

If you take a look at the G circle, that should give you the info you're looking for. Technically, longitudinal grip should be equal to lateral grip.

Sorry for going a bit off topic (but the rest of the thread is super helpful, as I practically had the same questions). But how exactly were you able to get two cameras synced + the data shown like that? It's such an amazing video - and great lap! The data you can keep track of is amazing, with throttle input, G's and even location on the track... super jealous!

I've been trying to figure out a setup before going to track and don't know which options are any good. Already have a smartphone + GoPro Hero 3+ BE...

David

Just got around to watching the video... ok ok ok enough about tires wanted to ask what your data acq setup is?:lol: