Alpine951

I got signed off last year to drive by myself in the next level of DE (Blue). When my instructor signed me off he said I could potentially jump into the level above soon (white). I drive on street tires and I was planning on staying with street tires for a while. i was also not trying to pursue moving into white yet. My 1986 951 has the stock suspension. I plan on upgrading over the winter. I had planned to get the suspension done and maybe after that pursue the next level. As i said my tires scream in the apex's. I know the line fairly well at the few tracks i curently drive at. I have heard some instructors say a screaming tire is a happy one. Even though i am driving solo, I plan to have some instructors ride with me on occassion to keep in line. If my tires are scraming in the turns then i am pushing it closer to the limit, which is a good thing, right? Just wondering what others think.


John

DCLee

Your street tires should pretty much be screaming all around the arc of the corner.

If the corner workers start screaming, on the other hand, you may be off-line...

Lee in D.C.

mdex

It depends on the tire... some make more noise then others. But if your tire is making noise or not is in no way indicative of how you are driving...

sjanes

John,

Depends on which end of the car is screaming. If it's just the fronts, it sounds like you are overdriving the entry to the corner and just plowing through it. If all 4 are making about the same amout of noise, then it sounds like you are at least balanced in the corner. Kinda hard to judge without being in the car.

Also, street tires make two very different noises that I refer to as "squealing" and "howling". A squealing tire is a happy tire that is closing in on it's limit. A howling tire has passed the limit and is just trying to grab whatever it can. This is the great thing about street tires, they give so much feedback.

John H

I have always been told your tires should be screaming the loudest at the apex.

DGaunt

The limit is the limit of the weakest link in the chain. This is usually tires on a P-Car running street rubber. Exceeding the limit of the tires beyond a "happy squeal" is just depositing expensive rubber on the track to no purpose. When the slip angle of a tire (the difference between where the tire is pointed VS where the car is going exceeds the optimum (8 degrees is a good median) the tire becomes and eraser and produces no additional lateral force. It just scrubs off speed converting energy into tire dust. If you insist on doing this for a whole run, you will eventually overheat the compound and the tires will "go away" becoming greasy.

Learning to drive at the limit includes knowing where the limit is for a given combination of hardware and tires and staying optimally close to it. Beating on your tires is not fast, it's just expensive. Upgrading your suspension this winter will probably highlight the shortcomings of the tires and force a decision.

JackOlsen

There's not much useful information you're going to get based on the noises your tires are making. All it means is that they're at -- or beyond -- the limits of adhesion. This could be good or bad, depending on how you're driving. You can throw your car all over the track, making lots of noise, and still be posting lousy laptimes.

Staying on street tires is a good idea, though (in my opinion). I still do virtually all of my track driving on BFGoodrich street tires, after four years of regular tracking. It forces me to work on being smooth, and also costs me a small fraction, over time, of what R-compounds would set me back.

Bob Rouleau

John (Alpine)

I can't add a lot. A car driven by a skilled driver on street tires will make the tires squeal. SJanes and others make the distinction of a "howl" which indicates you are overdriving the car and scrubbing off speed and rubber.
Jack O says (indirectly) that unless you are confident in your skills and consistency, staying with street tires is a good idea because (he didn't say but knows) R compound tires do not squeal until you are out of control. Unlike the street tires that give audible warning, the R compounds let go and slide without an audible (important word) warning. A driver sensitive to his car will "feel" the limit of adhesion and avoid the slide. Does this help? You've gotten good advice in the posts above, I just thought I'd try and clarify them a little.

Best,

JCP911S

Street tires are more forgiving and have a wider "breakaway" zone than R compounds. Some squeal is normal. Generally the squeal should start at turn in and increase steadily as you approach the apex as that is generally the point of maximum lateral accelleration.

That said, Sqeal doesn't really tell you all that much... more important is how the car responds to steering angle... as the tires approach their limit, the torque on the wheel will tend to lighten up... it is like the car is floating on the tires... at that point if you dial in more slip angle, the car will not change line much... all you are doing is scrubbing them.... try to train yourself to feel that point... that is where you want to be... the goal is to use the least amount of steering imput that will get you through the turn.... that is the breakaway point

I believe it is easier to find that point on streets as the speeds are slower and the breakaway zone wider. Once you get very comfortable with balancing the car at the breakaway point, it is then appropriate to try R compounds. They also have a breakaway zone, but it is much narrower, and you are going to be going alot faster.

IMHO students who move to R tires too soon have a hard time finding that zone on them. They can go pretty fast witout having to do that, and when the R tires do let go, it is much more abrupt, so they are lmore likely to spin.

The biggest downside to streets is that they retain heat, and are more likely to fade at the end of a session.... but that is also an important learning experience... just be aware of fade at the end of a session, learn how to detect it, and how to adjust to it.

JackOlsen

Bob says it better than me. Another way of seeing it is that street tires have less grip than better tires (I know, what a surprise), which allows you to learn better car control than if your tires are so good that they're basically carrying you around the track. The point of all of this is to 'make better drivers,' after all. Porsche already has the 'making better cars' part down pat.

Alpine951

A lot of great insight here. Thanks to all.

Jimbo951

I jumped to R compounds after 1 year (10 track days). In hindsight, I should have probably stayed w/ street tires longer, but I didn't. Part of the problem was my street tires that came with my car were quite old and were showing cracks between the blocks of the tire. I would not have driven with those tires a 2nd year.

My bigger mistake is I switched to Kumho V700's after 1 year, but i didn't re-do the suspension until after the 2nd year, hence I ran Kumho's on stock suspension for 1 year . I really chewed through tires due to uncontrolled/excess body roll. When I ran with too little camber, I scrubbed off the outside edge of the front outside tire, because all the turning forces were on the outside of that tire. When I put in more camber, I scubbed off the inside edge of the inside, front tire because that tire got dragged through the inside of the corner. Overall, it was not a happy year for tire management.

When I put on the stiffer suspensio, my tire woes went away.

RedlineMan

Alpine -

Some perspective. I had a student at Lime Rock a couple weeks ago with a 944S2. Leda fixed-damping coilovers, stiffer springs, lowered a bit. Toyo RA1s. He was a good mid-intermediate student, and we were lapping fairly quickly within the group. There was another kid there in Dad's S2. Bone stock on street tires. TWO whole days of track experience, and he was lapping 10-15 seconds faster than we were. Granted, his lines were not that crisp, but his car control was amazing. Frankly, I was stunned.

Granted, a lot of it was the driver. The kid is obviously a natural, college guy, no worries, while my guy was an early 40s father of two little-ens. But... !!!!

Point being, street tires CAN fly. It is often the search for a way to make them work that is the most important lesson. That, and the early and manageable breakaway that others have mentioned, are most helpful. Looking for ways to drive quickly without the grip to rightly do so is a very rewarding struggle. Those lessons learned at the edge of adhesion are key, will carry with you for a long time, but more importantly will stand you in good stead for any uprgrades.

I myself had come to the realization that I needed to sharpen my tools a bit if I wanted to progress. I have been on Rs for 8 years or so, drive very well geometrically, and quite quickly in general. Still, I knew there was more there, that I was the limiting factor, and I also knew I needed to have better amunition against that ever-looming high speed breakaway that was always just around the next apex.

The solution? OLD TIRES. I'm a pack rat, and can't stand to throw out tires with rubber left on them, no matter how hard they are. I've taken to dragging out all my old stones and running them to the max. I've been sliding all over the place. I've had to work on overcoming massive understeer, oversteer, 4-wheel-drift... you name it, I've had to work around it. It has been frustrating when I know I am just holding on when I could be flying on fresher rubber, but... you just screw your head back around and keep fighting.

Not only have I had a blast, but I can feel my confidence increasing. I work my butt off, but hear from spectators that the car was just floating, smooth as glass. I look at my tapes, and I'm right on top of the car, never giving it a chance to fly off the road.

I've raised my chops to the next level. I'm READY for more grip. BRING IT ON!

Good stuff for ANYONE, at ANY level!

tonytaylor

My previous car was a 944S2 which, IIRC, had the "turbo" suspension, which I believe to be way way to soft for track work. I'll wager your tyres are screaming due to excessive body roll.
I pretty much distroyed a perfectly good street tyre on my first track day in my 964, pretty much as a result of the thing just understeering everywhere. Prior to my next day I upgraded the suspension and tyre wear/screaming/understeer was much reduced. The change brought in other possibilities rather than just understeer.
Street tyres are fine upto the point they overheat when they become greasy and unpredictable and there is the problem of handling anomalies caused by differential tyre pressure increases.
I moved to MPSC after 6mths and don't regret it. They are designed for track work and don't chunk or melt and go greasy and the pressures remain stable and if they do slide all they want to do is grip; Slide on street tyres is more difficult to regain control of because they don't want to grip again. In short the MPSCs were more predictable.
I still run on street tyres in our damp conditions and if it starts to dry I can drive without trashing them but that's possibly due to being smoother and recognising their limitations - something I was less able at when I first started out. Sure, an experienced driver can go well on street tyres and appreciate their qualities but these were not as evident to me as a novice.

trumperZ06

I followed the "book" in learning car control. I started on "street tires", stock suspension settings and I was being passed by two buddies who modified their suspension and went to Hoosiers. They kept telling me I needed to go with Hoosiers and change alignment.

I stayed "bone stock" for about a year and concentrated on "smoothness" ! Then I went to a professional driving school and got educated!

Next I lowered the car and went with a race alignment... did this for another six months or so, and felt I was beginning to max the street tires.

So I went to DOT " R " tires and built up seat time and confidence.

My two Buddies are still on Hoosiers, they since have changed shocks, added some engine mods.... and they are still in intermediate group.

They are very fast... but also "loose" and are subject to the odd spin now & then! These guys are constantly "fiddling" with their alignment, tire pressure and complaining about their "tires".

Conclusion: for me... the "Book" was the proper way to learn! Ahh... I have been "instructing" for the past couple of years!