To R-Compound or not?
07-10-2004, 11:53 AM
#16
Addict
Rennlist Member
Rennlist Member
Hey;
I'm with Adam on braking performance, although the type of pad you are using does indeed play a BIG roll in this.
There is one point I might expand on.
If you have a car with just enough brakes for most cases - a 964C2 is a good example - then you might be fine with longer fluid intervals. However, take the same car, drop some weight, add a little power, but keep the same brakes (RS America), and then you are under-braked.
If you drive the C2 REALLY hard, or have the RS/A, you might benefit from shorter fluid intervals, as this keeps the fluid fresher and lower in moisture content. Lower moisture obviously means better heat handling. This idea is of particular relevance to stock class racers, because they are usually max-ing the performance of their mandatory stock brakes all the time, and therefore benefit from fresh fluid.
Panning out to get the bigger picture, what all of this should point out to you is that when you make a step up in one type of equipment (tires, in your case), you must try and think about all of the other systems that will be concurrently effected.
The domain of Unintended Consequences is where the slope gets the slipperiest!
I'm with Adam on braking performance, although the type of pad you are using does indeed play a BIG roll in this.
There is one point I might expand on.
If you have a car with just enough brakes for most cases - a 964C2 is a good example - then you might be fine with longer fluid intervals. However, take the same car, drop some weight, add a little power, but keep the same brakes (RS America), and then you are under-braked.
If you drive the C2 REALLY hard, or have the RS/A, you might benefit from shorter fluid intervals, as this keeps the fluid fresher and lower in moisture content. Lower moisture obviously means better heat handling. This idea is of particular relevance to stock class racers, because they are usually max-ing the performance of their mandatory stock brakes all the time, and therefore benefit from fresh fluid.
Panning out to get the bigger picture, what all of this should point out to you is that when you make a step up in one type of equipment (tires, in your case), you must try and think about all of the other systems that will be concurrently effected.
The domain of Unintended Consequences is where the slope gets the slipperiest!
07-10-2004, 12:12 PM
#17
It would seem that threshold braking is dependent on what the threshold is for the particular tire. Locking up street tires, no matter how good you are at braking technique, will eventually occur once you step over the threshold. Logic would say that the threshold on R-compounds must be much higher. Therefore, locking up on street tires should not automatically carry over to R-compounds, all other things being equal.
07-11-2004, 12:01 AM
#18
Race Director
Mike you are right, but I think you guys missed my point.
My point is that if you are having trouble modulating the brakes to pevent lock-up R-tires will just mask that bad habit. If you again push the limit of R-tires like you should you will once again have problems with locking the brakes. Just now I happens at a higher threashold.
Personally if you are having issues locking the brakes you need to learn to better modulate the pedal to prevent lock-up, but still use maximum braking. It is same as cornering speed. If you can't stop spinning on street tire the answer is NOT R-tires. The answer is to learn to adjust your technique, in most cases, and a few cases make sure the car is working properly.
If I was instruting a student that continualy was locking the brakes the answer is NOT R-tires. I work with them on their technique to try to improve that.
My point is that if you are having trouble modulating the brakes to pevent lock-up R-tires will just mask that bad habit. If you again push the limit of R-tires like you should you will once again have problems with locking the brakes. Just now I happens at a higher threashold.
Personally if you are having issues locking the brakes you need to learn to better modulate the pedal to prevent lock-up, but still use maximum braking. It is same as cornering speed. If you can't stop spinning on street tire the answer is NOT R-tires. The answer is to learn to adjust your technique, in most cases, and a few cases make sure the car is working properly.
If I was instruting a student that continualy was locking the brakes the answer is NOT R-tires. I work with them on their technique to try to improve that.
07-11-2004, 12:25 PM
#19
M758
Your point is understood and well taken. I should have noted that I was not having problems locking up the brakes (which I rarely do), only that they do lock up when trying to shorten the braking zone any more to keep up the people with sticky tires. I have reached the threshold limit of the tires, unrelated to technique. In other words, I am getting as much braking out of my street tires as possible, without locking up. Anyway, this is an interesting discussion by all.
Your point is understood and well taken. I should have noted that I was not having problems locking up the brakes (which I rarely do), only that they do lock up when trying to shorten the braking zone any more to keep up the people with sticky tires. I have reached the threshold limit of the tires, unrelated to technique. In other words, I am getting as much braking out of my street tires as possible, without locking up. Anyway, this is an interesting discussion by all.
07-12-2004, 04:50 PM
#20
Rennlist Member
I was at a simillar point with about 7 DE's and autocrosses, was pondering using R-Compounds, when a set of R-compounds were literally just given to me. I wore those out in DE, then won a second set when I won my class at autocross. I don't race, and maybe a fellow non-racer's perspective may help you decide.
What I found that the grip of the R-compounds are so high, you have to be going at very high speeds to get any slip angles from them. Throttle steer and car rotations weren't happening. The darn car just stuck to the pavement. Sure, I was going fast, but to get to that same "tossing the car fun" I had on street tires, I had to go even faster. It was fun for a while, then I realized I had a bit more anxiety and a bit less fun at those speeds. Things were happening so fast I did not feel I had the lightning reflexes yet to cope with what could happen. I just got back from a DE where I HAD to use street tires. I had a whole lot of fun tossing the car around the corners, making those P-zeros squeel at almost every corner and braking zone. And, you know what? I was passing a lot of cars on R-compounds! Gives one an added sense of accomplishment.
When to get R-compounds I think is a personal choice. I'd suggest you get a set now, and see how you feel. Do you like the increased speed they allow you to go? Do you still feel comfortable at the speeds needed to practice throttle steer, car rotation, or just tossing the car around? It's all about fun and learning. I don't think anyone can tell you when you are ready. You'll have to find out yourself.
Hope this helps.
What I found that the grip of the R-compounds are so high, you have to be going at very high speeds to get any slip angles from them. Throttle steer and car rotations weren't happening. The darn car just stuck to the pavement. Sure, I was going fast, but to get to that same "tossing the car fun" I had on street tires, I had to go even faster. It was fun for a while, then I realized I had a bit more anxiety and a bit less fun at those speeds. Things were happening so fast I did not feel I had the lightning reflexes yet to cope with what could happen. I just got back from a DE where I HAD to use street tires. I had a whole lot of fun tossing the car around the corners, making those P-zeros squeel at almost every corner and braking zone. And, you know what? I was passing a lot of cars on R-compounds! Gives one an added sense of accomplishment.
When to get R-compounds I think is a personal choice. I'd suggest you get a set now, and see how you feel. Do you like the increased speed they allow you to go? Do you still feel comfortable at the speeds needed to practice throttle steer, car rotation, or just tossing the car around? It's all about fun and learning. I don't think anyone can tell you when you are ready. You'll have to find out yourself.
Hope this helps.
