AX in the rain
10-17-2007, 10:27 PM
#16
I can't remember the name of the book but I agree with the comments. Porsche FTD went to a 993 C2 and non-Porsche FTD went to a VW GTi. There were pleanty of faster cars including a 997TT and a Mustang 5.0.
As per the above, part of the reason for my post is that my AWD should've done much better than RWD Porsches. I did better than average but a few RWDs got better times and I suspect it has more to do with tire pressures, suspension settings and tire widths than with my lines or whether I ran in more rain than my counterparts.
Tire pressures and suspension settings can make a huge difference in AX and I made changes to both of those variables which I think may have negatively impacted my car's performance. Truth is, I'm just learning how to adjust my PSS9s and I dialed them incorrectly. I also listened to the wrong advice on tire pressures and ran them too high. Just trying to get it right for next time.
As per the above, part of the reason for my post is that my AWD should've done much better than RWD Porsches. I did better than average but a few RWDs got better times and I suspect it has more to do with tire pressures, suspension settings and tire widths than with my lines or whether I ran in more rain than my counterparts.
Tire pressures and suspension settings can make a huge difference in AX and I made changes to both of those variables which I think may have negatively impacted my car's performance. Truth is, I'm just learning how to adjust my PSS9s and I dialed them incorrectly. I also listened to the wrong advice on tire pressures and ran them too high. Just trying to get it right for next time.
The rain is a great equilizer as someone else mentioned. Smoothness is key - steering, braking, accelerating. Must be smooth in the rain.
While this was years (about 15) ago, I took my parents Audi Quattro to a PCA AX. It was raining all night and all during the event. I thought for sure I would win.. that I was not only a fabulous driver but the car would propel me to even greater achievements... not so. Spanked by just about 50% of the folks there. Why? not beacuse of the AWD, but because of my low experience, at the time, and overconfidence that the car would solve all the problems.
RWD Porsches (911s) do have the advantage of all that weight on the drive wheels for traction... plus the transference of that weight to the fronts under braking. The 993 has great brakes and balance to begin with. Not sure why you are suprised one earned FTD.
btw, Henry Watts is the author of "Secrets of Solo racing" - an excellent AX and car prep book.
10-19-2007, 02:55 PM
#17
Rennlist Member
Thread Starter
Racer,
Answer to the first question: because that has already been accounted for. I'm not highly experienced but I've done enough AX, including another event in the cold rain where I got FTD in my class, to know my skill level in relation to my peers. Furthermore, I have always improved my times over the course of the day whereas the day in question I got my best time on my first run, I then changed my suspension settings and tire pressures (first time with PSS9s, which I screwed up) and my performance decreased from that point forward. I felt it and my times confirmed it. So, driver and driving aside, the purpose of my post is to further identify the variables that affect the performance of the car so I can use that info moving forward.
Why am I surprised that a 993 C2 got first place among 911s vs an AWD 993? Well, maybe I'm missing something but variables aside, my understanding is that FWD and AWD cars have an advantage over RWD cars in these conditions, especially when comparing RWD and AWD on the same car: a 993. However, I do find your comments about the balance of C2s very interesting, especially in light of the fact that the 993 C2 that won first place had heavy 19" RUF wheels, which would otherwise be a disadvantage. This was one of my initial queries: do heavier wheels provide an advantage in the rain?
Thanks for the heads up on the book...I do believe that's the title I was thinking of.
Answer to the first question: because that has already been accounted for. I'm not highly experienced but I've done enough AX, including another event in the cold rain where I got FTD in my class, to know my skill level in relation to my peers. Furthermore, I have always improved my times over the course of the day whereas the day in question I got my best time on my first run, I then changed my suspension settings and tire pressures (first time with PSS9s, which I screwed up) and my performance decreased from that point forward. I felt it and my times confirmed it. So, driver and driving aside, the purpose of my post is to further identify the variables that affect the performance of the car so I can use that info moving forward.
Why am I surprised that a 993 C2 got first place among 911s vs an AWD 993? Well, maybe I'm missing something but variables aside, my understanding is that FWD and AWD cars have an advantage over RWD cars in these conditions, especially when comparing RWD and AWD on the same car: a 993. However, I do find your comments about the balance of C2s very interesting, especially in light of the fact that the 993 C2 that won first place had heavy 19" RUF wheels, which would otherwise be a disadvantage. This was one of my initial queries: do heavier wheels provide an advantage in the rain?
Thanks for the heads up on the book...I do believe that's the title I was thinking of.
10-19-2007, 07:27 PM
#18
Its not unheard of to go out and have a quick run and struggle the rest of the time. That's happened to me a few times before. Typically because, so confident after the first run that more time was available to "take off" that I overdrove the car.. or made too drastic Tire pressure changes. It can happen.
911's have won MANY many world rallys - like Monoco.. Dakar etc. RWD with a rear engine placement is as good as FWD with front engine placement, maybe better - but you MUST know what you are doing. To balance the car without overdriving is key.
Unless my times are drastically far off others whom i am usually close to, small changes are best. You might learn to keep a log of conditions and settings and go from there. I'm not into that stuff (the data acqusition) and limit my changes to TP only.. rather than overwhelm and not know which change was helpful or not.
911's have won MANY many world rallys - like Monoco.. Dakar etc. RWD with a rear engine placement is as good as FWD with front engine placement, maybe better - but you MUST know what you are doing. To balance the car without overdriving is key.
Unless my times are drastically far off others whom i am usually close to, small changes are best. You might learn to keep a log of conditions and settings and go from there. I'm not into that stuff (the data acqusition) and limit my changes to TP only.. rather than overwhelm and not know which change was helpful or not.
10-19-2007, 07:39 PM
#19
Rennlist Member
Thread Starter
Thanks for the further input. I'm not into logging #s either and ultimately, I think skill makes a bigger difference. There is a good chance that I may have been overdriving the car but I also know that some of the changes I made had an impact.
FYI, my first run was .519 and the rest of my runs were in the .52 range with the exception of a bad run timed at .57. All 993s were in the .50 to .55 range with the fastest 993 (and FTD among all 911s) at .497. I may be splitting hairs here, but it's just that kind of sport.
FYI, my first run was .519 and the rest of my runs were in the .52 range with the exception of a bad run timed at .57. All 993s were in the .50 to .55 range with the fastest 993 (and FTD among all 911s) at .497. I may be splitting hairs here, but it's just that kind of sport.
Last edited by Wilder; 10-20-2007 at 11:51 AM.
10-28-2007, 10:16 AM
#20
Rennlist Member
I did my first autocross rain day yesterday. It was a BMW club test and tune with a very high number of instructors. I got at least a dozen runs on each of the 2 courses that were set up. Rain forced me to learn smoothness and my best time was less than 2 seconds off from a good driver in a 993TT AWD, and about a second slower that the STI, another good driver. I was suprised at the performance of the cup tires, tread depth is down to the indicators.
High point of the day was when I let an instructor drive my car. He pointed out some areas where I could put down more power when he rode with me. I was a bit different when he drove the RS. I could see he was having trouble with power delivery and was breaking the rear loose on many turns. Coming through the last pair of offsets before the timing lights he lost it and went off course bass ackwards in a 270 degree spin. Good thing he missed the timing lights.
High point of the day was when I let an instructor drive my car. He pointed out some areas where I could put down more power when he rode with me. I was a bit different when he drove the RS. I could see he was having trouble with power delivery and was breaking the rear loose on many turns. Coming through the last pair of offsets before the timing lights he lost it and went off course bass ackwards in a 270 degree spin. Good thing he missed the timing lights.
11-03-2007, 08:36 PM
#21
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Hey Louis,
I used my wet track set up for my suspension (soft) and I had fresh A032R tires which hook up really well in the wet. Look at my avatar, that was the same autocross and there were 4" puddles.
In the wet, you need to find a different line that avoids as many of the puddles as possible and redefine the apex of every corner. As Allan so kindly pointed out to me, it does come down to mathematics, the shortest distance between two cones is a straight line. In the wet you need to modify that with finding a line where you can threshold brake and turn in with out plowing, in slow and out fast. That autocross in the lake was a blast and now, next season, I get to do it with 100 more HP and a better suspension set up and I am so looking forward to it in the new 993. Expect me to call on you for some advice.
Bob
I used my wet track set up for my suspension (soft) and I had fresh A032R tires which hook up really well in the wet. Look at my avatar, that was the same autocross and there were 4" puddles.
In the wet, you need to find a different line that avoids as many of the puddles as possible and redefine the apex of every corner. As Allan so kindly pointed out to me, it does come down to mathematics, the shortest distance between two cones is a straight line. In the wet you need to modify that with finding a line where you can threshold brake and turn in with out plowing, in slow and out fast. That autocross in the lake was a blast and now, next season, I get to do it with 100 more HP and a better suspension set up and I am so looking forward to it in the new 993. Expect me to call on you for some advice.
Bob
11-03-2007, 09:39 PM
#22
Rennlist Member
Just to add to this Louis, at the most recent Slush where it was equally wet, I had a few thoughts that really helped me. My #1 goal for the day was to not be throttle-oversteering anywhere - oversteer in the dry is not such a big deal as you hook up again pretty quick but in the rain, it can take a ton of precious time before the tires grab again, and that equates to both a lot of wasted time and a lot of power that didnt go down on the straight. The other thing I focused on is I told myself that if I brake too early, I might blow 1/10 of a second that I lose from not carrying a little extra speed, but if I brake too late, I will definitely blow 1/2 of a second and be out of position for the exit. Since I'm not a perfect driver, I will statistically do much better if I give up 1/10 every time rather than 1/2 75% of the time, and nailing it the other 25% of the time, if that makes any sense?
-Mark
-Mark
11-04-2007, 04:42 PM
#23
Rennlist Member
Thread Starter
Thanks for the advice guys. Very good points all around. My last AX went much better after adjusting my tires pressures down 5lbs and adjusted my suspension settings. Last week I was only able to get three runs but my times were consistent and within a range that was more acceptable. Nevertheless, I did have Danny and Allan ride along and give me some very good feedback along the lines of what you guys have pointed out....be smooth, define the apex based on conditions and don`t be too agressive or it`ll cost time. I could`ve been smoother on one run and could`ve put down more power in two other runs but I have to wait until next weekend to find out how well I can put this info to practice.
