Virginia Motor Sport Club Discussion Forums

Results => Autocross => Topic started by: jloehlein on June 10, 2012, 02:31:39 PM



Title: 06/10/2012 Results
Post by: jloehlein on June 10, 2012, 02:31:39 PM
Results from today's race are posted here on MyAutoEvents (http://www.myautoevents.com/pls/mae/frmEventDetail.ShowResults?psEVENT_ID=12922).  I had to manually enter the first several people's first runs manually, so they show up as the last runs in the "Detailed Results" section.

Our next event will be a Novice school on July 28th followed by an autocross on the 29th, back at RIR.  See you then.


Title: Re: 06/10/2012 Results
Post by: rothaus on June 10, 2012, 03:04:58 PM
Man that was fast !

Thank you !


Title: Re: 06/10/2012 Results
Post by: travisb on June 10, 2012, 03:34:23 PM
Thanks! Is it possible to include the heat the person drove in? I always like to do some statistics with all the times and it would be interesting to see if there are trends as the day progressed.


Title: Re: 06/10/2012 Results
Post by: 90efcivic on June 10, 2012, 04:47:14 PM
thanks for getting the times up that fast Justin


Title: Re: 06/10/2012 Results
Post by: gunny on June 10, 2012, 06:53:03 PM
Fun event! cant wait till VMP later on in the year! My little vette needs to stretch its legs a little.
My gps tops me out at 45 mph! Pretty darn slow if you ask me, this is racing folks! Lets race.....

Gunny


Title: Re: 06/10/2012 Results
Post by: ccann26 on June 10, 2012, 08:55:52 PM
Fun event! cant wait till VMP later on in the year! My little vette needs to stretch its legs a little.
My gps tops me out at 45 mph! Pretty darn slow if you ask me, this is racing folks! Lets race.....

Gunny

We gotta let the "little guys" win some too


Title: Re: 06/10/2012 Results
Post by: jloehlein on June 11, 2012, 03:34:04 AM
Thanks! Is it possible to include the heat the person drove in? I always like to do some statistics with all the times and it would be interesting to see if there are trends as the day progressed.

see the attached Excel sheet.


Title: Re: 06/10/2012 Results
Post by: travisb on June 11, 2012, 04:17:22 AM
Thanks again!


Title: Re: 06/10/2012 Results
Post by: whiteryder on June 11, 2012, 06:01:11 AM
Wow, I think this little novice is starting to grow up!  :o
For the first time I actually noticed the effect of rising temps on my grip.

First run I had traction, but I wasn't pushing hard.  Next couple of runs the tires got
unexpectedly greasy and started letting go without their usual noisy warning.  I finally
got a clue and lowered my pressures a little, which helped a bit but with only 4 runs
I didn't have time to experiment any further.

I love my RE11s and have been singing their praises since I bought them last November.
So what gives?  ???  Just the fact this is the first time I've run them on a really hot day!

They are still awesome in warm, cool, cold, and even wet, without any babysitting. 
But in heat it looks like I'm going to have to pay more attention to those pressures.

Either that or get a third set of tires for mid-summer events....  lol



Title: Re: 06/10/2012 Results
Post by: jloehlein on June 11, 2012, 06:17:37 AM
all tires have an optimal temp range.  race compounds are usually a higher temp range than street tires, but they all "fall off" once they're too hot.  just use a garden sprayer to cool them down between runs.


Title: Re: 06/10/2012 Results
Post by: bobzdar on June 11, 2012, 10:52:17 AM
What were your pressures?  They may have just been getting too high due to the temp, not actually greasy.

We took some tire temps in staging and were only getting to 130ish degrees on the tires after a couple of runs, which shouldn't be hot enough to get greasy I don't think (street tires - dunlop direzzas).  I had set my tires hot last time and didn't touch them this time and had my best run and best grip on my final run.  I'm only running like 34 rear, 37 front hot.  A couple of m3 guys on same tires were running more like 39 and 42 (rear - front) but they're carrying 400-500 more lbs and front engine, hence the higher pressures and reverse bias.  Spread was like 2 degrees edge to edge, so I think they were pretty close.

It's nice to be able to feel changes like that in the car, I've finally driven mine enough to where I can start to make those adjustments and feel the changes.


Title: Re: 06/10/2012 Results
Post by: whiteryder on June 11, 2012, 04:12:28 PM
Mfr's recommended pressures (for daily driving) are 44 rear / 37 front.  After run 3 I think that's about where they were, front was maybe a bit lower.  I let out a couple of pounds at both ends for run 4, and I could feel it was a little better.  I was planning to let out some more for my next run - but there wasn't one.  Oh well!

I don't know how much an M3 weighs, but my early-model 997 is about 3100lbs.

I have a non-contact temp gauge in my track box, I'll make sure I get that out next time.  It would be interesting to track temps, pressures, and traction.  (Is there an app for that?  lol)


Title: Re: 06/10/2012 Results
Post by: KasbeKZ on June 11, 2012, 04:25:20 PM
thanks for getting these up so fast. learn me something on these results pages though... not that it's my class, but i'm seeing discrepancies so i want to see what i'm missing. the street tire and novice class results are all showing sub-40 second times. though, in the raw time and pax results, more realistic times are showing for them. how is this so?


Title: Re: 06/10/2012 Results
Post by: wahoo5 on June 11, 2012, 06:06:47 PM
Street tire and novice are paxed classes so you are only seeing the pax times there. Under raw times, you see their times before the pax index was applied. Make sense?

David


Title: Re: 06/10/2012 Results
Post by: bobzdar on June 12, 2012, 05:08:13 AM
Mfr's recommended pressures (for daily driving) are 44 rear / 37 front.  After run 3 I think that's about where they were, front was maybe a bit lower.  I let out a couple of pounds at both ends for run 4, and I could feel it was a little better.  I was planning to let out some more for my next run - but there wasn't one.  Oh well!

I don't know how much an M3 weighs, but my early-model 997 is about 3100lbs.

I have a non-contact temp gauge in my track box, I'll make sure I get that out next time.  It would be interesting to track temps, pressures, and traction.  (Is there an app for that?  lol)


The m3's are in the 3400-3500lb range.  My car is around 3050lbs.  You may want to try lower pressures, but I've never run the re-11's so wouldn't know what they necessarily like for autox (google may be able to help you).  I'm not sure what the recommended pressures are in mine, but I started at 38/38 last time and the rear end was all over the place.  After dropping the rear 4psi it gripped nicely but started to understeer just a little so I took 1psi out of the front and called it good.  I didn't touch the tires this time, balance was spot on.


Title: Re: 06/10/2012 Results
Post by: KasbeKZ on June 12, 2012, 06:41:11 AM
Street tire and novice are paxed classes so you are only seeing the pax times there. Under raw times, you see their times before the pax index was applied. Make sense?

David

i suppose so. i thought all calsses were paxed, but i guess they get specially paxed


Title: Re: 06/10/2012 Results
Post by: whiteryder on June 12, 2012, 08:10:53 AM
i suppose so. i thought all calsses were paxed, but i guess they get specially paxed

Every class has a pax multiplier. 

But both the raw times and pax times can be useful, it depends on what you are comparing.
So the results contain both, in separate tables. 

Generating the results is a bit of work, so I would hesitate to suggest making it any more complex.
But sometimes I think it would be nice if pax times were (say) a different color from the raw times.

Maybe someday we'll have a member with web scripting skills, who will generously volunteer to set
up something that displays the results in a more visually clear style... without adding any effort to
the job of uploading the data.


Title: Re: 06/10/2012 Results
Post by: travisb on June 14, 2012, 05:18:23 PM
I did some playing around with the numbers comparing times in each heat - http://img7.imageshack.us/img7/7667/timeunder46.png

I'm still learning, but I guess the temps were best during heat 2.

I also attached my spreadsheet if anyone's interested.

EDIT - Graph with axis titles - http://img85.imageshack.us/img85/2036/timeunder46b.png


Title: Re: 06/10/2012 Results
Post by: whiteryder on June 14, 2012, 06:16:35 PM
Is that how many runs were under 46 seconds ? If so your graph appears to show heat 1 as having the most.

Beautiful graph, but always helpful to include units on your axes!  :)

The difficulty with comparing times & heats is that you need to assume the car/driver capabilities
are evenly distributed across the heats, i.e. that ambient temp is the only variable affecting run times
for each heat.  One option might be to repeat these calculations across several events, so you get
data for the same driver/car combinations in different conditions.


Title: Re: 06/10/2012 Results
Post by: Blown_xa on June 14, 2012, 07:01:27 PM
Liked the layout, usually small courses are choppy... this one was flowing.  Even though I drive a fwd machine, I prefer a Corvette catered layout.  Installed lsd and changed gearing recently, 2nd gear good for 76mph... barley hit boost at RIR, but it was flowing enough to where I was pleased. Kudos to course designer.


Title: Re: 06/10/2012 Results
Post by: whiteryder on June 14, 2012, 08:19:43 PM
Liked the layout, usually small courses are choppy... this one was flowing.  Even though I drive a fwd machine, I prefer a Corvette catered layout.  Installed lsd and changed gearing recently, 2nd gear good for 76mph... barley hit boost at RIR, but it was flowing enough to where I was pleased. Kudos to course designer.

That'd be Engelbert.  He took a bit of heat from our higher HP comrades, I'm sure he'll be glad to hear he pleased someone.  ;)



Title: Re: 06/10/2012 Results
Post by: wahoo5 on June 14, 2012, 08:50:41 PM
Street tire and novice are paxed classes so you are only seeing the pax times there. Under raw times, you see their times before the pax index was applied. Make sense?

David

i suppose so. i thought all calsses were paxed, but i guess they get specially paxed

Results in all classes are not based on the pax index. Cars competing within any one class, e.g., AS or ESP, compete on raw time. Cars competing in a group of different classes are ranked based on the pax index. Novice and tire class are 2 such groups.

An overall ranking of ALL cars is also computed using the pax index. Some find it meaningful; others think it is very misleading and they sometimes use stronger language to describe their lack of affection for pax. Right, Bill?

David


Title: Re: 06/10/2012 Results
Post by: travisb on June 15, 2012, 07:56:45 AM
Is that how many runs were under 46 seconds ? If so your graph appears to show heat 1 as having the most.

That graph shows times under 46 seconds. Heat 1 did have more times under 46, but on average for the top 60% of the fastest cars in each heat, heats 2 and 3 were significantly faster.

I'm not picking on novices here, but novices tend to run in heat 2 and most likely heat 3. That is why I believe you see heat 1 times eventually become faster than the other heats. That may also be why heat 2 was faster than 3. Or maybe the track got too warm and times got a little slower. Or maybe just the majority of the faster cars ran in heat 2.

This is just for fun and not meant to make an excuse for my sucky time. :)


Title: Re: 06/10/2012 Results
Post by: travisb on June 15, 2012, 08:08:02 AM
Beautiful graph, but always helpful to include units on your axes!  :)

The difficulty with comparing times & heats is that you need to assume the car/driver capabilities
are evenly distributed across the heats, i.e. that ambient temp is the only variable affecting run times
for each heat.  One option might be to repeat these calculations across several events, so you get
data for the same driver/car combinations in different conditions.

Hi Beth, I updated the graph = http://img85.imageshack.us/img85/2036/timeunder46b.png

I agree that just looking at times from this one event doesn't really prove anything. If someone wants to provide me more data including heats run and times from previous events I would be happy to try and put something together.


Title: Re: 06/10/2012 Results
Post by: bobzdar on June 15, 2012, 11:55:41 AM
Liked the layout, usually small courses are choppy... this one was flowing.  Even though I drive a fwd machine, I prefer a Corvette catered layout.  Installed lsd and changed gearing recently, 2nd gear good for 76mph... barley hit boost at RIR, but it was flowing enough to where I was pleased. Kudos to course designer.

That'd be Engelbert.  He took a bit of heat from our higher HP comrades, I'm sure he'll be glad to hear he pleased someone.  ;)



I liked it as well, I didn't initially think I would but it was easy to tell where to go next so I didn't have to worry about getting lost and could concentrate on trying to take out the timing boxes at the end.


Title: Re: 06/10/2012 Results
Post by: ccann26 on June 16, 2012, 01:32:27 PM
Is that how many runs were under 46 seconds ? If so your graph appears to show heat 1 as having the most.

That graph shows times under 46 seconds. Heat 1 did have more times under 46, but on average for the top 60% of the fastest cars in each heat, heats 2 and 3 were significantly faster.

I'm not picking on novices here, but novices tend to run in heat 2 and most likely heat 3. That is why I believe you see heat 1 times eventually become faster than the other heats. That may also be why heat 2 was faster than 3. Or maybe the track got too warm and times got a little slower. Or maybe just the majority of the faster cars ran in heat 2.

This is just for fun and not meant to make an excuse for my sucky time. :)

Heat does have an effect on tires but different effects on street vs Race compounds a spray bottle of water can take care of that , but a novice in a later heat may not check his or her tire pressures between runs and start to slide more as the pressures raise. For weathered "a few years or more" autocrossers it may just depend on what the driver wants. If your "me" and you run heat 1 and work heat 2 you can go early and get your schoolwork that you have been procrastinating all week done... This may also be the case for people who have to travel for an hour or more to the event.. Or if you run heat 3 you can get your worker assignment done early and have the middle of the day to have a pizza delivered and watch where everyone messes up and take note :  )  heat 2 runners have plenty of time to watch, eat and prep their cars so they all have advantages.