Official FV Discussion: SCCA Runoffs 2010

Ed Womer
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by Ed Womer »

That is kinda of interesting info from the event. Brandon Peterson had the outright fastest trap speed for the week at 117.9055 during the race and I had the next fastest in Monday Qualifying at 117.6309 and we were the only ones to get into the 117's.

Ed
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by FV80 »

Ed Womer wrote:...117.6309 and we were the only ones to get into the 117's.

Ed
au contraire mon frere 8) . I also clocked a 117 in Q2.
And, Gary - thanks for the heads up... I was a bit bleary when I looked at the spreadsheet and didn't notice the tabs.

I wonder exactly where the speed trap is? Data says 'entrance to T5', but doesn't say how deep into the turn. It would seem logical to put it around the 4 or 5 marker, but I'm thinking it might be more like the 2 from the speeds. Since it's about 120 feet long, probably starts around the 2.5 and ends about the 1?? maybe?
It IS interesting data - something you could make yourself silly over :lol:
Seems the VAST majority turned their fastest lap on the LAST lap - wonder why that was too. Was the track getting better?
Steve, FV80
edit - according to the SCCA text describing the data, the trap is "approximately 750 feet before the Apex of Turn Five". NOW, I wonder what the spacing of the Markers is ??
The Racer's Wedge and now a Vortech, FV80
Speedsport
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by Speedsport »

What, you guys don't go out and carefully inspect the track during the week? :mrgreen: While I was walking around I saw where they had cut the transponder lines in the pavement approaching turn 5. (That plus the AMB box and extension cord running through the woods was a good clue). The trap was set up near the top of the hill right before the brake markers.

And for what it's worth, I had a lap in Q2 and during the race with trap speeds of 118.3. :P Do I get a consolation prize for that?
cendiv37
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by cendiv37 »

Mike, if you do get the consolation prize, you'll have to share it with me (Q3).

More of a booby prize for the week for me. :shock:
Bruce
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by FV80 »

I guess we're all focusing on OUR OWN speeds and times :lol:

This info from Greg Wieser at Road America...
"There are two timing loops in stretch between Turn 4 and Turn 5. I am not sure which one the SCCA hooked up or if they used both to capture top speeds through there. Anyway, going race direction the first loop is just before the #5 shutdown marker, I would guess about 50’ before. The second loop is about 50’ after the #5 brake marker, or half way between the #5 and #4 brake markers."

A bit further from our braking points than I thought. From that, I'd say we're over 120 (WOW!) JUST before braking... Or the SCCA speed calculation is a bit off. 120 feet is a pretty wide trap length - we're still gaining speed all the way through ... at least in most cases.

Hmmm. Just got another response from RA - "The trap starts at turn 4A and runs about 100 ft toward turn 5 stopping around the area where shut down markers begin at turn 5". A little difference of opinion although same general area. I guess at that point, it doesn't really matter - I was just curious about whether or not 'late braking' might be having an impact on the speeds.

MY data shows a top speed into T5 about 1/2 MPH less than the calculated trap speed, but mine is down around the 1.5 I'd guess. In the area of the trap, MY data is showing more like 10 MPH slower. But it's still interesting :P ... we can't REALLY be doing 125 into T5 ... can we??
FYI,
Steve, FV80
The Racer's Wedge and now a Vortech, FV80
Dave Gomberg
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by Dave Gomberg »

From the map I was given showing the timing loops and the distances between them, I had estimated that the first of the loops for the trap was about 750-1000 feet from the apex at T5. Since then, someone who seems to actually know where they are located, posted on another forum that the first trap loop is at 750 feet from T5 and that the second is 630 feet from T5. The map has the distance between the loops before T5 at 0.02284 miles which is 120.6 feet. So, I'd say the 750/630 numbers are pretty accurate. (I don't know where the brake markers are in relation to the loops, but if they are at 100 foot intervals, as is the case at many tracks, that would put the trap before the braking zone.)

Dave
brian
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by brian »

This is really some great info. I'm not too concerned with top speed since it is dependant on drafting and oh yea, PUSHING! :evil: The sector times are very interesting. Check and see who had the lowest times there, it's very telling. Some of the fastest cars on the grid were not that outstanding in the sectors. Kinda underscores the theory that RA is not the best measure of a vee.
The above post is for reference only and your results may vary. This post is not intended to reflect the views or opinions of SCCA and should not be considered an analysis or opinion of the rules written in the GCR.
Ed Womer
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by Ed Womer »

Damm,

After seeing Stevan's post I went back and looked at the trap speeds and did find that I missed some. I think what caused the problem is I thought that 116's were the best and only noticed 117's by Perterson and myself. Sorry guys but there were better and I rechecked again after noticing Bruce's comment and did miss his as well. So unless I am missing someone else it looks like 1st Q was Donnie Isley with a 117.1282 and me with a 117.6309. 2nd Q was Mike Varacins with a 118.3079 and Stevan at 117.6309. 3rd Q was Bruce Livermore with 118.3079 and Roger Siebenaler with 117.1282. The race was Mike Varacins with another 118.3079 and Brandon Peterson with a 117.7994.

What is interesting is Stevan and I had exactly the same speed to the 10 thousands as well as Isley and Siebenaler and Mike and Bruce as well. So I think Mike does deserve a conselation prize for being the fastest vee at the runoffs but unfortunatly Bruce you don't get to share since the tie breaker is that Mike did it twice to your once.

I guess the timing system seems to record a set time for certain times which is why there were duplicate times multiple times. It is hard to belive that timing to the ten thousands would allow duplicate times.

Ed
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by FV80 »

Timing is only to the thousandth - the "calculated speed" was done to the ten thousandth, based on the trap DISTANCE which was listed in miles to the ten thousandth. Since the distance was the same for everyone, that leads to duplicates to the ten thousandth. I guess their goal was to get a 'comparative measure' for all cars rather than the ultimate top speed. I still say it's quite a bit off, since there's NO WAY any of us could be going that fast at the point of the trap.... at least unless my data is WAY off. Anyone else look at their speed data about 2 thirds of the distance between 3 and 5?
Steve, FV80
The Racer's Wedge and now a Vortech, FV80
Dave Gomberg
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by Dave Gomberg »

Before you write off the published speed trap times, check some information from your data systems against this: the total track length is 4.04828 miles. That is 21374.9184 feet. If your data system is reporting anything significantly different, then anything it reports with regard to speed will be off proportionally.

Dave
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by FV80 »

Mine is reporting 21189ft (on my fastest race lap) - that's CONSIDERABLY closer (better than 99%) to the specified track length than what I suspect is the ACTUAL speed through the traps vs what SCCA is reporting. Of course, I COULD be going a LOT faster than what I think I am .. but I doubt it.
As for track length... the 'specified track length' IIRC is measured on the CENTERLINE of the track - *NOT* the "Racing line", so the 'raced' length can still vary considerably over the 'something' FOUR MILES of Road America.
Steve, FV80
EDIT - On a different SLOWER lap, my system measured 21369.8 feet (99.9760541 % "accurate") :-).
The Racer's Wedge and now a Vortech, FV80
jpetillo
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by jpetillo »

Steve, what was the maximum speed your data showed?
smsazzy
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by smsazzy »

Also, does your data use wheel speed, or GPS. If it uses wheel speed, did you measure the circumference of your (hot) tire to the .001 and input it before the session?

A .5 difference in circumference will show up as about a 2 MPH measured difference at 110 MPH or so. (Of course your actual speed is still the same, but your data system will show it faster or slower)

Did everyone go into the settings of their AIM system and update the circumference of the new tires?
Stephen Saslow
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by FV80 »

Steve & John,
John - if you mean my top speed into T5, then I already mentioned that it was within 1/2 MPH of the reported trap speed (for my car) - so "about 115" - of course several laps were slower than than that. If you mean top speed overall, that would be at Canada - I don't have it in front of me at the moment and I haven't combed through ALL my laps to verify, but IIRC I saw about 117.5 this year. (Last year I clocked a mid 118 into Canada at one point during the race).

As for Stephen's question - NO - I don't routinely measure the rollout every session - I just let it FLOW :-). I have checked it several times though and it seems to wander about 1/4 inch. I also haven't checked this "new" tire (last year's tire) since the change over, so my MPH could be off a bit. [the GY tire "size" is the same and the tire MOLD was the same, so it should be close (maybe?<G>)} < 2% is acceptable for me ( I generally only compare a few MPH points from session to session .. and mostly LAP TIMES between years) - but > 10% is not. As mentioned before, the SCCA trap speed 'window' runs around 103 - climbing to about 109 - "in the window" as far as I could guess (exactly where the window is). That's a bit "OFF" from the calculated 114-115 from SCCA. I have also checked against rear tire rollout vs gearing and RPM calculated speeds and I find them reasonably close to measured via AIM (NOTHING is perfect <G>).

Has anyone ELSE looked at their data with regards to trap speed? Anyone actually AGREE that they might be turning the approx SCCA speed in the trap window??? I still doubt it.
Steve, FV80
The Racer's Wedge and now a Vortech, FV80
Matt King
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by Matt King »

The data logger only records wheel pulses from the speed sensor, so you can go back into the AIM software and correct the tire circumference if it's incorrect.
billinstuart
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by billinstuart »

Y'know, I was driving/racing in the '70's, and crewed a buddy to several regional championships in the last decade. It's REALLY GREAT to see guys I ran with (well, behind) still competitive and active in Vees (sorry Stevan)..

Best wishes to ALL the Vee guys!!!

Bill
jpetillo
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by jpetillo »

FV80 wrote:Steve & John,
John - if you mean my top speed....

Steve, FV80
Steve, thanks. I was not specific enough in my question, but your answer was complete enough that you answered what I wanted, and then the next questions I would have had. John
Gdog
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by Gdog »

Pictures from turn eight , scene of the oil spill .
http://jwwwebdesign.smugmug.com/SCCA-Cl ... 3973_WQdvL
Speedsport
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by Speedsport »

I like how in the shots of me flying through the air and spinning around, you can see a valve cover in motion in the background. That means the valve cover was still on the track when we entered turn 8. How can there be a gallon of oil AND A LARGE METAL OBJECT in the track and not have a debris flag????? :roll:
jhenn4716
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by jhenn4716 »

Speedsport wrote:I like how in the shots of me flying through the air and spinning around, you can see a valve cover in motion in the background. That means the valve cover was still on the track when we entered turn 8. How can there be a gallon of oil AND A LARGE METAL OBJECT in the track and not have a debris flag????? :roll:
I was working rescue that day, when we arrived the valve cover was no longer on the track. It may have been hit by another car and flown off the track. But there was a very very wide path of oil thru the turn.
Jeff
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Victoracing
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Re: Official FV Discussion: SCCA Runoffs 2010

Post by Victoracing »

To save sorting time: go to shots 816, 819 - 820 at that jww site.
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