FST operational costs

[holmberg]

Over on the General Formula Car Discussion topic, I've been conducting a survey of operational costs for each class. Here I'm only interested in costs that differ significantly between the classes, and not, for example, entrance fees, hotel, food, etc.

Drivers from some classes have responded with data for their class, and the result is a spreadsheet in Google docs.

Here's what I have for this class. If you have changes, please reply below, and I will update the spreadsheet.

Class name: FST

Engine make: VW

Engine model: H4

Displacement: 1600

Power at crank, HP: 85

Torque at crank, ft-lbs: 100

Weight with driver, lbs: 1,125

Purchase new, $: 26,000

Tires set, $: 490 (American Racer)

Tire competitive heat cycles: 13

Engine rebuild, $: 1,700

Engine competitive hours: 53

Fuel $/gallon: 3.50

Fuel gallons/hour: 6

Brake pads set, $: 60

Brake pads hours: 27

Gearbox hours: ?
Gearbox rebuild, $: ?
Other operational costs, $:

Thanks,

Greg Holmberg

[Doug FST 5]

We run Hoosier club ford tires in the series races. To be honest I'm not exactly sure what a full set costs these days but I think it's closer to $600. We have guys running in the lead pack with over 20 heat cycles on them.

I figure about 13mpg for fuel consumption. That's close to your estimate if the lap average speed is about 80mph. Obviously that varies quite a bit track to track.

Doug FST 5

[holmberg]

We run Hoosier club ford tires in the series races. To be honest I'm not exactly sure what a full set costs these days but I think it's closer to $600. We have guys running in the lead pack with over 20 heat cycles on them.

I figure about 13mpg for fuel consumption. That's close to your estimate if the lap average speed is about 80mph. Obviously that varies quite a bit track to track.

I see the Hoosier CF tires (hard, R60A compound) at $149 for a front (43130) and $179 for a rear (43307). So $656 for a set. Plus mounting and balancing. Good to know 20 cycles are possible.

I see in the SCCA GCR that the American Racer 133 and the Goodyear R600 are also allowed. I just put in the AR tires since they are the cheapest ($490), and I know from Club FF that they have reasonable stick (about the same lap-times are the Hoosier spec FF tire with R60A compound) and a long life. The AR tire gives the FST class the lowest operational cost of all the classes ($485 per weekend, $108 less than FF in second place).

Does the AR tire also provide 20 competitive heat cycles?

As for fuel, I see that the FST track record at Thunderhill is 85.8 mph. At 13 mpg, that's 6.6 gal/hour. I'll put down 7.

Can you confirm the other data I have above?

By the way, I don't see any FST's registered for the Run-offs. Is FST not a national class, only regional? Or did it just not make the required participation this year?

[BLS]

FST is a regional class.

[Doug FST 5]

I've never run the AR tires so I can't comment on their life.

The rest of the numbers in the list look reasonable.

Doug FST 5

[holmberg]

I've never run the AR tires so I can't comment on their life.

The rest of the numbers in the list look reasonable.

Doug FST 5

How long does the gearbox last? What does it cost to rebuild the gearbox?

[rgu]

Just guessing but a seriously driven transmission should be looked at every 5 years.

I only know of three or four recent rebuilds and these cost the following:

1. A preventative maintenance rebuild $350
2. Cure 3rd gear pop out by re-bushing shift rod and replacing sychro parts $650
3. General rebuild replacing a mess $850-$1000

One thing worth noting the FST rules allow for the use of the superior Rhino case. It is much better at handling our 100 ft pounds of torque

[holmberg]

Just guessing but a seriously driven transmission should be looked at every 5 years.

I only know of three or four recent rebuilds and these cost the following:

1. A preventative maintenance rebuild $350
2. Cure 3rd gear pop out by re-bushing shift rod and replacing sychro parts $650
3. General rebuild replacing a mess $850-$1000

One thing worth noting the FST rules allow for the use of the superior Rhino case. It is much better at handling our 100 ft pounds of torque

So, when you say 5 years, you mean about 40 weekends = 133 hours on track?

I'm using a scenario of 25-minute sessions, 8 sessions per weekend (including a practice day), and 8 weekends per year. That comes out to 3.33 hours on track per weekend, 26.7 hours per year.

How does that compare to your definition of a weekend and a year of racing?

For example, should I enter this:

gearbox rebuild, $: 850
gearbox hours: 133

Which would come out to $6/hour = $21/weekend = $170/year for gearbox operational costs.

How does that sound?

Greg

[holmberg]

OK, it appears that all the discussions in all the communities have died out, so you can find the results in the spreadsheet.

[rgu]

The comparative perspective has some real benefits and of course detriments too. One thing I wish was better represented was the performance of the FST car. The track used for comparisons is a place where nobody fast ever ran an FST car. That’s a shame because driven by good drivers FST cars are way quicker than an 1125 lb car with street based suspension, 85 hp, fixed gearbox ratios and hard tires has a right to be. Check out George Podgorski’s one lap at the Glen this year.

https://www.youtube.com/watch?v=rji7GKhC40c&t=15s

[holmberg]

The comparative perspective has some real benefits and of course detriments too. One thing I wish was better represented was the performance of the FST car. The track used for comparisons is a place where nobody fast ever ran an FST car. That’s a shame because driven by good drivers FST cars are way quicker than an 1125 lb car with street based suspension, 85 hp, fixed gearbox ratios and hard tires has a right to be. Check out George Podgorski’s one lap at the Glen this year.

https://www.youtube.com/watch?v=rji7GKhC40c&t=15s

Yes, it's true. We don't have many Formula Firsts here in the San Francisco region of the SCCA. Only four FST's showed up all last year (2016), and this year, only one FST so far.

Maybe they're racing with some other organization, because there were also only 9 FV cars last year and two this year. Nine FV's have shown up for NORPAC divisional races so far this year. I know there used to be a whole lot more FV's in this region. I don't know where they've all gone.

The Thunderhill track record for FST was set by Blake Tatum at 2:00.256 in 2012 in his 2007 Crusader.

The FV record is 1:58.810 set in 2004 in a 1990 Caracal.

So that's a difference of 1.446 seconds over 2.866 miles. 0.505 seconds per mile.

How does FST compare to FV at other tracks? Closer? Possibly actually faster than FV?

FST has a better weight/power ratio than FV. But FV has stickier tires, so I'm not sure what the net effect is for lap times.


Greg

[Doug FST 5]

Some comparisons from notable courses that have been visited regularly by the Hoosier FST Tour.

Watkins Glen Long Course: FST 2:11.537 FV 2:14.288
Watkins Glen Short Course: FST 1;27.776 FV 1:28.997
Mid Ohio Club Course: FST 1:38.761 FV 1:39.262
Mid Ohio Pro Course: FST 1:37.795 FV 1:38.066
Road America: FST 2:39.559 FV 2:40.938
Road Atlanta: FST 1:39.303 FV 1:42.809


Doug FST 5

[holmberg]

Some comparisons from notable courses that have been visited regularly by the Hoosier FST Tour.

Watkins Glen Long Course: FST 2:11.537 FV 2:14.288
Watkins Glen Short Course: FST 1;27.776 FV 1:28.997
Mid Ohio Club Course: FST 1:38.761 FV 1:39.262
Mid Ohio Pro Course: FST 1:37.795 FV 1:38.066
Road America: FST 2:39.559 FV 2:40.938
Road Atlanta: FST 1:39.303 FV 1:42.809


Doug FST 5

OK, so FST is always faster than FV.

Track	length	FST	FV	Diff	diff/mile
Watkins Glen Long Course	3.40	2:11.537	2:14.288	2.751	0.809
Watkins Glen Short Course	2.45	1:27.776	1:28.997	1.221	0.498
Mid Ohio Club Course	2.4	1:38.761	1:39.262	0.501	0.209
Mid Ohio Pro Course	2.258	1:37.795	1:38.066	0.271	0.120
Road America	4.048	2:39.559	2:40.938	1.379	0.341
Road Atlanta	2.54	1:39.303	1:42.809	3.506	1.380

On average, FST is faster than FV by 0.560 seconds/mile.

I don't know which track is most like Thunderhill, but using the average says that FST should be 1.604 seconds faster around Thunderhill than FV. That would be a lap record of 1:57.206. Which would be 3.050 seconds shorter than the current FST lap record.

I could put 1:57.2 for FST into the spreadsheet, but I would feel a little guilty about that. That would make FST faster than FV and SRF3.

[Doug FST 5]

The spreadsheet is yours. I'd be inclined to keep the data set clean. Once the fudging begins the bitching will surely follow.

[Diamond Level Motorsports]

Yes, it's true. We don't have many Formula Firsts here in the San Francisco region of the SCCA. Only four FST's showed up all last year (2016), and this year, only one FST so far.

Maybe they're racing with some other organization, because there were also only 9 FV cars last year and two this year. Nine FV's have shown up for NORPAC divisional races so far this year. I know there used to be a whole lot more FV's in this region. I don't know where they've all gone.

The Thunderhill track record for FST was set by Blake Tatum at 2:00.256 in 2012 in his 2007 Crusader.

The FV record is 1:58.810 set in 2004 in a 1990 Caracal.

So that's a difference of 1.446 seconds over 2.866 miles. 0.505 seconds per mile.

How does FST compare to FV at other tracks? Closer? Possibly actually faster than FV?

FST has a better weight/power ratio than FV. But FV has stickier tires, so I'm not sure what the net effect is for lap times.


Greg

Greg, The Thunderhill FV record is bogas. It was a mistake and the stewards will not remove it. The true track record for a FV at TH is about a 2:03.?? When I drove my FST at TH last year I was running just slightly over Blake's tract record. I can see a 1:59.??? being possible. Comparing FST and FV lap times I agree with Doug's formula of around .5 sec. per track mile. I think that is very accurate.

[holmberg]

Greg, The Thunderhill FV record is bogas. It was a mistake and the stewards will not remove it. The true track record for a FV at TH is about a 2:03.?? When I drove my FST at TH last year I was running just slightly over Blake's tract record. I can see a 1:59.??? being possible. Comparing FST and FV lap times I agree with Doug's formula of around .5 sec. per track mile. I think that is very accurate.

This makes more sense.

I see that at a Major at Thunderhill in April, the fastest FV lap of the weekend was 2:07.903. The weather must have been fine, because the fastest FF lap was 3.563 off their record. If FV was the same off their record, that would put a proper record around 2:04. Which is similar to your memory for FV.

Also, when I graph all the classes' weight/power ratio against lap records, FV was a real outlier at 1:58.8. FV's weight/power ratio predicts a lap record more like 2:05 based on a best-fit line from all the other classes. (See spreadsheet.)

Also, if FST is 2:00.246, then add 1.604 for FV (.560 s/mi * 2.866 mi), and that comes to 2:01.85.

So all of this is saying 2:02 to 2:05 for FV. 1:58.8 doesn't seem possible for FV.

So, I'll put in the spreadsheet the official 2:00.256 for FST, and an estimated FV time of 2:04.