FC in solo

[bonedome]

So, where does a Formula C fit in solo? Looking at the GCR, it would appear that CMOD is the class but that sounds too obvious.

[-pru-]

I ran a 88 Swift SE3 in BM. Actually, the SE3 I owned was Jeff Watson's car who also ran the car in BM. Jeff, who won in CM with a Lola T540, trophied at Nationals in BM with SE3. cm-q interview the Jeff:

C Modified Quarterly V2-I4 / Fall 2000
Moving Towards the Web
Technical : John Goss / Pennon Composites
Interview

All in all, the FC was fun to own / drive, but was never a serious threat in BM against the FA/CSR/DSR cars. That is, you can have a lot of fun with a FC in BM, but do not expect to be competing for the win if a "real" BM is present.

[bonedome]

Were you running in BMOD because you were bumped up by the staff or because that's the actual class for an FC? I had to run an F5(FMOD) against D/E Mod several times because I was the only one in class.....somehow running a F5 against a solo vee didn't seem right when you compare engine size, gearbox vs no gearbox, suspension vs virtually no suspension, and so on. Still, since I'm just in it for the fun of it, all that doesn't matter. Heck, they could run me against A Mod and I wouldn't really care since the only one I want to beat is myself....

[ghoneycutt]

Bmod for winged cars that are not Amod

no wings in Cmod

[Dick R.]

Also the extra power, torque, and wheel width would not be "compensated for" by the higher weight of an FC.

S2000's are permitted in CM and Guy Ankeny won a while back. Now the S2000's are worth too much for vintage and whatever for serious Solo use it seems.

Some FC's have been converted to FF if the basic car was available in either config.

Dick

[Lynn]

Since we are talking about autocrossing FC's, we have one running BM in St. Louis. I was wondering if an integral first gear is needed for a Hewland LD200? Would gearing be similar to what the Fords are using in CM? The car is currently geared for whichever course at which the previous owner last raced it.

[Dick R.]

I have no idea what ratios and strength of gears are available for an LD200. However, even though a 2L (assuming Pinto) has more torque than a 1.6 it would probably still need a "mid 40's mph" in first gear for serious autocrossing I would think. What it takes to get there I don't know. It gets harder if the r&p is a 10:31. Overall I suspect that an FC will need somewhat taller gearing (after adjusting for engine rpm differences) than an FF to cover the somewhat higher speed potential in corners and straights . . . assuming the driver/car/tires are at least equal to a quick CM car.

[bonedome]

very interesting........

[ghoneycutt]

Dick's correct.
Target speeds:
1st-43
2nd-62
3rd-81

Not many choices for a LD200 the MK9 has many more lower gears ratios available to play with

for LD200- assuming 10:31, small venue autocross

13:37 fixed first for launch
15:36 2nd. to run most if not all of the course.

or: (not as desirable)
14:36 first (not fixed)
16: 35 second.

I run a FC with a mK9 at an airport autocross. Third gear is used more than at most courses.

12:38 fixed first for launch. Trying not to spin the wheels, just get the car rolling and accelerating.

With a 9:31 final, I get about 40 feet and have to shift to 2nd. With 10:31, its about 60 feet.

Most of the course is run in second. There are some 3rd gear spots. I don't go back to first.

Second gear is the most critical to get right. One tooth either way may result in loosing or gaining time by:

1) running out of gear and wanting to upshift, usually for a very short period of time then having to downshift to power through a corner.

you see it all the time at autocrosses. people banging the limiter for a period of time to save having to up-then-down shift. But I wonder, if you are on the limiter for more than about 3 seconds, are you loosing time as opposed to upshifting? If they need to use the clutch, the time to complete shifts is much longer than clutchless shifting as we can do (and I do). Clutchless downshifting is a learned skill.

2) having too high of a gear and lumbering the motor up to higher rpms. The motor would like to be on the upper rpm end so too much gear bogs the motor.

3) perfect 2nd. gear that spools the car up, tops out at the brake zone and lets you power the car through corners, slaloms and allows for some throttle-steering.

so for the LD200. pick a launch gear and tweak the second gear by experimenting or by venue size.

hope this helps
Greg

[Modo]

Take that limiter out of there for heavens sake!! Why??

[ghoneycutt]

I don't have a limiter. Many people do, though.

[Modo]

I hear you GH, havn't seen you out at Summit, always wanted to join you guys up there at the baseball stadium parking lot, thought it would be a big help at getting in and out of the carousel at Summit, that section can be a pain at times, thought you guys would excel there, squirt in, squirt out and gone!!!!

[Dick R.]

Take that limiter out of there for heavens sake!! Why??

Why not for an autox car with short gears?

Dick
CM85
85VD

[Modo]

Competition!!

[Dick R.]

The way I've looked at it over the years is to compare to drag racers who win the race with slower top speeds but quicker ET's assuming the same reaction times. Its all about time versus distance before the next corner. No concerns with being passed by somebody drafting by you.

For those of you with an HP scientific calculator (Solve function on mine) you can do what if's with different accel rates (from DA), distances, etc. Don't forget to be realistic about the coasting time and distance for even a clutchless shift. Then plug that coasting time and distance into your calculations. You might be amazed.

Dick
CM85

Dick's correct.
Target speeds:
1st-43
2nd-62
3rd-81

Not many choices for a LD200 the MK9 has many more lower gears ratios available to play with

for LD200- assuming 10:31, small venue autocross

13:37 fixed first for launch
15:36 2nd. to run most if not all of the course.

or: (not as desirable)
14:36 first (not fixed)
16: 35 second.

I run a FC with a mK9 at an airport autocross. Third gear is used more than at most courses.

12:38 fixed first for launch. Trying not to spin the wheels, just get the car rolling and accelerating.

With a 9:31 final, I get about 40 feet and have to shift to 2nd. With 10:31, its about 60 feet.

Most of the course is run in second. There are some 3rd gear spots. I don't go back to first.

Second gear is the most critical to get right. One tooth either way may result in loosing or gaining time by:

1) running out of gear and wanting to upshift, usually for a very short period of time then having to downshift to power through a corner.

you see it all the time at autocrosses. people banging the limiter for a period of time to save having to up-then-down shift. But I wonder, if you are on the limiter for more than about 3 seconds, are you loosing time as opposed to upshifting? If they need to use the clutch, the time to complete shifts is much longer than clutchless shifting as we can do (and I do). Clutchless downshifting is a learned skill.

2) having too high of a gear and lumbering the motor up to higher rpms. The motor would like to be on the upper rpm end so too much gear bogs the motor.

3) perfect 2nd. gear that spools the car up, tops out at the brake zone and lets you power the car through corners, slaloms and allows for some throttle-steering.

so for the LD200. pick a launch gear and tweak the second gear by experimenting or by venue size.

hope this helps
Greg

[Dick R.]

Competition!!

Which is why I have an adjustable limit rev limiter.

[Jim Garry]

From my observations, most FF's in autox use rev limiters. If you use a 12:38 or 13:37 or 38 without a rev limiter, you get into the low to mod 7000 range really, really fast. Do this 5 times a day (or 10 if you have a co-driver) for a 20 event season for a coupla years and the autocross rebuild schedule goes from once every 7 years down to something much more often.

[Dick R.]

Plus about the only chance you get to look at the tach in Solo is the start straight of a Pro Solo. Shift lights are typically not in the line of sight when you are really busy looking to one side or the other and your hands are moving the steering wheel really quickly.

Your choice frequently is to either short shift or use a rev limiter or have a heck of an engine budget for solo.

Dick
CM 85

[Modo]

Aaaaahh........Better to be out there than in the shop, point well taken....set a 7400????

[jdp526]

I started running a '90 Reynard at the local autoxs in January after refinishing a complete rebuild of a car I bought several years ago that was in terrible shape. I am having a blast driving the car and two weeks ago I was the second quickest car out of apprx 112 entries. A BM short wheelbase bike-powered car beat me by .4 sec.

I am running a bare chassis because I havent started/finished the body and wings for the car. Hopefully, I will have that done so I can get the car on a 'real' track later this year. So far car seems to handle pretty darn well even without bodywork and wings.

My pc died so I dont have exact gear sets but I did gear the car about as low as I could with some used gears I bought on here and elsewhere. I have to back off the throttle then short shift first gear, otherwise, I would be spinning the rear tires for a long distance. I am using a 13:37, 15:36, 17:33?, and a 19:? for autox gears. I have only found one location where I needed to shift up to third. Engine makes plenty of torque and I havent found it necessary to downshift into first on any of the courses our two clubs have set up so far this year.