cfdarch

Have just started autoXing this year w/ the local chapter of SCCA. Was curious as to how full or not full peole or running their gas tanks? The old weight vs. balance dilema. I have run both half & full and not sure I could tell any difference as the time spread between events and the rather pleasant suprise that I am noticably improving w/ each event. Also as mentioned previously on the board 2nd gear seems a little tall. The BMW M3's are hot coming out of corners in 2nd where I'm ******* it @ lower RPM's. I hope the answer is not to shift into 1st to often! Finding first w/o nicking reverse in the heat of battle is a challenge. Any thoughts short of ROW gearing???

Buck

I run autox's with the fuel light on. See the other thread on fuel levels posted by AustinL for my response to his question.

SkipSauls

Hi Cary,

I'm probably going to put the ROW gearing on my C4S after this year's track season to get it ready for next year. I haven't autocrossed the 993 yet, but at the DEs on the technical tracks around here I've found myself wanting a lower 2nd gear when exiting a tight turn. The 993 just isn't in the power band, and I have found myself lagging behind cars that are otherwise slower.

At two recent DEs I spoke with a few other 993 owners and they all experience the same problems. I have tried downshifting to 1st on a tight corner, but that doesn't work at all. The car quite obviously isn't happy, and I end up having to upshift almost immediately. I've also tried a number of different lines, different entry speeds, and so on, but I don't believe that there is much that can be done. I'd feel different if the more experienced 993 drivers and instructors said that they didn't have the same type of problem.

What baffles me is why the US cars used different gearing. Ride height differences I can understand due to legal requirements, but what is it about the US that made Porsche put higher gears for 2nd through 6th? Strange.

<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Flying Finn

[quote]Originally posted by Skip in Boulder:
<strong>...What baffles me is why the US cars used different gearing. Ride height differences I can understand due to legal requirements, but what is it about the US that made Porsche put higher gears for 2nd through 6th? Strange.</strong><hr></blockquote>

It's the (Swiss, I think) 'drive by' noise law... That's why stock 993 is so damn quiet too.

These things (ride height, tranny, sound) are just plain bad...

Ray Calvo

Been xcrossing for years in one 911 or another. I feel best performance on xcross where oversteer (or at least quicker steering) is a benefit is with 1/2-1/4 tank of gas - I do notice a difference vs. a full tank.

As far as shifting to 1st - I avoid it. A dopey $2 trophy isn't worth the expense of a tranny rebuild or to go to Euro gears (which might or might not help sufficiently; might help on one course but not another).

Tom W

Carey,

While relatively new to Autocrossing (2 day school and 3 events) I can offer the following observations:
For the first few events having an instructor in the car and full tank of gas is unlikely to have a big impact on your time. Until yopu learn good car control the little things will not matter. FWIW I run with about 1/2 tank that's 50:50 of 91:104 octane. My car is a daily driver and it's hard (and not worth the effort) to control fuel level that much IMO for my skill level.

RoW gearing will make a difference (I have modified gearing). It may also change the class that your car runs in. While I checked with the tech expert in SCCA to confirm I'm in ASP(-N), my placement could be challenged and stick me into a higher class.

Remember that mods to your car affect the class you are placed into, much more so in PCA events than SCCA, but if you concern is "doing well" remeber it relative to your class, not just everyone out there.

I'd recommend getting more seat time before you make the decision to spend significant money on mods like changing your gears. Then you can make an informed decision based on your experience and desires. (Yes, I did it backwards but that was because I had already paid to have my transmission torn apart to get it repaired.)

I think the best ow cost investment to significantly improve your autox times will be to get an extra set of wheels ($500ish) and put some Kuhmo's on them ($700). That will be a much bigger change (from my observations of my car to other 993s) than the gearing (and much cheaper).

Tom

cfdarch

Thanks for the responses!
Kim, unfortunately time seems to be the best way I can determine whether my control skills are improving. When I need a better run (lower time) I tell that guy (helmet in hand) who wants to hop a ride..."maybe next time"!
Buck, thanks for the link I will try to leave the house w/ less than a half a tank next time and work my way up to the fuel light scenario.
Skip, gee if I could only say it as well as you did! Ditto. If you do the gear swap please tell us how it goes.
Flying Finn, that is the list isn't it!
Mr. Calvo, I agree the downside of a bad shift in the daily driver makes no sense.
Tom, I do need to figure out the SCCA rules. Currently I'm listed A stock. I did get an extra set of wheels and am running Kumho ECSTA V700's 225/18's on the front and 265/18's on the rear. That change alone was phenomenal as I now have an inkling of what throttle steer is all about. Also did Gert's RoW M030 / Bilstein HD and this car stays flat and even under extreme throttle /braking the car seems much more poised. Last but not least RSR's for spectator enjoyment. For now I plan on driving more & saving my $$$$.

cfdarch

Kim

Agreed it really isn't time alone. In fact I usually don't check times closely when I'm running. Like you I try to be a little quicker w/ each successive run. I'm still working on finding the line consistently and w/ the kumho's figuring out just how much work they are really capable of doing. My 3 usual problems: 1. brake to early. 2. use the brakes to much. 3.Modulating the throttle out of corners. I've seen the good guys and they can hit the same spots time & again and do it smoothly! At this time I'm more experimental than methodical. One of these days I hope to be working on systhesis

Robert Collins - 96 993TT

Cary- Did you tell Silver Bullet I was out there bumming rides off you?!? It sounds like he was talking about my 200+ pound a$$!!

The M3's were both friends of mine and I rode with both. They do have a lower gear ratio in 2nd, so they stay in the power band at that track virtually the whole time.

Congrats on making your times better throughout the day. My M3 friend Greg told me you beat his time both days, even if you did brake too early. <img src="graemlins/nono.gif" border="0" alt="[nono]" /> Just think how much you'll beat them by once you get more confident. The silver M3 got an 85.148 for the day, but he had SERIOUS Kumho slicks on his car. Absolutely zero tread.

Anyway, great job out there! Looks like a great time. I'll see you out there soon, I think I'm getting the bug!! <img src="graemlins/c.gif" border="0" alt="[ouch]" /> <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

cfdarch

Robert

By adding a couple hundred pounds in the first outing it just makes it easier to be a little quicker the second time around. Beware of the bug. As Kim reminds us...we are on a very slippery slope.

Jim Michaels

Cary; not so fast. Unlike ole Buck, I run autox with at least a half tank, and the spare tire in place. I've even been tempted to throw a sand bag or two in the front trunk when the guy who wants to ride with me won't ride there. You might not want to pay any attention to what I do, however, because I also disconnect the front sway bar to soften the front end and provide some oversteer.

I haven't shifted back to 1st in years because it takes time and is scary to boot. Instead, I try to maintain momentum. I don't really want to slow down; I just want to change directions.

cfdarch

Jim

From a guy who lived in beautiful Blacksburg years ago I'm all ears! I have not removed the spare nor even the air compressor. Maybe I need to stuff those 200lbers like Collin's in the trunk for even better distribution! The instructor @ my 1st autox experience thru the local PCA club suggested a full tank has it's advantages. Regarding downshifting to 1st I currently only do it when I have to 180 around a single cone and exit speed is waty slow. Like Skip I can visualize some places where it would help w/ exit speed, but I would end up having to upshift so soon why risk it.
BTW if you happen to remember Mr. Fooz that will tell you how long ago it was when I lived in your fair town (is it a city yet?).

Greg Fishman

[quote]Originally posted by Jim Michaels:
<strong>because I also disconnect the front sway bar to soften the front end and provide some oversteer.</strong><hr></blockquote>

I thought about doing this at an autocross but didn't have the time. How bad does this make turn in, does the car get sloppy?

In my street car the only way to get oversteer was to pitch the car and dump the throttle. Dramatic moves that certainly didn't help my time any, but made it interesting . I only do one or two autox a year because it is really not much fun in a stock car even with Hoosiers.
Greg

TrackJunke

An idea for the 2nd gear not being short enough. Try left foot breaking into the tight corner and keep your foot on the gas at the same time to keep the revs up.

Jim Michaels

Cary: I've still got about 20 Fooz coupons. I've put signs up on 460 that proclaim that Mr Fooz will return some day.

Greg: Car turns in very well, and throttle application brings rear end around. It took me several runs to learn just how much throttle to apply, however. The first time I ran with sway bar disconnected I entertained the spectators and finished to a standing O. The same over-exuberant throttle application that once promoted more push now promoted a slide from the rear on almost every turn. Although I managed to catch them all, my time was very slow. My guess is that disconnecting the front sway bar lowers my time by one second or more on the average 60 sec tight course. If the course has fast sweepers, but no tight turns (extremely rare), I'm better off with the sway bar connected.

This is the third or fourth time I've described the disconnected sway bar approach on rennlist, so it may be wearing a little thin for some users. Thanks for your patience. I'm trying to quit, but I keep getting prodded.