steved0x

I track a 2000 Boxster S with 6 speed, and there are a few corners where I am not sure whether to stay in 3rd or go down to 2nd, like T7 at Road Atlanta or T12 at VIR.

In both of those corners, I seem to consistently have a vMin of 40 when I drop down to second, and vMin of 43-44 when I stay in 3rd. But my best lap time at each track was set when I dropped to 2nd, but because of traffic and other things, I don't feel it is as simple as that (aka I still don't know if 2nd is better). And I don't know enough about data to look at it and see. I do have an AIM Solo DL that I have been using and so the data is there once I can learn to use it. For now I mostly use it for lap times, predictive lap times, and data overlay for videos.

T7 at Sebring (vMin 36) is a no brainer to go to 2nd, but on some of the other corners it feels like it is right on the borderline between 2nd and 3rd, but by staying in 3rd and learning to roll more speed, I feel like staying in 3rd is the right choice.

T3 - vMin 53
T10 - vMin 49
T13 - vMin 55
T16 - vMin 55

Next time I go to Road Atlanta (T7) or VIR (T12), I wonder if I should focus on:

Roll more speed and leave in 3rd
Try and roll more speed, and don't overslow as I go to 2nd

What strategies do folks like for knowing when to try and roll more speed in a higher gear, or to get the downshift so they can pull better after the corner? Do you have a target RPM that if the corner takes you below, you like to get the lower gear?

Thanks!

Steve

sbelles

It always feels better to have more power coming out of the corner but that doesn't mean it's faster. Set a sector from corner entry to the end of the next straight and then run it both ways.

Veloce Raptor

IMO, roll more speed into the corner and remain in 3ed if you can, and pay attention to segment times rather that lap times.

mmuller

What this guy said ^^^^^

steved0x

Segment times, that will give me something to look for how to do, and maybe checking just segment times in the data analysis will be less daunting than looking at a whole lap and not knowing where to start,

Thank you!

trygve

I can give input based on my 2.5L Spec Boxster. The 5-speed has a shorter 2nd (and 3rd) gear than your Boxster S 6-speed, so the corners that are borderline for me are probably 2nd gear for you, and your borderline corners will be a few MPH faster, but the ideas are the same.

There are some slow corners where I used to downshift to 2nd, where I’ve learned to stay in 3rd for several reasons. It depends on the corner.

• If you have to shift back up to 3rd right away anyway, there may not be any benefit in segment time from that moment of additional 2nd gear torque. There’s time lost in the upshift that would be avoided.
• Downshifting & quickly upshifting creates two extra opportunities to screw up a shift and lose time to your competitors, especially in a race (vs. qualy or time trial) where track position is always important.
• Downshifting & quickly upshifting creates two extra potential wear/error events on the gears.
• In a tight corner where you can get wheelspin exiting in 2nd, it’s hard(er) on the transmission when the tires do hook up. If the lap time is the same either way, being kind to the transmission wins.
• Staying in 3rd gear and avoiding the complication of downshifting might give you more opportunity focus on rolling speed through the first part of the corner, and getting on the gas earlier, because you’ll have less torque to create wheelspin and therefore can hit the throttle more aggressively.

West coast examples:
At Sonoma, in the SPB I now stay in 3rd gear in Turn 4, where I used to use 2nd gear. But Turn 11 is definitely 2nd gear. Turn 7 is probably debatable.
Thunderhill Turn 14/15 is another one where I used to use 2nd gear, but found that my competitors were killing me there and so I decided to try 3rd and make the whole corner smoother and calmer, and I think it’s better. Similar case for Buttonwillow Star Mazda corner.

Veloce Raptor

One more point: the more gears we feel we have to go down, the more our brains tell us to brake. Less bake more gas is the faster way around...so not going down to 2nd may be an effective way of braking less and rolling more speed in safely

DTMiller

So much this.

I've found most gear issues get resolved by increasing the vmin. I'm sure that isn't always a possibility but start there. In other words, if it's close you can probably resolve it by rolling more speed which is probably better anyway.

mark kibort

You should be using the gear that allows you to come out of the turn, as closest to the max power range as possible. "over slowing "is a choice, just because you shift into 2nd, doesnt mean you need to "overslow". you can blip and change gears very quickly after initial turn in. this will give better control around the turn, and then as said, give much more exit power for acceleration. the downshift on approach asists braking so, keep the RPM above 4,000-5000rpm around the turn (if your redline is around 6500rpm) any lower than that, you could be sacrificing valuable hp for the exit.

the only time you should NOT select 2nd, is if you want to not have to shift, transmission is knotchy and you dont want to fight it, or have a turn that where shifting on the exit is upsetting the car and hard to modulate power (or in a rain situation)*
* many times being in a lower gear going into a turn, gives better control and allows the LSD to do its job.

mark kibort

I found the opposite on almost all counts... ........the only think i agree with you on is saving a shift if you a concern with your transmission, but there is really no more "wear being in 2nd vs 3rd" and slightly more wear making a shift. not much if you execute it correctly. if you are at max power, if you are not then you are just leaving time and control on the table. Going into turns on decel at higher rpm gives more rear end control to stay on the edge of adhesion much easier. especially turn 4 at sears and turn 14 complex thunderhill. when you downshift, all you have to do is add throttle to keep your speed up. Practice... it should be second nature.. dont drive around issues, get better, improve skills so that shifting not an issue.

Drew_K

ProCoach

ProCoach

Thundermoose

It's already been said but carry more speed. I think you can take that 12 at VIR at 45+. I suspect you're overflowing at 11. It's very easy to do IME. Peter's and Ross' track walk do a great job of explaining how to do 11.

mj951

Also, there's a sub-forum above for Data Acquisition and Analysis with some good reading and book recommendations to start breaking down your laps and data.