Tricky corners, how to know when to stay in 3rd and when to go into 2nd

[maytag]

Everything I know about this comes from Superbikes.... But the parts I'll tell you about most certainly apply to cars as well. :-)

There are two rules I always emphasize at the racetrack:

1) Three-Time World Champion Freddie Spencer always said "Go Fast in the Fast Stuff".
Everybody is slow in the slow stuff. If you want to beat somebody, it happens by learning how to go faster when and where it matters. Others have alluded to it here already: use the slow stuff to setup for the fast stuff.
Which brings you to rule number:
2) The quickest way to find the fastest way around a race-track is to learn it backwards.
Start at the fastest part of the racetrack, and ask "if I want to go fastest here, where do I have to be when I enter the straight? That means making that straight as LONG as possible (meaning you reach full-throttle earlier in the straight). So if I want to be able to be "here, this fast" at the beginning of the straight, then where and how fast do I need to enter the corner? .... etc ..... etc..... work your way backwards through the racetrack like that.

So the question is exactly as another commenter below has posed: which gear gets you the most speed at your braking point on the straight?

For me, in the car, I tend to think I can carry more speed through the corner and thus begin my straight from a faster start. But invariably the car understeers, scrubbing speed, and I can't get the car to turn so I end-up lifting the throttle and ruining my drive. Being a little more patient (going slower) earns me huge dividends on the drive out of the corner, and that equates to more speed all the way down the straight.

A Short-Shift (does this term work in the car-world?) can be very handy on occasion, when it lets you go WOT when you're tempted to get greedy, and it very slowly picks-up speed through the corner and is finally in the power by the time you're driving out. This is a very smooth way to exit a corner fast. But if you find you have to lift AT ALL, then you blew it and you should be in a shorter gear.
On the other hand, if you find you have lots of corner-exit left, then you aren't going fast enough and should probably be applying that throttle judiciously in a shorter gear.

Doe that all make sense?

[steved0x]

Originally Posted by The Radium King

you're over-braking on the downshift into the corner, vs not having enough torque on the exit.

try downshifting in the middle of the corner instead. i know, hearsay! just be smoooooth.

Originally Posted by Quadcammer

if you're not damn near ****************ting your pants at turn in, you got on the brakes too much.

I'd stay in third.

These! On these corners, at turn in, I am going too fast for second, but by the time I get to the apex and get back on the gas, I am lugging in 3rd. So I end up overslowing and getting my shift done, but then I can really rocket out of the corner in 2nd

If I can keep that extra 3 mph and still get my shift, I think I could pick up some time... And to do that, I am going to have to move the shifting into the turning phase while I am still trail braking, which carries more risk than shifting in a straight line. I have chirped the back wheels a time or two on a flubbed throttle blip, and I have seen cars upside down on the wall at T7 at Road Atlanta, so that is something to keep in my mind...

Originally Posted by thstone

This.

Even if you can roll 3rd gear through a corner, you may not be carrying sufficient speed to accelerate out of the corner very quickly because of lower torque at lower RPM's.

Thus, going thru the corner in 2nd, even though the cornering speed might be slightly slower, can result in a faster overall lap time because you will be at very high rpm on corner exit and get a great jump out of the corner and carry that speed all of the way down the next straight.

I experience this issue at Buttonwillow raceway in the Star Mazda turn in the counter-clockwise direction. I have found that going to 2nd and then hammering out of the turn results in a better lap time than rolling through in 3rd and waiting for the torque to come on as I exit the turn.

Of course, the best answer is to get good enough to go through in 3rd fast enough that the rpm's are high on corner exit!

Yes it is terrible to get a great run through a corner and then be lugging in 3rd I guess the question is, can I get fast enough through the corner for 3rd to be effective? In some turns, I have been able to get faster (like at T10 at Sebring which used to be right on the borderline between 2nd and 3rd for me, but now is a solid 3rd gear corner).

Originally Posted by Racer Boy

Does your data show your speed at the end of the straights? That is what you should look at, when comparing 2nd or 3rd gear in the same turn. You need to see which gear gives you the most speed at the end of the straight. As thstone says, it's about the acceleration coming out of the turn.

I recommend getting your downshifting done before the corner, so you can concentrate on getting through the corner as smoothly as possible. Downshifting in the middle of a corner is good way to unsettle the car, not to mention increase your chance of a mistake. Sorry RK, I think you are speaking hearsay!

This is the tricky one - last time I was at Road Atlanta, and I was running T7 in 3rd and getting a good run through there (43-44 mph). For some reason, on one lap, I decided to go to 2nd, got a 40 mph vMin, and as I was headed down the back straight, the predicted lap time started dropping... that lap turned out to be my fastest lap of the weekend and new personal best at Road Atlanta (1:48.something). So it seems like that definitely does answer it

If I can just get to where I don't overslow for the shift...

Originally Posted by jsceash

VIR I find I get the best launch out of T12 in second gear. The true tell is your brake point speed at the end of the back straight. If I come out of T12 in 3rd I top at 128-130. If I come out in 2nd I can reach 132-136. Its all uphill any torque you get converts to speed at the end.

Diamond the entry to 12 this also give some extra entry speed. Cut so your headed at the back rumble strip brake quick while straight then turn toward the inside rumble strip and as soon as you can lay on the gas drift out to the outside strip then it all acceleration.

My warm lap time at VIR is 2:19 in traffic to 2:15.5 in clear track

That is smoking fast! I watched your videos (and a couple of others, truegearhead, etc) before going to VIR before Thanksgiving, that was a fun weekend.

I think I got up to 129 on the back straight, launching in 2nd at 40 mph from T12, although I think I also got to 129 when I laucnhed in 3rd at 44 mph. When I get up to that speed it increments very slowly. I got to 140 mph at Daytona right around the start finish line after a long run from the bus stop through Nascar 3 & 4. I think you have a little more power, I love watching (and listening) to your videos.

I got a high 2:21 that would have been a 2:20 but I had to lift and give a point by right before hog pen. My next fastest lap was a 2:23 so that one lap was my flyer. I can't wait to get back.

Great discussion! Thank you everybody.

[steved0x]

Originally Posted by maytag

Everything I know about this comes from Superbikes.... But the parts I'll tell you about most certainly apply to cars as well. :-)

There are two rules I always emphasize at the racetrack:

1) Three-Time World Champion Freddie Spencer always said "Go Fast in the Fast Stuff".
Everybody is slow in the slow stuff. If you want to beat somebody, it happens by learning how to go faster when and where it matters. Others have alluded to it here already: use the slow stuff to setup for the fast stuff.
Which brings you to rule number:
2) The quickest way to find the fastest way around a race-track is to learn it backwards.
Start at the fastest part of the racetrack, and ask "if I want to go fastest here, where do I have to be when I enter the straight? That means making that straight as LONG as possible (meaning you reach full-throttle earlier in the straight). So if I want to be able to be "here, this fast" at the beginning of the straight, then where and how fast do I need to enter the corner? .... etc ..... etc..... work your way backwards through the racetrack like that.

So the question is exactly as another commenter below has posed: which gear gets you the most speed at your braking point on the straight?

For me, in the car, I tend to think I can carry more speed through the corner and thus begin my straight from a faster start. But invariably the car understeers, scrubbing speed, and I can't get the car to turn so I end-up lifting the throttle and ruining my drive. Being a little more patient (going slower) earns me huge dividends on the drive out of the corner, and that equates to more speed all the way down the straight.

A Short-Shift (does this term work in the car-world?) can be very handy on occasion, when it lets you go WOT when you're tempted to get greedy, and it very slowly picks-up speed through the corner and is finally in the power by the time you're driving out. This is a very smooth way to exit a corner fast. But if you find you have to lift AT ALL, then you blew it and you should be in a shorter gear.
On the other hand, if you find you have lots of corner-exit left, then you aren't going fast enough and should probably be applying that throttle judiciously in a shorter gear.

Doe that all make sense?

Makes good sense, I have heard Ross Bentley say something similar - often the big gains can be had in the fast corners. Another saying I have heard is that a common mistake is to go too slow int he fast stuff, and go too fast in the slow stuff.

Short shifting is a good technique - I have used it when building up to full throttle in fast sections like Bishop at Sebring - I am almost there, although it was pretty hot last time I was there so the car was down on power a little - I am going this weekend and it should be a lot cooler so we'll see if I can do it.