Shifting in a corner?

[ak]

At the track, I am finding myself having problem with taking a corner with the right gear. For example, Turn 1 at VIR. I really should be taking it with second gear, however with turn 2 coming up, it's more a long sweeper, so I downshift to 3rd on the straight and complete turn 1 and 2 in 3rd gear all together.(this is with 6 speed btw)

What do you guys do in a situation like this? I would like to downshift to 2nd and be in the sweet spot for power coming out of turn 1 but I would have to shift while still turning around turn 2 which is probably no good?

 

[nsxtasy]

For me, going through a turn is all about balance. The car is undergoing strong lateral forces so you need to keep it balanced so as not to break traction. For this reason, I don't shift in turns; I downshift going into the turn, so that I can keep the car in gear and on the power from before the apex to the track-out point. If using a given gear means that I'm going to run out of revs significantly before the track-out point, I go through the turn in the next higher gear.

I've only driven VIR in other cars, not the NSX, but turns 1 and 2 are really one, increasing-radius turn. If you run out of revs before the car straightens out exiting 2 (before the un-numbered left kink before 3), then I would use the next higher gear (i.e. third gear) all the way from the braking zone entering turn 1, rather than having to upshift from second to third in the middle of turns 1-2.

BTW, VIR Full seems to have an affinity for unnumbered turns. It's a course with 25 turns numbered 1 through 17a.

 

[Ponyboy]

Downshifting during a turn is tough, ak. It can be done but it's gotta be butter smooth. As Ken notes, the downshift may upset the balance of the car while in a cornering event. I'd just leave it in third - you'll save some time on the downshift from T1 (3rd to second) and T1 to T2 (second to third) by keeping it in gear. Still, there's nothing like real world testing. I would try it both ways, see how comfortable you are with downshifting in that corner, and which method is quicker.

Do you know your RPM levels as you aproach T1 and then going through that series of turns?

 

[ak]

Actually I'm talking about up-shifting in a corner I see F1 drivers do it all the time But then their shifting takes nano-second and probalby doesn't upset the car much. heh

 

[Ponyboy]

Actually I'm talking about up-shifting in a corner I see F1 drivers do it all the time But then their shifting takes nano-second and probalby doesn't upset the car much. heh

Understand. Still IMHO, you'd save time by minimizing shifts by keeping it in 3rd. In my experience, upshifting is heck of a lot easier than downshifting during a corner. If you can note your RPM during the cornering sequence and reference where your car makes torque that may help in making a determination as well.

Yeah, F1 drivers do it all the time. Of course, they have sequential gear boxes and traction control to help. Basically, change gear, stand on the throttle, and steer.

 

[CL65 Captain]

A supercharger or 3.6L would help tremendously... Then you have plenty of torque to get yourself out of the corner in 3rd. So my opinion is add one of the above and stay in 3rd. :biggrin:

 

[nimdivino]

Practice blipping the throttle on up-shifting. I know how scary it is in the middle of the turn and trying to shift. You can easily jerk the car and loose its balance by doing that. But if you really have too, blip the throttle and when done correctly, you'll be okay.

 

[Batmobl]

ill trade u for my 5spd... wider gearing... lol j/k ill leave this one to the pros on the board.

 

[stuntman]

Understand. Still IMHO, you'd save time by minimizing shifts by keeping it in 3rd.

Depends on what RPM he is at in 2nd during the corner. If he is at 6k rpm, yes it would make more sense to stay in 3rd. But if he's at 4-5k in 2nd and because the corner is an increasing radius, long corner. It would not make sense to lug the car in 3rd at 2-3k rpm, but rather stay in 2nd and upshift while tracking out (which isn't a big deal).

Practice blipping the throttle on up-shifting. I know how scary it is in the middle of the turn and trying to shift. You can easily jerk the car and loose its balance by doing that. But if you really have too, blip the throttle and when done correctly, you'll be okay.

Blip on upshift?


Upshifting in corners or at track out is normal and not a big issue. But like stated in my first response, if carrying the higher gear dosn't lug the car through the corner, then it's better to be in the higher gear. Upshifting in a corner isn't as controversial as downshifting in a corner.

 

[Ponyboy]

ak, saw this and thought of 'ya. Hope it helps.

 

[L8apex32]

I agree with Stuntman. Upshifting in a corner is not a big deal. What do you think is going to happen bad during the upshift?

I can tell you some of what is going on. First, are you secure in your seat? I find myself holding my long body in the seat with my arms in turns and this makes in-turn shifting more of an issue. Try to address this along the way to your solution, if you haven't already.

In a turn under acceleration, when you go to upshift, you lose the forward thrust temporarily. This will cause weight shift to the front and give your front tires more grip. It also reduces the grip in the back. There are some times when you might be turning so sharply that when you lift off the throttle you *could* induce some oversteer. One way to "fix" this is to turn less as you do your shift. At the same time you get off the throttle, turn less, do your shift, get back on the throttle, then turn more.

The weight transfer on a stock NSX from red-line in 2nd to the front during an upshit is not too large. You should be able to steer around the effect this has on handling without too much effort.

The next thing to consider is - how long does it take you to perform the upshit? In our cars and with our trannys, this can be done in fractions of a second. Didn't get the clutch in all the way? No big deal. Did you let the clutch out before it was in gear all the way? No big deal. Didn't lift off the gas too much? No big deal. See where I'm going? Cram it in there.

By upshifting quickly, there is very little time for weight transfer to occur and that means little effect on the line the car takes around the turn. I assume this is the problem you are trying to avoid - and a quick upshift solves this almost totally.

Two more quick things. If you know you are going to upshift in a turn and the process upsets your line, take a slightly later apex turn... and you'll find it easier to make the turn with the "less than ideal" effect the upshift causes. In other words, plan for it and steer/drive accordingly.

Finally, it is always better to stay in the higher gear when possible (which prevents the need to upshift). See which method is quicker. If you are behind a car that does similar laps as you, see which way you gain the most or lose the least. If that doesn't work, index the turn. (Index means to check your rpms at a point down the track and see which way leads to a greater speed at the later point.)

Be confident - cram it in there quickly and stay on the throttle!

 

[Bigglezworth]

I never downshift going through a corner as the car can quickly become unbalanced. I do however up shift through corners depending on the speed carried through it. I also do my best to ensure that the RPM's are always above 6K for any corner and takes away the guess work of which gear I should be in.

 

[Scin]

If it is faster to shift, then go ahead and shift. You will not be able to use the tires 100% for cornering, as the shift will slightly upset the car. However, if you can use 98% of the tires and shift and ultimately get down the straight faster and therefore around the track faster, do it!

 

[BioBanker]

Personally, I try to minimize the things that are happening in a turn for two reasons:

1) As NSXTASY said, upsetting the balance of the car is a less favourable thing to do than maintain it; and

2) I usually have my hands full anways.

If I found myself running out of gear mid corner, I would enter that corner in the gear I needed to leave it in next time around. I bet that that is a faster way through the corner anyways. It sounds to me that you're entering the corner in the wrong gear.

Are you braking with the engine entering the corner or only the brakes?

 

[nimdivino]

If you are in the middle of a turn, up-shifting can still loose balance, and depending on your gearing and modifications to your driveline, you might still loose couple hundreds of RPM to the next gear. For example for my other car, I have a lower-ring and pinion gear, and I have a 9lb flywheel. I loose a lot of RPMs in an upshift (which is pretty normal on my car anyway) but blipping the throttle does help and makes the engagement smoother, which also helps if you have to upshift in the middle of the turn.

I'm no where near pro so please correct me if I am wrong, I'm just basing my answers with experience.

niM

 

[Jason Weaver]

Just an opinion from someone who has a few laps under the belt at VIR in different street / racecars including the NSX from instructing to wheel to wheel racing. Turn 1 and 2 at VIR is definately not a 2nd gear corner. I would assume you are overslowing the car at turn in (not a bad thing) therefore the car seems not to be in optimal rev range initally after turning in.

As you get more time there you'll progessively start carrying more speed at both turn in and tracking out to the apex and be in more of an optimal rpm range. I'm not sure what kind of modifications your car has but there should be plenty of grip there with a mostly stock NSX through 1 and 2 in third gear using a fair amount of throttle.

Just my .02...any of that jumble make sense?

 

[nsxtasy]

Turn 1 and 2 at VIR is definately not a 2nd gear corner.

That's probably true for the six-speed, which ak (the original poster) has. However, second gear might be appropriate for the five-speed stock gears. Remember, with the five-speed, second goes all the way up to 81 mph (vs 74 for the six-speed). That might be enough to get you all the way around 1 and 2 and straightened out towards the unnumbered left kink, without running out of revs.

 

[ak]

Just an opinion from someone who has a few laps under the belt at VIR in different street / racecars including the NSX from instructing to wheel to wheel racing. Turn 1 and 2 at VIR is definately not a 2nd gear corner. I would assume you are overslowing the car at turn in (not a bad thing) therefore the car seems not to be in optimal rev range initally after turning in.

As you get more time there you'll progessively start carrying more speed at both turn in and tracking out to the apex and be in more of an optimal rpm range. I'm not sure what kind of modifications your car has but there should be plenty of grip there with a mostly stock NSX through 1 and 2 in third gear using a fair amount of throttle.

Just my .02...any of that jumble make sense?

I'm probably overslowing, that is true. Last few times I have been to VIR, I've always had problem with traffic and could never really practice the braking at the end of the straights.(Not a fan of braking full force right behind someone else) but could you take turn 1 at over 60mph with street tires? That's what I would need to do to stay in the optimal RPM range in 3rd. For stock geared 5 speed, that's defeinitely in 2nd gear range.

I guess I just need more practice.

 

[nsxtasy]

could you take turn 1 at over 60mph with street tires?

The problem with discussing speeds is, where in the turn are you referring to? At the end of the braking zone, where your speed is lowest? Going past the apex? Track-out?

I know in my ITR, for which second gear runs out at 60 mph, I take the entire turn in third gear.

 

[ak]

So I was at summit point earlier this week and was conducting some test. This is slightly different than shifting in a corner but...

The numbering of the coner on the map is kinda funky. Turn 5 is the hairpin and turn 9 is the right hander onto the straights.
For the back portion of the track, Turn 5-9(Hairpin to the backstraights), I tried taking Turn 5 thru 7 in 2nd, then shift to 3rd between 7-8, then take the rest in 3rd. I also took the whole portion in 3rd. It looked from my video footage that doing 5 and 6 seemed to give me a slight advantage but that tiny advantage went away when I shifted from 2nd to 3rd. At the end, I was coming out of Turn 9 pretty much at the same time in either case. I guess in this case, I'd probably benefit from leaving it in 3rd and concentrate on getting the best line....

 

[L8apex32]

So I was at summit point earlier this week and was conducting some test. This is slightly different than shifting in a corner but...

The numbering of the coner on the map is kinda funky. Turn 5 is the hairpin and turn 9 is the right hander onto the straights.
For the back portion of the track, Turn 5-9(Hairpin to the backstraights), I tried taking Turn 5 thru 7 in 2nd, then shift to 3rd between 7-8, then take the rest in 3rd. I also took the whole portion in 3rd. It looked from my video footage that doing 5 and 6 seemed to give me a slight advantage but that tiny advantage went away when I shifted from 2nd to 3rd. At the end, I was coming out of Turn 9 pretty much at the same time in either case. I guess in this case, I'd probably benefit from leaving it in 3rd and concentrate on getting the best line....

By measuring it like you are - that is called "indexing a turn". You want to measure both your segment time (from turn 5 to 9 or wherever you are measuring) and your exit speed. If your two techniques take the same time, use the one with the higher exit speed.

If you aren't super consistent, then use the higher gear until you can nail it each and every time. Then experiment with the lower gear.

You are doing exactly what race teams do to find quick lap times. Consistency first, then try to go faster.
YMMV

 

[Ponyboy]

ak, I certainly hope you didn't lose anything off your car at the track. That'd be humiliating - especially if lost during some sort of offroad excursion.:wink:

 

[ak]

ak, I certainly hope you didn't lose anything off your car at the track. That'd be humiliating - especially if lost during some sort of offroad excursion.:wink:

Stop stalking me in my photo gallery!