vantage

Thanks. Lotus shoots for 40/60 weight distribution even in mid engined cars, so there are some similarities to driving it like a 911, particularly on corner entry.

ChrisF

It's a matter of preference. In my 991RS, I tried both but found the PDK so good at gear selection that I ended up using it most of the time on track. So far, my impressions of the 4RS PDK is that it's even better thus my thoughts on going auto mode on track.

I find paddle shifting isn't as enjoyable to me as a full manual car. If I want to shift, I'll drive a manual car

mrd_spy

PDK Auto is slower end of , if you feel you need it to help you get round a track then thats all good, but people saying it's better and people saying you cannot fit 3 shift in is daft, learn how to drive and never buy a real manual car ! . Some times the Auto changes too much, some times it changes out the bend because it got it wrong, it don;t know there is a car in front if you catch one up so gets confuses why you are going a bit slower . I found Auto mode horrible. plus it's slower as it tries and get 9k revs from the car which is much slower than shifting earlier.
So you loose time every shift ! not gain time like people think !

GrantG

I’d be interested if you have any data to support this opinion? I can imagine that short-shifting might be helpful in certain (but definitely not all) situations.

mrd_spy

yes I have the data so not an opinion, but stands to reason as peak hp is 8450 rpm, performance box same day sames road. 100-200 kph full auto 7.4 seconds manual 7.2 seconds. add in you might hit this speed 4 or 5 times on even a small track that is 1 seconds lost a lap.

Also full auto does so many more changes a lap, when no need, so you must lost even more time. I thought auto was **** on track.

GrantG

Of course redline (and shift point) should be higher than the peak hp point on the tach. You have to also take into account the rpm at which you land in the following higher gear after an upshift. If you shift at the power peak, then you will be further from the power peak in the next gear than if you had shifted above the power peak. You need to maximize power/thrust over time (not at just the shift point).

Eric5280

You'd need repeated controlled testing. Also, the car dors not stand still for that .2 seconds, it's moving so you only gain a small time actual laptime advantage. Not 1 second. Need to calc the actual time gained over distance, not time to a speed.

mrd_spy

silly me. Yes you might only gain 1 meter I,ll have to put the data in a distance vs time graph.
it’s slower though either way, so if you chase times, shifting earlier is faster . 9k is just for laughs not performance.

mrd_spy

auto is slower, that's all that matters really is the point. Peak torque is 6750rpm. So for what ever reason torques, peak Bhp. Going to 9k is slower than going circa 8.5k ish.

GrantG

You may want to continue to experiment with this before making a generalized conclusion (and create data to compare for each case). I would guess redline (or nearly redline) shifting (manually, if you prefer) should be fastest in many circumstances. Neither shifting at peak torque nor peak hp is fastest in most cases (it's usually fastest at redline or very close to redline).

While the gearing of the 4RS is unusually low (achieved by final drive ratio), the spacing between gears has not been adjusted (and this is the more critical variable with respect to shift points). You want to control the rev drops into the next gear and shifting high up the tach is the best way to do this (aside from changing the gear stack).

With only 600 rpm between peak power and redline, you won't have fallen too far off the power peak by redline (but you will fall quite a bit below the power peak in the higher gear if you short-shift).

GrantG

Porsche does not set the redline at 9k for laughs. It's entirely performance driven. If it was faster to shift at power peak of 8,400 rpm, I assure you that's where the redline would be (it's much harder on the engine to shift at 9k than 8,400 rpm and Porsche doesn't do it for any reason other than performance).

There is no manufacturer that sets the redline at power peak - it's always higher and it's always done for a reason other than just to impress...

The only car that does not benefit from shifting above power peak is one with a CVT transmission.

KelvinC

Rennlist is the land of opinion-based, generalized conclusions.

Manifold

You guys should be careful about disagreeing with GrantG. He's a fountain of knowledge, and rarely wrong about anything related to cars.

lovetoturn

I just leave in auto most times and manually overshift when needed. You can have the best of both philosophies that way. The PDK is so smart that it will delay downshifts by just a hair into second gear coming off the main three straights of my track into tight 45 mph bends if I am going 100% vs (95% to 90%). So when I am working up the pressure and heat into the tires, I will manually override the PDK with an earlier down shift into second here and there under braking. I will also do an early upshift in three places to get the car into third for better torque management coming around some longer medium speed sweepers. If I am really going for that hot lap, I will let it ride in the higher rpms of second to get that momentary launch off the corner and just manage the slip angle.

I would suggest everyone try it both ways and also the hybrid method. That way you can be more engaged when you want to, and realize how good of a job the PDK really does. Then you can just put in auto and focus on all of the other aspects of tracking your car as fast as you can. I manually shifted 100% the first four times at the track under break-in and enjoyed it very much. Had to of course keep the revs down and was not at WOT. Everything was smooth and controlled. Then, once up to full tilt and all hell could break loose, I reverted to my auto/hybrid mode and haven't looked back. Everybody has an opinion, but I think all would agree that beginner to intermediate drivers will be faster in auto while advance to pro level drivers probably won't make much difference. To each his own.

Manifold

The Owner’s Manual is explicit that the car shouldn’t be tracked during the break-in period.