geoffucla

Hi all,

Just recently picked up a C4S launch car, and I absolutely love it! Still getting a bit used to the PDK, and I noticed that while cruising in basically any gear, the RPMs fluctuate up and down a bit--say total variation of 100RPM. It's something that you wouldn't see if you just glance down at the tach, but if you look at it for a second, you can see it moving up and down slightly, even though the speed is constant. It seems to have no effect whatsoever on the driveability of the car, or the power.

Anyone else with PDK notice this?

Thanks!

Geoff.

RED HORSE

Yep, mine does it. 8,500 miles on a C2S Cab with PDK. Thought I would ask them to check it when I have it in for the next oil change.

ADias

It's probably the e-gas compensating for torque demands. E-gas maintains torque demand requirements.

todd.

Never noticed, but I drive mine almost exclusively in manual. I'm taking a road trip this weekend, so, I'll keep an eye on that.

DRJMK

I do have a question and it maybe silly, but when i downshift, those RPM's go up. Am i downshifting too soon???? The scenario for me is when coming to a stop. should I let the computer downshift or should I do it manually??? Please don't flame me! My excuse is that I am female and don't drive a stick!!! But, I love my car!!!!
so, should we start a thread about 'how to drive the pdk in manual mode"?

gota911

Jen, no flaming here.

When you downshift (with a PDK or a manual transmission) the revs will go up because the lower gear ratio will cause (force) the engine to rev faster. That is why with a manual transmission, most people will "blip" the throttle to get the revs up so when the clutch is re-engaged, the transition to the lower gear is smooth.

When you downshift with PDK, the throttle should “blip” automatically to make a smooth transition to the lower gear. If you haven’t already noticed this, you might want to listen for it the next time you down shift. I know that you are still going through the break in process so you may not be aggressively downshifting, like down 2 gears in quick succession. If you do this, you should notice the car doing a more aggressive "blip" to match the revs for the lower gear.

When coming to a stop, you can let the car downshift or you can do it manually. It is totally your choice.

Hope this helps.

rijowysock

noticed this as well,.. figured was trying to save gas somehow.. figured thats why the droning as well.. not a fan of the droning for sure.. trying to save too much gas... rather use gas and not have droning.

Edgy01

If you have a PDK car they might as well remove the Tach and replace with anything else. You don't need the tach any longer.

PogueMoHone

^
Not true!

In manual mode, you can play with it and try to beat the program.

geoffucla

Thanks all.

Actually, I usually drive in manual mode too, and it happens then as well. In fact, it's basically in any gear any time (okay, maybe not in first, but I haven't paid attention to that) I would say it's under 3-4k RPMs. Probably just part of the design somehow, and it definitely could be related to keeping the constant torque, as mentioned above.

Red Horse, let us know what your dealer says when you take your car in.

Thanks--

Geoff.