Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum - View Single Post - Transmission/Clutch Slipping (OBD2 Plots)
View Single Post
Old 10-11-2012, 01:20 PM   #16
Focus Fanatic
PratoN's Avatar
Join Date: Jul 2011
Fan#: 88058
Location: Milwaukee, WI
What I Drive: 2012 Kona Blue Ti Hatchback, DCT

Posts: 4,272
Points 4,690, Level 43
Points: 4,690, Level: 43 Points: 4,690, Level: 43 Points: 4,690, Level: 43
Level Up 70% Completed
Level up: 70% Level up: 70% Level up: 70%
Forum Activity 2%
Activity: 2% Activity: 2% Activity: 2%
FF Reputation: 19 PratoN Great Standing Member
Buy-Sell-Trade Rating: (0)
Originally Posted by Ox-y-GenIII View Post
You are saying because of clutch slippage, but isn't it technically going to have to raise the rpms to stay at 55 mph because the car will need more torque to overcome the incline at the same speed?

its like walking up hill. You need more effort (rpm per say) to keep climbing the hill at the same speed.
Don't confuse RPMs with power (though, they are related.) You will need more gas and oxygen to climb this hill (which makes power) but you can create the same amount of power at different RPMs feathering it in 4th might make the same amount of power as moderate pressure in 2nd gear, etc. because that’s tied to torque and speed.

You don’t need to pedal your bike up the hill any faster to keep the same speed (bikes make more sense in this example); you’re just pushing yourself harder to keep the same rotational velocity. It’s easier to just downshift.

But what’s going on for the OP (and my own car) is that we’re at a relatively reasonable RPM range (1,200-1,500) for a slight incline and the clutch starts slipping so the RPMs go up but the speed of the car is going down. This results in some fun noises that shouldn’t happen. If we are truly bogging the engine down, the clutches shouldn’t slip, the car should just downshift – especially because this is an “automatic” transmission and Joe Scmhoe across the street doesn’t realize that he’s going to have to punch it and force it to downshift… nor should he have to do that. Because if there’s a car in front of him and he doesn’t have selectshift, he can’t easily force a downshift and is stuck with the clutch slipping.

I guess what I’m trying to say is: It shouldn’t happen.
2012 FF Ti HB Kona Blue, DCT, Built 5/24/2011, 401A + Ti Handling Package, Parking Technology Package, Winter Package, Moonroof, and MFT w/NAV at v3.8 157k miles and counting...
PratoN is offline  
    Reply With Quote