Downshifting?

[MikeE30325i]

well after driving the car regularly for awhile i now downshift regularly and pretty well. i can stil get better, but i am not doing it so bad that i will break something.

[backtrail69]

I do whatever I feel like... :P I can rev match, heel-toe, double clutch, clutchless shift etc etc.. :D

[euroshark]

The motronic system cuts fuel off if you have the throttle closed no matter what RPM you are at over 1000. So coasting at 3000rpm down to 1500, then popping in into another gear lower and watching the tach climb back up to 2500 will not use more gas.

How often do you guys miss shifts? I do it maybe once every 6months to a year, and thats if I'm distracted and its just kind of a "Doh!" moment.

No kidding, do we just have a bunch of retard drivers or something? I missed a shift ONE time in my e28, ever, and it was because as I was shifting from 2nd to 3rd, my shifter boot decided to come out of the hole and I mis-timed my shift because I looked down and thought "WTF?"

[Mr.SWISS]

Sometimes, sometimes r3vmatch, it's just a damn eta. The i is a slushy :curse:

[markseven]

The motronic system cuts fuel off if you have the throttle closed no matter what RPM you are at over 1000. So coasting at 3000rpm down to 1500, then popping in into another gear lower and watching the tach climb back up to 2500 will not use more gas.



No kidding, do we just have a bunch of retard drivers or something? I missed a shift ONE time in my e28, ever, and it was because as I was shifting from 2nd to 3rd, my shifter boot decided to come out of the hole and I mis-timed my shift because I looked down and thought "WTF?"

I was thinking about this thread a week ago...

Agreed that fuel is cut off when the throttle is closed (I assume the ECU cuts spark as well). Why is there still an audible exhaust note, a burble that sounds as though combustion is still occurring? Cylinder compression alone can't account for the exhaust note, can it?

[ivo316]

OK, but when you downshift you have better control of the car, the best way to prevent your rear end from going "loose" is downshifting, but youw don't HAVE to do it all the time, but if you are driving fast or close to the limit it's mandatory, your drivetrain is a lot cheaper than loosing it on a curve. The point of downshifting is to have the engine on the correct RPM range to have the right amount of power to get you safely through a curve ;)

About the fuel issue, remember carbs and fuel injection systems have a bypass that will still let fuel go into your chambers when you are downshifting, even if the throttle valve is closed, I'm not that familiar with motronic, I can't believe that any system cuts off the fuel completely, and if it does, it shouldn't.

[nando]

OK, but when you downshift you have better control of the car, the best way to prevent your rear end from going "loose" is downshifting, but youw don't HAVE to do it all the time, but if you are driving fast or close to the limit it's mandatory, your drivetrain is a lot cheaper than loosing it on a curve. The point of downshifting is to have the engine on the correct RPM range to have the right amount of power to get you safely through a curve ;)

About the fuel issue, remember carbs and fuel injection systems have a bypass that will still let fuel go into your chambers when you are downshifting, even if the throttle valve is closed, I'm not that familiar with motronic, I can't believe that any system cuts off the fuel completely, and if it does, it shouldn't.

there can't be any fuel going to the bypass if the injectors are shut off. and that's exactly what motronic does when you close the throttle... we've been over this a hundred times now.

[ivo316]

ok, sorry, I'm just old, carbs did have the bypass, I am a pre-fuel injection guy :(