DS mode

Re: DS mode

i tot down hill use lower gear. engine brake is an effect of it but to slow down down hill applying brakes still the way to go le. i tried in on Genting. I was on D mode without much stepping on the gas pedal, the car jus roll down slowing with good used of gear ratio decided by the car. if you driving like initial D. DS/M overide of cos better la.
 
Re: DS mode

Downshifting and using engine breaking wears out the engine? bwahahahah, funniest thing i have read all day. I really hope all those trucks dont use their exhaust brakes and downshift to slow down, engine spoil in no time.

Please lah, I SLAM my tranny into lower gears all the time to slow down, i hit corners to fast for the brakes to pull me up, must downshift one.

If got manual car, it is ok to downshift and engine wont spoil is it? Only on auto car cannot? hahahahahaha.

ITS a MACHINE, it doesnt care what you do, you wont hurt its feelings. The pistons are actually designed to go up and down, wether under acceleration or deccelaration.

sports mode rocks. Ive tried and tried to kill my diff and tranny, till this day i havent done it. Some solid stuff it must be made of. Wonder if it is steel
 
Re: DS mode

delrosa81;322935 said:
okok i know heel & toe not engine braking thats why I said off topic ma, u very the fierce leh....:(
dun worry lah I put extended remix down so that google can pickup and next time just copy paste the explanation mah ... i where got fierce? very pussy one ...
 
Re: DS mode

phil;323248 said:
Downshifting and using engine breaking wears out the engine? bwahahahah, funniest thing i have read all day. I really hope all those trucks dont use their exhaust brakes and downshift to slow down, engine spoil in no time.

Please lah, I SLAM my tranny into lower gears all the time to slow down, i hit corners to fast for the brakes to pull me up, must downshift one.

If got manual car, it is ok to downshift and engine wont spoil is it? Only on auto car cannot? hahahahahaha.

ITS a MACHINE, it doesnt care what you do, you wont hurt its feelings. The pistons are actually designed to go up and down, wether under acceleration or deccelaration.

sports mode rocks. Ive tried and tried to kill my diff and tranny, till this day i havent done it. Some solid stuff it must be made of. Wonder if it is steel
When I and you, Phil, learned to drive, engine braking was once NECESSARY because our brakes sucked. We had drums all round and crappy hydraulic fluid which boiled easily. Our cars were underbraked. So when going downhill for example, we were forced to engine brake, and even in street driving, that's what we did.

But today most cars have ample braking capacity on the street and even on downhills we will have sufficient reserves of braking power and the hydraulic fluid don't boil easy, especially for those who replaced with DOT5 stuff.

Whether on auto or manual cars, the disadvantages of engine braking are similar, except in that slushbox auto cars don't usually blip the throttle to rev match on downshift so that causes additional strain on the torque converter.

The issues are NOT normal wear and tear on the engine, as you said, engine pistons are supposed to go up and down and go on forever.

I summarize:

1) It's not necessary with today's big brakes
2) Your brakes lights don't come on, some people may just whack your bum
3) If no rev match done, it's called CLUTCH BRAKING or torque converter braking, and it wears the clutch or strains the torque converter a LOT for some moments.
4) Engine braking upsets the car if suddenly applied in the corners or in a slippery slope by causing the driving wheels to lose traction. Because engine braking is not managed by ABS, you WILL lose traction and there is a high probability of car spinning or being upset.
5) In engine braking you are transferring power to the drivetrain, including the engine, in an opposite direction from normal. Depending on how POWERFUL the engine braking effect is, and how low your gear is, the pressure required to open exhaust valves against compressed air in the cylinders is extremely high. In these instances the resulting load through the push tube back to the camshaft exceeds valve train loading capabilities. These excessively high pressures can quickly damage a valve train system.

All this being said, if you're coming down from Camerons or Genting, sure doesn't hurt to put your transmission on 3rd gear, and have the transmission control the descent. This is steady speed, without the detrimental effects of an `impulse' and you go on for a long time, and therefore more acceptable than engine braking on the street which involves many compression cycles.
 
Re: DS mode

i still have a car with 4 wheel drum brakes, haha!!

To me though, it's a machine, so I'm never concerned about strain, wear and tear etc etc. Have you seen the size of the brake pads on an E46? Same as a Honda CR 250, aint that big!

So morale of my story is, let the converter fry!! Good for nothing thing it is, deserves to be punished.
 
Re: DS mode

phil;323248 said:
I really hope all those trucks dont use their exhaust brakes and downshift to slow down, engine spoil in no time.

Truck drivers must use engine brake because their trucks are often underbraked as a consequence of aircooled brakes.

So the truck engine manufacturers, for diesel trucks, compensate by relieving pressures using mechanisms to open up the valves to relieve pressures.

In addition, the truck engines, and diesel engines in general, are made to withstand compression ratios of 24:1 compared to our 11.7:1 - and their valvetrains have a much higher loading capability for their valvetrain.
 
Re: DS mode

centurion;323306 said:
Truck drivers must use engine brake because their trucks are often underbraked as a consequence of aircooled brakes.

So the truck engine manufacturers, for diesel trucks, compensate by relieving pressures using mechanisms to open up the valves to relieve pressures.

In addition, the truck engines, and diesel engines in general, are made to withstand compression ratios of 24:1 compared to our 11.7:1 - and their valvetrains have a much higher loading capability for their valvetrain.

Notice i said exhaust brake.
 
Re: DS mode

I only know i had to use engine brake when i was taking my test for my license.

haha.
 
Re: DS mode

Hi everyone,

I have an E90 and my DS mode is not working. When I left press the shifter, the console still shows D mode. Any thought what could be wrong ?

Thanks ahead
 
Re: DS mode

press? did you shift it completely to the left? because from there you can shift it up and down to go into manual mode as well...

not just press .. but to push it completely to the left..
 
Re: DS mode

Yes, I did. Somehow, I can shift up and down once there, and feel the gear change .. but there is just no DS mode indicator nor the M1 to M6 stuff on the console.

I am sending it to workshop tomorrow. Just want to get some opinion from this forum. Thanks
 
Re: DS mode

oh yeah. sounds like there's something wrong with the display. go get it fixed. warranty! :D
 
Re: DS mode

Just a close loop here. The issue is with the electronic stuff. No problem with the gear box. They changed it and is now ok.
 
Re: DS mode

Is it normal for 1 second delay in car engaging gear after shifting gears in DS mode? Shifting gear + or - will engage after around 1 second later.
 
Re: DS mode

johnny;401350 said:
Is it normal for 1 second delay in car engaging gear after shifting gears in DS mode? Shifting gear + or - will engage after around 1 second later.

Mine is instantaneous.
 
Re: DS mode

For those who use DS, is the downshifting of gears very jerky when the car is travelling relatively slowly?
 
Re: DS mode

Mine's a E46 3 series & there is a delay for gears physically engaging after shift + or - in DS mode. Lag is :furious:
 
Re: DS mode

whiskyrum;401390 said:
For those who use DS, is the downshifting of gears very jerky when the car is travelling relatively slowly?

My E90 was having the same feel... brought back to PML, drove with tester and confirm the abnormal jerks.. it is even apparent in D mode...

PML reset the transmission program and till now seems ok.... but then i seldom use DS mode, hence unable to really tell....

hope this helps...

:)
 

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