How to go from 0

critical · 07-23-2010, 02:43 PM

I've been thinking about this for quite a while, and I still don't know the answer.

A good friend of mine has chipped his BMW 118d (136 bhp) to 164pk. They told him that they (the guys from the tuning company) had tested that a car accelerates the fastest when you shift right after the lines of hp and nm (torque) cross each other.

(At this site u can see his exact car (the white one) : http://www.cthchiptuning.be/nl/chipt...17-protec/136/ )

On his BMW that would be at about 3400 rpm and with every shift you go up, you need to shift at 100-200rmps later (to be the fastest - they said) ..

He now always shifts at 3600 rpm, he says, unless he is in fifth gear.

I always shift at 4000 - 4200 rpm with my 118d (PS 122), but now I don't know weither this is better (faster) or not.

On Youtube (movies) I only see people shifting at at least 4000rmps.

Could anyone make me wiser

Greetings

Negotiator · 07-23-2010, 07:02 PM

It looks like the engine tops at 4k as far as horsepower goes, which is where you would shift.

MrFukengruven · 08-01-2010, 03:42 PM

What do you have done with your 118d? Any chip/software or upgrade? Still, I would advise to shift before redline because the power tapers off towards redline because of the turbo size. If it was a very large turbo, you wouldnt have power fade, but since you have an economical, turbo-diesel, maximize the most power/torque band and shift at 3700rpm or so.

This is a chipped 118d dyno (flywheel horsepower, not wheel). Notice the power stays linear until 4000, then it falls off hard. That's probably why your friend shifts a bit later. But for a stock car, I'd shift before 4000 in my opinion.

good luck!

kyleb350 · 08-01-2010, 07:42 PM

On every dyno graph of a car's horsepower and torque, the lines will always cross at a certain RPM. Using HP and Lb. Ft., the lines will always cross at 5200 RPM.

I think just as a basic rule of thumb, it's best to shift when the HP starts to dip down again.

SteveMD · 08-03-2010, 03:36 PM

Quote:

Originally Posted by kyleb350

On every dyno graph of a car's horsepower and torque, the lines will always cross at a certain RPM. Using HP and Lb. Ft., the lines will always cross at 5200 RPM.

It's 5252RPM

07-23-2010, 02:43 PM	#1
critical Registered 7 Rep 4 Posts Drives: 118D White - M Package Join Date: Jun 2010 Location: Belgium iTrader: (0)	How to go from 0 - 100 the fastest (shifting with a diesel) I've been thinking about this for quite a while, and I still don't know the answer. A good friend of mine has chipped his BMW 118d (136 bhp) to 164pk. They told him that they (the guys from the tuning company) had tested that a car accelerates the fastest when you shift right after the lines of hp and nm (torque) cross each other. (At this site u can see his exact car (the white one) : http://www.cthchiptuning.be/nl/chipt...17-protec/136/ ) On his BMW that would be at about 3400 rpm and with every shift you go up, you need to shift at 100-200rmps later (to be the fastest - they said) .. He now always shifts at 3600 rpm, he says, unless he is in fifth gear. I always shift at 4000 - 4200 rpm with my 118d (PS 122), but now I don't know weither this is better (faster) or not. On Youtube (movies) I only see people shifting at at least 4000rmps. Could anyone make me wiser Greetings
	Appreciate 0 Tweet Quote

07-23-2010, 07:02 PM	#2
Negotiator Lieutenant 42 Rep 539 Posts Drives: 07 GTI Join Date: Jan 2008 Location: Fairfax, VA iTrader: (0)	It looks like the engine tops at 4k as far as horsepower goes, which is where you would shift.
	Appreciate 0 Quote

08-01-2010, 03:42 PM	#3
MrFukengruven Private 21 Rep 87 Posts Drives: 1999 E36 //MThrizzle Join Date: Jul 2010 Location: Norwalk, CT iTrader: (0) Garage List 1999 E36 M3 [0.00]	What do you have done with your 118d? Any chip/software or upgrade? Still, I would advise to shift before redline because the power tapers off towards redline because of the turbo size. If it was a very large turbo, you wouldnt have power fade, but since you have an economical, turbo-diesel, maximize the most power/torque band and shift at 3700rpm or so. This is a chipped 118d dyno (flywheel horsepower, not wheel). Notice the power stays linear until 4000, then it falls off hard. That's probably why your friend shifts a bit later. But for a stock car, I'd shift before 4000 in my opinion. good luck! Last edited by MrFukengruven; 08-01-2010 at 03:51 PM..
	Appreciate 0 Quote

08-01-2010, 07:42 PM	#4
kyleb350 Brigadier General 420 Rep 4,710 Posts Drives: '21 X3MC Join Date: Jun 2008 Location: Milwaukee iTrader: (6)	On every dyno graph of a car's horsepower and torque, the lines will always cross at a certain RPM. Using HP and Lb. Ft., the lines will always cross at 5200 RPM. I think just as a basic rule of thumb, it's best to shift when the HP starts to dip down again.
	Appreciate 0 Quote