Rolf@promotec said:
probably going to be a very expensive 100Nm then
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Read the WELCOME ALL BMWFANATICS post.
How does Software Tuning work...
- Thread starter XMAX
- Start date
probably going to be a very expensive 100Nm then
XMAX
///Member
the e60 m5 had the function whereby the car ran at 400bhp normally and at 507bhp when the M button was pushed.
I wonder if its possible to do this when tuning a car. for example, would it be possible to only have that extra kw and torque when a Steptronic car is switched to DS or the M1 to M6 mode and have the car run its normal tune in D mode.... (once again a strange thought, but still trying to learn)...
I wonder if its possible to do this when tuning a car. for example, would it be possible to only have that extra kw and torque when a Steptronic car is switched to DS or the M1 to M6 mode and have the car run its normal tune in D mode.... (once again a strange thought, but still trying to learn)...
R
Rolf
Guest
//M-Buttons work differently
There is a complete map to which the ECU switches when the driver pressed M
Software tuning / remapping can or better should be done at this map only so the driver can always revert back to "normal" mode.
There is a complete map to which the ECU switches when the driver pressed M
Software tuning / remapping can or better should be done at this map only so the driver can always revert back to "normal" mode.
Arbee
Honorary ///Member
XMAX said:
My car and your car are software only, no hardware mods. Tobofey has done software +decat + WMI. Not sure about Mos1ted, but i think he has Downpipe + Software
Thats the reason why there power is much higher than ours.
Mine is on a conservative, very mild map. IIRC, the boost is up 0.2 only. You will need to get your file read to actually see whats going on, i suspect yours might be boosted a bit more.
R
Rolf
Guest
dvst8 said:
--------------------------------------------------------------------------------
Thats aftermarket ... a JB4 can do that as well... ask Twinz, he will explain!
CyberMatix
New member
Interesting thread - I thought i would add my R2 (used to be 2c - inflation) as well. My apologies to the members that know this stuff, but there might be some that don't (I have some family members in the motor trade that definitely don't know this stuff, and refuses to accept reality if I point it out).
The torque vs horsepower debate has been raging almost as long as there have been cars, and there are a few automotive myths associated with this topic.
Some people (not the peeps here mostly (I hope)) believe there are two magic "things" that makes your car go slow, fast, or faster.
The one magic "thing" is torque (NM) and the other magic "thing" is power (kW). In some cases it is said torque is good/better, and in other cases power is good/better. An oft repeated statement is that if you want to drag a trailer up a hill, or have good acceleration from standstill (or overtaking capability), you need good/better torque, but for the best top speed you need more/better power. While there is some truth in this statement, it is not the whole story.
In actual fact there is just ONE thing that makes your car go fast or faster, and that is the directional FORCE (measured in Newtons (N)) that your tyres exert on the road surface. According to Newton's laws this force will make your car accelerate according to the formula:
F = m * a
where F is the force, m = the mass of your car, and a is the acceleration. So the more force you have on your tyres, the faster you will accelerate, and the heavier your car (more mass) the slower you will accelerate.
So where does this force come from - it comes from the torque delivered to your rear wheels. This torque is passed through your diff, the gearbox, and comes from the engine, where the torque is generated by massive timed explosions in your cylinders that puts a Force on the crankshaft. So you start off with Force (explosions in cylinders), it gets converted to torque (in the crank), goes down the line and gets converted back to force at the tyre's surface.
As you start moving there are some counter forces/torques that work against your car's fastness, and those are the opposing (negative) force of the car's rolling resistance (that increases the faster you go), the opposing force of the air resistance (that increases the faster you go), and the opposing torque caused by the mechanical losses induced by the friction in your transmission and diff (that also increases the faster you go).
When you hit top speed the motive force on your wheels (coming from the engine), and the counter forces/torque due to rolling resistance, air resistance and mechanical losses, balance (cancel) each other out exactly. So the exact same formula F = ma still applies, but F (from the engine) minus F (from the counter forces/torques) = 0.
So F(=0) = ma and m stays the same, so a = 0. And your (top) speed stays constant (you don't go any faster).
So if you want a higher top speed for your car, you need more force, to overcome a bit more of the counter forces/torques generated. Where do you get this force - more torque.
Notice that nowhere in this discussion the term, Power, was used.
So where does power (kW) come in. Well power is just a convenient (and sometimes/mostly confusing) way of measuring the "stongness" of your car. The power is converted directly from the torque by the formula:
Power = Torque * RPM (engine revs per minute) / (some constant value).
So the value of Power and the value of Torque refers to exactly the same magic "thing" that happens in your engine, so there is only one "thing" that propels your car, not two "things".
What makes it confusing is that the term "RPM" is included in the formula. That means that for every Torque point on your dyno graph (at a certain value of RPM) , there will be a corresponding Power point on the graph, and they will have the SAME relationship to each other, given by the above formula, ALWAYS (no exceptions EVER). So if you increase your Power at a certain RPM point (by tuning or running a different engine map), your Torque will increase, and if you increase your Torque your power will increase. Always. So this idea that you can exchange torque for power is also not strictly true, and just adds to the confusion.
So if you need better acceleration, get more torque. If you need a higher top speed, get more torque. If you want to brag about your car, get more power.
So what makes one car go faster than another. Well it is the torque distribution over the RPM range that makes the difference. It is the amount of torque you can get to your driving wheels as you go through the gears, where your RPM varies greatly, that matters.
The common practice of quoting PEAK torque value or PEAK power value for a car also doesn't tell the whole story, and in some cases is pretty useless. You can have a car with a very high peak torque (or power) value (a peaky tune), but a bad torque distribution over RPM, compared to a car with a lower peak torque (or power) value but a much broader torque distribution, and the car with the lower peak torque/power value will probably accelerate faster and have a higher top speed than the "peaky" car. A car with a "peaky" tune will be mostly faster on a race track, but will be almost useless in traffic.
As Carol Shelby (from AC Cobra fame) said, horsepower sells cars, but torque wins races.
Here is an article that explains it probably better than me.
http://www.largiader.com/articles/torque.html
PS: All dynos measure only torque, not power. The power curve you see on your dyno graph is CALCULATED by using the above formula, not measured.
The torque vs horsepower debate has been raging almost as long as there have been cars, and there are a few automotive myths associated with this topic.
Some people (not the peeps here mostly (I hope)) believe there are two magic "things" that makes your car go slow, fast, or faster.
The one magic "thing" is torque (NM) and the other magic "thing" is power (kW). In some cases it is said torque is good/better, and in other cases power is good/better. An oft repeated statement is that if you want to drag a trailer up a hill, or have good acceleration from standstill (or overtaking capability), you need good/better torque, but for the best top speed you need more/better power. While there is some truth in this statement, it is not the whole story.
In actual fact there is just ONE thing that makes your car go fast or faster, and that is the directional FORCE (measured in Newtons (N)) that your tyres exert on the road surface. According to Newton's laws this force will make your car accelerate according to the formula:
F = m * a
where F is the force, m = the mass of your car, and a is the acceleration. So the more force you have on your tyres, the faster you will accelerate, and the heavier your car (more mass) the slower you will accelerate.
So where does this force come from - it comes from the torque delivered to your rear wheels. This torque is passed through your diff, the gearbox, and comes from the engine, where the torque is generated by massive timed explosions in your cylinders that puts a Force on the crankshaft. So you start off with Force (explosions in cylinders), it gets converted to torque (in the crank), goes down the line and gets converted back to force at the tyre's surface.
As you start moving there are some counter forces/torques that work against your car's fastness, and those are the opposing (negative) force of the car's rolling resistance (that increases the faster you go), the opposing force of the air resistance (that increases the faster you go), and the opposing torque caused by the mechanical losses induced by the friction in your transmission and diff (that also increases the faster you go).
When you hit top speed the motive force on your wheels (coming from the engine), and the counter forces/torque due to rolling resistance, air resistance and mechanical losses, balance (cancel) each other out exactly. So the exact same formula F = ma still applies, but F (from the engine) minus F (from the counter forces/torques) = 0.
So F(=0) = ma and m stays the same, so a = 0. And your (top) speed stays constant (you don't go any faster).
So if you want a higher top speed for your car, you need more force, to overcome a bit more of the counter forces/torques generated. Where do you get this force - more torque.
Notice that nowhere in this discussion the term, Power, was used.
So where does power (kW) come in. Well power is just a convenient (and sometimes/mostly confusing) way of measuring the "stongness" of your car. The power is converted directly from the torque by the formula:
Power = Torque * RPM (engine revs per minute) / (some constant value).
So the value of Power and the value of Torque refers to exactly the same magic "thing" that happens in your engine, so there is only one "thing" that propels your car, not two "things".
What makes it confusing is that the term "RPM" is included in the formula. That means that for every Torque point on your dyno graph (at a certain value of RPM) , there will be a corresponding Power point on the graph, and they will have the SAME relationship to each other, given by the above formula, ALWAYS (no exceptions EVER). So if you increase your Power at a certain RPM point (by tuning or running a different engine map), your Torque will increase, and if you increase your Torque your power will increase. Always. So this idea that you can exchange torque for power is also not strictly true, and just adds to the confusion.
So if you need better acceleration, get more torque. If you need a higher top speed, get more torque. If you want to brag about your car, get more power.
So what makes one car go faster than another. Well it is the torque distribution over the RPM range that makes the difference. It is the amount of torque you can get to your driving wheels as you go through the gears, where your RPM varies greatly, that matters.
The common practice of quoting PEAK torque value or PEAK power value for a car also doesn't tell the whole story, and in some cases is pretty useless. You can have a car with a very high peak torque (or power) value (a peaky tune), but a bad torque distribution over RPM, compared to a car with a lower peak torque (or power) value but a much broader torque distribution, and the car with the lower peak torque/power value will probably accelerate faster and have a higher top speed than the "peaky" car. A car with a "peaky" tune will be mostly faster on a race track, but will be almost useless in traffic.
As Carol Shelby (from AC Cobra fame) said, horsepower sells cars, but torque wins races.
Here is an article that explains it probably better than me.
http://www.largiader.com/articles/torque.html
PS: All dynos measure only torque, not power. The power curve you see on your dyno graph is CALCULATED by using the above formula, not measured.
R
Rolf
Guest
I luv your post.... bit confusing for the odd member maybe but absolutely correct and well explained in close to laymans terms
:joy:
Sent from my GT-I9000 using Tapatalk
:joy:
Sent from my GT-I9000 using Tapatalk
bmwforlife
///Member
Cybermatix thanks for the explanation I ashamedly also spoke crap like torque is hillclimbing and power is better than torque
R
Rolf
Guest
True indeed Charles!
Everybody jumped on the torque and power wagon (me included) where the answer could have been soooo easy:
Software tuning works exactly like the oldfashioned methods with jets for carburators, spark advance and if turbo boost increase.....
only that its done the white collar way
Sent from my GT-I9000 using Tapatalk
Everybody jumped on the torque and power wagon (me included) where the answer could have been soooo easy:
Software tuning works exactly like the oldfashioned methods with jets for carburators, spark advance and if turbo boost increase.....
only that its done the white collar way
Sent from my GT-I9000 using Tapatalk
CyberMatix
New member
Twinz said:
Sorry, I guess I was a bit off topic here.:=):
I'm no expert on BMW SW tuning (have a bit of experience in older V8 designs where the ECU is a bit more primitive), but my take on the matter is that the ECU controls all the engine parameters over the engine rev range, and by fiddling with these parameters you effectively change the engine torque distribution curve. On a non-turbo car you can shift the torque curve up a bit higher in the rev range (to the right in the dyno graph) so you will get more performance if you drive the car hard (that petrolheads sometimes tend to do for some or other crazy reason). You can also increase the overall torque curve levels (move the graph upwards on the dyno graph) which will also make you car faster overall.
A more dramatic effect is of course with a turbo car where you can increase the boost over the rev range by forcing more air and fuel into the engine's combustion chambers and therefore shifting your torque (and power) distributional curve higher, and therefore make your car faster.
This is as I see it how the maps feature of the JB4 works - choose a different map and you get a different torque distribution curve.
This is how I understand it.
R
Rolf
Guest
....however, even "magic" has its limits
Sent from my GT-I9000 using Tapatalk
Sent from my GT-I9000 using Tapatalk
Cyber...Its cool...the OPs answer is somehow in-bedded in most responses so far. I think, tuning is not rocket science yet it requires tremendous experience, skill and art. The outcome must be a car that is immensely driveable, stronger, frugal and retains the feeling of being "stock" in daily driving. :thumbs:
Rolf...you so right :thumbs:
Rolf...you so right :thumbs:
CyberMatix
New member
Twinz said:
Yup, agreed.
I still however have a bit of the old V8 musclecar mentality in my head. To make the car faster just get high compression forged pistons, a head with massive valves and double valvesprings, a 850 CFM double pumper Holley carb, Edelbroch manifolds. To go fast just dump large amounts of fuel into the thing. When the fuel runs out, which it often does, go to the gas station and fill it up again.
No stupid computer ECU nonsense stuff, I don't trust anybody (not even myself) writing software that actually works.:rollsmile:
///Shaun
Banned
@ XMAX no need to say who i am :lol:
Anycase Hardware is the key.
I have downpipe and Xcede Software with Sherwin tuning the car to perfection meaning all my power is higher in the rev range as opposed to having a kak load of torque and power at low rpms which would have just left me sitting and spinning crazily at the line. My boost increments were very subtle and not boosted hard. If one is to boost a car hard , yes one can easily achieve power but at what cost is the question to ask.
Also take note that adding water/meth with hardware like downpipe can easily yield another 10-15kw (proven on many different cars)
I would rather take the Dyno reads with a pinch of salt and get the car to perform on the road. Having a kak load of Torque does not equate to a car being faster.
Judging from your power quoted i rekon its good for a 13.6-8sec run on the 400nm but all depends how quickly your power comes in and how quickly it dies. I know this cause i achieved those times with much less power that what you quoted. It was only after i added downpipe did i get the car retuned that yielded higher numbers.
I would highly suggest doing downpipe especially now that you have software. EGTs must be going through the roof at the moment in your car and in my opinion making it really unsafe and will lead to hardware failure/breakages.
Sorry for not answering the question of how a car is tuned. Different tuners choose different methods to achieve power. For me the key is hardware as opposed to having a car boosted hard. use or dont up to you.
For the dyno numbers/queens. Add in a Diesel Booster it will easily give one the numbers they want to see.
Most important thing to remember is no two cars are the same.
Anycase Hardware is the key.
I have downpipe and Xcede Software with Sherwin tuning the car to perfection meaning all my power is higher in the rev range as opposed to having a kak load of torque and power at low rpms which would have just left me sitting and spinning crazily at the line. My boost increments were very subtle and not boosted hard. If one is to boost a car hard , yes one can easily achieve power but at what cost is the question to ask.
Also take note that adding water/meth with hardware like downpipe can easily yield another 10-15kw (proven on many different cars)
I would rather take the Dyno reads with a pinch of salt and get the car to perform on the road. Having a kak load of Torque does not equate to a car being faster.
Judging from your power quoted i rekon its good for a 13.6-8sec run on the 400nm but all depends how quickly your power comes in and how quickly it dies. I know this cause i achieved those times with much less power that what you quoted. It was only after i added downpipe did i get the car retuned that yielded higher numbers.
I would highly suggest doing downpipe especially now that you have software. EGTs must be going through the roof at the moment in your car and in my opinion making it really unsafe and will lead to hardware failure/breakages.
Sorry for not answering the question of how a car is tuned. Different tuners choose different methods to achieve power. For me the key is hardware as opposed to having a car boosted hard. use or dont up to you.
For the dyno numbers/queens. Add in a Diesel Booster it will easily give one the numbers they want to see.
Most important thing to remember is no two cars are the same.
S
SP33DYV
Guest
"Hardware will eventually fail and software will eventually work" comes to mind:rollsmile:CyberMatix said:
