[freebird_76]

I made a search in this forum and internet web sites, but could not find the chart for 5.20d 184 Hp engine. I need this to calculate best manual shifting points considering the gear ratios-power-torque.

If anyone has it, please post here the link or the file itself.
Thanks.

[HighlandPete]

Originally Posted by freebird_76

I made a search in this forum and internet web sites, but could not find the chart for 5.20d 184 Hp engine. I need this to calculate best manual shifting points considering the gear ratios-power-torque.

If anyone has it, please post here the link or the file itself.
Thanks.

Superchips have a 320d 184 bhp dyno graph of original output, plus remap.

http://www.superchips.co.uk/curves/BMW20D184hp.pdf

HighlandPete

[freebird_76]

Originally Posted by HighlandPete

Superchips have a 320d 184 bhp dyno graph of original output, plus remap.

http://www.superchips.co.uk/curves/BMW20D184hp.pdf

HighlandPete

Thank you for the timely answer Pete.
I am sort of new in this issue but, since it belongs to 3.20d, would not the powertrain effect give different results ?

Or does this only belong to engine performance, not on the wheels?
I just want to know.
Thank you very much..

If someone finds a dyno chart for a 5.20d please post here...

[HighlandPete]

Originally Posted by freebird_76

Thank you for the timely answer Pete.
I am sort of new in this issue but, since it belongs to 3.20d, would not the powertrain effect give different results ?

Or does this only belong to engine performance, not on the wheels?...

I imagine the engine performance for the 520d is very similar, or identical.

Any gearchange patterns you are seeking, are worked out on the drivetrain ratios (each gear and final drive) plus wheel/tyre size, as you are probably aware.

I'm not quite sure what you are after, other than theoretical change points, as the torque curve being very flat allows for a great deal of flexibilty on the diesel.

I'm sure the 'feel' of the torque curve will give a very good idea on where to aim at on up changes. Looks as if dropping back to anything around 2,000 rpm will make pretty good progress with best consumption.

HighlandPete

[copello]

Aren't the optimal times for shifting apparent on dash (Part of Efficient Dynamics) ?

[bimmer_335]

I'm impressed by the torque numbers !!!

[freebird_76]

Originally Posted by HighlandPete

I imagine the engine performance for the 520d is very similar, or identical.

Any gearchange patterns you are seeking, are worked out on the drivetrain ratios (each gear and final drive) plus wheel/tyre size, as you are probably aware.

I'm not quite sure what you are after, other than theoretical change points, as the torque curve being very flat allows for a great deal of flexibilty on the diesel.

I'm sure the 'feel' of the torque curve will give a very good idea on where to aim at on up changes. Looks as if dropping back to anything around 2,000 rpm will make pretty good progress with best consumption.

HighlandPete

Ok here we go: the oficial information can be found at Page 31 of paper and page 16 of pdf X3 catalogue. (Peges may vary from language to language)

Since it is engine graph, probably not on the wheels, then if we use gear rations from 5.20d then we are ready.

[freebird_76]

Originally Posted by copello

Aren't the optimal times for shifting apparent on dash (Part of Efficient Dynamics) ?

This is also what I am wondering. I will compare theoretical shift points with actual in full auto.

Besides I can decide where to shift manually (paddles ie.) for best result..

[freebird_76]

Here is the engine diagram for X3 2.0d x-drive.
I will post the Transmission Torque vs RPM table by each gear soon.

[freebird_76]

For best acceleration I think, we should minimize the difference in the torq before and after the shift.
(Thanks to www.datsuns.com for information)

[freebird_76]

So according to the diagrams, it is obvious to shift 4500 Rpm (Redline) in gear 1 and 2. I need some time for precision calculation for the others.

[freebird_76]

To see better, we divide thee engine speed by speed ratios and find transmission speed. When we look at new chart, the intersecting line indicate optimum shifting points before the Red Line.



(thanks to http://www.welltall.com/ymc/discovery/car/shiftpt.html ...transmission torque session)

[freebird_76]

As we see the above chart, even if the gear lines intersect with the next gear line in gears 3 to 8 the residual RPM can be neglected.
To summarize, the BMW engineers made a very good design and if we go Red Line in each gear, we will have optimum shift poins for 2.0d engine.
If we plan to have some modifications, then we need to re-evaluate the dyno chart for optimum shifting points...

[HighlandPete]

Originally Posted by freebird_76

So according to the diagrams, it is obvious to shift 4500 Rpm (Redline) in gear 1 and 2. I need some time for precision calculation for the others.

Not sure what you are actually trying to prove/achieve by the graphs.

Why not drive the engine and find out how it performs? Many of the smaller diesels do not benefit from chasing the last few rpm. As you see in the graph (BMW and Superchips) the power falls off the cliff at around 4,000 rpm, and it can literally feel like that, under load in some examples.

I assume you drive diesel engine cars, and realise that much over 4,000 rpm in normal tune, (4,500 in the 35d bi-turbo) can be such a small gain in acceleration times for a much bigger fuel load. BSFC also rises rapidly as you get to the inefficient rpm where pumping losses and friction don't help at all.

OK, you can chase the redline, but why not change a bit lower and pick up maximum torque and run to peak power again, rather than aim at the wall before each change?

I know some reckon acceleration times are as fast, in some examples, when snatching gears at lower rpm, rather than pushing past peak power and getting nothing in return.

HighlandPete

[freebird_76]

Originally Posted by HighlandPete

Not sure what you are actually trying to prove/achieve by the graphs.

Why not drive the engine and find out how it performs? Many of the smaller diesels do not benefit from chasing the last few rpm. As you see in the graph (BMW and Superchips) the power falls off the cliff at around 4,000 rpm, and it can literally feel like that, under load in some examples.

I assume you drive diesel engine cars, and realise that much over 4,000 rpm in normal tune, (4,500 in the 35d bi-turbo) can be such a small gain in acceleration times for a much bigger fuel load. BSFC also rises rapidly as you get to the inefficient rpm where pumping losses and friction don't help at all.

OK, you can chase the redline, but why not change a bit lower and pick up maximum torque and run to peak power again, rather than aim at the wall before each change?

I know some reckon acceleration times are as fast, in some examples, when snatching gears at lower rpm, rather than pushing past peak power and getting nothing in return.

HighlandPete

Thanks for the comments Pete. I am familiar with diesels and I got your point. I will do exactly what you have said. I know the dyno chart for particular car is also more realistic then factory charts. Even the real life is more real

However, I forgot to mention that my car is in its "Break in" period.
I plan to go by the book and cannot go over 3500 RPM in the first 2000kms.
Then advised to go over gradually.

In the mean time, I read about the shift points and applied it into my car on paper. I wanted to share this information on Optimum Shifting Points and its humble application (5.20d) with people.
I will go to road and try it maybe try a top speed run in Autobahns of Germany

I also had to mention that BMW engineers already designed the gears accordingly.

[HighlandPete]

Thanks for the clarification, "understand" your interest. Your charts/graphs do show a good set of gears. 7th is the only one that seems to put a little blip in the flow. But nothing to bother about.

BTW, don't be too soft with the break-in period, work it a bit, even up to 3,500 rpm, you don't want an oil burner through bore glazing.

HighlandPete

[freebird_76]

Originally Posted by HighlandPete

Thanks for the clarification, "understand" your interest. Your charts/graphs do show a good set of gears. 7th is the only one that seems to put a little blip in the flow. But nothing to bother about.

BTW, don't be too soft with the break-in period, work it a bit, even up to 3,500 rpm, you don't want an oil burner through bore glazing.

HighlandPete

Thank you again Pete,
Good point. What I do is; after seing 100 centigrade on the temperature gauge, if road conditions and traffic are favorable, I go from 1500 to 3500 RPMs manually then let the engine slow down itself in the same gear. Again so on, until I got bored. This way I can hold my pace up but change engine speed. If need more speed then shift up and do almost same RPMs. I pay attention not to got kick down or max abrupt throttle. I gradually increase the throttle. I hope this helps in break in period.
I remember reading articles for Motorbike break ins. With behaving similar in first 20-30 kms.
They claim that it extended the life for cylinders and had a good seal..

[Stephanbmw]

Hi there,

I'm new on this forum, and found out that this is an very interesting forum.
I'd like to know what the ideal shifting point is for my 520D f10 Manual 6spd transmission.
I found out that going to the redline isn't ideal for the acceleration.

Can anyone help me with the ideal shifting point, for a 6 spd manual tranmission?

[Stephanbmw]

Can anyone help me with optimal shifting points for a 520D f10 6spd manual?
I like to know the gear ratios, thanks in advance!

[SomeRandomer123]

Originally Posted by HighlandPete

Not sure what you are actually trying to prove/achieve by the graphs.

Why not drive the engine and find out how it performs? Many of the smaller diesels do not benefit from chasing the last few rpm. As you see in the graph (BMW and Superchips) the power falls off the cliff at around 4,000 rpm, and it can literally feel like that, under load in some examples.

I assume you drive diesel engine cars, and realise that much over 4,000 rpm in normal tune, (4,500 in the 35d bi-turbo) can be such a small gain in acceleration times for a much bigger fuel load. BSFC also rises rapidly as you get to the inefficient rpm where pumping losses and friction don't help at all.

OK, you can chase the redline, but why not change a bit lower and pick up maximum torque and run to peak power again, rather than aim at the wall before each change?

I know some reckon acceleration times are as fast, in some examples, when snatching gears at lower rpm, rather than pushing past peak power and getting nothing in return.

HighlandPete

I see what you mean - our 330d's fall off the power after 4000rpm and our red line is at 4800 with the rev limiter at 5000. Do you "short shift" as such, when you want to get the maximum out of your N57?