rpm shift levels.??

[Wulvndawg]

Ok so my 318ti 1995, has the stock motor in it, no swap yet, and what i'm wondering is at what rpm's are everyone hitting 2nd...3rd...4th...5th....

The reason I ask is cause the po had a stupid loud exhaust by magnaflow installed and i think i'm short shifting the car because of the noise levels...

[Wulvndawg]

Really? 41 views but nobody watches there rpm shift levels.....awesome....

[John Firestone]

As you might suppose from your own experience, many of us shift by ear rather than eye.

That said, I stay below 3000 rpm while the engine is warming up, but often shift close to the rev limiter when passing on backroads. To stay focussed on the road, I have an anticipating, shift-up warning chime that times the shift for 6400 rpm. (The timing varies with the gear.)

[Wulvndawg]

k i'm confused, are you telling me that i should be shifting at 6400 rpm? thats redline....
And yes i know shift by ear, but as I said the exhaust is stupid loud and making me short shift..

[John Firestone]

Redline is 6500 rpm – which makes all the difference.

I prefer to shift around 4000 rpm: to try to save on $2+/liter fuel but not completely waste a wonderful BMW sport engine. On our tree-lined backroads, however, 4000 rpm is usually my minimum while passing. Passing there is the most risky, lawful situation you can put yourself in (on average, 3-4 people die each day because of the trees), so it is prudent to be brief.

ADDED THOUGHT: I cruise the Autobahn at over 5000 rpm. Would I grow deaf in your car?

[Wulvndawg]

Yup you would be deaf in a week or so....I just dont have the cash right now to worry about the exhaust....

And yeah on the autobahn I would be running my rpms up high also....I meant on average city streets.....lol, Guess I should have been a little more clear on that...

[Wulvndawg]

And after looking at my rpm gauge this morning redline does not start at 6500rpm, it starts at 6250rpm. Or at least that is where the first red bar shows up. But all that aside, if I am running it to 3000rpm or just above to make each shift, is that too high or to low or just right? It feels right but the noise level of the exhaust that sounds like a metal coffee can full of rocks at lower rpm's is deafening...and sound like donkey. I guess the best answer is to start looking for a new exhaust system. I was told that to return the exhaust to stock it would be expensive as hell....Anyone have any options for a sporty exhaust but a quiet one as well? The quieter the better.

[John Firestone]

The table I am looking at gives 6300 RPM as the maximum sustained engine speed and 6500 rpm as the maximum instantaneous engine speed. Above that, the rev limiter kicks in.

I found a plot of my rev limiter:



The controller that logged this data measures in 33 1/3 rpm steps.

[Wulvndawg]

M44...Not sure if I mentioned it but I have a 95 318ti which I believe means I have the m42 engine...the 1.8L. That would account for the 6250rpm redline start over your 6500rpm redline start. Oh, just rechecked my first post and yes I did mention the year....they changed to the 1.9L engines in 96.

[hotmilk400]

between 3k and 4k is average. less than 2800 and you suffer no power in the next gear. i have an m44, but it shouldn't change much

[Wulvndawg]

Thank you, So if I run the rpms up to 3000 or higher then i will not be short shifting the car. Ok, thanks for all the input guys I actually learnt a lot from these discussions, as I do from most on this site. Much appreciated.

[pdxmotorhead]

At ~4000 is when DISA opens isnt it? I shift at about 4500 to 5000.. Most of the time.. The 4 cyl does not like being lugged. Mine has 200K and its banged off the rev limiter a lot.. Heck I drive at 4000 on occasion..

Cheers.
Dave

[John Firestone]

Originally Posted by Wulvndawg

M44...Not sure if I mentioned it but I have a 95 318ti which I believe means I have the m42 engine...the 1.8L. That would account for the 6250rpm redline start over your 6500rpm redline start....

The 6300/6500 RPM numbers I quoted are out of "Jetzt helfe ich mir selbst", Vol 153, for the M40 and M42. In the text explaining the table, the authors mention the sustained engine speed is derated 200 RPM, and suggest derating it a few hundred rpm more would be sensible for a longer engine life. The figures may be rounded to two significant figures: there is no way to tell from the text.

[John Firestone]

Originally Posted by pdxmotorhead

At ~4000 is when DISA opens isnt it?...

The 1996/1997 BMWNA Fast Facts Handbook gives 4800 for the M42 and 4200 rpm for the M44. I think it might be fun to add a fun-zone LED that lights when it opens.

[Wulvndawg]

"add a fun-zone LED that lights when it opens"

I could get behind that. I personally really feel the car pull at about the 4000-5000 rpm range and of course it continues past that, but it seems to start really pulling at about 4000rpm.