Shifting points- what rpm is too much?

[ScottDetroit]

I have a 95 M3 with the Jim C. Euro intake and chip. When I really get into my cars power, I try shifting at around 6500 rpms (just where the red starts on the gauge). Am I setting myself up for future over revving problems? Should I shift earlier than 6500 or am I driving my car within its limits? Thanks for any info, ScottDetroit

[tampaturbom3]

you will not over-rev on an upshift....
overrevving is from downshifting into the wrong gear by accident and mechanically, the engine is forced to turn far higher rev's than designed too.
the computer will prevent an overrev on acceleration while shifting into the right gears.
shifting from 6500 to 7000 is the best place. there is a chart that bob has that shows driveshaft torque optimum shifting spots,,, but,, at least on my car,, from 6500 to 7000 is a very short period of time,,, so shortly after hitting 6500, make the shift. my opinion.

[Kevlar]

optimal shifting from what i remember.

1st - 2nd -> 7100rpm
2nd - 3rd -> 6750 rpm
3rd - 4th -> 6500 rpm
4th - 5th -> 6200 rpm

but these are only from what I remember, I have conducted no such tests.

[TurboBMW3]

http://www.turbobmw.com/m3shiftp.html

for optimal shift points for m3 (courtesy of Gene Liu)

[Kevlar]

Originally posted by TurboBMW3
http://www.turbobmw.com/m3shiftp.html

for optimal shift points for m3 (courtesy of Gene Liu)

Nice!

[M3Jokster]

guys, the shifting that you guys are suggestion is for racing.......not daily normal driving right?
tell me this is true.....bc i generally shift when my rpm is around 3K or the norm 20 mph, 30 mph, 40 mph then 55 mph. to me i do that so it does not put any Unnecessary stress to the engine and saves on gas.....and u guys might know, in california it's about $1.75 - $ 1.85 per gallon of super unleaded 92 octane. so, if i shift like this, is it bad on my engine?

95 M3, ECIS intake and chipped

ps, i drive like this before and after mods....Dont get me wrong guys.....when i feel the need for power, (cops not around) i shift like u guys suggested above.

[gerry_miranda]

Here is what I found:

E36 M3 3.2 Optimum Shift Points

I have calculated the optimum shift points for the BMW M3 with a stock 3.2 liter engine and with a Conforti software upgrade. The hp/torque data was taken from the Bonneville Motor Werks web site and 245/40ZR17 tires were assumed. The green lines are the rear-wheel power curves (in kWatts/10) for each forward gear, assuming 15% drivetrain losses. The cyan lines correspond to rear-wheel tractive force (in Newtons, again assuming 15% drivetrain losses) for each gear, while the yellow lines correspond to engine RPM. As can be seen on the graph, the points where the power curves cross each other (equal power before and after the shift) also correspond to where the rear-wheel force curves cross each other (equal rear-wheel torque before and after the shift) and result in the best overall acceleration (neglecting flywheel/inertia effects). If the rev limiter is set lower than the optimum shift points, then naturally one must shift at redline for best acceleration. Please keep in mind that a different final drive ratio or tire size will shift the curves in the horizontal axis (shift point speed will be different), but the optimum shift point RPM will remain the same.


Gear Ratio
1st 4.20:1
2nd 2.49:1
3rd 1.66:1
4th 1.24:1
5th 1.00:1
Reverse 3.89:1
Final Drive 3.23:1




Stock 3.2 M3:

The stock M3 powerband isn't well matched to the car's gearing. It is too narrow for the relatively widely spaced gears and the rev limiter won't let you shift at the optimum shift points. You will feel a flat spot after every gear change. At least it's easy to figure out when to shift: at redline.


Gear Shift Optimum RPM Redline Speed
1st - 2nd 7,150 6,800 37 mph
2nd - 3rd 7,080 6,800 62 mph
3rd - 4th 6,920 6,500 89 mph
4th - 5th 6,720 6,500 119 mph



Landsharked 3.2 M3:

This is a much nicer combination. Jim Conforti's software really shines. The powerband is now significantly wider and the revised rev limiter lets you shift at the best RPM or stay in a gear a little longer thru a curve. The flat spots between gears are less pronounced, especially between 70-150 mph, were the power is virtually uninterrupted! After 150mph, the engine runs out of steam as it approaches top speed of about 155-160 mph. Perhaps the car will go faster with a slightly taller final drive, but this would increase the 0-60 times.


Gear Shift Optimum RPM Redline Speed
1st - 2nd 7,020 7,000 38 mph
2nd - 3rd 6,840 7,000 62 mph
3rd - 4th 6,660 7,000 91 mph
4th - 5th 6,540 7,000 120 mph



--------------------------------------------------------------------------------

This page was last modified on 20 October 1999 by Luis Marques.

[Kevlar]

Originally posted by M3Jokster
guys, the shifting that you guys are suggestion is for racing.......not daily normal driving right?
tell me this is true.....bc i generally shift when my rpm is around 3K or the norm 20 mph, 30 mph, 40 mph then 55 mph. to me i do that so it does not put any Unnecessary stress to the engine and saves on gas.....and u guys might know, in california it's about $1.75 - $ 1.85 per gallon of super unleaded 92 octane. so, if i shift like this, is it bad on my engine?

Under average to normal conditions... my shifting patterns vary. Most of the time, I do what I can to keep the RPMs above 2000rpm.

[tampaturbom3]

well,, racing,,, or going to work,, the grocery store,, out for a paper,,, Lol
nah,, i actually skip 4th gear and go right into 5th many times,, i don't always go flat out...
but when i do.............yeeeeehhaaaa

[QuestMCoupe]

you skip 4th gear? lol...you car must be crazy fast. and you drive it everyday?

[RobH]

M3's love to breath at higher RPM. It isn't a mustang. If you notice the engine actually runs smoother at 4000 than at 3000 rpm. I don't feel you are doing your car any favors by babying it this way.

[gerry_miranda]

Originally posted by RobH
M3's love to breath at higher RPM. It isn't a mustang. If you notice the engine actually runs smoother at 4000 than at 3000 rpm. I don't feel you are doing your car any favors by babying it this way.

I also find myself driving around at 3000RPM. It just seems to be more at home and comfortable there. Any lower I feel like I'm lugging the engine.

[SlickM3]

As a former riceburner driver, I was very accustomed to shifting at relatively low rpm. This carried over to the M3, and I developed a habit of shifting well below 3K during warm-up, then up to 3K most of the time. I lately started to mod this habit, by shifting the warmed up engine at 4K or so... the car responds much, much better, and I don't feel like a lazy driver anymore.

[Vok]

Originally posted by SlickM3
As a former riceburner driver, I was very accustomed to shifting at relatively low rpm. This carried over to the M3, and I developed a habit of shifting well below 3K during warm-up, then up to 3K most of the time. I lately started to mod this habit, by shifting the warmed up engine at 4K or so... the car responds much, much better, and I don't feel like a lazy driver anymore.

WTH kind of rice burner were you driving?? A lot of them redline well past where the E36 M3 redlines. They're considerably more rev happy.

[SlickM3]

I drove an 84 Celica with 22R engine. Not a high revver, but a very, very reliable and inexpensive car. I drove it for eleven years. Needless to say, I trust I'll drive my M3 for at least as long... unless I get the bug for an E46 version in a couple of years, hehehe...

[Vok]

So it was old rice? :) I doubt I could keep driving the same car for 11 years. Did you go straight from the Celica to the M3? That'd be a huge difference.

[Buddha]

http://www.prestage.com/carmath/dynochart.asp

try this link...

[SlickM3]

Yes, it was very,very old brown dirty rusty rice. It had 185000 miles, worn timing chain, leaking head gasket. I knew I'd not fix it, so I drained the oil and filled it with the cheapest WalMart gunk I could buy. I then drove it 25 miles to CarMax. Upon checking the oil level, I found that it had <i>risen by about 1 inch</i>, due to the extra coolant flowing into the crankcase. I sold the car for $99.00 to CarMax. I'd been studying bimmers for about five months, having started at the 318ti, then the 325, then 328, then, well... you know: 1997 ///M3 coupe.
I held off a long time, found exactly what I wanted, and ponied up the dough. I'm very happy with my car, and intend to care for it and keep it for many, many years. It could well be my son's first car in about 12 years.

[Vok]

Lucky kid if he gets to start on an M3 :) Even if the M3's almost the same age as him.

[BMWmusic]

A lot of useful information here.

[LuxoM3]

Yeow - is this THE oldest thread?!

[Mauritius36]

A lot of useful information here.

just why?

[AngryWhopper]

A lot of useful information here.

:lol You bumped a 9 year old thread to say that?

[psmura]

Good to know!

[lilml01]

stress to the engine and saves on gas.....and u guys might know, in california it's about $1.75 - $ 1.85 per gallon of super unleaded 92 octane.

haha!! Now were lucky if its under $3.00 per gallon.

[I3MW]

A lot of useful information here.

Thanks. I'm not just saying that. The site that used to hold this info and the graphs that went a long with it are now defunct.

If only there was a way to get those graphs back that would be cool, if not oh well, I'll save what I can get.

[Esteban213]

Oldest thread i've ever seen.

[clytle]

A lot of useful information here.

49ers4life- I love your pic!! i remember that episode.... it was a good one. Just had to point that out:D

[325laguna]

shifting at the point where the power starts dropping off ( by looking at the dyno graph) has always worked best me, most area under the curve.

[clytle]

i usually shift right around 3000 as a general rule through all gears. i do mostly city driving and come across ALOT of stop lights. i like 3000 cuz its plenty of range to get up to speed and have plenty of range left in case i need it (IE smoking a Mustang GT on Main St hehe).

[Volf]

This thread is like a time machine. Epic thread status achieved.

[arthothezilvian]

haha!! Now were lucky if its under $3.00 per gallon.


Haha, I was just going to quote that too. Imagine gas was that inexpensive? less than 30 bucks for a full tank. The last time I even had myself a full tank is when I just bought the car and my parents filled it up for me. lol