is this normal @low rpm?

raywong · 09-26-2011, 12:37 AM

Could someone do a test for me please? I am not sure something is wrong with my M3. Thanks.

1. put on 3rd gear
2. cruise at 1500 rpm
3. floor the gas pedal

what is your result?
a) the car accelerate slowly from 1500 to 2000rpm very smoothly, and pick up torque after 2000rpm.

b) the engine climb very roughly from 1500 to 2000rpm, you can feel the hesitation, bumpiness, shaking for a brief moment, but smooth out right after 2000rpm.

1MOREMOD · 09-26-2011, 12:54 AM

a) dont drive at 1500-2000 rpm
b) your car isnt warmed up so dont mat it

raywong · 09-26-2011, 01:41 AM

Quote:

Originally Posted by chriszeh

a) dont drive at 1500-2000 rpm
b) your car isnt warmed up so dont mat it

a) why can't I drive at 1500-2000 rpm? any scientific explanation?
b) what do you mean by my car is not warmed up?

Small Yellow · 09-26-2011, 01:48 AM

Its normal.. the 1500-2000rpm is like turbo lag...

raywong · 09-26-2011, 02:15 AM

Quote:

Originally Posted by HuangYiChao

Its normal.. the 1500-2000rpm is like turbo lag...

yes I understand the lag of power, I am talking about the roughness/knocking of the engine, is that normal for this car? My other V8 car doesn't is smooth at low rpm. My 1973 Dino misfires too at low rpm full throttle when the carburetors were out of tune. I would expect the M3 ECU to be able to regulate a/f ratio and retard ignition timing at low rpm high throttle situation, but it really felt like engine misfiring due to rich mixture.

Prince_of_Persia · 09-26-2011, 03:08 AM

For cruising, always keep the RPM around 3000 - 5000 rpm. For racing, keep it above 4500 rpm. Just sharing my experience with my car

raywong · 09-26-2011, 03:59 AM

Quote:

Originally Posted by Prince_of_Persia

For cruising, always keep the RPM around 3000 - 5000 rpm. For racing, keep it above 4500 rpm. Just sharing my experience with my car

thanks! I normally drive my car pretty hard and I keep my rpm near red line on the track. I only want to know if something is wrong with my M3, I want to rule out the possibility of broken engine mount or faulty spark plug or ignition coil... I am waiting for someone to tell me "it's normal, my M3 does that too, enjoy your car!"

immiketoo · 09-26-2011, 06:28 AM

There's nothing wrong. Its called lugging the motor and it's a condition of high load and low torque. It's also generally ill advised to do it.

raywong · 09-26-2011, 07:25 AM

Quote:

Originally Posted by immiketoo

There's nothing wrong. Its called lugging the motor and it's a condition of high load and low torque. It's also generally ill advised to do it.

it is not lugging in my case. if you want to know how lugging feels, go uphill @1300rpm on 4th gear. you will know when you feel the vibration and the shuddering.

jphughan · 09-26-2011, 09:31 AM

Other V8s might do fine under those conditions because they probably don't have nearly as high of a redline. When I'm just cruising I personally shift as follows:

1>2: No earlier than 15 mph (except when starting from a rolling stop)
2>3: No earlier than 30 mph
3>4: No earlier than 40 mph
4>5: No earlier than 50 mph
5>6: No earlier than 60 mph

I'm pretty sure under all those conditions I'll be turning more than 1500.

Grail05 · 09-26-2011, 09:38 AM

1500 is too low for our cars... its a high revving engine...

and why would you want to shift at that point... shift at 2.5 to 3.5

even the shift indicator will tell you to shift at 2-2.5k....

stefan · 09-26-2011, 09:50 AM

Quote:

Originally Posted by immiketoo

There's nothing wrong. Its called lugging the motor and it's a condition of high load and low torque. It's also generally ill advised to do it.

Not quite lugging, but the way the S65 is tuned, particularly when cold, you are nearly doing exactly that. So I agree with this post. Keep revs around 2000+ and be gentle while cold. Expect a lack of smoothness (isn't it awesome though?)

Edjay · 09-26-2011, 10:02 AM

Its normal. Its caused by a loose nut behind the wheel.

That motor is struggling at that low rpm. Most other v8 has more low end touque. This motor need to be rev abit higher.

jphughan · 09-26-2011, 10:22 AM

Quote:

Originally Posted by Edjay

Its normal. Its caused by a loose nut behind the wheel.

I would say there's a different kind of loose nut behind a different kind of wheel here....

apecush · 09-26-2011, 10:30 AM

Quote:

Originally Posted by Prince_of_Persia

For cruising, always keep the RPM around 3000 - 5000 rpm. For racing, keep it above 4500 rpm. Just sharing my experience with my car

You must love wasting fuel.

I have zero issues cruising around town at 2000 rpm. Best fuel economy generally happens around 2500 though.

raywong · 09-26-2011, 11:19 AM

I just want to clarify. I don't have an obsession to drive at 1500-2000rpm. But in real life situations like traffic jam, or slowing down for stop sign, going over speed bump... who would actually shift down to 1st gear every single time. It really feels like misfiring, and I want to know if anyone else getting that.

Edjay · 09-26-2011, 11:35 AM

Everyone is telling you normal. But if you really think something is wrong have a shop look at it.

mdosu · 09-26-2011, 11:37 AM

Quote:

Originally Posted by raywong

it is not lugging in my case. if you want to know how lugging feels, go uphill @1300rpm on 4th gear. you will know when you feel the vibration and the shuddering.

no that's shuddering is your car about to stall. lol.

Nelrock · 09-26-2011, 12:26 PM

Quote:

Originally Posted by mdosu

no that's shuddering is your car about to stall. lol.

+1
The closer you get to stall speed, the more sluggish it's going to get. The whole point of having gears is so you can use one appropriate to the speed you're at.
There's nothing wrong with the car, there's something wrong with the driver. Quit being lazy...shift your gears!

1sikbmr · 09-26-2011, 12:29 PM

Quote:

Originally Posted by Edjay

Its normal. Its caused by a loose nut behind the wheel.

SchnellM3 · 09-26-2011, 12:41 PM

Quote:

Originally Posted by apecush

You must love wasting fuel.

Don't we all

abehwang · 09-26-2011, 01:03 PM

Quote:

Originally Posted by apecush

You must love wasting fuel.

I have zero issues cruising around town at 2000 rpm. Best fuel economy generally happens around 2500 though.

and what is your fuel economy going 2500rpm?

09-26-2011, 12:37 AM	#1
raywong Private First Class 42 Rep 132 Posts Drives: E92M3 Join Date: Jun 2011 Location: Hong Kong iTrader: (0)	is this normal @low rpm? Could someone do a test for me please? I am not sure something is wrong with my M3. Thanks. 1. put on 3rd gear 2. cruise at 1500 rpm 3. floor the gas pedal what is your result? a) the car accelerate slowly from 1500 to 2000rpm very smoothly, and pick up torque after 2000rpm. b) the engine climb very roughly from 1500 to 2000rpm, you can feel the hesitation, bumpiness, shaking for a brief moment, but smooth out right after 2000rpm.
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09-26-2011, 12:54 AM	#2
1MOREMOD - 11817 Rep 23,187 Posts Drives: Race car-> Join Date: Mar 2009 Location: check your mirrors iTrader: (5)	a) dont drive at 1500-2000 rpm b) your car isnt warmed up so dont mat it __________________ 02 Tiag e46 M3\|6MT\|GC plates\|MCS c.o.\|GC bars\|GC race control arms\|GC bushings\|BW eng. & tran. mounts\|subframe kit\|BW race shifter\|BW Jaffster\|Euro header\|BW exhaust\|K&N c.a.i.\|Epic race tune\|Rouge pulleys\|Seibon CF hood\|CSL bumper\|apr gt 250 & splitter\|ST-40\|XR-2\|SS lines\|half cage\|Recaro profi\|Profi 2 harness\|BMWpedals\|BW studs\|
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09-26-2011, 01:48 AM	#4
Small Yellow Track Addict 110 Rep 813 Posts Drives: 2010 BMW M3 E92 \| 2008 Z4M E86 Join Date: Oct 2009 Location: Orange County, California iTrader: (0)	Its normal.. the 1500-2000rpm is like turbo lag... __________________ BMW ///M3 Coupe Completed November 16, 2009 Received December 29,2009
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09-26-2011, 03:08 AM	#6
Prince_of_Persia Colonel 248 Rep 2,513 Posts Drives: 6MT E92 M3 Join Date: Aug 2010 Location: Vancouver, BC iTrader: (1)	For cruising, always keep the RPM around 3000 - 5000 rpm. For racing, keep it above 4500 rpm. Just sharing my experience with my car __________________ AW\|FR 6MT E92 ///M3
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09-26-2011, 09:31 AM	#10
jphughan Brigadier General 594 Rep 4,488 Posts Drives: '16 Cayman GT4 Join Date: Mar 2011 Location: Austin, TX iTrader: (0)	Other V8s might do fine under those conditions because they probably don't have nearly as high of a redline. When I'm just cruising I personally shift as follows: 1>2: No earlier than 15 mph (except when starting from a rolling stop) 2>3: No earlier than 30 mph 3>4: No earlier than 40 mph 4>5: No earlier than 50 mph 5>6: No earlier than 60 mph I'm pretty sure under all those conditions I'll be turning more than 1500. __________________ '16 Cayman GT4 (delivery pics, comparison to E92 M3 write-up) Gone but not forgotten: '11.75 M3 E92 Le Mans \| Black Nov w/ Alum \| 6MT (owned 5/2011 - 11/2015)
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09-26-2011, 09:38 AM	#11
Grail05 Putcha ang ganda... 279 Rep 5,441 Posts Drives: 17 F82 M4 Join Date: Feb 2010 Location: Los Angeles, Brea CA. iTrader: (10)	1500 is too low for our cars... its a high revving engine... and why would you want to shift at that point... shift at 2.5 to 3.5 even the shift indicator will tell you to shift at 2-2.5k.... __________________
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09-26-2011, 10:02 AM	#13
Edjay First Lieutenant 4 Rep 350 Posts Drives: 08 E90 AW, 76 2002 Join Date: Jul 2011 Location: Sacoftomatoes Ca iTrader: (0)	Its normal. Its caused by a loose nut behind the wheel. That motor is struggling at that low rpm. Most other v8 has more low end touque. This motor need to be rev abit higher.
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09-26-2011, 11:19 AM	#16
raywong Private First Class 42 Rep 132 Posts Drives: E92M3 Join Date: Jun 2011 Location: Hong Kong iTrader: (0)	I just want to clarify. I don't have an obsession to drive at 1500-2000rpm. But in real life situations like traffic jam, or slowing down for stop sign, going over speed bump... who would actually shift down to 1st gear every single time. It really feels like misfiring, and I want to know if anyone else getting that.
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09-26-2011, 11:35 AM	#17
Edjay First Lieutenant 4 Rep 350 Posts Drives: 08 E90 AW, 76 2002 Join Date: Jul 2011 Location: Sacoftomatoes Ca iTrader: (0)	Everyone is telling you normal. But if you really think something is wrong have a shop look at it.
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