M3 idling set to 700 RPM?

[sapote]

Have anyone coded the DME to have the idle lowered, to 700 rpm for example, and how is the engine running? Very rough, somewhat acceptable?

[Jimbo's M]

I'll answer your question with another...Why would you want to dick with the DME over this?

[Lukem3]

On a stock engine don't mess with idle. The only time u need to is with a vanos delete or bigger cams

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[180SXTCY]

He probably has a set of sticks in it and isn't happy with how it sounds so lowering the idle would probably make it sound lumpier ?

[Icecream]

He probably has a set of sticks in it and isn't happy with how it sounds so lowering the idle would probably make it sound lumpier ?

that doesn't sound like sapote...plus lumpy idles usually sound like sh*t. drummmvrum_______drummmdumiamanidiotbvrumm_____vrv r ummdrummmm

[Arith2]

He wants it to idle like a cammed LS obviously. Actually lowering the idle would lower oil pressure so I wouldn't personally but you gain gas efficiency. Can't say mileage because you're not moving at idle. I think it can handle it because when there are misfires it idles lower than 700. Oil pressure though.

[jbfrancis3]

Obviously

[sapote]

I have no reason to think M3 oil pump output per rpm is less than a M54 engine which is idling around 700 or lower. But of course this depends on individual engine condition.

[SliM3]

Never tried to go lower, but I would think lowering rpm that much would wreck havoc on torque management for accessories, idle sync and idle control valve duty cycles. Raising rpm is obviously easier because those conditions are already mapped; whereas anything below 870 would be considered crank/post-start as far as the DME is concerned. I'm only hypothesizing tho!

[sapote]

Tranny synchro works hard to bring the input shaft from 870 rpm to zero when you shift gear with car stopped. The lower the rpm the less wear on the synchro. This is important when there is no source for those synchros. When engine already operates in close-loop control with O2 feedback, why it requires to be idling at 870rpm is what I want to know; for a nice sexy engine sound selling point or due to a technical reason.

At cold start the rpm is higher than 1000 and I waited until it drops below 900 before shifting gear.