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Discussion Starter #1
Okay -
I had been driving for about 5 minutes-
an open road presented itself-
"should be warm enough by now for the high cams", thinks I-
1st gear, floor gas, launch! zoom!zoom!zoom!zoom!-
I'm about to hit the high cams! ... here it comes!
6k ....... then ..... RED LIGHT!
WHIR-CHUG! WHIR-CHUG!

Crap!

My car had given me the 'i'm not warm enough yet' high cam SMACKDOWN!

So...how do I know when it's ready??

Do I have to wait for it to get above ~170 degrees or so?

---
Glossary:
WHIR-CHUG (my impression of ~6.2k falling to 5.5k then surging back to 6.2k then falling again before I realize what was happening)
 

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Discussion Starter #3
Really?
Did I guess exactly right? It's 170?
What about 165 or so? I'm wondering what sign the computer gives me that it's now okay to rev.

-doma
 

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Wait until the temperature becomes visible on the readout, then you know its okay to play.
 

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Patricko said:
Yea, what he said. That's why there is a temperature display...;)
 

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Discussion Starter #7
Ahhhh.
I had noticed that the display doesn't appear at first but then comes on later ... today I didn't even look to see what it said, or if it was there at all, before I punched it.

d'oh.
-doma
 

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As others have said the temp readout is blank until it's up to about 165 or so. I was told by the LCU folks that you need to be at or above 168 to get above 6200 & use the 2nd cam.

Anyone autoXing should take note to warm-up their engine before their 1st run. I typically like to see 180 before getting on the cam, but I'm just being conservative.

Kiyoshi
 

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I never hit the high cam before the temp reads 180 either.

I figure driving for 4-5 more minutes to let it get to full temperature won't kill me.
 

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I like to avoid high Rs until not only the water is up to temp, but the oil too.

My E30 M3 has a factory oil temp gage. BMW M says to stay under 1/2 RPMS (4000 in that case) until you hit at least 122 F oil temp. This usually happens about 5 minutes *after* the water hits normal temperatures.

Maybe I'm being overcautious but I try to do this with every car I drive hard. Supposedly it's better for the pistons (better lube) and for the oil seals (lower oil pressure to contain since the oil thins out when it warms up). If you have ever driven a car with a mechanical oil pressure gage you know that revving a cold motor leads to sky high oil pressures. This might not be good for things like the crank seals.

On the Elise the shift light will go on somewhere north of 5000 and the limiter by about 6000 when you are not warmed up. You can rev it all the way once the temp gage displays a number (~158-159F) or maybe it's a bit later. Try not to keep hitting the cold rev limiter when you are warming up the car. Just because you can hit 6000 doesn't mean you should.
 

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I was told 172 degrees.

I am glad the ECU is smarter /more cautious than I.
 

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I'm with you, Randy. I'd be foolish if the motor let me. :rolleyes:
 

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I'll second what Stan mentioned about the oil temp. Unfortunely, in the Elise the oil temp lag is probably much worse than in other cars due to the higher volume of oil and the extra cooling due to the oil coolers. Anyone know if the oil system has a thermostat to the coolers?
 

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>>I'll second what Stan mentioned about the oil temp. Unfortunely, in the Elise the oil temp lag is probably much worse than in other cars due to the higher volume of oil and the extra cooling due to the oil coolers. Anyone know if the oil system has a thermostat to the coolers?<<<

Yes we have thermostats controlling flow to the oil coolers. So they are not delaying our warm up at all. Were we to have a water based cooler then the warming water would more quickly heat up our oil, which would be nice. While warming up the motor at moderate loads, the oil itself gets warmed up quite a bit in relation to sustained RPMs due to the action of the oil pump. So for example a steady 3500 will warm up the oil faster than a steady 2500. On the track part of the heat comes from the engine output itself and part from the great amount of oil pumping effort made by the pump. You can greatly affect oil temps by changing oil viscosity. At steady highway speeds thin stuff heats up less than thick stuff due to the easier pumping. Maybe a 20 F difference with BMWs.

Stan
 

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Stan said:
Maybe I'm being overcautious but I try to do this with every car I drive hard. Supposedly it's better for the pistons (better lube) and for the oil seals (lower oil pressure to contain since the oil thins out when it warms up). If you have ever driven a car with a mechanical oil pressure gage you know that revving a cold motor leads to sky high oil pressures. This might not be good for things like the crank seals.
You're right to wait for the oil to warm up, but I don't think you have to worry about the crank seals. The oil is really only under pressue until it comes out from under the main bearings. With cold oil the higher viscosity will make for more work for the rings, and also, you'll likely bypass the oil filter, which typically has a check valve to keep too much pressure from building up behind it.
 

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>>>You're right to wait for the oil to warm up, but I don't think you have to worry about the crank seals. The oil is really only under pressue until it comes out from under the main bearings. With cold oil the higher viscosity will make for more work for the rings, and also, you'll likely bypass the oil filter, which typically has a check valve to keep too much pressure from building up behind it.<<<

Maybe engine designs vary in this regard. Some designs have been through numerous rear main seal updates, and many always leak a bit. Personally I'm comfortable with generally using moderate revs and loads (which can still be pretty fast) until a bit after water temp is achieved. So for example at an autocross I may have the engine idling during the Driver's meeting since SS tends to go off first and sometimes I am one of the very first cars. Or after coming back from a work assignment I'll start it up even before cars need to line up.
 

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Hmmmm. Here's an idea!

How about this idea...

Hacking into the Elise's CAN bus to pull off the right digital signatures isn't something I'd prefer to do but let's have someone plunk a digital multimeter on the coolant temperature signal that leads up to the ECU to read what "she says" when it's good to run up on the high cam. Someone in the driver's seat read off the dash gauge, someone in the engine bay read and record off the multimeter...

What would this signal be good for?

Well the new BMW M3's tachometer has a "moving" LED redline that slowly moves up until you're good to go. We don't quite have that - but we can simulate it.

An tiny 1" 10-LED array of say, 4 red, 2 yellow, 1 green, 2 yellow and 1 red could be elegantly displayed in the cubbie under the start button. First 4 reds are cold, yellow are warm and green is good-to-go on the hi-cam. The last three are overheating/danger.

A VERY simple circuit could be created to provide a one-time high-low pulsed signals (or a steady high state) when both the green level and perhaps the 2nd last yellow.

- a one time beep or digital announcement would let you know you're green - good-to-go on the high-cam.

- a series of beeps or a more serious annoucement would let you know you're beginning to overheat.

I like the digital announcement idea. You'd be driving around for 5 minutes and then suddenly a nice female voice (aren't ALL sports cars female?) comes from behind the dash (or through the aux-in stereo...) that says something like "Elise at peak engine performance. Have a nice day.",or "Hyperdrive ready." ;) ;)

I'd personally just record Hailey (my 2-year old) who screams "go daddy go!" everytime I attack a corner... and use that.

I know it's bling-ish but the look on your passenger's face when the car announces "Redline enabled", "High cam ready for activation", "Warm up sequence complete" or a simple "Hold on."

The important warning would be "Engine overheating" or if you're feeling facetious "Danger to manifold" ;)

It would take less than 4oz of weight if it was somehow piped through the aux jack of the stereo; probably another 4oz for a micro amp and a tiny speaker.

What do you think?
 
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