How warm before High RPM, Boost?
 

What are the guidelines to prevent pre-mature wear or failure of engine / drivetrain during cold weather. I am using 0W-40 oil.

Presently I do limit RPM's according to CLT, but full boost is still available, right from the start.

Should I be using restraint until at full operating temp? By full perating temp, I would mean anything over 180*F, based on use of such thermostats by those who track and race.

I only use WOT after my Oil Temperature has reached at least 70´s and water 80´s.

I also have Rpm limit according to CLT in case but I use good sense to not use full boost ;)

Just personal opinion, but I never, ever, no matter what, ever, go past about 10-15% throttle until completely warmed up (needle dead in the middle). Boost is not even in question until that point.

Its extremely harmful to put stress on a cold engine, that's when the most wear happens

And on the flip side, I've never warmed up any car I've ever owned - street or strip. Stupid? Maybe. Hasn't burned me yet in 26 years of owning cars.

Agreed - I don't "warm it up" either, and don't see any need to sit there and idle it wasting time and gas.

Many seem to agree :party:

Yeah, but I've always flogged on 'em right away as opposed to your approach stated above.

I do this as well. I never get to the autocross early enough to get an early run group, and never have time to warm up the car in the paddock. Start it up, pull up to the starting gate, flag, and into boost.

I back into my garage at night so that I can hit boost pulling out in the morning.

Not that I recommend this to others, but it seems to work for me.

I follow the warmup plan outlined above. Nothing gets it warm like boost. I don't use coolant based limiting, either.

I too use 0w-40, which I like to think helps.

:laugh: now that's pretty boss right there

Wuss. Real turbo Miata owners hit full boost in reverse!

--Ian

the faster you boost, the quicker the pistons warm up, the less time it's running out of tolerances :P

This I can add. I spent a lot of time tuning EAE temp compensation holding AFR's during any boost / temp scenarios I might encounter. So, the car doesn't feel cold even when it is. When I was N/A, it felt like it was stiff when cold, so warming it up with gentle driving seemed natural.

The manual says crank, wait 10 seconds, drive. I didn't see anything else about taking things easy. But that is N/A.

As far as boost warming things up. If I am at 160* CLT and make a single boost run up to 6K, CLT goes straight to 190*. Braineack and Deezums are 100% right about that.

I remember when Scott also said that he boosts in the driveway, so I kind of thought he might have that perspective.

Like so many other questions, many answers.

I think I will tend to leave things as they are, which is to say be more concerned with low temp RPM than low temp throttle; not go crazy with cold power, but not beat myself up if I feel the need to punch it.

In for more thoughts / experiences.

Coolant temp is irrelevant. The arguments about not romping on it when the engine is cold have to do with oil temperatures, because cold oil is thicker and thus has a harder time making it through small orifices into the bearings/etc. Oil temps lag coolant temps substantially during warmup.

How significant this really is with synthetic multi-weight oils on a modern street engine, I have no idea. BMW cared enough about it to have a variable redline on some cars based on oil temp. Real race cars have external oil pre-heaters that get run for a while before they start the engine.

--Ian

120° oil before applying full load or high rpm. Coolant temp doesn't really matter unless you WUE is set crazy rich and you are worried about washing cylinder walls. Most engines have long since opened the tstat by the time they have 120° OT.

Emilio, I presume the tstat you are referring to is the coolant tstat, and therefore are saying that even Vlad is not being conservative enough, i.e. waiting for coolant to come to temp may not be enough to get the oil to 120*, which is the important criteria.

If so, I'm also hearing that pulling the "oil heater" hoses off the engine, a common practice, may not be the right thing to do, as far as warm-up is concerned.

I spent a handful of years working in a machine shop building prototype surgical tools and short production runs of exotic weirdness jobs my boss would quote. I'm not an engineer or a metallurgist, but I have seen first hand what thermal expansion does to things like aluminum. For that reason alone, I warm up my car in the morning.

I'll also be leaving the stock Miata oil cooler/preheater in place when I build my engine. Some people remove it as a "failure point" but its something I'm willing to tolerate for perceived benefits.
^^ Emilio gets it. I know you can set up a custom limiter in the MS3 if you add an oil temp sender to it, or you can add a low temp indicator light as a visual warning and use the big limiter between your ears ;)

I wait for oil temp to hit 180. I try to stay out of boost until then. Maybe conservative but with forged pistons it makes me feel all warm a fuzzy to know they are expanded a bit before I bring the pain.

This is my approach, although my oil cooler thermostat is a tad enthusiastic and, with street driving, it takes a long time to get past 160. I'm thinking of covering it with a blanket for street use.

Definitely most ideal to watch oil temps
However, for those of us with street cars, we gotta settle for water temp gauge :(

[QUOTE=EO2K;1188775]I have seen first hand what thermal expansion does to things like aluminum. For that reason alone, I warm up my car in the morning.

I have to agree with EO2K about thermal expansion, the piston expands before the head, which expands before the iron block. If you don't wait until your oil is around 150 or your street car is fully warmed up, your pistons will loose some of their clearance with the block and wear prematurely. Possibly leading to piston noise :vash: