"cold engine" are the electronics restricting the power ?

[S3000]

Ok im driving a subaru WRX and the engine hasn`t got the satisfying power after starting up.It needs at least 10-15 miles to get the full power out of the engine.
I know the ECU has to do something with this... but dont know how it exactly works.

Anyway are there cars with a plent of power right from the lower RPMs ? without the electronic whos restricting the power ?

[varsas]

Well, you could buy a car without an ECU, I dare say an old American car with a carburettord V8 would give you the low down grunt you want...even from stone cold. Nothing will restrict power, it's up to your mechanical sympathy. My old Land Rover is noticably less powerfull from cold though, I assume because the tappetts havn't closed up.

It's actually not a good idea to use full throttle/high revs or otherwise abuse the engine when cold, because the oil will not be protecting the engine correctly and some parts may expand as they warm, closing up otherwise wide tolerences (i'm thinking tappets...but there are probably others.)

It's entirely believable your ECU is restricting power when cold, I imagine it's restricting boost? BMW M5's would have a variable rev-limit which rises as the engine warms up to operating temperature.

[rb5230]

S3000 said:

Anyway are there cars with a plent of power right from the lower RPMs ? without the electronic whos restricting the power ?

Yes there are, but you would not be doing any engine any favours by thrashing it from cold. Luckily your car knows better than you eh!

[kambites]

At a rough guess it's monitoring the oil temperature and holding the engine back until the oil is actually lubricating properly.

[kambites]

Oh I don't know... it might lunch its turbos before the bottom end lets go

[Baz Tench]

...Makes a mental note to steer clear of any future purchases with 'Mr S3000, 7 Shubbery Avenue' listed as the previous owner on the log-book.

Edited by Baz Tench on Tuesday 1st February 18:31

[busta]

Instant full power from cold? Sounds like you need a G-Wiz! Or a lesson in mechanical sympathy.

[S3000]

busta said:

Instant full power from cold? Sounds like you need a G-Wiz! Or a lesson in mechanical sympathy.

how is the TESLA ? a bit pricey tough..

[kambites]

A push bike?

[Diabolik]

Am I the only one who thinks 10-15 miles sounds a bit excessive? Should only take a few minutes to get up to temp, shorely?

By shorley, I mean surely.

[kambites]

Diabolik said:

Am I the only one who thinks 10-15 miles sounds a bit excessive? Should only take a few minutes to get up to temp, shorely?

In my experience water will be up to temperature after about five to ten minutes; oil takes at least twice that.

[TheEnd]

It's quite common to have rev limiters that move depending on temp.

I'm sure I have heard of plenty of people with BMW M3s that don't get to full limits if they are driven gently.

[kambites]

Rev limiters are quite common (and a bloody menace if you get a loose connection on your temperature sender - cue ECU completely cutting fueling at 7000rpm mid corner). I'd guess that limiting the power at lower revs is a turbo thing to protect the turbos, but I don't actually know.

[anonymous-user]

std scoobs have a boost derate with engine temp (inverse), this in conjunction with the enormous transmission friction when cold (especially this time of year!) do make them feel a bit sluggish at first. I wouldn't expect the effect to last more than 5 or 10mins of decent speed driving (ie >50mph)

[varsas]

Diabolik said:

Am I the only one who thinks 10-15 miles sounds a bit excessive? Should only take a few minutes to get up to temp, shorely?

By shorley, I mean surely.

I assumed the OP drives everywhere at 150mph, so it only takes about 5 mins to cover the 10 miles.

[Asterix]

Didn't the previous lot of BMW 'M' engines have a closed rev range of 5k until the engine was warm enough?

[indi pearl]

High reving Honda engines (NSX, S2K etc) have a limiter that prevents full revs untill warm. I guess other Japanese cars are the same.

[Baz Tench]

Asterix said:

Didn't the previous lot of BMW 'M' engines have a closed rev range of 5k until the engine was warm enough?

Yes they did...

http://www.rogueengineering.com/bmw/OTMP.html

[Chicane-UK]

It's another one of those things that you wish they taught people as part of driving lessons. Cars need to be allowed to get up to temperature before using the full spectrum of revs if you want them to last any more than a few months!

[mnkiboy]

My old Focus ST170 was very down on power when cold. Felt like a 1.6. I believe the RenaultSport Clio's are similar.

15 mins is about average to get the car fully warmed through I would say.