Opinions - Cold start turbo engines

[happy and angry]

And I said it's physically impossible due to metallurgy contraints for it to even make it there. Whether you are standing on the gas or not.

Our second gear tops out at what, 85 km/h? (54mp/h or so.) If some jackass has the car pegged at 120 km/h in 3rd, misses a shift into 4th and puts it in second, and then dumps the clutch, it's more than possible for the engine to race beyond the rev limiter. The car is in gear, and it's still moving forward at 120 km/h. All that weight and momentum and gearing alone are making the engine spin far faster than it should. It's not like there is a physical limiter on revs, just a throttle cutoff. It takes time and heat for parts to metallurgically fail, and from the story, it even sounds like it was the over-racing that caused the engine to fail (among other abuses). I'm just curious what part failed: crank, probably. Oh, and you can figure out about where the engine was turning very easily, just by figuring out how many km/h you do per 1000 RPM in the given gear, and then just divide how fast you were going when you put it in gear by that number.

 

[SwampAss]

the motor would have fragged long before 14k. This was in a BMW M3 says the OP.

It's moot anyway.

 

[happy and angry]

the motor would have fragged long before 14k. This was in a BMW M3 says the OP.

Maybe. "Long before" implies it takes time to get up there. On a missed shift like that, the engine is going from 6000 RPM to something far, far too high in a few tenths of a second. It's entirely possible to hit those speeds before it frags.

It's moot anyway.

Yup. There was a link a few posts back that explains it better than I am, anyway.

 

[Sacrilicious]

given enough stress, would it not make sense that a rod just snaps? metal breaks in more ways then bending. if you stress it hard enough, it WILL snap.

i'm not saying that i know that 14k is enough to make something snap, but i'm just pointing out that sometimes, things CAN just blow on you without first revving up to some insane rpm. for an exaggerated example: if you're going 100mph and somehow managed to downshift into 1st, i REALLY don't think you're going to be able to rev up to close to 20krpms before the parts in your engine just snap in half.

 

[nig3]

heh. yeah. Or nig3 needs to troll a bit harder. It would be physically impossible to rev a motor with a redline of 8k or less all the way to 14k.

And please, if anyone has a more concise understanding, please step in but:

Current metallurgy will only allow for pistons to travel a certain number of feet per second before s*** goes NESW. Unless the M3 he is talking about has almost no stroke and an enormous bore, it's not revving to 14k let alone 10k.

The motor would have never supported it even *IF*! there was some sort of electronic sensor reading to have recorded that.

yeah dude it was a mechanical over rev, no rev limtor can stop that!! and yes M3's do store store highest rpm code before the motor exploded. didnt try to hijack thread just making a point not to be like the idiot neighbor i had and please let your car warm up.

 

[Hirudin]

I had a neighbor who would do the "start the car then rev it for a while" warm up procedure. The best part is it was a big truck (old Ford Bronco maybe) and the dude always did it at 5 in the morning.

I'm sure he probably woke up 30 people in his apartment complex every morning.

 

[BlackJack]

...probably cause you DID! (argh)

I was joking. Of course, I always wait until the revs go from between 2 and 3 to below 1 and then i'm good to go.

 

[CosmoMS3]

Remote start on MS3?

Did anybody install remote start on the MS3? Does it void the warranty?

 

[chufa]

I'm new to Mazdas and I'm not sure what Mazda recommends for the MS3, but for my previous Audi S4 (twin-turbo engine), the manufacturer recommended to avoid long warm-ups, and start driving ASAP. Actually, the car would give off a strong gasoliney smell which leaked to the interior if left idle in the cold for too long.

 

[Falconx84]

Did anybody install remote start on the MS3? Does it void the warranty?

it can only be voided if what you did caused something to break. So if you cut and splice wires and the problem was caused by the spliced wires, thats the only way it could be voided. And the burden of proof is on mazda

 

[SPEED305]

back to idling....its no good. I learned that at the ASE master program.

 

[kragan76]

Did anybody install remote start on the MS3? Does it void the warranty?

I installed one on my SVT Ford Focus and the dealership never balked at it. Since Ford has controlling share in Mazda, I would assume the same applies here. However, different dealerships react differently to modification.

One thing that I did that may have helped was I installed a switch on the clutch bypass. With the switch in the "on" position the ECU thought the clutch was in and allowed the car to start. In the "off" position the ECU sees the clutch out (as it is) and won't allow the car to start. This came in handy whenever I let anyone else drive my car or when I would vallet park. I always wanted to have bypass triggered into the e-brake, but never bothered to take the time to figure it out. When I put one on my MS3, I will be sure to take the time to figure it out.

 

[MainMan141]

When you start the car it will revv high , its trying to build oil pressure. when the rpm's drop thay will still be above normal.... just wait a fue sec. after that first rpm drop and youll be ok,,, but you dont relly want to gas it for about 10min,,, thats about when the oil has reached temp (and your engine).(2thumbs)

 

[Silver Ecstasy]

Just wanted to let everyone know Thanks for your inputs. Both my Trailblazer SS, and my former 05 GTO (both of which have ls2 6.0 liter V8's) take FOREVER to warm up. I have a remote start, and I usually let it run for about 3 minutes. Even after 3 minutes, the engine is still cold and so is the HVAC heat.

I'm hoping that's different on the MS3 i'm looking at buying, because I'm considering not taking the risk and installing a remote start on a manual.

(So what's this talk about using e-brake/not using e-brake?)

 

[Rainforests]

On cold mornings I usually let the idle revs fall until about 1250 or 1000. It doesn't take too long to warm up after that. I definitely wait until it is below 1500 though.

After seeing the post below mine, I also shift no higher than 3000 until the needle has moved to the middle position (or just below as I dont think it is ever in the exact middle)

+1