Stop-Start - is it worth it?

[SumoDog68]

Originally Posted by prktkljokr

My 2009 Smart Fortwo MHD has a starter generator, it looks like a alternator and spins the drive belt to start the car, the car does not even have a starter motor

Its quite a odd feeling when the start stop is working, you can feel the motor turn over silent with no stater noise, then it fires up

When I had it on the hoist the last time I had a good look around and it actually has a place for the starter to go cast into the engine and its machined to accept a starter, but it just has a thin tin block off plate covering the opening.

I think all the different manufacturers have their own way of starting with the start stop set up, be it starter motor, generator, fuel and spark or a combination of two for the most efficient and quick start it requires.

I have the small circuit board fitted now so it does not come on unless I press the button for it to be on, the way it should come from the factory I think.

Starter motor and alternator (generator) are combined in one unit - so technically it still has a starter motor . Engine is conventional Mitsubishi 3cyl that has starter motor deleted .

[prktkljokr]

Originally Posted by SumoDog68

Starter motor and alternator (generator) are combined in one unit - so technically it still has a starter motor . Engine is conventional Mitsubishi 3cyl that has starter motor deleted .

I have 5 of them and 4 parts cars, The W451 has a 3B21 engine that only came in the Smart but supplied by Mitsubishi, they are very similar to the 3A90 in the Mirage I have had a few of them too, they are easier to work on in the Mirage though , they do suffer from belt failure due to the start stop function which kills the motor if your not paying attention, thats why I add the reverse pulse board to disable the option at start up.

The Turbo version 3B21T motor has a starter and alternator, and does not come with the stop start function at all.

The later W453 has the Mercedes M281, Nissan / Renault supplied motor, no generator starter like the W451, they are quite reliable they have the start stop though, you can also put a reverse pulse board to disable the start stop in them which is good.

Also have the W450 that does not come with the start stop feature thank god, but had the Mercedes M160 turbo motor thats only good for 120,000 ks then its rebuild time .

Its beyond me why they thought it was a good idea to put start stop in a car that weighs 750kg that is so fuel efficient already, I doubt if the emission savings would be enough to warrant the option, then to top it of use a system with the alternator starting the car with the serpentine belt?

[Yellow_Festiva]

Originally Posted by SumoDog68

From their spiel :

fuel is injected into the cylinder and the start motor applies a small amount of torque to the crankshaft, all of which makes for a more refined and quicker start

They use starter motor to apply "small" amount of torque. People tend to skip detail and most believe that Mazda does not use starter motor to restart.

For example, Mazda has a technology called i-Stop that doesn’t use a starter for restarts at all. It uses engine combustion. As a driver releases the brake pedal, the fuel injector in one cylinder fires, and the spark plug ignites, allowing the engine to start with combustion, rather than an electric starter motor.

http://bestride.com/research/buyers-...ine-components

There are also some systems that don't require the starter motor to be activated, but start the car via compression – effectively bump starting the car while it's stationary.

Fuel is pumped into the combustion chamber which forces the piston down thus kick starting the combustion process.

https://haynes.com/en-us/tips-tutori...logy-explained

[Crazy Dazz]

Originally Posted by Yellow_Festiva

I did correct myself regarding that.

Special (uprated?) batteries could also be for the electronics that need to keep going when the car is off.

There is a special category of "Stop Start" batteries. What the difference is, I have no idea. I imagine they're designed for a slightly deeper cycle??

[Crazy Dazz]

For example, Mazda has a technology called i-Stop that doesn’t use a starter for restarts at all. It uses engine combustion. As a driver releases the brake pedal, the fuel injector in one cylinder fires, and the spark plug ignites, allowing the engine to start with combustion, rather than an electric starter motor.

I imagine in a direct injection engines, with decent compression that could work.

There are also some systems that don't require the starter motor to be activated, but start the car via compression – effectively bump starting the car while it's stationary.

Fuel is pumped into the combustion chamber which forces the piston down thus kick starting the combustion process.

???
Fuel or Air?

Starting Big Diesels with compressed air used to be reasonably common

[Yellow_Festiva]

Originally Posted by Crazy Dazz

I imagine in a direct injection engines, with decent compression that could work.



???

Fuel or Air?



Starting Big Diesels with compressed air used to be reasonably common

Fuel, they forgot to add that they they spark the cylinder to kickstart the engine.

Starting diesels with compressed air?

I've seen a model of tractor that starts with a shot gun shell. Guess which country lol.

Sent from my SM-G973F using Tapatalk

[SumoDog68]

Originally Posted by Yellow_Festiva

http://bestride.com/research/buyers-...ine-components



https://haynes.com/en-us/tips-tutori...logy-explained

From your Haynes manual :

As Stop-Start places extra demand on components you need specific, powerful batteries and more robust starters and engine mounts.

For Mazda specifically , their advertising material conveniently skips the use of starter motor but if you read description which i quoted in previous post it clearly mentions that starter motor is used. Their illustration also shows it being activated.
I am quoting Mazda about Mazda product and you are quoting Bestride ? Wonder who knows Mazdas better ?
From Mazda :
fuel is injected into the cylinder and the start motor applies a small amount of torque to the crankshaft, all of which makes for a more refined and quicker start

[SumoDog68]

Originally Posted by prktkljokr

I have 5 of them and 4 parts cars, The W451 has a 3B21 engine that only came in the Smart but supplied by Mitsubishi, they are very similar to the 3A90 in the Mirage I have had a few of them too, they are easier to work on in the Mirage though , they do suffer from belt failure due to the start stop function which kills the motor if your not paying attention, thats why I add the reverse pulse board to disable the option at start up.

The Turbo version 3B21T motor has a starter and alternator, and does not come with the stop start function at all.

The later W453 has the Mercedes M281, Nissan / Renault supplied motor, no generator starter like the W451, they are quite reliable they have the start stop though, you can also put a reverse pulse board to disable the start stop in them which is good.



Also have the W450 that does not come with the start stop feature thank god, but had the Mercedes M160 turbo motor thats only good for 120,000 ks then its rebuild time .

Its beyond me why they thought it was a good idea to put start stop in a car that weighs 750kg that is so fuel efficient already, I doubt if the emission savings would be enough to warrant the option, then to top it of use a system with the alternator starting the car with the serpentine belt?

It looks like you know them quite well , great to see people get a focus on a particular car model and gain great expertise . Forums pitch everyone to be on the same level but there are vast differences in the experiences and knowledge which can lead to confusion at times .

[kevino]

Another cost to stop start systems is what traffic engineers call greenwaste.

If you come up to a red light behind say 5 cars equipped with stop start frequently you will not get through the green as the extra 8 seconds delay combined plus the one or two looking at their phone.
There is no fuel saving as 3 vehicles miss the green light and are traffic delayed.

I had an LZ Focus with stop start till recently. At 4.5 years I fitted a new battery. It had stop start but i turned it off each trip. The battery supplier most stop start cars need a new battery every 2/2.5 years.

[fiestaz]

Our Mazda is still on its original battery at 4 years old with stop start always left on.

[GasoLane]

Originally Posted by Yellow_Festiva

Fuel, they forgot to add that they they spark the cylinder to kickstart the engine.

Starting diesels with compressed air?

I've seen a model of tractor that starts with a shot gun shell. Guess which country lol.

A Lot of Mack's had them, some were retrofitted to KW's as well.

I drove a Mack with one, it's ok so long as it starts first go. After three tries you need to find another Truck to refill your air tank

[roKWiz]

Originally Posted by GasoLane

A Lot of Mack's had them, some were retrofitted to KW's as well.

I drove a Mack with one, it's ok so long as it starts first go. After three tries you need to find another Truck to refill your air tank

Never run out of air with this guys 3508 air starter cylinder. Start at around the 5 min mark.

Sorry off topic.