Hi 147Alfaguy, sorry cant answer your question but i do like the law of cars over a certain power being excluded for novice drivers, here in the UK you can go and but a 600hp Ferrari and drive it as soon as you pass your test, funds allowing of course.

Does the same law apply to modifying cars as well

 

Our laws are State based. You pretty much get free reign in Tasmania and in the Australian Capital Territory (Canberra) which sits inside New South Wales where it’s much more strict along with Victoria, South Australia, WA, and Queensland.
The rule is 130kW per tonne so does include modified cars....You’d have to get someone else local to me with experience of registering modified cars to respond knowledgeably. All I know is police have a habit of defecting highly modified cars usually on the pretext of safety.

 

The manual I have for my (diesel) Giulietta gives only one figure for max power, but two for torque, for all models. It gives the 1750TBi power as 172.5kW (235 bhp), and torque as 300Nm in Normal and 340Nm in Dynamic. I'd always understood it that Dynamic changes the torque curve but not power output, although I guess it will change how the power is delivered.

 

For the 1.4 multiair at least, I think you get a 10seconds of the higher torque output in dynamic as overboost at full throttle, for overtaking,ect. Might be the same for the Tbi engine.


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The remap would have to credible to the German authorities. Aftermarket wheels and spoilers have to be TUV approved and described on the registration document.

 

Hi,
My 2017 Veloce TBi shows 240 BHP in both Dynamic and Normal modes. I have never tried All weather. The car is not modified, it is just a very low mileage example.

 

So Dynamic provides the over-boost down low giving that inflated torque figure but up around red-line all things even out so power in both modes is the same. Is that the correct conclusion? Looks like a bespoke tune might be called for after all. I think further discussion with people further up in our RMS (registration and licensing authority here) than those at the front counter is required. Thanks for the replies.

 

In the UK these things are, as far as I’m aware, done using the manufacturer’s declared ‘official’ figures. So for road tax purposes, for example, the banding is determined by the official CO2 figures. The alternative is to put each individual car on a rolling road.

Is there nothing in state law/regulations that says where the power-to-weight figure has to come from?

 

I have no idea. I am thinking of telling the authorities that my other car is a 4C (which it is) so which of the two would they prefer my son to drive?
The Giulietta isn’t much over the threshold anyway, so maybe trying to convince them that real-world engine performance in hot and humid Sydney has it less than 130kW/tonne, in reality.

 

My Giulietta manual shows different numbers, perhaps yours is later or for different spec.
172.5 kW and 1.32 tonnes so has power/mass ratio of 130.68 kW/tonne. So close! You need another 6.9kg.

Unladen mass with all fluids and 90% fuel. Without optional equipment.

 

This says that the manufacturer’s figures are used https://www.rms.nsw.gov.au/roads/licence/driver/prohibited-vehicle-definitions.html
It seems that any engine mods list here will also mean a new driver can’t drive it
https://www.legislation.nsw.gov.au/...">Text</span>"&fullquery=((("Road Transport (Driver Licensing) Regulation 2017")))

 

Always wondered what the differences are on the 2.0 JTDm? Dynamic is totally different power wise, unless its been on a dyno how do we know what modes have what power?

 

No difference in power. The only difference is peak torque and where in the rev band it is. https://www.manualslib.com/manual/808959/Alfa-Romeo-Giulietta.html?page=233#manual
Probably differences across individual cars with the same engine but not huge.

 

Hello.
Wrong . results dyno test Original Natural power: 141.62CV at 3838rpm
Original Dynamic power: 148.02CV at 3573rpm
Original Natural torque: 324.5Nm at 1648rpm
Original Dynamic torque: 382.6Nm at 1956rpm

Its a matter off legislation.:cheeky:

 

Thanks for the link, I couldn't see that in my handbook ? with the torque been 30 nm does this produce more bhp? P.s im daft!

 

I think - might be wrong - that more torque gives faster acceleration and more power gives more top end speed. There’s probably a complex link between the two but torque is turning force, so the engine’s ability to turn the gearbox and hence the wheels. Power is the engine’s ability to move a given mass.
https://auto.howstuffworks.com/difference-between-torque-and-horsepower.htm
is an interesting read.

 

I think - might be wrong - that more torque gives faster acceleration and more power gives more top end speed.

A technical answer to the question of, “What makes acceleration: torque or horsepower?”, is torque.

But torque at the wheels—not at the engine.

And becauase acceleration is torque at the wheels, the real answer is horsepower, because horsepower encompasses not only the engine’s torque but the total torque that gets delivered to the wheels.

So more WHP = faster acceleration.

 

I would have though more torque produces more power but I know nothing ha! I've had my car remapped via a custom ECU. It's going to be on a dyno next month. I'll ask to try all 3 modes and see if there is a difference. I can almost certainly feel it.

I cannot find a direct link to more torque = more bhp so should be interesting to see the difference if there is any.

 

Its not an easy concept is it?
Ill give you an example which works for me
The 1.4petrol relevant version and 2.0 diesel have both 170hp.
The diesel has masses more torque

In a head to head the petrol prob sneaks it(for varying reasons)
Now, stick 4 adults in each car and do the same race and the diesel will trounce the petrol ?

 

As I understand it peak BHP/KW is the same.
Peak boost also unaffected IIRC.
D mode gives 100% throttle for just 40% movement of the go pedal.

 

I’m wondering if anyone knows or can tell me where to find the actual max power figures for the 1750Turbo engine of a Giulietta Veloce in each of its three modes.

Squadra Tuning knows for D and N mode:

Euro 5:
https://www.squadra-tuning.nl/chiptuning/alfa-romeo/giulietta/qv-235-pk/

Euro 6:
https://www.squadra-tuning.nl/chiptuning/alfa-romeo/giulietta/qv-tct/

 

My hypothesis about the extra puff down low and in the mid-range but not up top appears to hold true too. Thanks for taking the time to find and post the graphical data, hdvp.

 

You need work to get something done. And that source of work in our case is engine power, measured in kW or HP. That power gets out of the engine via rotating shaft. Calculating power of a rotating shaft is quite easy if you have the speed (RPM) and torque. You just need right units and you multiply them. And that is a tricky bit for (especially turbocharged) car engines. You have a lot of torque at low RPM, so your power (multiplication of the two) is not as big. As RPMs rise, torque drops slightly, but as RPMs rise faster power goes up. At some point torque starts to drop faster and your power decreases even as RPMs rise. So the max power in N and D mode could be the same, as at that (max power) RPM, torque output in both modes is the same. But at low RPM torque output in D mode is higher, therefore power output at low RPMs is higher, therefore you accelerate faster.

Tricky thing when comparing diesel and petrol cars is the gearbox. Gearbox is a device that can change RPMs and torque, but only so that their multiplication stays the same (so in reality power stays the same). That is why it is really important that your gearbox is calculated properly. If you have two cars that drive with the same speed and have the same size tires, those tires rotate at the same speed. When you accelerate you add torque to them. If you multiply added torque with rotating speed of tires you get power, which should be the same (if there are no losses in transmission) as the power that your engine is capable to give out at the RMP that the engine is currently running on.
So who will accelerate faster, 170HP diesel or 170HP petrol? The one that has better calculated gearbox and a driver that knows how to use it.

I hope I helped clarify something and not add more confusion.

 

So who will accelerate faster, 170HP diesel or 170HP petrol? The one that has better calculated gearbox and a driver that knows how to use it.

In that case (if weight, grip and aerodynamic is same, and unless gearbox is calculated in a not normal way) then acceleration 0-1000 m will be pretty much the same.
Give one car 30 whp more and it wil be faster.

 

What about going up a incline? I gather the car with more torque? The same as having a car full? I'm trying to understand torque & HP. Difficult task ha!

 

Same...
You are overthinking this...
In the car with less torque at a given rpm you simple shift down, for adding more hp to the wheels.

 

You are right that the second car will have to upshift (not downshift) soon, but at that moment when it is at 5500RPM it will produce more whp. That was the point. If we look at the longer time period, think will of course change and probably the 200HP car will get the advantage (as it has more engine power).
What I wanted to demonstrate is that quoted max torque from engine does not mean most torque/power on the wheels at all times. Because that is what people sometimes think. If I failed to do so and I just added to confusion I apologize. :depressed:

 

Yes a typo - upshift pf course.

Simply use the gearbox to convert engine torque to most whp at any time.
Higher torque at a given rpm is just "nice" to keep rpms and gearshifts down.

My son have a modded Citroen C2 VTS with 140hp@6700 rpm / 160Nm@5500 rpm
Curb weight 1080 kg (7,7 kg/hp)

Wife have a Giulietta MA 1.4 170 TCT with 170hp@5500 / 250Nm@2500rpm
Curb weight 1355kg (7,9 kg/hp)


Weight to power are pretty much even but have a look at the differences in torque..!
They are neck to neck in acceleration, however the C2 VTS does nothing below 4500 Rpm and you have to drive it like a maniac

When driving 60 km/h side by side the Gulietta will easily fly away in 4th gear if the C2 was not in 2nd gear since lack of torque at low rpm

 

Of course, that is why torque curve is so important. Citroen is not turbocharged and has 4 valves per cylinder, therefore has torque curve that is gradually increasing and reaches max at 5500RPM (quite high RPM). This means, low torque coupled with low RPM gives you very small amount of power. Hence "it does nothing bellow 4500RPM". Giulietta on the other hand has a turbocharger which gives it high torque at low RPM. High torque coupled with low RPM gives you medium power and it is actually quite OK to drive.
So Giulietta is not faster due to torque being 90Nm higher, it is faster because it has much better torque curve (a lot of torque available through whole RPM range). As you cannot have an engine with low max torque and great torque curve and a lot of power at the same time (without insane RPM range), max torque figure in technical specification is not really necessary. It just confuses people. It would be much better if instead of max torque you would be provided with torque curve. Or maybe this would confuse non-technical people even more. I do not know, but I would like to have it.
Usually when people say to me that max torque is really important I ask them if I should instead of QV with 340Nm buy a 150hp diesel with 350Nm, as apparently it will be at least as fast if not slightly faster. Then they get confused.

 

And so, you just confirmed my point. Anyway, I went way off topic already, so will leave it here.

 

Are you saying the manual is wrong because your individual dyno figures differ from the manufacturer’s official figures?

 

The manual is not wrong but due to legislation matters (hp) the reality cant be written.dynamic mode gives you 7 hp more.100%