Is There Any 'True' Replacement Of Displacement?

[TSIVipul]

"There Is No Replacement Of Displacement"- Enzo Ferrari

Personally saying, I strictly believe in these words said by that great engineer of all times. Today also we can see the cars fitted with various types of power upping techniques like forced induction, variable valve timing etc but still the higher displacement engines are preferred by most of the companies when it comes to ease of driving, responsiveness throughout the rev range etc.

So guys, simple question...
Do you people think there is some 'true' replacement of displacement? And yes, try to explain your point..this thread can help learn a lot in terms of engine design and technologies.

 

[350Z]

I expected a healthy discussion in this thread. But let me break the ice. I’d have opted for the first choice but driving the Volkswagen Polo GT TSi leaves me in two minds.

Drive Safe,
350Z

 

[Releesh]

Turbo lags, maintenance and lasting of turbo made me to select 2nd option.
I am still in old school and if get a chance i'll still select the increased CC non turbo engine than smaller cc turbo engines whether petrol/diesel.

 

[TSIVipul]

@350Z: Thanks buddy for breaking the ice, let's see how it goes on now.

Higher the displacement, better is the overall response and of course responsiveness. Even if a 1.0 l engine is producing 120 bhp and a 1.5l engine is producing 100 bhp of peak power than also I'll prefer the one with a higher displacement because it will be able to produce the peak power at a comparatively lower rpm as well as will be delivering a better torque spread too.
Hence, by any ways I'll any day prefer a bigger engine with a smaller turbo than a smaller engine fitted with the mother of a turbo..

 

[ss80]

I always go with the 2nd option, Larger the Engine (cc) the better it is. I have driven a handful of diesel cars with turbo (Vento, Punto, Ritz, Scorpio, Enjoy, Swift etc) Although in a short TD the smaller engine with turbo will impress you (Beat diesel for example) on the highway, I am sure everyone loves the bigger displacement cars.

If there was true replacement for displacement, then Enjoy & Ertiga would have replaced Innova, Tavera, Scorpio etc. In the Indian Market I feel the companies are trying to push smaller engines (1.3MJD) with turbo, trying to woo the customers who are already used to the bigger hulks (2.4 & 2.5Ltrs diesels).

 

[mercedised]

Yes, there is! Forget liquid\gas fuel powered cars and bring ELECTRIC cars. You would get the desired torque and power straight from 0 RPM to the limit. I love electric cars for their low running costs (except battery). But, the higher initial costs and lack of consumer awareness is what keeping the electric vehicles still 10 years away from getting cheaper to buy.

 

[TSIVipul]

I always go with the 2nd option, Larger the Engine (cc) the better it is. I have driven a handful of diesel cars with turbo (Vento, Punto, Ritz, Scorpio, Enjoy, Swift etc) Although in a short TD the smaller engine with turbo will impress you (Beat diesel for example) on the highway, I am sure everyone loves the bigger displacement cars.

Smaller engines with turbos may impress you with that so called kick or say spike in performance but what about the turbo lag they offer in return for that spike? Smaller the engine, bigger turbo it needs to produce same amount of power at same rpm as compared to any bigger engine and hence more will be the turbo lag. Same is the story of responsiveness throughout the rev range, the way the bigger engines pull very cleanly throughout the rev range and the way the bigger engines demand very minimal gearshifts as compared to smaller engines in hilly driving or city driving simply gives them an upper hand.

If there was true replacement for displacement, then Enjoy & Ertiga would have replaced Innova, Tavera, Scorpio etc. In the Indian Market I feel the companies are trying to push smaller engines (1.3MJD) with turbo, trying to woo the customers who are already used to the bigger hulks (2.4 & 2.5Ltrs diesels).

Exactly, the smaller engines may have very good figures on paper but the story drastically changes when it comes to real world driving. Take an Octy for example, that car with a 1.9ltr engine used to produce just 90 BHP of power and around 21kgm of torque. These figures are somewhat similar to what my corolla offers and what an SX4 or Fiat Linea offers. Then what makes the difference? Well, the real world driveability is what makes the difference. The way the Octy deliver its power very smoothly and the way it responds to the throttle inputs makes the difference.
Similarly one can drive a Hyundai Verna 1.6 CRDi and an Optra Magnum 2.0 TCDI to understand this difference. In other words after experiencing many cars I am still with Mr. Enzo Ferrari for the famous saying by that engineer - "There Is No Replacement Of Displacement".

Yes, there is! Forget liquid\gas fuel powered cars and bring ELECTRIC cars. You would get the desired torque and power straight from 0 RPM to the limit. I love electric cars for their low running costs (except battery). But, the higher initial costs and lack of consumer awareness is what keeping the electric vehicles still 10 years away from getting cheaper to buy.

Buddy I am already involved in the designing and fabrication of an electric powertrain with a 3 phase induction motor coupled to a variable frequency AC drive. No doubt that the motors offer a fantastic torque delivery but here on our point, what is displacement in motors? They are all about the current they draw, the flux, the field and the torque they produce. Still I agree to your point completely, electric drives are the future and amazingly they really have the capability to outrun our fuel powered engines.

I expected a healthy discussion in this thread. But let me break the ice. I’d have opted for the first choice but driving the Volkswagen Polo GT TSi leaves me in two minds.

Drive Safe,
350Z

Vibhor my dear then you need to drive a Fiat Linea T-Jet, the 1.4l engine packs far more performance than this 1.2(Still in petrols, the Ford 1.6l is sweetest engine and I am sure you will agree on it).
BTW, being honest to yourself can you say that this 1.2l turbocharged petrol motor is as much fun to push around you your 1.6l Ford one is? I think Fiesta 1.6 still packs more punch and performance despite of having lesser power and torque and a higher weight as compared to the 1.2 GT TSI. Right?

 

[mercedised]

Buddy I am already involved in the designing and fabrication of an electric powertrain with a 3 phase induction motor coupled to a variable frequency AC drive. No doubt that the motors offer a fantastic torque delivery but here on our point, what is displacement in motors? They are all about the current they draw, the flux, the field and the torque they produce. Still I agree to your point completely, electric drives are the future and amazingly they really have the capability to outrun our fuel powered engines.

That's Great! Please do share the platform on which you are working and the rough plan of what you are trying to achieve. How you would be converting the DC from the batteries? Does'nt it means loss of energy when converting from Dc to AC? On the note DC motors are also cheaper, but shifting speeds instantly will be a problem in DC motors. How much HP motor/drive are you using? and what is the load?

 

[TSIVipul]

That's Great! Please do share the platform on which you are working and the rough plan of what you are trying to achieve. How you would be converting the DC from the batteries? Does'nt it means loss of energy when converting from Dc to AC? On the note DC motors are also cheaper, but shifting speeds instantly will be a problem in DC motors. How much HP motor/drive are you using? and what is the load?

well, here we go off topic because this thread is basically meant for the purpose of sharing engine technologies and the effect of various factors and engine tunings which I guess is quite tough to do or maybe members are unwilling for the same.
Right now we people are under the process of designing and simulations. For this purpose we are using MATLAB software(you can recommend if you know anything better than that).
For the purpose of DC to AC conversion we will be using inverters(custom made ones) thanks to the power electronics based devices and definitely there will be energy losses but that is better known to the people from inverters division of my team. basic reasons for using AC motors are their better reliability, overall better torque delivery, better speed regulation and we can easily attain regenerative braking by using a variable frequency drive.
Our basic target is to attain 0-60 under 4 sec and a top speed of around 105-110 kph with the two seater vehicle weighing a maximum 350 kg inclusive of both the drivers. The motor which we have selected right now is a 12 horse power three phase 4 pole induction motor and as per my calculations this motor is already more than what we need for the task, but then excess of power is better than deficient of power, we can easily manage the acceleration or tops speed or regeneration or braking by simply varying the frequency using our variable frequency drive.
I am planning to open a separate thread for the purpose, rest I guess you are also an electrical engineer and hence expecting suggestions from your side too. Rest the best thing than an automobile enthusiast can do is live his enthusiasm by building his own car, and I am happy(and very busy too) doing the same.

 

[mercedised]

For the purpose of DC to AC conversion we will be using inverters(custom made ones) thanks to the power electronics based devices and definitely there will be energy losses but that is better known to the people from inverters division of my team. basic reasons for using AC motors are their better reliability, overall better torque delivery, better speed regulation and we can easily attain regenerative braking by using a variable frequency drive.
Our basic target is to attain 0-60 under 4 sec and a top speed of around 105-110 kph with the two seater vehicle weighing a maximum 350 kg inclusive of both the drivers. The motor which we have selected right now is a 12 horse power three phase 4 pole induction motor and as per my calculations this motor is already more than what we need for the task, but then excess of power is better than deficient of power, we can easily manage the acceleration or tops speed or regeneration or braking by simply varying the frequency using our variable frequency drive.
I am planning to open a separate thread for the purpose, rest I guess you are also an electrical engineer and hence expecting suggestions from your side too. Rest the best thing than an automobile enthusiast can do is live his enthusiasm by building his own car, and I am happy(and very busy too) doing the same.

MATLAB is the best, there are endless possibilities with it. So, this seems to be a engineering final year/ Masters project? Is it?

Keeping the costs down would be tough if you are using Li-ion batteries. And this regular batteries I think would get heated too much, what's your solution for this? It will be a four wheeler but how many motors would you be using? Would it be a chain drive or direct drive? 100 Kmph looks tricky, I am waiting and excited on how you would be able to achieve those figures for a long time keeping in mind extracting healthy mileage from the vehicle. Achieving a greater speed might be an easy task but getting higher mileage in today's perspective with meeting the demands of enthusiastic driving habits is tough.

Anyways, you have the master tool MATLAB which will ensure that the final design is near to perfect. I have respect for another fellow MATLAB'ian.

Best of luck with your project and yes please do start a separate thread. That would ensure that the pure knowledge/experience gained by you, flows smoothly for the benefit of the community members.

 

[TSIVipul]

Well, I haven't given a thought to battery cooling and all, please pour some of your experience in this field.
Is it possible to use air cooling? Since our vehicle is planned to be a chain driven RWD with a flywheel also mounted on the rear axle itself hence we are planning to mount the batteries up front. We don't need a very high range but are expecting upto 3-4 hours of run time for our motor using the regular inverter batteries. So can we use any kind of air cooling system by making some sort of air dams etc up front to cool the batteries.

 

[mercedised]

Is it possible to use air cooling? Since our vehicle is planned to be a chain driven RWD with a flywheel also mounted on the rear axle itself hence we are planning to mount the batteries up front. We don't need a very high range but are expecting upto 3-4 hours of run time for our motor using the regular inverter batteries. So can we use any kind of air cooling system by making some sort of air dams etc up front to cool the batteries.

3-4 Hours seems too much. How much VAh battery will you be using? Batteries heat's-up mostly while charging. For the vehicle set-up you might have to test and try if the batteries are heating-up significantly. As you said you would be using the batteries continuously for 3 hours atleast, adding a fan to cool the batteries would'nt be a bad idea. You could try a small radiator fan, but that would also mean that additional energy will be consumed, for this matter you can add an additional switch which would turn-off the fan at times.

 

[TSIVipul]

Today got a chance to drive a Getz CRDi and man that 1.5lts CRDi engine is a cracker, seriously quick the car is BUT Bigger engines are simply mind blowing. How? Simple, the 2.0 TDI M/T Laura also has same power output and weighs a lot more than Getz but is still far more responsive when it comes to driving.

3-4 Hours seems too much. How much VAh battery will you be using? Batteries heat's-up mostly while charging. For the vehicle set-up you might have to test and try if the batteries are heating-up significantly. As you said you would be using the batteries continuously for 3 hours atleast, adding a fan to cool the batteries would'nt be a bad idea. You could try a small radiator fan, but that would also mean that additional energy will be consumed, for this matter you can add an additional switch which would turn-off the fan at times.

I guess we will be using 2 batteries with rating of 75Ah(24V) each with the motor requiring 14.2 A of current. Since these days I am a bit busy with business also hence unable to monitor exactly where my team has reached till now. Will be attending college after Thursday I guess and then I can post the clear picture. Run time is not 3-4 hours, it was the target I gave to my team and provide me with what all we need to attain this at lowest possible price and keeping the weight also lowest possible. Right now I guess with this setup we won't get anything more than 45-50 minutes of battery run time. Rest I'll be able to post the exact results in 2-3 days.
For the cooling of batteries I am doubtful if blowing air on the batteries(of course they are made of plastic) will give any desirable results. Any other method for cooling? Else I guess instead of using a radiator fan we can simply use an air dam up front with an air straightner placed in it. In other words use the Venturi effect to blow cold air on the batteries(it is same as a radiator but will not require a fan).

 

[TSIVipul]

Driven an Ertiga just an hour back. The car produces 90 bhp and offers a goo torque of around 20 kgm and all this mated to a fantastically set gearbox with the gear ratios set just right to enhance maximum driveability with optimum fuel consumption.
But, the Ecosport which has the same output with a 1.5 ltr unit is simply in an another league. I mean the way it responds to throttle inputs and one need not to wait for the revs to reach a point where turbo may start feeding enough air to engine.

It all zeroes down to same point again, turbocharging and all can be done but the basic thing still has the biggest effect on the drive.

Same is going to be Mobilio also I guess, 1.5 ltr unit is going to make it quite well driveabe.

 

[bhvm]

I can shed some light on the matter.
I have Fortuner 3.0L 171 PS 383NM Torque
and safari 3.0L. 116PS 300NM torque
i also have XUV500 2.2L 140PS 330NM torque

Actually,the XUV 500 has highest top speed, Highest Acceleration figures and most advanced engine.
However there IS A DIFFERENCE with these Big Boss 3.0L monsters. Safari has lowest Torque etc figure but has tremendous torque compared to all above. The same is evident when taking Speed breakers in 2nd gear in 3.0Ls but needs 1st gear in 2.2L XUV 500.

Some excerpts from my XUV thread-
>Fortuner has tremendous low down torque and engine clipping is absent ! What a relief. You can dump the clutch in Idle speeds and Fortuner Lunges forward; whereas XUV 5OO clips out with a loud THUD.

http://www.theautomotiveindia.com/f...eview-decals-audio-led-mods-4.html#post305118

http://www.theautomotiveindia.com/f...eview-decals-audio-led-mods-2.html#post286664