Go Back   Team-BHP > BHP India > The Indian Car Scene


Reply
 
Thread Tools Search this Thread
Old 17th October 2011, 10:07   #16
Distinguished - BHPian
 
sgiitk's Avatar
 
Join Date: Dec 2007
Location: Kanpur
Posts: 7,162
Thanked: 3,757 Times
Default Re: What happened to low end torque of today's small cars?

This is not unexpected. The main reason is Shorter stroke engines. A short stroke (oversquare) design is becoming more and more popular. This design permits making the engine higher revving and more powerful, at the cost of low end torque.

Just compare the Kappa and Epsilon engines of Hyundai and you will know.

One reason for the popularity of longer strokes, was the old RAC formula of the 50's of calculating the 'taxable hp' of an engine which favoured the undersquare design. Also, a smaller bore meant a more compact engine.

Last edited by sgiitk : 17th October 2011 at 10:10.
sgiitk is offline   (12) Thanks Reply With Quote
Old 17th October 2011, 10:47   #17
BHPian
 
avisidhu's Avatar
 
Join Date: Dec 2010
Location: Chandigarh
Posts: 618
Thanked: 456 Times
Default Re: What happened to low end torque of today's small cars?

Quote:
Originally Posted by krish82 View Post
Where as My Optra 1.6 Petrol, feels sluggish of the start, but it has so much mid range torque that, when i put my foot in accelerator in 5th gear @ 50km/hr it pulls pulls and pulls till what ever speed.
I'm sorry but how does 50kmph in 5th gear constitute mid range?

Quote:
Originally Posted by rohanjf View Post
This technique works in i10 too, but I notice that the RPM rises till 2000 after the clutch is pressed, and then gradually comes down to idle. My feeling is that the ECU assumes that I am going to upshift, and to make sure that there is no loss of torque when 2nd gear is engaged, it pushes the RPM up.
Its most probably due to the anti stalling mechanism present in today's cars, but would love to know otherwise if the experts here think so.

Quote:
Originally Posted by sgiitk View Post
This is not unexpected. The main reason is Shorter stroke engines. A short stroke (oversquare) design is becoming more and more popular. This design permits making the engine higher revving and more powerful, at the cost of low end torque.
That was informative sir, thanks for sharing. So does this also impact the FE? Because like most members here even I was under the impression that low end torque reduction plus short gearing has been done keeping in mind just the FE consideration.
avisidhu is offline   Reply With Quote
Old 17th October 2011, 11:14   #18
Senior - BHPian
 
kiku007's Avatar
 
Join Date: Apr 2005
Location: Brisbane
Posts: 1,610
Thanked: 1,223 Times
Default Re: What happened to low end torque of today's small cars?

Even I'd like to know. I don't understand how lowering the low end torque can improve FE.

Not just small cars. The Ikon 1.6 and 1.3 L rocams had better low end than the fiesta's 1.6L duratec.

Also this is wrt petrol only. The modern diesel cars are easy to drive in b2b traffic provided they have a light clutch.
kiku007 is offline   Reply With Quote
Old 17th October 2011, 11:53   #19
Senior - BHPian
 
avishar's Avatar
 
Join Date: Oct 2008
Location: kolkata/bangalore,india
Posts: 2,411
Thanked: 686 Times
Default Re: What happened to low end torque of today's small cars?

I agree with this observation wholeheartedly.

I drive an Alto K10 and below 2k rpm,the engine is very sluggish.At the end of the day i would not say that the low end torque is terrible,its pretty much adequate,but the terrible traffic sense and our roads requires sudden braking and gear changes!

I mean,we have to drive almost bumper to bumper,even if traffic is moving at a fair speed,because even if you keep some gap,someone is going to try and muscle thier way in.So you have to keep pace with the front car,suddenly if he accelerates you better move also,and this where the car feels sluggish if it is in say 4th or 3rd.

I never had such a problem with our old carb 800,and in the first few days of driving the Alto,i stalled the car umpteen times!The engine constantly has to kept on the boil,and i believe for me its less of a performance issue and more of a safety issue,because i think having power on tap is very important for indian road conditions.
avishar is offline   Reply With Quote
Old 17th October 2011, 16:28   #20
GTO
Team-BHP Support
 
GTO's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 47,749
Thanked: 89,406 Times
Default Re: What happened to low end torque of today's small cars?

Completely agreed with Sgiitk! Shorter stroke + higher power demands appear to have resulted in the loss of low end torque. Man, what a hatchback the Santro is in the city. Simply awesome driveability, not a single new hatchback comes close in terms of driving convenience.

I think the situation worsens with the diesels. No more naturally-aspirated oil burners. Turbo-charged is the current norm, with nearly all diesel cars suffering from <2000 rpm lag (few exceptions like the Micra & Figo though).
GTO is offline   (2) Thanks Reply With Quote
Old 17th October 2011, 16:58   #21
BHPian
 
Ascari's Avatar
 
Join Date: Sep 2011
Location: Bangalore
Posts: 101
Thanked: 63 Times
Default Re: What happened to low end torque of today's small cars?

@GTO True.The Santro was an amazing city hatch,amazing drivablity indeed.I had a Santro during my college years and boy oh boy it was fun driving it in the city! I test drove a Palio 1.2 and it felt so slow in the city that it bordered on the cumbersome.The brakes and the hydraulic steering of the Santro were really sharp too.It was the point and shoot weapon for our urban chaos.

Modern hatches including the expensive one's like the i20 are just too heavy and detuned to offer better FE.I really think this is the order of the day and petrolhead's like us just have to move on with the times.I think the future is bleak if you are petrolhead what with the ever increasing prices of petrol.The loss of the hydraulic steering to electric steering was a victory of economics over the joy of driving.

IMHO in the not too distant future,the only options for petrolheads would be to buy expensive supercars and that is very sad.The only light at the end of the tunnel is if manufacturers decide to offer us small turbocharged petrol engines.Yes,turbo lag would be a problem,but a small turbo or a VGT might solve the problem.It may not be as good as a naturally aspirated engine but it's the best compromise in today's world.A 600 cc turbo charged engine with the power of a 1 litre engine would ensure both FE and power.The VW TSI engines have already proven this.All they need to do now is to improve driveablity low down.I really don't think all diesels have turbo lag,the laura for example is pretty drivable in the city with the torque kicking in at low rpm's.

Last edited by Ascari : 17th October 2011 at 17:26.
Ascari is offline   (2) Thanks Reply With Quote
Old 17th October 2011, 18:16   #22
Senior - BHPian
 
Join Date: Aug 2010
Location: Delhi
Posts: 2,133
Thanked: 1,006 Times
Default Re: What happened to low end torque of today's small cars?

Well I have the Alto K10, and without AC it has enough low end torque to pull from stop in second gear. The problem starts when you have the AC on, then you are bound to use the 1st gear at below 20 km/h speeds as in stop and go traffic.

I have noticed that in first gear, if I release the clutch when stopped the car will pull and stabilise at 10 km/h. In fact today I tried third gear down to 10 km/h momentarily and it pulled.

Today the design is for higher speed driving, which means higher revving engines, and high revving engines have much less torque on the whole compared to the low revving engines, as the nett HP is a product of torque and speed, we get more HP but lower torque, which contributes to higher FE. In order to accommodate low speed driving a lot of manufacturers are using shorter ratios in the first two/three gears, and longer ratios in the higher gears. The whole idea of "Overdrive" is to help cars achieve higher speeds, at lower engine speeds, hence higher FE. Some newer vehicles have started coming with two overdrive ratios!
__________________
Quote:
Originally Posted by Ascari View Post
IMHO in the not too distant future,the only options for petrolheads would be to buy expensive supercars and that is very sad.The only light at the end of the tunnel is if manufacturers decide to offer us small turbocharged petrol engines.Yes,turbo lag would be a problem,but a small turbo or a VGT might solve the problem.It may not be as good as a naturally aspirated engine but it's the best compromise in today's world.A 600 cc turbo charged engine with the power of a 1 litre engine would ensure both FE and power.The VW TSI engines have already proven this.All they need to do now is to improve driveablity low down.I really don't think all diesels have turbo lag,the laura for example is pretty drivable in the city with the torque kicking in at low rpm's.
The demand for extreme performance will always be there. If the manufacturer does not provide a low cost performance car, you can always get the ECU of your favourite car remapped for performance. That is what rally enthusiast do anyway (in good old days you simply added multiple carburetors, a tuned multibarrel exhaust and a performance air throttle). As BMW and other manufacturer's have shown, production engines are being tuned to various states of power and torque to suite the target clientele.

Last edited by Rudra Sen : 17th October 2011 at 22:55. Reason: merging post.
Aroy is offline   Reply With Quote
Old 17th October 2011, 20:04   #23
BHPian
 
Join Date: Oct 2006
Location: bangalore
Posts: 335
Thanked: 274 Times
Default Re: What happened to low end torque of today's small cars?

Now My 2p

Now let's take the petrols first .

In-order to reduce costs and increase fuel efficiency ,manufacturers are trying to produce the same amount of power from a low displacement three cylinder engine as they would from a comparatively larger displacement 4 cylinder engine . For obtaining the same bhp from a low displacement engine ,they are pushing the power band higher and higher up .Power = TorqueRPM . So max torque is produced higher up the rev range .The positive effect of that is higher max power but at the cost of poor low end torque.To compensate for this manufacturers are resorting to variable valve timing but it is too expensive to implement in A/A+ segment cars . Another way to compensate is to employ shorter gearing but that penalizes fuel efficiency .especially in the ARAI cycle .Everybody knows how much bragging rights ARAI figures provides to the manufacturers .

Now coming to the diesels .Because of the Excise limit everybody is resorting to
turbocharging in-order to keep the power figures to respectable levels .Now take
the example of the Fiesta's 1.4 tdci motor ..It had a very good bottom end but now Ford
was lagging behind in peak power so they bored out the motor and employed a bigger turbo
the result higher peak power at the cost of significant turbo lag in the new Fiesta. Now ford
did not have the option of bringing in the 1.6 tdci available abroad because of excise limit .
The naturally aspirated diesels with big displacements are inherently more responsive but because of excise limits the days of naturally aspirated diesels are almost over at-least in
A/B segment cars .

Last edited by needforspeed88 : 17th October 2011 at 20:09.
needforspeed88 is offline   Reply With Quote
Old 17th October 2011, 20:45   #24
Senior - BHPian
 
longhorn's Avatar
 
Join Date: Nov 2009
Location: Chennai
Posts: 1,154
Thanked: 290 Times
Default Re: What happened to low end torque of today's small cars?

Tell me about it. My M800 5 speed is much more fun to drive than my Ritz. Even after all these years this baby never ceases to amaze me. Whoever mated that 5 speed gearbox to the F8D did an amazing job. The word flat spot does not exist in her dictionary. Beautiful response in all gears (for an 800 cc engine). The Ritz is nowhere in comparison in the first gear.
longhorn is offline   Reply With Quote
Old 17th October 2011, 21:23   #25
BHPian
 
misquitas's Avatar
 
Join Date: Jun 2008
Location: Panjim
Posts: 859
Thanked: 272 Times
Default Re: What happened to low end torque of today's small cars?

Quote:
Originally Posted by GTO View Post
Man, what a hatchback the Santro is in the city. Simply awesome driveability, not a single new hatchback comes close in terms of driving convenience.
Quote:
Originally Posted by Ascari View Post
@GTO True.The Santro was an amazing city hatch,amazing drivablity indeed.I had a Santro during my college years and boy oh boy it was fun driving it in the city! I test drove a Palio 1.2 and it felt so slow in the city that it bordered on the cumbersome.The brakes and the hydraulic steering of the Santro were really sharp too.It was the point and shoot weapon for our urban chaos.
The more I read about the virtues of the Santro, the more I'm inclined to consider this aging yet proven, no-nonsense and reliable workhorse over the Eon for my wife, before Hyundai decides to drop the Santro engine (in favour of some newer 3-cylinder engine) or worse still...decides to drop the Santro altogether.

My friend regrets a bit in not having opted for the Santro in 2009, as he eventually settled from the Wagon R.
misquitas is offline   (1) Thanks Reply With Quote
Old 17th October 2011, 23:29   #26
BHPian
 
avisidhu's Avatar
 
Join Date: Dec 2010
Location: Chandigarh
Posts: 618
Thanked: 456 Times
Default Re: What happened to low end torque of today's small cars?

Quote:
Originally Posted by misquitas View Post
The more I read about the virtues of the Santro, the more I'm inclined to consider this aging yet proven, no-nonsense and reliable workhorse over the Eon for my wife, before Hyundai decides to drop the Santro engine (in favour of some newer 3-cylinder engine) or worse still...decides to drop the Santro altogether.

My friend regrets a bit in not having opted for the Santro in 2009, as he eventually settled from the Wagon R.
All I can say is, a huge majority of crazily driven vehicles on my daily commute on the NH from Dhaula Kuan to Gurgaon used to be Santro's, which left me wondering as to what's so special about this vehicle that everyone is driving it like crazy

I guess in saner hands, it would be a fun to drive vehicle rather than the nuisance I had come to believe it to be.
avisidhu is offline   Reply With Quote
Old 18th October 2011, 00:26   #27
BHPian
 
johnruben's Avatar
 
Join Date: Sep 2007
Location: Bangalore
Posts: 213
Thanked: 73 Times
Default Re: What happened to low end torque of today's small cars?

I have driven my cousin's alto K10 and didnt find its under-torqued in city traffic, it had very good pickup and also gear shifts were not frequent.

I guess future cars might come up with a switch to make torque adjustable for city and highway drives OR just go and get yourself an Automatic
johnruben is offline   Reply With Quote
Old 18th October 2011, 09:27   #28
Distinguished - BHPian
 
sgiitk's Avatar
 
Join Date: Dec 2007
Location: Kanpur
Posts: 7,162
Thanked: 3,757 Times
Default Re: What happened to low end torque of today's small cars?

Quote:
Originally Posted by needforspeed88 View Post
Now coming to the diesels .Because of the Excise limit everybody is resorting to
turbocharging in-order to keep the power figures to respectable levels .
In Common Rail Engines Turbocharging is nearly universal. Of course excise results in 1.5 being treated almost like a Lakshman Rekha. What we ideally need esp. for city runabouts is a peppy turbo motor coupled to a good auto box. This will cover most sins of turbo lag etc.

A similar logic can be applied to Petrol engines since blown small engines are coming.
sgiitk is offline   (1) Thanks Reply With Quote
Old 18th October 2011, 11:10   #29
BHPian
 
A350XWB's Avatar
 
Join Date: Oct 2009
Location: BLR/FRA/STR
Posts: 791
Thanked: 528 Times
Default Re: What happened to low end torque of today's small cars?

Quote:
Originally Posted by GTO View Post
Completely agreed with Sgiitk! Shorter stroke + higher power demands appear to have resulted in the loss of low end torque. Man, what a hatchback the Santro is in the city. Simply awesome driveability, not a single new hatchback comes close in terms of driving convenience.

I think the situation worsens with the diesels. No more naturally-aspirated oil burners. Turbo-charged is the current norm, with nearly all diesel cars suffering from <2000 rpm lag (few exceptions like the Micra & Figo though).
+1. The engine characteristics have changed over time and I feel that the newer engines are more rev happy, at the cost of low end.
I own a 2006 eRLX Santro and it's simply awesome to drive in the city. It out-accelerates cars, twice or thrice it's price. It is not rev happy, but till 40 Kmph, the acceleration is superb, which is a wonderful thing in city traffic. I still prefer the Santro for maddening Bangalore city traffic and the Figo for more relaxed routes.
A350XWB is offline   Reply With Quote
Old 18th October 2011, 11:32   #30
BHPian
 
Join Date: Oct 2006
Location: bangalore
Posts: 335
Thanked: 274 Times
Default Re: What happened to low end torque of today's small cars?

Quote:
Originally Posted by sgiitk View Post
Of course excise results in 1.5 being treated almost like a Lakshman Rekha.
.
There in lies the problem

Because of the excise limit we have an Altis with a puny motor and
massive turbo lag . We have the new fiesta with a 1.5 bored out motor
instead of the 1.6 tdci . I can understand if it was lower segments but
cars like Fiesta and Altis trying to take benefit of excise cut at the
cost of turbo lag is sickening .Fiesta and Altis run bigger turbos to
keep keep power levels respectable, instead they should have gone for
a bigger displacement with a smaller turbo which they won't , cos that
would take them out of excise limit .

Last edited by needforspeed88 : 18th October 2011 at 11:33.
needforspeed88 is offline   (1) Thanks Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
What is planned, never happened. What ever happened, was not planned. mjothi Travelogues 23 10th January 2011 11:00
Same issue - opposite effects on low end torque Jeep Technical Stuff 6 26th June 2008 13:38
Increase Low end torque in Swift Petrol pshyamsundar Modifications & Accessories 5 4th April 2007 12:30
Mod for low end torque in Swift talk2anand Technical Stuff 34 31st October 2006 10:20
giving the Swift some low end torque and fatter wheels theEnd Modifications & Accessories 14 21st November 2005 19:07


All times are GMT +5.5. The time now is 08:35.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks