Discussion in 'Technical' started by gururajanv, Jun 2, 2010.
Forget GTO .. U can take his reviews with a pinch of salt. He is an undercover agent for Honda
OT alert - Attitude aside (rubbing people the wrong way), I don't think he is a Honda agent. He speaks of the Fiat Linea T-Jet with the same high praise as he does of the Honda City. Personally I can't fault his technical knowledge.
Guys, please stick to topic. It's a request.
As is, we've got a much more interesting issue on our hands, namely - noisier engines producing more power , rather than this UFO /JTO/ STD PCO wotever.
Mods- Can we move all the interesting posts regarding 'noise and power' to hangout under a new thread?
Coming back to the topic; I see only 2 reasons why the 1st and 2nd gears are short.
1) easier city navigation.
2) the 2nd gear is shorter for the ones who love to skip 1st gear to move off from a stand still.
as for discussing gear ratios there is no hope with the current 5 speed tranny what fiat needs to do get that 6 speed gear box from Europe (for all complaining).
But then we actually dont need the 6 speed in India because our "average" highway speeds are max 100km/h (legal 80km/h) there are some exceptions that average 130+::V.. but the 5 speed is more than enough.
A car in India spends more than half of its life in 1st and 2nd gears.
In europe the legal limits itself are around 120km/h improved roads etc.. lesser 1st & 2nd gear speeds.
Fiat-India played it safe using the palio box but atleast they should have bought the 6 speed in the tjet!!
Do they deliberately decrease fuel supply in first and second gear for better fuel efficiency? Once during test drive the sales person told this explanation. Also it is true that first and second gears are the most misused gears. People generally deep press the accelerator pedal in first and second gear.
The first gear is super short, no doubt. But that is merely to : Enable a easy start from a dead stop. No matter what the load ( well, within reasonable limits) and the incline , this gear helps in an easy start.
The second gear is a bone of contention here. I've not driven the Punto 75 much , about 3-4 kms, so cant comment on it's second gear .
But in the Linea MJD , the second gear is not as Satanic as people have made it to be. It is OK , and can be used from very low speeds as well. How this helps - When moving very slowly, you don't need a downshift to first gear.
I've forgotten the exact rpm's , but upshift at around 2500rpm from 2nd to 3rd, and you're bang in the turbo zone. No performance hampered.
So, i don't really think FIAT goofed up on the Linea's gears. Keep the engine in it's happy zone and you'll be fine. And Linea has a wide powerband, not a "peaky" one.
5 speeds are more than enough for the Indian Linea MJD. Unless you want a Corolla D4D like 6 speed. Reason being , the 6 speed will have a super overdrive 6th gear for efficiency purposes, needing a downshift to overtake anything substantial. I know this is speculation here, but it's the way most manufacturers are going at it.
I have been experiencing frequent stalling of my T Jet in 2nd gear, especially in slow city traffic where you have no choice but to be in second gear. I referred this to TASS, but they are telling there is nothing wrong with the car. Is this problem due to short gearing ratios in 1st and 2nd gears or something to do with clutch and accelerator coordination?
@ Sandip: I also face this issue often. I suspect it happens because I have a habit of shifting into 2nd gear (in back-to-back traffic) instead of 1st even if the car is just about moving. Courtesy the taller gears, below 5-7kmph or so, we should shift to 1st gear.
Basically, instead of having no choice but 2nd gear, you have to shift between 1st and 2nd gears.
First of all, the car seems to have excessive (terrible) engine braking in 1st and 2nd gears. Here is what wikipedia says:
"A mechanism related to the exhaust brake is back-pressure from a turbocharger. In turbodiesels with variable-vane turbos, the vanes will close when the accelerator is released, which creates a back-pressure braking effect similar to an exhaust brake. Even fixed turbos, especially larger ones, will cause some back-pressure when they are below the turbo threshold (albeit not the the same extent as a variable turbo) and contribute to the braking effect."
I have to agree with the above observation that there is a braking effect when the accelerator pedal is released.
And so we need to rev up more to remain in the powerband in the next gear up. Just try upshifting on uphill. Even on a moderate incline, 2nd to 3rd would require 3000 rpm for a clean shift. Forget 1st to 2nd, unless of course somebody can teach me some gymnastics to play with the foot pedals. And you need to move fast with the gear lever before the rpm drops.
Also I think, the rpm drops quickly while shifting because of the shorter gearing.
Quoted out of context.
The above explanation deals with a specific exhaust brake system,and not engine braking in general.
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