Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 21st August 2005, 00:57   #16
Senior - BHPian
 
veyron1's Avatar
 
Join Date: Mar 2005
Location: Mumbai
Posts: 1,426
Thanked: 37 Times
Default

Quote:
Its not as simple as that. The 800 is a much lighter car at 650 kg approx. as opposed to the Swift which is on the wrong side of 1000 kg. Further, to control the weight of the heavy Swift axle (it is VERY beefy compared to the puny 800 axle), you need heavier dampers. So, instead of improving ride, this may affect both ride AND handling effectively.
agreed, the 800 is much lighter and the rear dampers have to contend with a light load. but the pressure and load ratings of the gas-charged dampers for the rear axle of the 800 are supposed to be good. the thing is, the damper mountings and brackets have to be of the same length, for the swift and the 800. everything else can be altered, including different rebound spring valves, to alter the compression/ rebound characteristics. the important thing is to match the mounts....but if any heavier load rated aftermarket gas charged dampers are available, that have the same size mounts, then that would be better...

Quote:
Play around with the pressures at the back to improve ride. This works very well, especially if you are the only one in the car. For example, the recommended rear pressure on my car is 32 psi but I am not happy with anything more than 26.
that's okay when you are driving alone in the city, on harsh roads at low speeds. but it's not such a good idea to keep lower tyre pressures than recommended. the main reason being that there is an increased chance of the tyres bursting while going at high speeds as compared to higher pressures. also, your fuel efficiency is affected adversely... and if you look into it more deeply, the sidewalls have to face more stress due to the reduced pressure and lack of support, and your tyre life gets significantly reduced; and not to mention, your chances of getting a puncture increases... in fact, you should always keep the air pressure in your tyres 2-3 psi more than the recommended rates... the only time to SLIGHTLY decrease the tyre pressures, are when you are trying out for 1/4 mile times, or when you are stuck in mud while off-roading...it's a trick commonly used in SUV's to get out of tricky situations (have tried it myslef)...

p.s- mods, please delete post#12.... a double post, by mistake...
veyron1 is offline   Reply With Quote
Old 21st August 2005, 07:29   #17
Awaiting Email Confirmation
 
Join Date: Jun 2005
Location: ERNAKULAM
Posts: 947
Thanked: 317 Times
Default You guys have your concept a bit awry

All gas filled dampers have oil in them. It is the oil that damps the oscillations of the suspension mass. Gas cannot do the same on its own though theoretically all fluids can do the damping. Remember that all gases are also fluids. Nitrogen is added as gas to prevent foaming of the oil in gas filled dampers to improve effeciency of the dampers. Chance of failure in gas filled dampers is slightly higher. Please follow the links if you wish to know more or type gas dampers in google or yahoo search.

http://www.eu.tenneco-automotive.com.../gas_shock.htm

http://www.tirerack.com/suspension/t...o_sport_rd.jsp

I hope these links clear the confusion of gas filled dampers.

Bye and wear your seatbelts.

Last edited by drpullockaran : 21st August 2005 at 07:39.
drpullockaran is offline   Reply With Quote
Old 21st August 2005, 12:05   #18
Senior - BHPian
 
aseem's Avatar
 
Join Date: Jul 2005
Location: Delhi
Posts: 1,737
Thanked: 416 Times
Default

Well I guess now I know the difference between gas charged and oil filled shock absorbers. However the problem still remains that the ride quality (this can be due to tyres) is on the harsher side specially on the rear. I have a year old Esteem and the difference between the ride quality is substancial. It almost gives me like Santro like feeling where the car just bumps and rattles on bad roads. The reason I am concerned is not that I travel on bad roads, as most of my daily journey the problem is not even there thanks to the good delhi roads. However the reason I am concerned is that I like to travel a lot to Manali, Jim Corbet, Jaipur, Agra, Shimla and Chandigarh etc. I make a minimum of 2 trips every month. Now I am concerned that all states dont have good roads, and if the ride cant improve I would have to go in my esteem... :( So maybe I was wrong if I said I wanted to change the oil dampers to gas charged absorbers, as this seems to be a herculean task. So my question now is what are known tried and tested ways to improve the car ride from harsher to a smoother ride, like changing tyre pressure etc.
aseem is offline   Reply With Quote
Old 21st August 2005, 15:08   #19
Senior - BHPian
 
ananthkamath's Avatar
 
Join Date: Jul 2005
Location: USA
Posts: 1,194
Thanked: 46 Times
Default

Quote:
Originally Posted by veyron1
but the pressure and load ratings of the gas-charged dampers for the rear axle of the 800 are supposed to be good.
Dampers have no load or 'pressure' ratings as you term them . They are specified only by the parameters that MPower outlined. Oil pressure is a design parameter which does not appear in the specification.

If the 800 ones work, good for Aseem. I'm just saying that the chances of them working are not that high. Dampers go with the springs they were designed for. For example, the leaf-sprung 800 has different dampers to the coil-sprung one, and I'm not talking just about the mountings.
ananthkamath is offline   Reply With Quote
Old 21st August 2005, 15:16   #20
Senior - BHPian
 
ananthkamath's Avatar
 
Join Date: Jul 2005
Location: USA
Posts: 1,194
Thanked: 46 Times
Default

Quote:
Originally Posted by aseem
I have a year old Esteem and the difference between the ride quality is substancial. It almost gives me like Santro like feeling where the car just bumps and rattles on bad roads.
The Esteem has better ride due to the fact that it has independent suspension at the back. That 'Santro-like feeling' you describe is common to most cars with a non-independent dead axle at the back.

I don't know about the condition of roads in the places you mentioned, but if it doesn't involve high speeds then you can definitely try lowering the tyre pressure. It works.

Or, if you want a simple non-technical solution which has worked for me, use sand bags in the boot. I know, its insanely crude, but it sure as hell works.

Ananth
ananthkamath is offline   Reply With Quote
Old 21st August 2005, 21:27   #21
Distinguished - BHPian
 
Mpower's Avatar
 
Join Date: Mar 2005
Location: Bangalore
Posts: 10,432
Thanked: 1,682 Times
Default

Maruti 800 is seriously underdamped. Anyone whose driven an 800 on our wavy country roads know how it bounces up and down like a pogo stick
Mpower is offline   Reply With Quote
Old 22nd August 2005, 13:21   #22
BHPian
 
chandan's Avatar
 
Join Date: Jul 2005
Location: sakleshpur
Posts: 250
Thanked: 44 Times
Default

guys,
why is it that premium hatchbacks donot have independent suspension,inspite of them being called Premium ???
Quote:
Originally Posted by ananthkamath
The Esteem has better ride due to the fact that it has independent suspension at the back. That 'Santro-like feeling' you describe is common to most cars with a non-independent dead axle at the back.

I don't know about the condition of roads in the places you mentioned, but if it doesn't involve high speeds then you can definitely try lowering the tyre pressure. It works.

Or, if you want a simple non-technical solution which has worked for me, use sand bags in the boot. I know, its insanely crude, but it sure as hell works.

Ananth
chandan is offline   Reply With Quote
Old 23rd August 2005, 00:04   #23
Senior - BHPian
 
veyron1's Avatar
 
Join Date: Mar 2005
Location: Mumbai
Posts: 1,426
Thanked: 37 Times
Default

Quote:
Dampers have no load or 'pressure' ratings as you term them . They are specified only by the parameters that MPower outlined. Dampers have no load or 'pressure' ratings as you term them . They are specified only by the parameters that MPower outlined.
the "load" rating that i was quoting was for the shockers are specified in kgs- each damper is specified at manufacturing stage to withstand a certain amount of pressure in terms of kgs (along with other parameters) to ensure proper results. for example, my safari's rear shockers (which also came with a aftermarket, dealer endorsed, gas-charged option) was rated at 650 kgs (last time i checked) max. at each axle end- meaning a combined load rating of 1300 kgs for the rear axle - and this was for the rear axle shock absorbers, not the max payload applicable at the rear axle.
veyron1 is offline   Reply With Quote
Old 25th August 2005, 07:02   #24
Awaiting Email Confirmation
 
Join Date: Jun 2005
Location: ERNAKULAM
Posts: 947
Thanked: 317 Times
Default Independence not the holy grail.

Having an independent suspension at the back is not the holy grail to having a good ride at the back. My junk trap indica has independent setup at the rear and my Palio GTX has torsion beam setup at the rear. The Indica with new shock absorbers does not even come remotely close to the Palio GTX in terms of ride quality let alone compare it to the normal Palio 1.2 which is slightly softly sprung in comparison to the GTX. You have to design the suspension from ground up taking into cosideration the unsprung mass and also the total loading of the the rear suspension. You have to choose between harsh ride on smooth roads (which will generally give you a well damped ride on rough undulating roads) and floating ride like the Maruti 800 on smooth roads( which will thow you around on rough undulating roads). Bye and wear your seatbelts
drpullockaran is offline   Reply With Quote
Old 25th August 2005, 13:52   #25
Senior - BHPian
 
ananthkamath's Avatar
 
Join Date: Jul 2005
Location: USA
Posts: 1,194
Thanked: 46 Times
Default

Yes I do agree that a badly setup independent does no better or is even worse than a beam axle. However the problem with the Indica is not one of high unsprung mass but a large spring rating. If you have 3 people in the back, the balance and grip of the car changes totally. The single rate spring used there is a compromise for cost purposes. A progressive at the back would do wonders for the Indica's ride.
ananthkamath is offline   Reply With Quote
Old 26th August 2005, 01:59   #26
Distinguished - BHPian
 
Mpower's Avatar
 
Join Date: Mar 2005
Location: Bangalore
Posts: 10,432
Thanked: 1,682 Times
Default

Indica V1 was a pure trailing arm and the geometry was flawed for both ride and handling.

The V2 has a strut with tri-link arrangement. Supposed to be a vast improvement over the V1.
Mpower is offline   Reply With Quote
Old 26th August 2005, 09:47   #27
Senior - BHPian
 
ananthkamath's Avatar
 
Join Date: Jul 2005
Location: USA
Posts: 1,194
Thanked: 46 Times
Default

Quote:
Originally Posted by Mpower
Indica V1 was a pure trailing arm and the geometry was flawed for both ride and handling.
Can you please elaborate on why you think it was flawed for both?

Quote:
Originally Posted by Mpower
The V2 has a strut with tri-link arrangement. Supposed to be a vast improvement over the V1.
As far as I know, both the V2 and V1(so to speak) had the same rear suspension. Its only in the Indigo that they have tri-link....
ananthkamath is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Are my swift's Shock absorbers dead!!??? grizzly Technical Stuff 55 10th December 2015 13:57
Swift VDi - Spring noise in shock absorbers username Technical Stuff 12 4th December 2015 08:08
Are gas shock absorbers really superior in absorbing bumps? mithun Technical Stuff 40 3rd August 2015 20:17
gas filled shock absorbers Ironmarine Technical Stuff 1 24th July 2006 13:38


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

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