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


Reply
 
Thread Tools Search this Thread
Old 15th May 2009, 08:47   #1
Senior - BHPian
 
rkbharat's Avatar
 
Join Date: Sep 2006
Location: Gurgaon/New Delhi
Posts: 1,590
Thanked: 608 Times
Default SX4 ZXi GC - Myth or Reality ?

I have been thinking about this from the day I bought SX4. Though the specs says that it has got 190 mm for GC which is more than the on paper GC for Innova and Scorpio and not much less from Safari.

But when visually, side by side, I feel the GC is less than Innova and Scorpio. Only the rear looks better cleared. From side it looks just better than other sedans. Though its breez to clear the tallest speed boulders, without any problem

How do we really calculate and compare ?

Please help before I overestimate the GC of SX4 Zxi and land in soup.
Name:  SX-gc-compare.bmp
Views: 1596
Size:  827.9 KB
rkbharat is offline   Reply With Quote
Old 15th May 2009, 10:54   #2
BHPian
 
Join Date: Apr 2009
Location: Gurgaon
Posts: 447
Thanked: 2 Times
Default

Dear RK,

There is a slight catch as I believe when these companies tell you GC they tell you the height of the chasis but do not tell you the lowest point of the vehicle, which means that even if the GC is more a car still be lower in practical GC value
SamtheLeo is offline   Reply With Quote
Old 15th May 2009, 11:06   #3
Senior - BHPian
 
akshay4587's Avatar
 
Join Date: Mar 2005
Location: Chandigarh/Mohali/Ambala Cantt
Posts: 3,756
Thanked: 1,552 Times
Default

AFAIK GC is measured from the lowest point under the vehicle,isnt it?
akshay4587 is offline   Reply With Quote
Old 15th May 2009, 11:12   #4
Senior - BHPian
 
rkbharat's Avatar
 
Join Date: Sep 2006
Location: Gurgaon/New Delhi
Posts: 1,590
Thanked: 608 Times
Default

Ok does that means that though the Chasis of Innova or Scorpio gives higher GC impression from SX4, but they have parts lower from chasis?
Quote:
Originally Posted by SamtheLeo View Post
Dear RK,

There is a slight catch as I believe when these companies tell you GC they tell you the height of the chasis but do not tell you the lowest point of the vehicle, which means that even if the GC is more a car still be lower in practical GC value
Quote:
Originally Posted by akshay4587 View Post
AFAIK GC is measured from the lowest point under the vehicle,isnt it?
rkbharat is offline   Reply With Quote
Old 15th May 2009, 11:17   #5
Sha
BHPian
 
Sha's Avatar
 
Join Date: Dec 2008
Location: Canberra
Posts: 539
Thanked: Once
Default

GC is measured from differential bottom to the ground.
Sha is offline   Reply With Quote
Old 15th May 2009, 11:33   #6
BHPian
 
Join Date: Apr 2009
Location: Gurgaon
Posts: 447
Thanked: 2 Times
Default

Quote:
Originally Posted by rkbharat View Post
Ok does that means that though the Chasis of Innova or Scorpio gives higher GC impression from SX4, but they have parts lower from chasis?

I meant to say the vice versa, May be SX4 has a higher chasis value but being built in a Sedan style, it will have parts closer to the ground. Isnt it
SamtheLeo is offline   Reply With Quote
Old 15th May 2009, 11:45   #7
Senior - BHPian
 
vnabhi's Avatar
 
Join Date: May 2007
Location: DC -> DC
Posts: 5,264
Thanked: 1,233 Times
Default

AFAIK, GC means the distance between the lowest part of the car and the ground. I am sure an SX4 has good GC. If you see a Safari or Innova from the side, they might look a lot higher, but if you look from the rear, you will find their axle much below--and I believe that is the lowest point of those SUVs
vnabhi is offline   Reply With Quote
Old 15th May 2009, 12:32   #8
Team-BHP Support
 
tsk1979's Avatar
 
Join Date: Feb 2005
Location: New Delhi
Posts: 22,953
Thanked: 15,639 Times
Default

In case of vehicles like innova/safari etc., the lowest point is the rear diff. However all other parts sit much higher.
SO you can't really compare GC with those vehicles.
Moreover with ladder on frame vehicles, that is the laden GC, in the SX4 as weight increases expect GC to go down by 10-15mm atleast as 190mm is laden.

So if you are wondering who will scrape a speedbreaker first, it will be the SX4 inspite of having same minimum GC as the MUVs, however if you are driving on a farm road with wheels in ruts, the rear diff of an MUV may scrape before the engine bottom of SX4 starts scraping.

SO SX4 does have more GC than cars, but with MUVs, the lowest point is such that the "actual GC which matters" is actually much more
tsk1979 is offline   Reply With Quote
Old 15th May 2009, 12:32   #9
BHPian
 
Join Date: Dec 2008
Location: Hyderabad
Posts: 257
Thanked: 2 Times
Default

The ground clearance figures provided by manufacturers are measured when the cars are totally empty - no passengers, no fuel and nothing in the boot. Passengers and a full tank of fuel and stuff in the boot will make a significant difference that will vary from car to car. That could be another reason for the difference that you see between an Innova and an SX4 on the road.
straightdrive is offline   Reply With Quote
Old 15th May 2009, 12:56   #10
Senior - BHPian
 
rkbharat's Avatar
 
Join Date: Sep 2006
Location: Gurgaon/New Delhi
Posts: 1,590
Thanked: 608 Times
Default

Quote:
Originally Posted by SamtheLeo View Post
I meant to say the vice versa, May be SX4 has a higher chasis value but being built in a Sedan style, it will have parts closer to the ground. Isnt it
Well actually you got it wrong, basically I am saying that visibly GC of SX4 looks less than Innova or Scorpio, but on papers its high. but we just got some response for that

Quote:
Originally Posted by vnabhi View Post
but if you look from the rear, you will find their axle much below--and I believe that is the lowest point of those SUVs
Yes Exactly

Quote:
Originally Posted by tsk1979 View Post
as 190mm is laden.
You mean unladen, right?

Quote:
Originally Posted by tsk1979 View Post

So if you are wondering who will scrape a speedbreaker first, it will be the SX4 inspite of having same minimum GC as the MUVs,
I agree SX4 will hit first, because front clearance is more in MUVs/SUV. but than as it reaches to rear, MUV's definitely will scrap. So one has to do the same calculation in both cases. When challenged by speedbreakers High GC sedans will have to be more careful while entering and MUV have to be more carefull while leaving speedbreakers.

Thats my layman understanding.

Quote:
Originally Posted by straightdrive View Post
That could be another reason for the difference that you see between an Innova and an SX4 on the road.
Not really, I am just watching all these cars from window
rkbharat is offline   Reply With Quote
Old 15th May 2009, 13:13   #11
Team-BHP Support
 
tsk1979's Avatar
 
Join Date: Feb 2005
Location: New Delhi
Posts: 22,953
Thanked: 15,639 Times
Default

Quote:
Originally Posted by rkbharat View Post
You mean unladen, right?
Yes laden for MUVs and unladen for SX4

Quote:
I agree SX4 will hit first, because front clearance is more in MUVs/SUV. but than as it reaches to rear, MUV's definitely will scrap. So one has to do the same calculation in both cases. When challenged by speedbreakers High GC sedans will have to be more careful while entering and MUV have to be more carefull while leaving speedbreakers.
No.
The lowest point is the rear diff. Which lies between both rear wheels. So when both wheels rise, so will this diff. Only if rear overhang is very long, and speed breaker is higher than the body height(which is usually 240mm or so atleast) you will not hit. Here angle of departure comes info play.
this of it this way.
For hitting front also, it depends on angle of approach.

So when you approach speedbreaker, you will hit if the speedbreaker has angle of approach more than the vehicle. So a higher GC vehicle may hit and a lower GC vehicle may cross over if the former has a worse of angle of approach.
When front wheels go over the hump, and rear wheels are still yet to ride the hump, vehicle will hit of the height of the center body is less than height of the vehicle. Therefore a shorter vehicle will be better off.
Normally the way speedbreakers are constructed, you will see at the center part of the vehicle has most chance of scraping.
Esp in case of poorly designed speadbreakers which are very steep. The front literally falls down and suspension momentarily goes through full travel, temporarily drastically reducing the GC.

Thats why you have the "Accelerate while leaving bump" technique to avoid this. Acceleration causes suspension to expand in a FWD car, and you momentarily gain GC.

For example look at this thread
http://www.team-bhp.com/forum/techni...ver-angle.html (What is "Ramp Breakover Angle")

So to sum it up, having a very low center diff will not cause problems on speedbreakers, as both the wheels along with the diff rise, however if there is a solitary rock lying on the road, this part can hit. Ditto for ruts
tsk1979 is offline   Reply With Quote
Old 15th May 2009, 13:22   #12
Senior - BHPian
 
rkbharat's Avatar
 
Join Date: Sep 2006
Location: Gurgaon/New Delhi
Posts: 1,590
Thanked: 608 Times
Default

Thanks, that makes it clear. Now may be that is why SX4 has the front and rear edge portion bent upward, to provide breakover angle.


Quote:
Originally Posted by tsk1979 View Post
Yes laden for MUVs and unladen for SX4

No.
The lowest point is the rear diff. Which lies between both rear wheels. So when both wheels rise, so will this diff. Only if rear overhang is very long, and speed breaker is higher than the body height(which is usually 240mm or so atleast) you will not hit. Here angle of departure comes info play.
this of it this way.
For hitting front also, it depends on angle of approach.

So when you approach speedbreaker, you will hit if the speedbreaker has angle of approach more than the vehicle. So a higher GC vehicle may hit and a lower GC vehicle may cross over if the former has a worse of angle of approach.
When front wheels go over the hump, and rear wheels are still yet to ride the hump, vehicle will hit of the height of the center body is less than height of the vehicle. Therefore a shorter vehicle will be better off.
Normally the way speedbreakers are constructed, you will see at the center part of the vehicle has most chance of scraping.
Esp in case of poorly designed speadbreakers which are very steep. The front literally falls down and suspension momentarily goes through full travel, temporarily drastically reducing the GC.

Thats why you have the "Accelerate while leaving bump" technique to avoid this. Acceleration causes suspension to expand in a FWD car, and you momentarily gain GC.

For example look at this thread
http://www.team-bhp.com/forum/techni...ver-angle.html (What is "Ramp Breakover Angle")

So to sum it up, having a very low center diff will not cause problems on speedbreakers, as both the wheels along with the diff rise, however if there is a solitary rock lying on the road, this part can hit. Ditto for ruts

Last edited by rkbharat : 15th May 2009 at 13:26.
rkbharat is offline   Reply With Quote
Old 15th May 2009, 13:52   #13
Team-BHP Support
 
tsk1979's Avatar
 
Join Date: Feb 2005
Location: New Delhi
Posts: 22,953
Thanked: 15,639 Times
Default

Quote:
Originally Posted by rkbharat View Post
Thanks, that makes it clear. Now may be that is why SX4 has the front and rear edge portion bent upward, to provide breakover angle.

Nope! Its not for breakover angle.
Its for approach(attack) and departure angles
Name:  angles.jpg
Views: 1880
Size:  19.4 KB
tsk1979 is offline   Reply With Quote
Old 15th May 2009, 13:58   #14
Senior - BHPian
 
rkbharat's Avatar
 
Join Date: Sep 2006
Location: Gurgaon/New Delhi
Posts: 1,590
Thanked: 608 Times
Default

Oh yes, actually I meant the same, but used the wrong term
Quote:
Originally Posted by tsk1979 View Post
Nope! Its not for breakover angle.
Its for approach(attack) and departure angles
rkbharat is offline   Reply With Quote
Old 15th May 2009, 15:33   #15
BHPian
 
thalavoy's Avatar
 
Join Date: Jun 2004
Location: Chennai
Posts: 389
Thanked: 62 Times
Default

SX4 in its original form factor (also Fiat Sedici) is a soft roader (like Adventure/Fusion) types. Hence the angles and higher ground clearance.
thalavoy 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
PCD Variation Bolts (aka Wobble Bolts) - Myth versus Reality PatchyBoy Tyre & Alloy wheel Section 31 21st December 2015 18:43
SUVs & the Bullying effect: Myth or Reality? smartcat Street Experiences 140 31st March 2014 00:02
SX4 Zxi or ANHC? EDIT : Bought SX4! abhi182 Sedans 153 21st December 2009 15:54
Swift to SX4 - Booking a Black SX4 Zxi - Some queries on Pg3 joy_swift Sedans 68 28th August 2009 16:08
Ferrari Challenge - New Concepts of the Myth salil_kulkarni The International Automotive Scene 4 19th November 2005 12:04


All times are GMT +5.5. The time now is 21:37.

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