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


Reply
 
Thread Tools Search this Thread
Old 24th November 2009, 14:54   #16
Team-BHP Support
 
benbsb29's Avatar
 
Join Date: Nov 2006
Location: Brisbane
Posts: 8,022
Thanked: 3,478 Times
Default

Quote:
Originally Posted by nairrk View Post
I was driving my car (fiesta-168mm GC) ) with 4 people on board and never had any bottom scrap incident in any of the speed breakers.
By the looks of it, yours is a car which predominantly runs in Kerala where such car-breakers are uncommon. In Bangalore, where the thread starter is located, this is a major issue since there are speed breakers every few meters, one bigger than the other.

Now, back to the topic.
benbsb29 is offline   Reply With Quote
Old 24th November 2009, 14:57   #17
Senior - BHPian
 
nairrk's Avatar
 
Join Date: Sep 2009
Location: Payyannur-Kannur district
Posts: 2,106
Thanked: 31 Times
Default

Did Accent brought down their GC recently?
I owned a Accent GLS 2001 model and the GC mentioned there was 172mm which is better than most of the other cars (ofcourse I dont remember any bottom scrapping. I drove the car for almost 3.5 years -the car was mostly used in Chennai).

As you correctly said, one cannot do anything with the speed breaker, but only way out is to try some modication to the car?
nairrk is offline   Reply With Quote
Old 24th November 2009, 15:10   #18
BHPian
 
Join Date: Feb 2008
Location: Bangalore
Posts: 224
Thanked: 2 Times
Default

Quote:
Originally Posted by nairrk View Post
Did Accent brought down their GC recently?
I owned a Accent GLS 2001 model and the GC mentioned there was 172mm which is better than most of the other cars (ofcourse I dont remember any bottom scrapping. I drove the car for almost 3.5 years -the car was mostly used in Chennai).
Thanks Nairrk. My accent is a 2000 model. It's very interesting to hear that your Accent never had this issue. That reminds me - while a mechanic had told a few months back that my shocks are weak, two mechanics including a shock up mechanic said that the shocks were perfect and need not be changed - what was needed was a spacer to increase the height by an inch to take care of the scraping.

Benbsb is right, in and around Bangalore, there are a lot of car breakers!
harsha.cs1 is offline   Reply With Quote
Old 24th November 2009, 15:40   #19
BHPian
 
WhiteKnight's Avatar
 
Join Date: Mar 2006
Location: Bangalore
Posts: 828
Thanked: 73 Times
Default

Quote:
Originally Posted by harsha.cs1 View Post
In this regard, I wanted to know people's experience with body lift kits or spacers, as many people call it.
To my understanding,

1) Body Lift could be done on Body on frame construction-not on monocoque.

2) Body lift does not increase GC directly. It allows you to fit a larger tyre which would in turn increase GC.

So, if my understanding is correct, the options left to you are the ones discussed here (Thanks to rjstyles69)
WhiteKnight is offline   Reply With Quote
Old 24th November 2009, 15:48   #20
Senior - BHPian
 
Join Date: Nov 2007
Location: Bangalore
Posts: 2,376
Thanked: 528 Times
Default

Quote:
Originally Posted by harsha.cs1 View Post
While a one inch raise would surely be a boon and sort out the issue of bottoming out, the main issue arising I understand would be the handling.
One inch is way too much to consider, even if there is a feassible way to increase the GC. The difference between the GCs of cars having good GC(ex: Cedia at 175 mm) and really bad gc (EX: ANHC at 160mm) is in the range of 10-15 mms. Increase of 10 mm can make considerable difference.

Last edited by Guna : 24th November 2009 at 15:49.
Guna is offline   Reply With Quote
Old 24th November 2009, 16:04   #21
Team-BHP Support
 
Jaggu's Avatar
 
Join Date: May 2004
Location: Bangalore
Posts: 17,748
Thanked: 7,468 Times
Default

Very interesting topic

What i would suggest:
  • Higher side profile tire - A one size upsize helps with minimal effect on handling and improves the ride. Though the crispness of handling might suffer, also if the car already has a soft suspension (Hyundai Verna egs) it can further hamper the high speed handling. So in such case either upsize the rims and go for taller but lower profile tires (again one size bigger) if not read below mentioned.
  • Better/Stiffer shock/spring combo - Try an after market shock which will not really sag when loaded. Low speed ride might suffer a bit, but if one opts for reputed brands which has variable/staged damping, this can be controlled.

Also if modifying (stiffer shock) always do it on all four wheels, otherwise it can result in serious handling issues and disasters!

Personally i wont recommend spacers since there are very few shops in India who can execute these jobs well. Most often its just add few inches under the shocks, which will play havoc with cars handling.

Lift kits on the other hand are for specific purpose like offroading/show car etc and will work best in such situation, might not deliver the best results when it comes to normal roads especially at higher speed. Remember the thumb rule; higher the speed = lower C of G.

Quote:
Originally Posted by harsha.cs1 View Post
Having said that I totally agree with Nairrk that the cars are built after a lot of R&D after considering the best dynamics. However, when faced with issues, i sometimes believe that some modifications have to be done, provided only if we are convinced that the advantgages outweigh the disadvantages. And that is the reason behind this exercise.
Its quite normal for suspension parts to age with kms and no of years, so simplest and most straight forward job is to do regular servicing of parts (say every 40k kms) and complete replacement (say at 80-100k kms). Which will do wonders to the car handling and GC.

Last but not least, lil bit of patience and modifying your driving style while approaching speed breakers should help.
Jaggu is offline   Reply With Quote
Old 24th November 2009, 16:05   #22
BHPian
 
Join Date: Feb 2008
Location: Bangalore
Posts: 224
Thanked: 2 Times
Default

Quote:
Originally Posted by WhiteKnight View Post
To my understanding,

1) Body Lift could be done on Body on frame construction-not on monocoque.

2) Body lift does not increase GC directly. It allows you to fit a larger tyre which would in turn increase GC.

So, if my understanding is correct, the options left to you are the ones discussed here (Thanks to rjstyles69)
In that case, i guess the option left to explore would only be spacers!
In fact, most of the queries here are with respect to spacers. The thread shown by rjstyles and you is useful - however, the posts in it are focussed on upsizing the tyre - which isnt an option for me because I have recently invested in new Michelin XM1 plus tyres.
harsha.cs1 is offline   Reply With Quote
Old 24th November 2009, 16:08   #23
Team-BHP Support
 
Jaggu's Avatar
 
Join Date: May 2004
Location: Bangalore
Posts: 17,748
Thanked: 7,468 Times
Default

Do a service of your car struts and spring assembly, change the rubber bushes and see if it helps. Nothing major but should help a bit. If opting for spacers (i dont recommend) go for max 1/2-1 inch ones.
Jaggu is offline   Reply With Quote
Old 24th November 2009, 16:24   #24
BHPian
 
Sprucegoose's Avatar
 
Join Date: Jan 2006
Location: Mumbai
Posts: 311
Thanked: 38 Times
Default

I have an OHC, and its been raised a bit too.
I'm also running stiffer suspension.
Handling is good [probably because of the stiff suspension and 205/50R15 Yokohama S Drives]
But under full load [3 people in the back] the exhaust does touch big speed breakers.
Sprucegoose is offline   Reply With Quote
Old 24th November 2009, 16:28   #25
Senior - BHPian
 
vinod_nookala's Avatar
 
Join Date: Aug 2007
Location: Mumbai
Posts: 1,737
Thanked: 411 Times
Default Dont alter any thing- live with it

Quote:
Originally Posted by Jaggu View Post
Very interesting topic

What i would suggest:
  • Higher side profile tire - A one size upsize helps with minimal effect on handling and improves the ride. Though the crispness of handling might suffer, also if the car already has a soft suspension (Hyundai Verna egs) it can further hamper the high speed handling. So in such case either upsize the rims and go for taller but lower profile tires (again one size bigger) if not read below mentioned.
  • Better/Stiffer shock/spring combo - Try an after market shock which will not really sag when loaded. Low speed ride might suffer a bit, but if one opts for reputed brands which has variable/staged damping, this can be controlled.
Last but not least, lil bit of patience and modifying your driving style while approaching speed breakers should help.
with Jaggu here completely. I have two cars at home, Wagon R and Indica DLG turbo.

Problem with Wagon R-

1. Soft suspension and scrapes on speed breakers under belly.
2. under full load it literally sits on its bump stops
3. handling is not up to the mark due to tall boy design and soft suspension

Problem with Indica-

1. Bad approach angle

On bad roads i find Indica better. suspension doesnt bottom out and doesnt scrap under belly often under full load. Wheel wells are larger and hence it can take one size up tyre easily with no rubbing of tyres what so ever.

Locality roads must be a big point of consideration while selecting the car. Most cars wheel wells cannot take one size plus tyres in terms of profile. Spacers reduce tyre life and is not recommended.


I have altered my driving style according to the car i drive. Iam more cautious in Wagon R specially on speed breakers.

In the end, you just have to live with it or change the car with a higher GC if the problem is acute!


p.s- One can try harder shock absorbers which prevent car from bottoming out. Ride will suffer but this is the best compromise one can make

Last edited by vinod_nookala : 24th November 2009 at 16:30.
vinod_nookala is offline   Reply With Quote
Old 24th November 2009, 16:37   #26
BHPian
 
devrajman's Avatar
 
Join Date: Mar 2009
Location: Bangalore
Posts: 504
Thanked: 116 Times
Default

Quote:
Originally Posted by vinod_nookala View Post
with Jaggu here completely. I have two cars at home, Wagon R and Indica DLG turbo.


I have altered my driving style according to the car i drive. Iam more cautious in Wagon R specially on speed breakers.

In the end, you just have to live with it or change the car with a higher GC if the problem is acute!
Perfect thing to do. I agree too.

I have Zen with OEM 13" rims still it scrapes big speed breakers in Bangalore when fully loaded. I make sure, i take the speed break at an angle to avoid scraping.
devrajman is offline   Reply With Quote
Old 24th November 2009, 16:43   #27
Senior - BHPian
 
rjstyles69's Avatar
 
Join Date: Sep 2006
Location: Bengalooru..
Posts: 4,345
Thanked: 789 Times
Default

Quote:
Originally Posted by harsha.cs1 View Post
RJstyles - I understand that you have tried it in the past - did you try it in your scorpio? Ya, getting stiffer shocks I believe could help in this regard and might end up improving handling, as opposed to spacers.
GC has never been a problem with the Scorp' pal . In the past I used to drive an alto, then a baleno and have tried my hands at it. Wasn't the best of the experiences to speak off. Stiffer suspension is the way to go.
rjstyles69 is offline   Reply With Quote
Old 24th November 2009, 17:39   #28
BHPian
 
Join Date: Feb 2008
Location: Bangalore
Posts: 224
Thanked: 2 Times
Default

Thanks Guys.
Ya, Jaggu, as usual, has hit the nail on the head! Patience is the way to go, however, the reason I am considering this option is that i am running out of its. On a more serious note, going dead slow on breakers is something i always do, and i do take bad bumps diagonally if the situation permits. however, i would rather avoid the occasional scraping, if i would.

Quote:
Originally Posted by Jaggu View Post
Do a service of your car struts and spring assembly, change the rubber bushes and see if it helps. Nothing major but should help a bit. If opting for spacers (i dont recommend) go for max 1/2-1 inch ones.
That apart, since tyre upsize is not an option, a strut and spring service should work fine. Any clue what all is done in such a service? I guess checking oil seals, maybe changing shock up oil and replacement of worn out bushes etc. would be involved.
Is the oil ever changed or are the old shocks just discarded if the oil has gone kaput? Moreover, changing oil itself may help in firming up the ride if the right oil is chosen, right? Is there any other way of firming the shocks by servicing them?
And if i have to change the shocks, then i will surely go for gas ones!

Rjstyles, thanks. I saw ur scorpio in the garage and was perplexed as to why anyone would try it with a scorp in hand!

Sprucegoose, how much did the stiffer suspension cost? also, what is the size of spacers you used to raise it? Were the spacers made of aluminium or layered rubber? Thanks.
harsha.cs1 is offline   Reply With Quote
Old 24th November 2009, 19:39   #29
BHPian
 
Sprucegoose's Avatar
 
Join Date: Jan 2006
Location: Mumbai
Posts: 311
Thanked: 38 Times
Default

Quote:
Originally Posted by harsha.cs1 View Post
Sprucegoose, how much did the stiffer suspension cost? also, what is the size of spacers you used to raise it? Were the spacers made of aluminium or layered rubber? Thanks.
I got a set of pedders sports ryder suspension [springs and dampers] market price is about 60 ~70 K

I don't think any spacer have been used though...
Sprucegoose is offline   Reply With Quote
Old 25th November 2009, 10:16   #30
BHPian
 
Join Date: Feb 2008
Location: Bangalore
Posts: 224
Thanked: 2 Times
Default

Quote:
Originally Posted by Sprucegoose View Post
I got a set of pedders sports ryder suspension [springs and dampers] market price is about 60 ~70 K

I don't think any spacer have been used though...
Thanks Sprucegoose.
60-70K is not exactly the kinda budget i am looking at
harsha.cs1 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
having a lowprofile tyres higher rimsize Vs having high profile tyres smaller rimsize rider60 Tyre & Alloy wheel Section 26 12th September 2017 23:28
Ideal dimensions of a Speed Breaker mjothi Technical Stuff 21 8th September 2015 08:26
Which Tyres Are Better? Tubeless Or Low Profile? 1self Tyre & Alloy wheel Section 17 26th October 2009 12:24


All times are GMT +5.5. The time now is 12:24.

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