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Old 15-09-2012, 06:35 PM   #11
psfong
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Quote:
Originally Posted by dtech View Post
part numbers change (based on the RPO , ie. replacement part number)

base on picasso 1.6t, there is only one part number (no newer)


the difference is in the anti roll bar
the early ones had 22mm diam, then 22.5, then 23
the firmer (less body roll) comes from the stiffer bars

the shocks for 2.0 AL4 and 1.6 EGS is the same

some minor differences in the springs but its not significant, more for different variants of the vehicle (eg factory trims)
Pardon all my noobs question. So does adding strut bar and anti roll bar really helps?
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Old 15-09-2012, 06:46 PM   #12
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Originally Posted by psfong View Post
Pardon all my noobs question. So does adding strut bar and anti roll bar really helps?
have to understand how it works
springs/shocks control up and down motion while chassis stiffness and anti roll bars control cornering/twisting

upsizing anti roll bars will help to make it stiffer, but it will change understeer/oversteer characteristics of the car, the same way lowering/rim offset/width all affect slightly

french cars (the non sports versions) are usually tuned for comfort and have a softer chassis than the germans, so going too firm (over the limits) on the lowering/stiffness , as i mentioned earlier will have some adverse ...effects

Last edited by dtech; 15-09-2012 at 06:50 PM.
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Old 15-09-2012, 06:50 PM   #13
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http://www.performance-car-guide.co....uspension.html
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Old 15-09-2012, 08:03 PM   #14
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hello psfong,

you never need to apologise for asking any sort of question :-)

suspension theory is something that is very complex; sometimes, even the manufacturers get the balance wrong.

let's try thinking about it this way.

i speak as the son of a doctor schooled in Western medicine, but - having said that, it's a bit like the differences in philosophy between Eastern and Western medicine.

Western medicine tends to treat the symptoms on a reactive basis, Eastern approaches try to consider things more holistically (as far as i know).

for each model of car, the manufacturer has to decide what the big picture is. within the CitroŽn range, for example, the DS5 big picture (in terms of ride-handling balance) is very different from the GC4P big picture, and is also different from the C5 big picture.

by 'big picture', i refer to the way the car's suspension system, steering, recommended tyres, tyre pressures, overall weight distribution all come to play a part in what is known as the ride-handling balance.

even within the topic of 'ride', it can be broken down into sub-parts, such as springs (absorbency of initial surface imperfection) and dampers (subsequent absorbency of the initial perturbation). in terms of handling, other things come into play, such as suspension geometries and anti-roll bars (not to be confused with strut bars), and also, overall torsional stiffness (which is in turn in part determined by the choice of materials (types of steel), weight, cost, etc.

Volvos, for example, have very very high torsional stiffness, but that does not necessarily translate to great handling, because the manufacturer has other priorities in mind for the big picture of Volvos.

that is what dtech refers to when he talks about "adverse effects".

by changing after-market springs, dampers, and other parts, one is more adopting a Western medicine approach, seeking to tinker here and there at parts which can be relatively easily accessed and in a reactive manner.

so to answer your question as to whether these "help" or not, they "help" in the sense that they address one part of the problem, but they do not "help" in the sense that - because they are after-market - they cannot seek to address the big picture balance (only the manufacturer, or an in-house tuner like AMG) can do that (at great, great cost to the owner (i'm not talking about a mild AMG makeover but more like leaving the car with AMG for a month kind of thing)).

so, something that might help with one sub-part of the ride (stiffer springs), would have a negative effect on one aspect of handling (oversteer / understeer).

also, do not confuse a stiff ride with good handling.

if only the springs are changed and nothing else, then the car will just ride bouncily along the road, because the whole purpose of the springs is to absorb the energy of surface imperfections.

and this bouncy riding along the road would, of course, have negative implications with respect to handling, because the weight distribution would be dynamically changing in a fairly unpredictable manner (the purpose of having good dampers).

:-)
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Old 15-09-2012, 08:27 PM   #15
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Wow, thanks dtech and voyager. I have been driving for 13 years and yet no one had explained to me in such details! Really kudos to you guys!
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Old 15-09-2012, 10:44 PM   #16
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when "zhnging"
the route to go first is always tyres>rims>spring/shocks

no point fitting crap (cough falken/firenza/nexen/westlake..etc) with stiff shocks...mm why does this formula look common on the korean cars/wrx-es

go for a stiff sidewall from the sportier range of michelin/conti/pirelli
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Old 15-09-2012, 10:46 PM   #17
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found the older s40s handle well, the 03-07 batches
the 08 facelift onward gained some weight but not sure if they swaped the stuff below, massive understeer (when cup corner fast)
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Old 15-09-2012, 11:27 PM   #18
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Quote:
Originally Posted by nextreal View Post
Lennie, my previous MPV was an Ody. It was modded to the max - TC, bodykit, bbk, struts, Euro lamps, chrome rims... The only thing I didn't mod was the suspension, due to the low bodykit. And these are only the exterior bits.

When I migrated to the GP, I was like you. No bodykit, no bbk, not aftermarket chrome rims... At one time I was contemplating on customizing a bodykit just for this car. But after around 6 months of ownership, it all died down. Ended up with only rims and ICE upgrade albeit a few aesthetic "mods" here and there.

This was the first unmodded car after a long while, but I was glad. This GP didn't suit too many performance mods. It's meant to a relaxed ride for the family. So enjoy the comfort... for now.
Yeah I understand it's a family car don't get me wrong but what I am saying in particular is that no aftermarket shocks besides the OEM and I understand spring rates, high CG etc but this body roll is crazy man lol... Yeah well I guess I truly have to live it with it and do up all the cosmetic portion(excluding bodykit) to this GP which I have just started today already lol... Thanks guys for the comments, suggestions, feedbacks
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Old 15-09-2012, 11:32 PM   #19
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Originally Posted by auto_emocion View Post
You probably bought the wrong 7 seater. The Subaru Tribeca or Exiga would suit u more.
Honestly I tested the Tribeca and I love it but my wife found it to be too big to her liking, she say 'too big, I am afraid I cannot park and I don't think I want a Subaru anymore' because I blew my subbie engine before and she was in it when it happened, I guess phobia hahahahahaa
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Old 16-09-2012, 10:20 AM   #20
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zhng too much
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