Some simple modification stuffs to ask you experts.. =)

[Wolverine]

WOW ..Power lay ....power.....

[Sapience]

you sound like your sunny is very unstable? i would think it is stable enough for daily commute, unless you are talking about tracking with your sunny

[Eazterence]

Wow.. 4.5cm sounds quite alot? =)

[Eazterence]

My Sunny is really stable. But I want to find out how to improve on things like lesser noise and better performance.. =)

Edited January 2, 2006 by Eazterence

[Turbonetics]

  Quote

coilover is a full set of suspension include the absorber and spring which is custom made

to suit each other...will be more safer and also some of them the damping and height can be adjust...popular brands are koni,tein..etc...

 

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was told changing a Coilover is better than just changing the Springs or absorber only rite...lest the coil over is suited for one another.. able to get wht u want.

rather than knw able to knw wht u r going to get if u change either spring or absorber??

 

 

yah...definitely coilover is better....

if u change the spring and absorber,u must know which spring to go with which absorber to give u the best performance...which many ppl duno....

[Psfong]

Does bigger Rims = Better Braking as well? Anyone?

[BlueSi]

All your intended mods do not give you more power, infact it'll mostlikely make your car slower.

 

1) When a car is lowered, its CG is lowered so more dynamic stability, i.e. you can probably corner at a higer speed more comfortably, but this also depends on proper suspension setup. Lowering a daily driver, you just give yourself more trouble because you run the risk of scraping or cracking stuff underneath if you hit a bump, your ride becomes worse, you might have alot of trouble when you need to tow the car coz tow equiptment might not be able to clear under ur car. your turning radius will suffer as the stock suspension geometry is not ment to be lowered. Loweing will usually give you camber, causing uneven tire ware unless you install camber kits to correct the camber again.

 

To lower your car correctly, you need to buy ur car specific coilover kit. This will include beefier dampers that might have a few different settings, and stiffer springs. The springs need to be stiffer so your lowered car will not bottom out when u hit a bum and damage stuff under ur car, this will also mean a harder ride.

You should change ur suspension bushings to stiffer ones too to compliment the new coilovers, these too make ur ride harder and they also tend to squeek alot. To reduce the noise, you need to constantly oil them.

Cutting stock springs to lower your car is a major nono. When you cut a spring, the spring constant is changed. Using the stock dampers on these springs will put alot of stress on them and very soon they'll rupture and leak.

You'll also need to get camber kits for both front and back to correct your car's camber. Camber change depending on howmuch you lower the car. Sometimes you can use metal spacers to push your camber back out, but if its too much, you might have to get the kits.

 

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[BlueSi]

2) Bigger rims dont give you a more stable ride. Its wider rims that might give you more traction from a launch, or stability on high speeds.

 

Bigger rims+tires=bigger wheel. This difference in wheel size means a different offset from stock. The bigger you go, the more "off" your speedometer will read. You are also adding more rotatonal mass to your car, which is what reduces power and makes your car launch slower. You might want to get really expensive forge rims that are strong, big and lighter than stock, but due to the difference in size, the whee's mass distribution is also different. If you dyno your car with lighter but bigger rims, you see you actually lose power.

Some people need wider rims to accomodate wider tires coz they've done so much to their car's that the power and torque are factors more than stock, and they need more traction or they'll just be burning rubber, but these are also the ppl who need to beef up everything else in the car to make use of all the extra power, stuff like custom transmission, clutch, axals chassis stiffening, engine internals ......

Wider tires are more stable at high speeds. 110-130kph is not high speed. Since you're not going to be driving at 140-150mph much in Spore, you probably dont need wheels that are that much wider than stock, unless its for aesthetic reasons.

 

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[Yc86]

  Quote

My Sunny is really stable. But I want to find out how to improve on things like lesser noise and better performance.. =)

 

lolx... better performance & lesser noise dun seem to go v.well together

same with comfort & performance...

 

spoilers no use 1, most install for cosmetics only..

below a certain speed of say 80mph or ard 150+kph they create more drag than useful downforce.... esp those GT wings, end up FC goes up

 

somemore most cars now all FWD, spoiler shd be infront to push the front down for more traction, rear more for stability only. prob when braking or cornering...

 

bigger rims/tyres also means increase in wheel weight.. which means loss of wheel HP

it takes more power to accelerate wheel weight than onboard weight

Edited January 4, 2006 by Yc86

[BlueSi]

3) Spoilers here u mean the "wing" on the trunk? Those are purely for aesthetics. They dont do anything for a daily driver but block your rear view mirror. They are alittle more useful on full race units, but then again, the ones they use are not the same ones you can buy. These "Wings" are essential on F1 cars. So unless you have a 500kg, 1000hp car ... you probably wont need them.

 

For these wings to actually affect your car's CG, you need to be driving at pretty unsafe speeds ... >150mph? And they probably work better in those cases for rear wheel drive units. The idea is to have down force on your driving wheels to get more traction.

 

So, as you can see, many stuff ppl do to their cars are not too much "performance" but more aesthetics.

 

Just my 2 cents worth =)

 

 

[Eazterence]

Wow.. BlueSI, you're great.. Thanks alot.. =)

[BMW320i]

Sir I beg to differ the "wing" is all that useless below 150mph.

 

Even at 0 mph, these "wings" also make great Stand Up Tables for you to take your lunch on any given busy day at the coffee shop.

[Kespher]

seen 'wings' at the sides of the front bumper of many ride (with body kits). Heard they are supposed to reduce drag..any truth abt this??

[Piertiong]

  Quote

More stable :

Lowering your ride. Put more stability parts. *lost comfort.

 

sorry but what do you mean by put more stability parts?

 

is it after lowering, ride becomes harder, more vibration, parts may loosen, and need to put absorbers to the things that might get loose and drop off?

[Adawang]

Ask Johnny , he is the expert.

 

Look fast , sound fast can oready, no need to go fast

 

Ah Hock can do sticker for u

 

GT spoiler bigger than car, wind blow, car go backwards.

[Chneo1982]

actually i think selecting your own dampers and springs would be the best way if you really really wanna customize your ride according to your needs.

 

For that you need to know the k (stiffness) value of the spring and c (damping constant) of the damper. With these values, you can use softwares like Matlab to model the response of your suspension system. With different excitation forces on the system, the matlab is able to give you how the system is gonna respond to the forces.

 

For example if you want a bouncier ride (comfort), you can choose a damper with lower c. If you are taking corners fast you might wanna set the system with high k and critically damped (meaning damping ratio almost to value of 1).

 

If really depends on how you want your ride to be. Modelling of this mechanical system is definitely not easy for normal road conditions because road surfaces are not constant ie potholes, unleveled etc. For race tracks (more constant road conditions), teams will need their drivers to go round the tracks several times to collect data of the road surface, and these data will be able to help them with the modelling of the settings they need for the particular track.

 

It's really a tough thing to get the suspension system right, even if you get a coilover, you will not know what reaction you will get from your car. this is because it depends on several factors such as the car speed, the uneven-ness of the road surface, the weight of your car, weight of your rims etc.

 

So basically suspension system is best to leave it stock, cos unless recommendations are given from an experienced mechanical engineer, i personally think it is not very advisable to listen to those who sell suspension stuffs....hehehheehee

Thanks.

Edited January 25, 2006 by Chneo1982

[Piertiong]

that's why must go fast if suspension is hard, car too slow the ride becomes very bumpy.

[Chneo1982]

ya it's true.... there's this transmissibility of motion thing. If you go faster, you will go beyond the natural frequency of the system and thus there will be no serious vibrations.