Brake and coilover setup (discussion)

[grog]

you're missing the point about bigger brakes. The larger diametre discs give increased leverage, and better stopping power. This is simple physics.

The diameter has nothing to do with leverage, leverage is the ratio of the surface area of the primary and secondry piston tops.

[hrd-hr30]

you're missing the point about bigger brakes. The larger diametre discs give increased leverage, and better stopping power. This is simple physics.

The diameter has nothing to do with leverage, leverage is the ratio of the surface area of the primary and secondry piston tops.

you Charade boys should stick to your own forum. obviously the laws of physics differ in that parellel dimension. Do you seriously believe a larger diametre disc does not give increased braking leverage? the size of the disc relative to the size of the tyre determines the mechanical leverage of that combination. Easiest example to give you here is to consider a 4WD that came standard with a 31" tyre. Monster truck man wants to fit 38" Super Swampers - what effect will that have on the car's braking performance? I'll give you a hint - its exactly the same effect it will have on the car's accelleration. that's mechanical advantage (or in this case, disadvantage) at work.

I was going to go into some detail about the effects of a change in master cyl size, but you're obviously struggling to differentiate between the mechanical leverage advantage of a larger diametre disc and the hydraulic system anyway, and I don't want to jump too far ahead of you!

[Ghostrider]

Depends on the adjustment.

The Agress S13 tops that I have allow for up to 4 + degrees of negative camber, but put them in reverse to suit R30 and there is barely 1 degree of adjustment.

[Ghostrider]

The diameter has nothing to do with leverage, leverage is the ratio of the surface area of the primary and secondry piston tops.

Are you for real??? or just a simple PRE SCHOOL drop out???

Your suggestion says that to move a given object, there is zero advantage using a 10 foot lever oppose to a 1 foot lever, or pushing your car on your own Vs 10 people pushing your car.

And where is there primary & secondary pistons in any braking system???

When I started out on my project, one of the main concerns of the engineers, was the size of the brakes Vs power/speed of the vehicle over standard.

With any engineer necessary vehicle modification that improves performance, there is a mandatory requirement to show a relevent improvement to the braking system.

[hrd-hr30]

And where is there primary & secondary pistons in any braking system???

best I can figure out is its some sort of obscure reference to the size of the master cyl and caliper pistons, but like you I've never heard anyone refer to them this way. But what would I know?

[gslrallysport]

The diameter has nothing to do with leverage, leverage is the ratio of the surface area of the primary and secondry piston tops.

WTF??? Yep.. i'm with you hrd...

diameter definately effects leverage, which is inversely proportional to the pressure required....

i never claimed bigger brakes weren't a good thing, but i think wot adam was trying to say was in most circumstances tyres are generally the weak link to begin with...

my two cars weigh 800 and 900kg, both have pads rated to 650 degrees, and both run RBF600 brake fluid, so for everything i do (rally and circuit) my brakes are fine, and in my case, tyres are always the weak link...

i agree with everything that's been said (well.. except grog)... but i was supporting adam in wot he was saying about tyres...

btw, for the record.. my grandma's car running yoko slicks pulled this from 100k's... so don't tell me tyres aren't a factor....

time accel accel distance

(s) (m/s^2) (g) (m)

2.43 11.43 1.17 33.75

2.51 11.07 1.13 34.86

2.43 11.43 1.17 33.75

2.33 11.92 1.22 32.36

[grog]

you Charade boys should stick to your own forum. obviously the laws of physics differ in that parellel dimension. Do you seriously believe a larger diametre disc does not give increased braking leverage?  the size of the disc relative to the size of the tyre determines the mechanical leverage of that combination. Easiest example to give you here is to consider a 4WD that came standard with a 31" tyre. Monster truck man wants to fit 38" Super Swampers - what effect will that have on the car's braking performance? I'll give you a hint - its exactly the same effect it will have on the car's accelleration. that's mechanical advantage (or in this case, disadvantage) at work.

I was going to go into some detail about the effects of a change in master cyl size, but you're obviously struggling to differentiate between the mechanical leverage advantage of a larger diametre disc and the hydraulic system anyway, and I don't want to jump too far ahead of you!

I apoligise, i thought you were refering to the leverage resulting in the force of the pad onto the disc. Last time i argue on the net drunk..

And where is there primary & secondary pistons in any braking system???

The primary being the piston that the foot pedal actuates and the secondry being the one that creates force on the pad.

[Boof]

Boof,

You run yours with positive camber in that case. Mine are AGRESS not GReddy as previously mentioned.

No matter, not as pretty as these.

Nope mate im running negative camber, i can run that much negative that maybe an inch of the front tyre has a contact patch on the road (i wouldn't do it but i can) All my suspension (coil overs @ all 4 corners) are JIC quite like the setup if maybe a touch to stiff...

Adam i think you need to come for a ride in one of our cars before you ask why do you need coil overs and 4 pot brakes

[Adam_RSX]

I havent seen your car on the road for umm... a couple of years

Mine does quite well for itself, it has far too much grip on the slicks and I'm not a heavy braker.

Plus cops don't look at my car because its standard height and doesnt bounce around

[Boof]

I havent seen your car on the road for umm... a couple of years

Mine does quite well for itself, it has far too much grip on the slicks and I'm not a heavy braker.

Plus cops don't look at my car because its standard height and doesnt bounce around

Its been on the road **** ya!! Just not when your around

Yeah mine does bounce around a fair bit but what can you do???

[Ghostrider]

Change your spring rates or the dampening of the shocks

[Adam_RSX]

Why not just get the correct springs and dampers in the first place, why bother with getting coilovers

[Ghostrider]

Why not just get the correct springs and dampers in the first place, why bother with getting coilovers

That's pretty smart Adam, so! what is correct???????

Pedders, King, Lovells, Henderson's, Jumbos etc, they're all spring manufacturers in Australia and all their respective springs are different, so! I ask, WHAT ARE CORRECT???????????

I have 230lb/in front & 200 rear in my MR30, 350lb/in Front & 300 rear in my PNV, a mate of mine has 700lb/in front & 550lb rears in a 200B club car, V8 Supercars run a similar set of rates, so really, WHAT IS CORRECT?????????

[Adam_RSX]

I've got an idea....... Spend $1000 getting coilovers into the car. Then start experimenting with different spring / shock combinations at $? a pop for each set of springs

OR

Just start experimenting with different spring / shock combinations at $? a pop for each set of springs.

In both cases you'd be silly not to start with adjustable dampers so the cost of experimenting is just in the springs. I'd start by getting Industrial springs to make up a set that are about an inch lower than standard and a rating that will give about the same ride as the standard ones, maybe a tiny bit stiffer. It wouldn't be overly hard to work out what rating it needs to be. Then determine whether you want the front or rear harder or softer and get them made. Or you could go ask someone who knows what they're doing like Darren at Fulcrum for their advice.

Personally I'd probably stick with the slightly lower springs and start mucking around with sway bars instead, I find that my standard springs give an ok ride and the car handles very nicely at speed on my tyres

[Ghostrider]

I've got an idea....... Spend $1000 getting coilovers into the car.  Then start experimenting with different spring / shock combinations at $? a pop for each set of springs

OR

Just start experimenting with different spring / shock combinations at $? a pop for each set of springs.  

In both cases you'd be silly not to start with adjustable dampers so the cost of experimenting is just in the springs.  I'd start by getting Industrial springs to make up a set  that are about an inch lower than standard and a rating that will give about the same ride as the standard ones, maybe a tiny bit stiffer.  It wouldn't be overly hard to work out what rating it needs to be.  Then determine whether you want the front or rear harder or softer and get them made.  Or you could go ask someone who knows what they're doing like Darren at Fulcrum for their advice.

Personally I'd probably stick with the slightly lower springs and start mucking around with sway bars instead, I find that my standard springs give an ok ride and the car handles very nicely at speed on my tyres

Adam,

For starters, my JIC Coilovers are 50mm shorter in overall length than standard, so when fitted it went down 50mm from the start.

As for experimentation, that is THE ONLY WAY, depending on which purpose you want the car for.

None the less, NOTHING can be achieved without first weighing the car, and that has to be done with road scales, not just a simple trip to a public weigh bridge.

The spring rates will be calculated to offset the differences in weight, and to balance the car.

Remember this, all the spring is designed to do in a standard road car is hold it up and not let it hit the ground. End of story.

The shocks or dampers then control the spring in both rebound and compression strokes.

There is a general rule of thumb and that is, control the roll with sway bars and tune the springs.

If you just want a quick road car, the suspension tuning is entirely different to a race car that can be driven on the street.

In nearly 100% of cases, the springs & shocks in Jap imports are all DRIFT based and entirely to hard for normal street driving.

[hrd-hr30]

a mate of mine has 700lb/in front & 550lb rears in a 200B club car

a club car? as in Improved Production? the thing would never turn in on the Yokohama A032R's! Those kind of rates are for racing slicks only!

There is a general rule of thumb and that is, control the roll with sway bars and tune the springs.

It depends what your talking about. For road cars, this method will work adequately and keep a more comfortable ride, but for track work its totally the wrong way to go about it. Springs should be used as the primary tool for getting the balance right. Swaybars should only be used for fine tuning or adjusting the balance. Big swaybars can create big problems for track cars. If its for the road, I don't really know why you'd want (let alone need) to increase the spring rates - my HR30 is very firm as it is with standard suspension (even still has the standard 'adjustable' shocks! set on hard) and handles surprisingly well at standard height.

None the less, NOTHING can be achieved without first weighing the car, and that has to be done with road scales,

most club level race cars are built, setup and raced without ever being corner weighted. Corner weighting is about setting cross weights, which can make the last little 1% in becoming a genuine outright contender on the race track after everything else is sorted. It's not used for selecting spring rates. For a road car its a total waste of time.

As is adjustable suspension. It's useful for a race car, IF you know what effects a change in roll centre height, or bump/rebound adjustments will make, but for the road its a total wank. On a well setup race car, a 5mm change in front ride height can make a significant enough difference to the rollcentre and axis that it can totally change the on-limit balance of the car. A street car will be far less sensitive to the same change due to a range of reasons such as the much more conservative geometry and significantly lower mechanical grip.

Besides, 90% of street cars have the ride height dictated by aesthetics rather than function, and most just see camber as a way of getting bigger rims under the gaurds!

[stu_r30]

nothing to do with the front bar, but i know i'll get a response this way,

i found a kaaz lsd for $1500 front some business in vic, wanted to know whether the long nose r200 has 10mm or 12mm bolts on the crownwheel....?

[stu_r30]

and ah, any more news on the front bar, im getting antzy...

[V8skylineMAN]

The primary being the piston that the foot pedal actuates and the secondry being the one that creates force on the pad.

umm...dont you mean Master cylinder and slave cylinder?

primary and secondary...never heard that one before.

[B0oStEr]

R30 front bar???

I think I must be in the wrong thread... or everyone else is.