the all aussie dribble thread!

[tdi-rick]

Actually they aren't totally gutless, unless comparing to an F2, V8 Supercar, etc. (any of which I would have driven in a heart beat if offered a drive. Hell, that's why I drove the old Torana's and stuff I did too, blokes were silly enough to either want me to chassis test for them or a couple of times offered me a race drive )

FWIW the ARDC did some lunchtime drags at a National meeting at Amaroo back in '91 I think and over 200m the only car that beat Troy Dunstan's RF90 Van Diemen FF was Colin Bond's RS500 Sierra, and then only by a bumper.
None of the Sports Sedans could touch it, it's all about power to weight and getting that power to the ground.
One of the blokes I raced against, (Richie F) was bet that he couldn't beat a bloke in a heavily modified Phase III, so he wheeled his Swift FF out of the trailer in a street in one one of Sydney's leafy suburbs and they had a drag race down a suburban street in the middle of the night.
The car without lights won

Re tyres, they've never used a road tyre, it's always been a dedicated race tyre, can't remember what Formula Vee's ran, think that might have been a road tyre ?
Current tyre supplier is Avon Motorsport, and has been since about '98. Dunlop Motorsport (English Dunlops, although we tested some Japanese Dunlop slick radials once) supplied them for about three years prior to that, and Avon supplied prior to that.

Suspension is everything on the track, suspension is worth more HP than HP found in the engine on the dyno, it's your suspension that ultimately allows the tyre to generate its maximum lateral force, but what's optimum on the track is bloody awful on road and vice versa.
Trying to optimise the suspension is why we used to go testing all the time, we used different springs and anti-roll bars at each track, and although I couldn't afford them when I raced, it's why we used $2500 shock absorbers on customers cars. BTW, that's $2.5k per corner. (triple adjustable Ohlins TT44's)
I'd alter spring pre-load, camber and caster, toe, rake, roll centres, weight distribution, ackerman and dampers just trying to optimise the setup.

On road you need much more compliance than on track just to cope with the everyday lumps and bumps, and you need the compliance in suspension bushes for NVH and comfort. The wheel alignment is optimised for nice straight steering and optimum tyre life, not maximum cornering grip.
Even the steering rack is rubber bushed on a road car for NVH, and these are things that destroy handling and ultimate road holding on the track.
In a track car you don't want compliance in these areas, you want precision.

Karts work because they do, it comes back to power to weight, tyre contact patch area to mass and they have such a low CofG.
Actually you can adjust quite a few chassis parameters in a kart, much as you do in a car.
Track width, (the main adjustment) front and rear 'anti-roll bars' (chassis stiffeners) toe, weight distribution are all adjustable and they adjust the 'suspension', that chrome moly chassis.
I raced sprint karts for nearly three years back in the eighties and there's nothing like having your arse only 1/2" off the track @ 125km/h with only a thin piece of fibreglass between.

 

[David (saltas)]

I saw a novel

Hang on I'll get my reading glasses and a fresh drink.

 

[David (saltas)]

Everyone has heard of progressive suspension

Not everyone has heard of digressive suspension

Traditionally shocks have more damping force at higher shaft velocities, and that’s why they are called progressive shock absorbers. These shock absorber design have multi-stage valving to cater to various types of road conditions. Despite of these multi-stage valving, they are quite different from digressive valving, which is opposite of how shocks have been traditionally valved.

A digressive shock absorber has stiff, progressive damping at low shaft speeds (less than 3 inches per second). This helps to control car body motion like roll, dive and squat. At this point, it functions like a typical stiff racing shock absorber. At higher shaft speeds, between 3 to 10 inch per second the damping force is more or less constant despite the rapid change in shaft velocity! The result is the suspension is kept supple in response to bumps and irregularities in the road, therefore traction is maintained on bumpy roads by reducing suspension hop, yet provides a firm ride, even at the high damping rates needed for body motion control. First used with success in off-road racing, digressive shock absorbers have only recently made their way into the on-road racing area.

 

[David (saltas)]

What does all that mean

the shocks resist all slow rates of change so it can work like a really stiff sway bar in a high speed corner with nice smooth steering inputs not the simulation of a combination lock style that kids think is cool) but if you hit a pot hole in the middle of the corner the shock moves very fast to keep the tyre in contact with the road surface

(I don't want to start talking about what happens with poor sway bar settings front rear miss match thats why V8 super cars are adjustable buy the driver.)

 

[tdi-rick]

Actually we were using digressive valving in the mid nineties

It was all the rage so you could ride ripple strips, at least with those that got right into damping.

Penske used a dished piston (3* ??) which pre-loaded the stack. Can't remember how Ohlins did it as they used the same piston for digressive/linear and progressive valving.

I have the Koni's in the front of the Landy with digressive bump valving.
I've had them open quite a few times swapping shims and valves.

 

[tdi-rick]

What does all that mean

the shocks resist all slow rates of change so it can work like a really stiff sway bar in a high speed corner with nice smooth steering inputs not the simulation of a combination lock style that kids think is cool) but if you hit a pot hole in the middle of the corner the shock moves very fast to keep the tyre in contact with the road surface

[snip]

Basically all your transitions (pitch/roll/squat) happen at low shaft speeds (usually <4"/sec) so by changing the low speed valving in the damper you can influence transition behaviour and actually alter the balance of the car without compromising chassis compliance as happens when you add more (stiffen) spring or bar = more mechanical grip and faster lap times

 

[MCW]

Actually they aren't totally gutless, unless comparing to an F2, V8 Supercar, etc. (any of which I would have driven in a heart beat if offered a drive. Hell, that's why I drove the old Torana's and stuff I did too, blokes were silly enough to either want me to chassis test for them or a couple of times offered me a race drive )

Nah motorwise they are gutless Rick The FF's do get the power to the ground extraordinarily well though because even their power to weight isn't anything to write home about. They probably work out to about 250bhp a tonne or something but would flog a road car even in a straight line with way more hp per tonne than that.
Like I said mate, they stick to the road like sh*t to a blanket but their impressive lap times come from the overall package, not suspension redesign, more continuous suspension adjustments to suit all of the conditions plus every other adjustment under the sun. In fact I don't think the basic suspension design of the FF's has changed in a long time - please correct me if that's the case mate.
You might be right in regard to the control tyres and Formula V's. All my Mallala race meeting books have long gone but I remembered something about Ducaros They are good treads even on a road car. Anyway Rick, how the hell did you even fit in a FF???
The highlight of Mallala was watching the R32 GTR's monstering every other car out there back when they first hit the scene. They were an impressive machine and from what I remember a stock road going GTR's 0-100kph time was quicker than the Group A Commodores and Falcons at the time. I remember sitting there with my old film camera taking a few rolls of snaps only to get them developed and find that I'd caught only the arse end of EVERY single race car that day

 

[tdi-rick]

I saw a novel

Hang on I'll get my reading glasses and a fresh drink.

Matt started me !!!

I thought I'd forgotten all this crap, it's all from another lifetime :msp_scared:

 

[MCW]

Matt started me !!!

I thought I'd forgotten all this crap, it's all from another lifetime :msp_scared:

All good Rick. Remember the heading of this thread old son Let us make sure we live up to the dribble bit!

 

[David (saltas)]

OLD bike racing saying

Springs are for steering shocks is for bumps

this is due to the fact that you can adjust the ride hight, think roll centre for the back shock,
front forks springs adjust the ride hight that changes the steering angle (also adjusted by moving the forks up and down in the triple clamps , think wheel alignment.......... no don't thats a longer conversation about steering geometry that changes the toe in / toe out depending on were your pointing the wheel.

Just think turns in faster but is nervous in a straight line, or wont turn in fast enough, pushes the front but hooks up on the way out of the corner.

bike riders move they weight around to load or unload the front / rear suspension just to frustrate the engineer who is trying to make the bike work better. joking but not, be it car or bike FF HQ etc each type has a style that suits the design philosophy.

Case in point Russell Ingall had to change his style when he went to Stone brothers because they have a different philosophy on what makes a car fast. They made an engine with a different power delivery so they changed everything to suit so it could make the tyres last. Stone brothers engine customers had difficulty utilising the way the power was delivered because they changes the suspension to look after the tyres and not the driving style and suspension as a package.

It took Russell almost two years to learn the stone brothers way.

 

[tdi-rick]

Matt, you can't get a better suspension than a double wishbone suspension, which is why real race cars still use them (as do the V8 Supercars, there is nothing stock underneath them anymore )

Wishbones have a better camber change curve compromise from bump to roll than any road car has.
The common road car McMpherson strut (think Commodore, Camry, even Porsche 911, etc) is really crap in roll, it's camber gain curve is roughly equivalent to the chassis roll angle which is why they need so much negative camber to work properly on the track.

The chassis and suspension design on an FF is free, as long as it's ferrous material (so no carbon) so if someone could come up with a more effective suspension design they would and no one has yet.

F1 and Champ cars suspension is seriously compromised for their aerodynamic packaging, it over-rides everything else.

And no, I didn't fit very well and some I didn't fit in at all :msp_sad:

 

[MCW]

Matt, you can't get a better suspension than a double wishbone suspension, which is why real race cars still use them (as do the V8 Supercars, there is nothing stock underneath them anymore )

On the back? The sooner they dump the live rear axle the better on the Group A's (if they already have then I apologise!). Then they can dump the current Group A limitations as well. What I hated about the demise of other manufacturers is that the current cars only similarity with the road going versions is their body shape. I have hardly given a toss about the Group A's since they banned turbos although don't mind a bit of biff at Bathurst. Last time I was at the Clipsal 500 (paid for by a chemical company ) I enjoyed the support races more than the Group A's. Oh and the grid girls...
Yes the old chicken wishbone has certainly stood the test of time mate

 

[David (saltas)]

In fact I don't think the basic suspension design of the FF's has changed in a long time - please correct me if that's the case mate.

If you mean that have a bell crank with a push rod to the coil over damper then that might be a fair introductory explanation.

Active suspension was banned in formulae one but Nigel Mansel's car in 1983 had no springs.

some were hydraulic, some worked on tracks that were laid by three men with shovels but they were heavy and used a lot of power think lotus and Ayrton Senna Detroit street circuit and Monte-Carlo verses Williams lighter system with limited activeness think Piquet at Monza

1991 they had a car that read the track before it got their but it did not work in bad weather think radar and lasers
1992 Nigel Mansel flogged everyone stupid and all the other teams complained about the cost of developing these systems so it active suspension was banned for the 1993 season and has not been allowed ever since.

 

[David (saltas)]

Ding Ding Ding, Winner Winner Winner chicken dinner { sound of winning the chook raffle at the pub }

Double wishbone camber gain from having a longer bottom wishbone compared to the top.

 

[tdi-rick]

OLD bike racing saying

Springs are for steering shocks is for bumps

[snip]

With car dampers the rule of thumb is

"rebound controls the chassis

bump controls the unsprung mass"

and you're dead right that different categories required different 'philosophies'

We used to compromise with springs and bars, using more spring than, say in the UK as our tyres and often tracks were grippier.

The rule was "springs control grip, bars control balance"

But, when you start running the optimal wheel rate (spring) for maximum grip, you'll be running too low a roll resistance and the car will 'fall over' through a turn with instant roll oversteer.
I won a race at Eastern Ck once laying huge great darkies right through turn one, big ovesteer slides @ 210km/h as I knew no better but it impressed the guy behind
I kept going down in spring searching for more grip.
I could have added more rear bar (i had a selection that were all adjustable) but in a car without an LSD you'll unload the inside rear wheel very quickly when you start adding more bar for roll control. (an anti-roll bar is a lateral load transfer device, it transfers load from the inside wheel to the outside wheel across that axle, as well as diagonally to the outside opposite wheel)
Dampers work, but too much low speed bump can still compromise grip and will bleed down in a long enough corner and at that stage (fourth or fifth race ??) I had non adjustable Bilsteins.

The compromise, and it works beautifully is to add more spring at the rear until the car starts to flat slide, then back it off a touch (25lb/in or so) and run minimal bar.
Maximum grip with maximum control and the fastest corner speed.

Another big compromise everyone used was to run nil droop suspension in the front end, which means that if you pick the front end of the car up the wheels don't drop at all.

As you accelerate out of a turn the car squats, transferring load off the front axle to the rear.
This reduced load on the tyre leads to instant undesteer, right when you don't need it, so you either understeer off the corner exit or get out of the throttle, and you never get out of the throttle.
I followed Craig Lowndes through an entire race (my second ever !) marvelling at how much steering lock he had to use to keep his recalcitrant steed on the black stuff. I've never seen that much understeer and still go quickly before or since
By reducing the droop travel to zero you effectively slow the load transfer and it effectively reduces corner exit understeer.

 

[tdi-rick]

V8's still use a live axle but it's pretty trick.

The hubs have a CV joint and you can alter the camber and toe so they run a small amount of negative camber and toe in.

Unsprung weight is the biggest killer when using a live axle, camber control in roll is excellent (as there's no camber gain at all ) and what most all engineers don't realise is that the suckers toe out badly on acceleration (unless designed properly) particularly road car based ones.

Toe out on the rear of a rear wheel drive car is bad, it makes for very unpredictable handling on corner exit :msp_sad:

They apparently are introducing a new chassis at some stage and it'll be independent all round, but I don't really keep up with what's happening, I only watch the bikes these days

 

[billyj]

speaking of bikes was another good result in the early hours of this morning. hope everyone remembered to tape it

 

[tdi-rick]

speaking of bikes was another good result in the early hours of this morning. hope everyone remembered to tape it

Can't get friggin Channel Ten and I woke up at 5:15 so it was all over red rover :msp_angry:

 

[billyj]

keep an eye on the one hd guide usually theres a replay later in the week.

 

[David (saltas)]

I can remember a time when lounds went very fast in a HRT but some times the diff broke on the start line.

It was evident that his car had negative camber in the rear but nobody else did.

They did some machining of the ends of the axles and the diff centres and cut the axle tubes off and welded them back on with some camber.