Eastern Creek

How did you guys go today against the Porsches? Did you make them show some respect for their history? Did the VWRX get a run?

Alex and Deiter did well I clocked a few 1.57 laps (unofficial), they showed no respeft for the sweeper at the end of the main strait and apart from one or two Porsche they were the only crew going through without braking.
They were a lot faster than most of the Porsches. The VWRX was there but only got off the trailer they worked on it all day but gave up in the end.

The GT3 Rs was most impressive but I spose for $400,000 plus it should be!
A great days entertainment and i will be there again.
Mitchell

Cool. I didn't see you there.... I had to leave at noon. I saw an early yellow 911 spin at the end of the straight halfway around that long corner... WOW.:jesus I took 2 rolls of old fashioned film. I'll put them up here when I get the chance... Bill

yeah thats when I got there,as you letf. I have some shots in pit lane and will post when I get organised.
mitchell

i'm looking forward to seeing these pics! :bounce

kai

Who owns this "VWRX" you speak of??

look in members rides

It's not Reub's one, it's the bright Orange one built up the Central Coast. I Don't know the guy's name that owns it though. It's got 19s, slicks and a big bump in the middle of the bonnet. It's a trailer track car.

This one...

Jon Van Look

He lives near Nambucca

well

the day was great but unfortunatly JVL had some fuel pump probs and didnt even get one run. My brother with the green super bug did a 1:56.8 mins with slicks and i did a 2:01.5 min with street tires but had awsome fun drifting most corners, PICs to come. Dieter threw some 10 year old A008 yokies on and slicks on the front and turned into a drift session!!!

alex

wish I was there in the toyota giving you some thing to follow !:bounce

ALWAYS seems to be a problem with that JVL car :jesus

ALWAYS seems to be a problem with that JVL car

I saw it run at the nats drags... has it run at any roundy-round events yet? Curious to see how it has performed.

Just to answer some of these quotes on my car ,yes there is a few probs and the car is not of the show room floor this is a ground build up and still learning.First run it had was 2003Raliegh Raceway and was 2secs of the hillclimb champ that day not bad for its first run.EasternCreekdrag strip 13.4 with a problem called bumpsteer which caused me to back of at the 600ft mark and still made top 8.Yes i also had probs at Oran Pk after 15 laps the elec causing probs within the car .Eastern Raceway well thinking probs solved,fuel pumpshit it self and spiked the computer and wiped of memory,we tried hard to get it fix but now go.I just liked to thank the people who understand and stood by and hoping that i got it going.Trust me it was a very expensive day costing 600dollars trying to run.Some people would say "why didnt you test the car before coming"the answer is the new elec set up was finished at 1pm,got the car home to put it back together,finished that at 6pm,tried to start car no go change to back up plugs no go,race back to Coffs for octane fuel,about 9pm dump old put new in no go.Check spark from leeds plenty of.Rang Richard at VForce to see if had any turbo plugs yehyeh.1am left home and that how much iam committed to motor racing and this what it all about.Ive been in motor racing for a long time and it takes 110%these are the ups and downs of motor racing.JVLRacing

How was it running at Oran Park before the probs developed?

The arse end works fantastic,the fronts still need tuning and i had that done for the creek.The car into corners was unreal but felt very unstable down the straight which is bumpsteer.

That JVL car is a beauty to the eye, magnificently built with all possible effort. It looks fast just standing still. It looks so good everyone wanted to see it on the track. There was a lot of effort but unfortunatly didnt go .
Hope to see it on the ytrack sometime.
Hey gayanne can you explain bump steer for us ? Does the weight of the subi have any thing to do with it? Looks like you have shed a lot of pounds on the thing? what does it weigh?
Mitchell

always good to see ppl on tracks I know, so I get some idea of a comparison 🙂

I have only been in timed events at eastern creek and oran park south with PB's of 205 at EC (my old toyota crown) and 53.2 at OP south (in a mate's toyota crown he was kind enough to offer me for the event, my crown only managed 57.2). All on street tyres though.

I can't wait to see what the VW will do when it's finished!

go the crown:thumb........its now a porsche eater !

hahah I think some of the porsches are more than capable, but the driver's dont want to break them maybe? 😀

Hey Waltermitty,thanks for those words,best way to explain bumpsteer is that two wheels are playing tuggle war against each other.One tyre wants to go one way the other goes opposite and causes the car to come unstable at high speeds.AS the car lifts at speed the steering becomes light which pushes the arms out causing toe out on both sides .When you slow down the car becomes stable.This is a very technical side of set up.JVLRacing

Mate sounds like a nightmare , sounds like the 'death wobbles we used to get on the old surfer sam skate boards or on the old malvern star dragsters must be a trill at 200 klms through the sweeper! so do you need more downforce on the front?
Mitchell

[Edited on 20-9-2004 by waltermitty]

No mate nothing to do with downforce.JVLRacing

gayanne wrote:Hey Waltermitty,thanks for those words,best way to explain bumpsteer is that two wheels are playing tuggle war against each other.One tyre wants to go one way the other goes opposite and causes the car to come unstable at high speeds.AS the car lifts at speed the steering becomes light which pushes the arms out causing toe out on both sides .When you slow down the car becomes stable.This is a very technical side of set up.JVLRacing

you have absolutely NO idea...............do you?

"Fire in the hole"

[Edited on 21-9-2004 by speedster356]

hahahha

Ahem... bumpsteer? Something to do with bumps and steering... perhaps?

that could be right....

grow up guys

:cry mummy!!

Bumpsteer, as its name suggests, is a condition where the car deviates to some extent from the driver's intended path due to bumps - suspension movement. Similar compromised handling charateristics can also be caused by body roll on corners and when braking (many cars' suspensions tend to 'dive' at the front and lift at the back when the brakes are applied which can lead to unwanted steering behaviour)

A mis-match between suspension and steering geometry - due to careless design or inappropriate modification - is always the cause. Most cars suffer from it to some degree, although good designs keep it to a bare miniumum.

To keep this explanation reallly simple, LP and BJ Beetles are (technically, at least) most prone to it, due to the very simple design of the front suspension, with the suspension working in one 'plane' (along the centreline of the car) and the steering in another (across the car). When the wheels rise and fall due to road surface irregularities, or when diving under brakes, the wheels tend to steer themselves slightly, independent of steering input, due to the mis-match (for want of a better term) between the arcs of movement of the tierods and the arcs of the trailing arms.
In stock ride-height Beetles, the gemonetry is set-up so wheels tend to toe-in under brakes, which assists stability. Beetles that are lowered with no extra attention to steering/suspension geometry, tend to toe-out making them liable to 'dart around' under brakes. It's all made worse by the fact Beetles have a short- (drivers side) and long (passenger side) tie rod design. The two different lengths mean there are two different radius arcs described when the suspension moves, meaning the the wheels tend to toe in (or out) at different rates. All good fun!
To my knowledge, the very best suspension set up for eliminating bump steer is an upper and lower A-arm set up with rack and pinion steering and anti-dive characteristics built in. Far better than struts, or the old Beetle geometry - but it costs more to manufacture from an OE point of view. Having said that, careful modification within the architecture of a standard Beetle front end can reduce bumpsteer and roll-steer, and increase high-speed stability, giving very good handing both on-road an on-track.
Technically, none of this stuff is very hard - especially for a car intended for circuit work with limited suspension travel. Nissan (Fairlady) and Lotus (Elan), to name two, got this stuff right decades ago. High speed stability can be improved by increasing caster, but that's another subject matter altogether... Get the rack placement wrong, or the tie-rod/suspension arm relationship wrong, and you might as well be playing Meccanno with bits of tube...

[Edited on 21-9-2004 by VWCOOL]

[Edited on 22-9-2004 by VWCOOL]

Good effort writing VWCooL,its spot on but each car reacts differently.The way ive explained it is what is happening with my car.Your last paragraph mention about the steering which was my problem.What ive done is changed height of the steering tie rods.JVLRacing

[Edited on 22-9-2004 by gayanne]

gayanne I think you need to look at the toe in (both at static and at slight raised such as what happens under acceleration and high speed) castor angles, and possible aerodynamic lifting of the car. If you arent running an air dam at the front then chances are the front is lifting at speed, causing it to feel unstable.

I agree - the handling problems you are having, JVL, probably aren't related to bump steer. Not may bumps on a track... It's aerodynamics. You need to hunker the front down at speed - not have it lift! Maybe you have the centre of aerodynamic pressure in front of the centre of mass of the car, which will make it tend to dart sideways immediately it gets 'not square on' with its direction of travel due to minor surface irregularities etc. It's possible to get a BJ Beetle to track straight qnd be stable on-road, at upwards of 180km/h with mildly-modified factory geometry...

you must fix the problem not the result of it. find out if its aero or geo thats causing the bump steer. no ppoint in trying to fix the bump steer if its the car floating casuing the problem.

EasternCreekdrag strip 13.4 with a problem called bumpsteer which caused me to back of at the 600ft mark

A half track powered run giving at 1/4mile ET of 13.4????

Judging by other cars that come off the power at half track and have similar full track ETs that would have put the 1/8th at about 6.25 seconds?

One would be imagining a 9 or very low 10 second car...

i thought craig was being sarcastic 🙂

Anyway we should all chill out a bit 😀

No, I think Craig was being serious. It seems that gayenne:
a) has a problem with his car's handling and
b) Has a problem with the understanding of the problem, IYKWIM

I attempted to clarify what bump steer means - and that itshould have very little to do with straight-line stability - and also to point JVL in another direction, that of his car's aerodynamics, to possibly help him diagnose his car's evil handling.
After all, if many of us can get a $500 Beetle to handle on-road and on-track with a few well-spent dollars and tricks, surely gayenne can expect similar from a purpose-built track car?

HotRodMatt wrote:

EasternCreekdrag strip 13.4 with a problem called bumpsteer which caused me to back of at the 600ft mark

A half track powered run giving at 1/4mile ET of 13.4????

Judging by other cars that come off the power at half track and have similar full track ETs that would have put the 1/8th at about 6.25 seconds?

One would be imagining a 9 or very low 10 second car...

Hi Hot rod that what happen at 660ft not 600ft my mistake, the car done 8.4 at 660 with backing of.JVLRacing

Hey thanks for the help VWCool iam sure i will take this on board.The car does have an undertray ,runs 0 toe,+5 caster.There are no real accurate way to get bumpsteer right without a bumpsteer gauge soon to by one.Ive been using test program from abook toget accurate as possible.The aero ive spent big money on with smoke testing (a long story) i will check it again.At this moment i need to get the car to be reliable and that takes bum in seat time and more dollars. But i will check everything .JVLRacing

A bumpsteer gauge will tell you that you have bumpsteer - but you already know that (if, in fact, you have bumpsteer) but I don't think it will tell you how to fix it. You can see bumpsteer by hoisting the car... the wheels will toe out/in as the car is raised and the suspension droops. Fixing bumpsteer requires a good look/analysis at the geometry of the front end - the relationship between control arms/tierod pivots and their lengths etc etc etc

VWCOOL wrote:A bumpsteer gauge will tell you that you have bumpsteer - but you already know that (if, in fact, you have bumpsteer) but I don't think it will tell you how to fix it. You can see bumpsteer by hoisting the car... the wheels will toe out/in as the car is raised and the suspension droops. Fixing bumpsteer requires a good look/analysis at the geometry of the front end - the relationship between control arms/tierod pivots and their lengths etc etc etc

[Done all of that where car was toeing out when jacking and adjusted control arms and shim tierod arms lot better then before.JVLRacing

surprised you run 0 toe, even on a road car (RWD) you run a touch of toe-in to compensate for slack in materials, which brings it back to 0 when in motion.

JVL, the car is a credit to you. It's amazing you've designed the suspension from scratch. I'm sure it will take some time to get the bugs out.

All the hillclimb guys do is bind up there standard suspension so the thing handles like a go cart. That Torrens blokes car handled like crap at Oran Park.

So does my HSV... I think you'll find that Craig's car is set-up for winning hill climbs - something it does very well! - not high-speed track work!

Yep always learning,refuse to be a arm chair expert thanks for the support.JVLRacing

Alex, why the hell did you guys go drifting at a Porsche track day? Hope you didn't get in the way of anyone going for club points :P

Just remember you can drift anything 😉 http://drift411.com/forums/index.php?act=Attach&type=post&id=119

hahha im in the lead in that one!!!

So do all you guys have IRS with some sort of LSD?
Or is some one still running with an open box and swing axel (Like me 😀)
I'd be interested in a comparision in times between swingaxel and IRS

Thay are all IRS. Dieter has a slippery diff, and was running slicks. I gon't know about the rest.:thumb

we are all irs and with LSD. Swing axle is not the best for a quick track car.

Alex you should know that wih my background I am unbeatable in a golf cart.
Mitty

ahhahhaa yeh yeh we'll see about that!!!

I'm good in a shopping trolley:tree

restocal wrote:JVL, the car is a credit to you. It's amazing you've designed the suspension from scratch. I'm sure it will take some time to get the bugs out.

All the hillclimb guys do is bind up there standard suspension so the thing handles like a go cart. That Torrens blokes car handled like crap at Oran Park.

HEHEHEHEHEHE....handled like crap and still did 54's with a standard gearbox and no LSD...................if you bind up your suspension you certainly won't WIN hillclimbs,,,,,,,,,,show's you have NO IDEA as well !

Give up Retro.

lol

Jnr Holzl,

You're a bit young for LSD but what are you using, Quaiffe or ZF?

You should be under 2 minutes with all that horsepower?

im using a ZF, how old do u hav to be? im happy with my time seeing as im only on street tires and i still hav abit of under steer only my second time on any race track and was my first at eastern soo im sure lap times will improve as i sort the setup of my car.

Alex

i traded my nappies in for a ZF 😉

This is me after runnig out of lock and cookin 3rd gear goin backwards!

my brother having some fun on the last session of the day.

Look at the outside rear wheel...

The cars sitting nice, go the struts.

im dying to do a strut chassis for my car!!!

just posted my ride on www.germanlook.com