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Author Topic: What is really the problem using a beetle as a drag racer?  (Read 106405 times)
Jyrki
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« Reply #30 on: July 16, 2012, 21:31:07 pm »

Reading past posts on this subject it appears there's almost a prejudice against running wings on a Bug, and as such people are quick to dismiss it, even though they haven't tried it for themselves.  

I for one believe a wing makes a big difference, but I still try to manage without one (I like my cars to have standard looks if possible).
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« Reply #31 on: July 16, 2012, 21:40:10 pm »

The front didn't rise at top end (but it was only doing 230km/h). No aero stuff in the car, 930kg. I am also aware of one very fast Beetle with ride height sensors; no issues at very high speed.

This is interesting stuff Jyrki, no lift in the front end? But you also talk about the angle of the spring plates, you don't say exactly what was wrong with it, but I would guess your arms was pointing down to the torsion bars. What angle do you use on your ladder bars?


Hi,
Maybe the word 'angle' was not correct. With the first setup a long time ago the transmission was raised too much and it messed the rear suspension. Later with the ladder bars (32") I started with 11" Instant Center height; it was ok, maybe a little too big wheelies. After the first test raised them one step to 12". This seemed to work with the Center of Gravity etc. of that car.
I can check my corner weights - they're in the note book in the garage.
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Jyrki
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« Reply #32 on: July 16, 2012, 21:42:33 pm »

A clutchless gearbox would help a lot to not shock the drivetrain banging in gears,im using the Finnish gear and they are not really clutchless,
they seem to work fine in a NA application but not with the tourqe a turbomotor is producing,you just cant get it out of gear under load
 whitout using the clutch
//Patte

Patte, that's what I have. I have zero experience as the car is still under construction. Do you use ignition cut when shifting?
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richie
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« Reply #33 on: July 16, 2012, 21:55:35 pm »

The front didn't rise at top end (but it was only doing 230km/h). No aero stuff in the car, 930kg. I am also aware of one very fast Beetle with ride height sensors; no issues at very high speed.

This is interesting stuff Jyrki, no lift in the front end? But you also talk about the angle of the spring plates, you don't say exactly what was wrong with it, but I would guess your arms was pointing down to the torsion bars. What angle do you use on your ladder bars?


Hi,
Maybe the word 'angle' was not correct. With the first setup a long time ago the transmission was raised too much and it messed the rear suspension. Later with the ladder bars (32") I started with 11" Instant Center height; it was ok, maybe a little too big wheelies. After the first test raised them one step to 12". This seemed to work with the Center of Gravity etc. of that car.
I can check my corner weights - they're in the note book in the garage.
Jyrki


The angle of the springplates does seem to make a huge difference to traction and hence grip all the way down the track,finding the balance between ride height and traction is quite difficult,that is the only reason I can see for doing a torsion raise,to get the center of gravity down and keep the springplate at the correct angle

cheers richie 
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« Reply #34 on: July 16, 2012, 22:15:41 pm »

What would be considered the correct angle of the spring plate at ride height?
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« Reply #35 on: July 16, 2012, 23:52:35 pm »

Here's a good write up on how to launch a v8 car http://www.how-to-build-hotrods.com/tuning-4-link.html



Reading this gives the impression we are in the same boat... We have a fixed instant center lengthwise, and a fixed wheel base. But center of gravity can be adjusted slightly up and down, and can be moved forward by adding weight up front. The instant center can be moved down by raising the gearbox... A lot of work yes...but can the laws of physics actually tell if the engine is in the rear or the front if the center of gravity is in the same place?

I understand that a live axle is a different beast to the IRS since that does all sorts of movements by design. But I believe that Pattes rear suspension would behave like a live axle with ladder bars.
« Last Edit: July 17, 2012, 06:42:35 am by JHU » Logged

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Udo
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« Reply #36 on: July 17, 2012, 06:54:28 am »

I think there are too much bad chassis out there . a lot of people think they can do it better or can save money. For me the only ones are the RLR , he has the most experiance . I looked around for a longer time to find a good car - i like the old mild steel chassis from ron most . And i also think the new chrom molly chassis are sometimes too light weight. V8 chassis must be different - engine in front -

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Berger
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« Reply #37 on: July 17, 2012, 08:01:45 am »

Now I think we are getting somewhere!  
A lot of useful information has been provided her now, thanks, and keep it coming Smiley

As for the suspension I think we need someone to calculate and design a 4-link setup for the beetle that bolts into place where the torsion spring used to sit. As far as I can understand, we do not need to go for the ladder-bars if the 4-link is designed to hit the correct instant center. If the 4-link also is designed strong enough to handle enough hp, the problem with "steering rear wheels" is solved.

It also seems like removing weight from the front of the beetles body is just making things more difficult, so I guess keeping all the steel up front, and removing as much as possible in the rear is a good idea to equal the weight and make a more reasonable center of gravity.

It also seems like the traditional rear wing needs to be redesigned, because it`s main function is to add side stability, brake the wing effect of the car, and not to make downforce. I guess it needs to be moved further up on the roof, have larger side panels and a zero degree mid section with a brutal flip at the rear.
  
Also focus one making a automatic/clutch-less transmission that works would be of great benefit I think.

This is my summary, this far.. Smiley
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« Reply #38 on: July 17, 2012, 08:22:02 am »

As for the suspension I think we need someone to calculate and design a 4-link setup for the beetle that bolts into place where the torsion spring used to sit. As far as I can understand, we do not need to go for the ladder-bars if the 4-link is designed to hit the correct instant center. If the 4-link also is designed strong enough to handle enough hp, the problem with "steering rear wheels" is solved.

The 4 link needs to be double to be able to control the IRS side on each side... or you need to connect the IRS hubs with a tube beneath the gearbox, going side to side.  Like 4x4 Voyagers have:


4 links is a smart way to get the instant point where you cant practically have them, but they only sort of work(the point moves as the suspension is traveling thru the arc). Meaning they are not optimal either. But when you are building a race car, I cant see the problem of adding ladder bars...?  But also they need to need to be double.
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« Reply #39 on: July 17, 2012, 08:25:23 am »

V8 chassis must be different - engine in front -

If, and that's a big IF, you can get the same point of gravity in a bug by weighing it down... as in a V8 car... the chassis would not know where the engine was.
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richie
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« Reply #40 on: July 17, 2012, 08:35:55 am »

V8 chassis must be different - engine in front -

If, and that's a big IF, you can get the same point of gravity in a bug by weighing it down... as in a V8 car... the chassis would not know where the engine was.

That is one of the points I was trying to make,get theweight bias better and it makes less difference where the engine is,as I have some down time with the car at the moment I have been trying to take weight from the back of the car by using different materials etc,but then I will add the weight back in to the front of the car where it is needed,I dont need a light car thats for sure Wink

cheers richie
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« Reply #41 on: July 17, 2012, 09:19:40 am »


The 4 link needs to be double to be able to control the IRS side on each side... or you need to connect the IRS hubs with a tube beneath the gearbox, going side to side.  

4 links is a smart way to get the instant point where you cant practically have them, but they only sort of work(the point moves as the suspension is traveling thru the arc). Meaning they are not optimal either. But when you are building a race car, I cant see the problem of adding ladder bars...?  But also they need to need to be double.
What do you mean "The 4 link needs to be double to be able to control the IRS side on each side.."?

By the way, the De Dion tube design you hinted at was used on the original Frameworks-chassied Bugpack Pro-Sedan back in 1988/89. It never handled, but I don't know why. It was rebuilt as a swing-axle car and finally went on its roof in a big way...

Here (sorry for poor pics) is the rear end of No Mercy under construction – probably the most stable, consistent chassis car in its day:

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« Reply #42 on: July 17, 2012, 09:37:30 am »

What do you mean "The 4 link needs to be double to be able to control the IRS side on each side.."?

What I mean is to be able to use the collected knowledge of the V8 boys, our rear wheels needs to move in the same way as they do on a live axle.
I not believe for a minute that just changing things to work the same fixes anything, but when you are at that point you can follow the v8 boys lead...  you have people and books to guide you.

By the way, the De Dion tube design you hinted at was used on the original Frameworks-chassied Bugpack Pro-Sedan back in 1988/89. It never handled, but I don't know why. It was rebuilt as a swing-axle car and finally went on its roof in a big way...

I knew of that, and there is a current bug in Sweden that use/used the same set up. I don't think he had to much luck with it( in the tens?).

Here (sorry for poor pics) is the rear end of No Mercy under construction – probably the most stable, consistent chassis car in its day:



Yes that's another way of getting it "linear"...  I don't think using swing with 4-link is same thing at all...
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« Reply #43 on: July 17, 2012, 09:39:49 am »

I dont see any benefit using a fourlink suspension unless you mount the whole drivetrain in a subframe and use a live axle
letting the tranny and motor work as a rearaxle on a frontmotor car with fourlink  Huh

As our rearaxle(tranny) is fixed in one place, the only adjustment we can do(as i see it) is by moving the ladderbars up or down
or with a trannyraise increase the angle on the the springplates making it squat more(ladderbarsin lowest point) or less(highest point)
Its the tranny that lifts the car so making the car heavier in front is probably the right way to adress wheelie problems and lift at high speeds.

The De Dion design is probably the only way to keep the rearwheels from steering under load,but it is a heavy desing.
Pizzo bros used it with a fourlinksetup on the fastback in the 80s  Smiley

//Patte
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dannyboy
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« Reply #44 on: July 17, 2012, 19:12:55 pm »

bear in mind i know nothing about chassis design but formula v cars flip the diff and run the motor mid mount would this not help balance out the weight in a tube chassis car?
i think there would still be plenty of room behind the seat to fit it in?  Undecided
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« Reply #45 on: July 17, 2012, 23:52:23 pm »

I dont see any benefit using a fourlink suspension unless you mount the whole drivetrain in a subframe and use a live axle
letting the tranny and motor work as a rearaxle on a frontmotor car with fourlink  Huh

//Patte

Bingo -- There is the VW problem -- -- No matter how we mount the axles -- 98% of the torque the is transmitted to the car goes through the transmission and it's mounts -- until someone comes up with a way of tuning that we will be mired in the 50's suspension design
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« Reply #46 on: July 18, 2012, 01:59:49 am »

The biggest problem with a beetle as a drag racer (as I see it) is weight bias.

A V8 ProStock car is probably the most efficient leaving setup you can possibly get, so that's our benchmark.

Now take ~600lbs. off the nose of the car and re-attach it 2ft past the centerline of the rear tires.

Just for fun, take away half the treadwidth from the slicks

AND half the sidewall height from the slicks
AND cut the wheelbase down to about a skateboard
AND give it huge relative frontal area and a really bad shape

- Now see if it will go straight.
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« Reply #47 on: July 18, 2012, 07:06:33 am »

I dont see any benefit using a fourlink suspension unless you mount the whole drivetrain in a subframe and use a live axle
letting the tranny and motor work as a rearaxle on a frontmotor car with fourlink  Huh

//Patte

Bingo -- There is the VW problem -- -- No matter how we mount the axles -- 98% of the torque the is transmitted to the car goes through the transmission and it's mounts -- until someone comes up with a way of tuning that we will be mired in the 50's suspension design

I am really failing to see why we can not use the 4-link with the same effect as on a front engine car? Please explain Smiley

Here is a example of what I have in mind

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« Reply #48 on: July 18, 2012, 07:56:57 am »

I am really failing to see why we can not use the 4-link with the same effect as on a front engine car?
I guess there was no point in my posting photos of the rear end of No Mercy... IRS and four-link set-up that ultimately ran 9.80s in 1994 (yes, 18 years ago...) on just 2.1-litres. Chassis was one of two VW chassis built by a V8 chassis expert - the only other VW chassis he built was Kawell's 'Blackie'. So this was the only rear-engined VW he ever built. He started with a clean sheet and applied his V8 knowledge to the VW. It worked and very well. So I have no idea at all why people keep either suggesting four-bar on a VW won't work or asking 'why can't we use four-bar on a VW?  I guess either my car never existed or there are people here who have built similar designs and proved it doesn't work. Jon Webster, who I consider (as do many others) to be the best chassis builder in the UK and certainly Europe, too, measured and drew out my chassis when I took the car to him for set-up. He concluded that it was just about perfect. We did discuss a strut front end but no point as we didnt want to lose any more weight from the nose. OK, I'll just sit back now and let the experts get on with the discussion!  Grin
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« Reply #49 on: July 18, 2012, 07:58:22 am »

red9 design in the UK make somthing like that for T2 its all bolt on ther were going to do it for T1 as well but dont know if they have done yet, heres my take on the rear suspension not sure what you make of it i have posted pictures before but comments welcome Smiley



cheers andy
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« Reply #50 on: July 18, 2012, 08:44:16 am »

Keith, I sympathise. You had a car that ran super straight and consistent and almost two decades ago, when most were happy running 15s. When I considered a rear wing on my car, I made an educated decision to seek advice from those with experience; like yourself. It paid off, and my car benefitted massively, though perhaps not aesthetically  Cheesy. Yet, like your four link, the wing also seems to be cast aside and given only passing consideration. Why is it we feel the need to re-write the rules on how a Bug should or shouldn't work when there are already cars out there proving the point?
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« Reply #51 on: July 18, 2012, 08:55:57 am »

Ok,it appears the main issue is we dont actually know what we are doing Shocked Cheesy  There are several different ways that work,to a certain extent,but as we dont build every car the same there is no real data to say how well it will work,and to what performance/hp level.
I think we have suspension solutions in place that will get the power to the ground ok,but what happens when you throw in some variables? track conditions changings over the 1/4,track temp,winds,both side winds and head or tail winds,oil on the track from a previous car[how many actually have a diaper on there car? WHY NOT?

Keiths old car worked well,but what happens if you add 500lbs to it in the wrong places? or 500hp more,the engines have been gaining in hp and torque the last few years,the developemnt is there along with better more efficient turbos and the Efi allows us to control it,the transmissions are stronger but really the chassis design hasnt changed at the same pace
Leif's car was a development of his old car,pressumably built better and stronger,he knows what he is doing,has lots of experience as a driver and I have no idea what happened to cause the incident that started this thread,but sh$t happens

Udo,
you wrote that you think the chromoly chassis are sometimes to lightweight?but we as the customer dont size the tubing or thickness,that is up the the chassis builder,I personally dont think they take into account what the customer is actually going to try and do with the car,they just build the same chassis regardless of what its going to be,N/A,turbo,blower,nitrous whatever.I think they need to stop thinking of keeping it as thin and light as possible,we dont have 260hp N/A engines or 400hp turbo engines anymore,things have moved on from that,we add weight to our cars anyway so why not start with thicker stronger tubing?


Rudy's new beetle has a four link rear suspension on it,with 3 lateral links from the hub to chassis rails,its similar to No mercy in the pics Keith posted,it seems to work well,but he is still at the beginning of the journey with that car,only time will tell if it is good enough when more hp and speed is applied to it.

But how many of us actually use the adjustment built into the suspension? and know what is going to happen when we make those changes,moving the arms up or down in th eholes,spreading them further apart at the front or narrowing them down? with the previosly mentioned V8 pro stock car all the data is there,they have done more passes testing this year alone than most of us have just done passes in our lives


The main reason we crash is >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>  



 BUDGET  Shocked


Its true if we had the budget we would have the ability to employ all the brains and tools needed[software,wind tunnels,experts,tuners etc]



cheers richie
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Patte
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« Reply #52 on: July 18, 2012, 09:30:06 am »

Keith i didnt say that a fourlink dont work on a vw,my point is that we can not use it the way it was design for,setting the pinionangle etc.
In our application it will just work as a ladderbar with the possibility to move the instantcenter alot more forward than a ladderbar by setting the angle
of the upper and lower bars.

there is at least 2 VWs in Sweden that runs a Chassis shop fourlink setup and they seems to work fine but they are NA,in USA there have been a few
crashes using Chassis shop chassis with high hp turbos,so the problem seems to be there regardless of the setup we use.

I agree with Richie and i think one of the solutions would be accepting the fact that our enginens are producing more hp and tourqe now and build the rearends
strong enough to handle it and not just as light as possible.

//Patte
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« Reply #53 on: July 18, 2012, 09:32:22 am »

I am really failing to see why we can not use the 4-link with the same effect as on a front engine car?
I guess there was no point in my posting photos of the rear end of No Mercy... IRS and four-link set-up that ultimately ran 9.80s in 1994 (yes, 18 years ago...) on just 2.1-litres. Chassis was one of two VW chassis built by a V8 chassis expert - the only other VW chassis he built was Kawell's 'Blackie'. So this was the only rear-engined VW he ever built. He started with a clean sheet and applied his V8 knowledge to the VW. It worked and very well. So I have no idea at all why people keep either suggesting four-bar on a VW won't work or asking 'why can't we use four-bar on a VW?  I guess either my car never existed or there are people here who have built similar designs and proved it doesn't work. Jon Webster, who I consider (as do many others) to be the best chassis builder in the UK and certainly Europe, too, measured and drew out my chassis when I took the car to him for set-up. He concluded that it was just about perfect. We did discuss a strut front end but no point as we didnt want to lose any more weight from the nose. OK, I'll just sit back now and let the experts get on with the discussion!  Grin

Keith, Bergers reply was not aimed at you, as you obviously have beliefs in the V8 way, it was aimed at the ones that do not.

Can you tell us anything more about your set up? In you pictures the 4 link seem to be parallel? Was this how you ran it? Did you and your chassis builder tune it on the track together, or did you follow something like the diagram I posted earlier?
Why do you think no one (?) have followed your lead? Are people aware of your chassis set up, I mean did you do any chassis articles on the car or something like that?
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« Reply #54 on: July 18, 2012, 10:03:17 am »

Yet, like your four link, the wing also seems to be cast aside and given only passing consideration.

Matt, Ricihe wrote something about your car being nervous at the same speeds as other bugs without wings are still stable. If that is true, how can a lacking wing be the source of your problems? With all due respect!
If going middle eights and sevens are going to be done *safely* the setting out point must be as good as possible before fitting the wing... of course the wing is needed to do the numbers no doubt about that.

Why is it we feel the need to re-write the rules on how a Bug should or shouldn't work when there are already cars out there proving the point?
This threads starting point was Leif's accident... his car, along with several other cars that have crashed in the last year were all following the rules as you call them, built by the best out there...  So should we stop trying, ignore the losses (keep going), or have a debate about the rules?

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« Reply #55 on: July 18, 2012, 10:30:15 am »

Keith i didnt say that a fourlink dont work on a vw,my point is that we can not use it the way it was design for,setting the pinionangle etc.
Who says in what way a four-link should be used? Four link technology has been used on all kinds of cars for many years – look at every Grand Prix car in the 1960s and early '70s – they all ran four-link at the back. More than anything it's a simple way to offer a no-bind, yet adjustable, way to locate the rear wheels/hubs. That a V8 live-axle car can then use it to adjust pinion angle is a bonus but not necessarily the whole raison d'etre behind the four link. Just my 2c.


Keith, Bergers reply was not aimed at you, as you obviously have beliefs in the V8 way, it was aimed at the ones that do not.

Can you tell us anything more about your set up? In you pictures the 4 link seem to be parallel? Was this how you ran it? Did you and your chassis builder tune it on the track together, or did you follow something like the diagram I posted earlier?
Why do you think no one (?) have followed your lead? Are people aware of your chassis set up, I mean did you do any chassis articles on the car or something like that?
OK, sorry – I misread the message... The links were parallel in those photos purely by coincidence simply because that was when I first got hold of the chassis as a pile of parts – I just bolted it together like that as it was an obvious simple way to do it. I also ran the car quite often like that – it results in a very 'soft' launch (the Instant Centre is at infinity – in front or behind the car...). The one advantage of this if you are at a track with varying conditions (as is often the case in the UK, with varying track temperature, inconsistent track prep – maybe that's improved now!) then you could rely more easily on using rear shock settings, tyre pressures and changing the length of the limiting straps on the front shocks. All quick and easy changes that could be made in the staging lanes.

By running the top link horizontal, and the lower one raised at the front, the car would hit fairly hard but keep the nose planted on the ground. I didn't like the way it felt, from what i remember, and the one time I experienced tyre shake (NEVER to be forgotten!) was with it set like this. By dropping the bottom link, the car pulled the wheels more easily but would 'bog'. Now, when I set it so the instant centre was behind the car, it became a different animal altogether. Wit the top link on the upper setting, the bottom link on the lowest, the car felt more like a pan car to drive, and didn't respond well to shock adjustments.

In the end, because I was more interested in consistency (I had a championship to win/defend), I generally ran the car with the bars parallel (OK, a cop-out!) or with the IC set low.

Bear in mind, these are my memories from nearly 20 years ago – I may not be 100 per cent correct, but all I do know is it was a lovely, easy car to drive.

As for why no-one followed my lead, well, at least one other UK car was built using a 'copy-cat' rear end, but not very well executed. That was the 'Cold Sweat' channelled sedan of Murray Griffin. Since then, I have had several requests over the years for details of the rear end – there is one chassis builder in the UK right now who is building a car for a customer who has asked for details "because it worked".

Turning briefly to the matter of CDS or chrome-moly – everyone is forgetting the main advantage C/M has over CDS: it has a fantastic 'memory'. CDS chassis will gradually twist with time – do your corner weights, alignments etc after several runs, and the chances are you'll discover things have moved. A chrome-moly chassis doesn't suffer from this – that's another reason why my car was very consistent, I think. Overall, the car was no lightweight, and probably heavier than most CDS chassis cars with lightweight bodies.

Cheers all for listening to the ramblings of an old git. Cheesy
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Der Kleiner Panzers VW Club    
12.56sec street-driven Cal Looker in 1995
9.87sec No Mercy race car in 1994
Seems like a lifetime ago...
richie
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« Reply #56 on: July 18, 2012, 11:06:28 am »

A car being currently built in USA by a lesser known chassis build[no offence Doug Wink ] were they are not following the "monkey see,monkey do" path followed by so many,will be intersting to see how it all works,

then how to get the weight bias nearer a front engined car by the quickest and fastest vw style car around
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richie
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« Reply #57 on: July 18, 2012, 12:35:51 pm »

Keith i didnt say that a fourlink dont work on a vw,my point is that we can not use it the way it was design for,setting the pinionangle etc.
Who says in what way a four-link should be used? Four link technology has been used on all kinds of cars for many years – look at every Grand Prix car in the 1960s and early '70s – they all ran four-link at the back. More than anything it's a simple way to offer a no-bind, yet adjustable, way to locate the rear wheels/hubs. That a V8 live-axle car can then use it to adjust pinion angle is a bonus but not necessarily the whole raison d'etre behind the four link. Just my 2c.


Keith, Bergers reply was not aimed at you, as you obviously have beliefs in the V8 way, it was aimed at the ones that do not.

Can you tell us anything more about your set up? In you pictures the 4 link seem to be parallel? Was this how you ran it? Did you and your chassis builder tune it on the track together, or did you follow something like the diagram I posted earlier?
Why do you think no one (?) have followed your lead? Are people aware of your chassis set up, I mean did you do any chassis articles on the car or something like that?
OK, sorry – I misread the message... The links were parallel in those photos purely by coincidence simply because that was when I first got hold of the chassis as a pile of parts – I just bolted it together like that as it was an obvious simple way to do it. I also ran the car quite often like that – it results in a very 'soft' launch (the Instant Centre is at infinity – in front or behind the car...). The one advantage of this if you are at a track with varying conditions (as is often the case in the UK, with varying track temperature, inconsistent track prep – maybe that's improved now!) then you could rely more easily on using rear shock settings, tyre pressures and changing the length of the limiting straps on the front shocks. All quick and easy changes that could be made in the staging lanes.

By running the top link horizontal, and the lower one raised at the front, the car would hit fairly hard but keep the nose planted on the ground. I didn't like the way it felt, from what i remember, and the one time I experienced tyre shake (NEVER to be forgotten!) was with it set like this. By dropping the bottom link, the car pulled the wheels more easily but would 'bog'. Now, when I set it so the instant centre was behind the car, it became a different animal altogether. Wit the top link on the upper setting, the bottom link on the lowest, the car felt more like a pan car to drive, and didn't respond well to shock adjustments.

In the end, because I was more interested in consistency (I had a championship to win/defend), I generally ran the car with the bars parallel (OK, a cop-out!) or with the IC set low.

Bear in mind, these are my memories from nearly 20 years ago – I may not be 100 per cent correct, but all I do know is it was a lovely, easy car to drive.

As for why no-one followed my lead, well, at least one other UK car was built using a 'copy-cat' rear end, but not very well executed. That was the 'Cold Sweat' channelled sedan of Murray Griffin. Since then, I have had several requests over the years for details of the rear end – there is one chassis builder in the UK right now who is building a car for a customer who has asked for details "because it worked".

Turning briefly to the matter of CDS or chrome-moly – everyone is forgetting the main advantage C/M has over CDS: it has a fantastic 'memory'. CDS chassis will gradually twist with time – do your corner weights, alignments etc after several runs, and the chances are you'll discover things have moved. A chrome-moly chassis doesn't suffer from this – that's another reason why my car was very consistent, I think. Overall, the car was no lightweight, and probably heavier than most CDS chassis cars with lightweight bodies.

Cheers all for listening to the ramblings of an old git. Cheesy

Keith,

as I am not totally sure of what affect what changes  what affect on a 4 link car as in relation to bar angles can you tell me how you would set it up for ultimate ET with say twice the hp you had back then? oh and so as not to crash Smiley

i am reading "Doorslammers,The chassis book" by Dave Morgan at the moment to try and learn more but it is making my head hurt Roll Eyes  I am much better at understanding by trying things and seeing what happens than by theory Smiley


cheers richie
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Cars are supposed to be driven, not just talked about!!!   


Good parts might be expensive but good advice is priceless Wink
Neil Davies
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« Reply #58 on: July 18, 2012, 13:00:36 pm »


i am reading "Doorslammers,The chassis book" by Dave Morgan at the moment to try and learn more but it is making my head hurt Roll Eyes  I am much better at understanding by trying things and seeing what happens than by theory Smiley


cheers richie

Ah, a kinaesthetic learner!  Cheesy Richie, it is great that you are willing to try different things - I've never seen suspension like in the back of your new cab before, like I think I said to you at Shakey earlier this year. How do you think it compares to a regular IRS rear end given that you've run very similar times in both cars?

Keith, I had a quick look at the pictures on my phone but I can't see them on the big monitor here at school, but it looks like the two lower links that make up the lower wishbone were completely independent to each other, and rose jointed at each end? Would that allow the rear hub carrier to rotate as it moves up, controlled by the four-link bars? I'm trying to get my head around how it works before I can think about the why!
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2007cc, 48IDFs, street car. 14.45@93 on pump fuel, treads, muffler and fanbelt. October 2017!
richie
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Posts: 5687



« Reply #59 on: July 18, 2012, 13:11:43 pm »


i am reading "Doorslammers,The chassis book" by Dave Morgan at the moment to try and learn more but it is making my head hurt Roll Eyes  I am much better at understanding by trying things and seeing what happens than by theory Smiley


cheers richie

Ah, a kinaesthetic learner!  Cheesy Richie, it is great that you are willing to try different things - I've never seen suspension like in the back of your new cab before, like I think I said to you at Shakey earlier this year. How do you think it compares to a regular IRS rear end given that you've run very similar times in both cars?


And you never will again on my car,its going in the bin Shocked Angry       

There are some things that apparently I cant say on the internet Roll Eyes


Version 2 should be ready for SCC Smiley

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Cars are supposed to be driven, not just talked about!!!   


Good parts might be expensive but good advice is priceless Wink
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