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Author Topic: What is really the problem using a beetle as a drag racer?  (Read 105625 times)
Berger
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« on: July 16, 2012, 08:11:00 am »

Seeing a alarming high number of crashes at the top end of the drag strip over the last few years, I think it`s time to put the searchlight on and ask, what is really the problem using the beetle as a drag race car?
Knowing that involved in these crashes are all top notch cars and experienced drivers (but this thread is not about the individual race cars), I think there has to be a common factor that makes these accidents. Compared to "traditional front end engine" drag race cars, the beetle seems problematic, and accidents are more "common". So what is the problem and what can we do about it?

Is it the aerodynamic problem that causes the car to be unstable at high speed? We know the beetle has little weight at the front wheels, and tends to rise at the end like a wing at high speed, but is this really the problem or problem alone? Other drag race cars with similar aerodynamics, as hot rods and `30 - `40`s style cars does not appear to have a similar problem?
 
Is the use of a high HP/torque turbo engine contributing to the problem? Is the fact that this type of engine makes maximum effect at the end of the drag strip an issue? Compared to a blower/supercharger engine, the turbo engine has a more "champagne bottle cap behavior", and is this why so many experience unstable car or tire slip at the end of the track? Do we need a engines that delivers more stable hp/torque?

Or is it the weight distribution, the rear engine? Maybe there is a limit to how fast a car with the beetle type of weight distribution can go? Thinking of an arrow, we all know the only way to make a arrow go straight, is to have most of the weight at the tip of it. Try to add weight at the tail, and it never goes straight.

Maybe we have to face the fact that a mid 8 sec beetle is at the limit, and to go faster we have to really "think again"?

I know there are many, many experienced beetle drag race drivers here at the lounge, and I hope that we can use the experience and our minds to come up with some new ideas and maybe solve some of this challenge.

Berger   
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bang
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« Reply #1 on: July 16, 2012, 08:27:12 am »

yes that give us somthing to think about when building cars.

many of the cars crashing is tube chassis cars and many of them with struts. names like Geers, alan fore, vw paradise, tekken, and now nystrψm. all struts cars. maby it is just me or does it effect the cars in the top speed end.

hope you guys have commets to this.
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richie
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« Reply #2 on: July 16, 2012, 09:59:30 am »

I have several thoughts on this issue,some I will not post as they are far to contraversial for a public forum, Peter makes a valid pint,but there are thousands of strut cars out there that dont have any problems with the engine in the front,I dont see Stians problem caused by the struts and i know the Hater crash wasnt caused by that,or my own crash either

Of those cars you mentioned Peter,which chassis were designed and built by which builder?

And mostly the cars were already out of shape way before the top end,but we keep in it to long,learning to get out of it,slow the car down,pull the chutes whatever you need to do but not to grab anohter gear and keep on it is the most difficult thing to learn.it seems to take a bad accident to make you realise its not worth it to get a time,if you get out of it there will be another chance to run "that number"

Also I feel alot of tracks dont take VWs seriously,what some of the cars need in the way of track prep and conditions is better than a Top fuel car,and similar to a Pro mod car,at Tierp last year i had this problem,the track was good,but then someone oiled one lane,and the clean up was rushed,and after that it just wasnt good enough for a high hp car but they are only VWs right so it doesnt matter Angry

This year at santa pod they have a problem,which has been admitted by the big man who runs the show,around the 1/8 mile the track had some problems,so they leveled it and scraped it just beofre the easter thunderball,but watching yesterday it still hasnt recovered completely,cars are still wandering around at the 1/8th mile area,several cars have crashed after loosing control there  since this track improvement !!!!
Jim smiths crash was a year ago,happened at the same spot before they made the improvements!!!

The picture is from one of my passes at easter,it go so out of shape I was sure i was going to crash,but imidiately go of the power,tried to control it,breaked but couldnt get it right,then pulled the chute and managed to save it.[thanks to Julian Hunt for the photo]
Having struts made no difference to what happened,now suspension design and set up,that is a different subject altogether

I am still working on a front end aero improvement that i can fit to my car,and hopefully will be able to fit onto the front of other cars as well to help them


Berger for your stats,I think at least 5 cars and one dragster have crashed in england this year,and NO VWs Wink  We are only aware of what affects our little world to a certain extent Smiley 

We really need the input of all the experienced drivers to give there own feelings on what happens or happened to get a good selection of views

cheers richie
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BeetleBug
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« Reply #3 on: July 16, 2012, 10:21:17 am »

Look at a airplane wing, curved on top and flat underneath. Any similarities with the shape of a beetle? Then listen to the guys with height sensors on their cars and they will tell you that their car is higher at high speed compared to when it stands still and this goes for both the front and the rear. Then I take it for granted that you somewhere on the strip need to either let of the throttle and perhaps even touch the brakes. This will of course also effect the handling. I also find it really interesting that the serious racers have started to add weight at the right places on their cars making them more stable. Not to forget the short wheel base on our cars and the fact that driving a beetle is like trying to throw a hammer and asking it to fly with the handle first.

BB
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richie
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« Reply #4 on: July 16, 2012, 10:31:14 am »

Also add in the manual transmission which when you shift allows the car to unload,then the torque as it comes back onto boost and loads the chassis back up trys its hardest to un-settle the car,having watched the video of the 2 cars I know[new beetle from brazil and rotary engined black mamba 1303] that are using sequential or clutchless shifting go down the track so much smoother I think it is another huge step forward,when do you see a car suddenly get out of shap for no reason? if they are hard in 3rd or 4th gear it doesnt happen,but change gear and all hell can break loose Shocked

As kalle wrote more and more are adding weight to make the cars un VW like in weight distribution,getting nearer to 50/50 weight split which has to help keep the car stable at speed,and maybe we have to accept that the beetle shape we all love may become "ugly" to make it safer with aerodynamic additions but they sure look ugly all scratched up after its gone wrong Sad

Richie
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Fastbrit
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« Reply #5 on: July 16, 2012, 10:39:52 am »

Don't know if I count as being an experienced driver any more, but I have put in my fair share of passes over the years in both tube chassis and pan cars, some good, some bad, some plain dangerous.

I know very few people will want to agree but a lot of accidents I've witnessed over the years have been ultimately down to driver error. You have to accept that a SWB car like a Beetle, with the shape it is, is not the most obvious vehicle to build an all-out race car. But as long as you accept the limitations, then fine. The important thing – as Richie demonstrated – is to read your car: don't be a hero, and don't fight it. Many accidents are caused by over-correction or simply holding onto the wheel too tight. Most cars want to move around a little – OK, let them. I usually hold the wheel fairly lightly in one hand, occasionally two, and allow the steering wheel to move as it wishes. If the alignment is correct and there's plenty of caster built in, a car will want to run straight. It's when you feel it move and try to prevent it that things get ugly.

There are situations when external forces come into play, of course: track condition, cross-winds etc, but part of being a good driver is making yourself aware of the situation before you make a pass. If you don't trust a lane, if at all possible, don't run in it. There's nothing worse than staging with the thought in mind that you might crash. Chances are you will because you won't be thinking logically (or 'safely'), and will tend to fight the car.

If the car is properly aligned, there is no binding in the suspension, the corner weights are equal side for side (how many VW racers corner-weight their cars – with a tank of fuel and a the fully-suited driver in place?), tyre pressures are equal – and the circumference of each rear tyre is the same (yes, they do vary...), then you should be OK.

Car prep and driver prep – get them right and you have a fighting chance of making it the finish line in one piece.

OK, I'll go back to the retirement home now... Smiley
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BeetleBug
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« Reply #6 on: July 16, 2012, 10:55:08 am »

Also add in the manual transmission which when you shift allows the car to unload,then the torque as it comes back onto boost and loads the chassis back up trys its hardest to un-settle the car,having watched the video of the 2 cars I know[new beetle from brazil and rotary engined black mamba 1303] that are using sequential or clutchless shifting go down the track so much smoother I think it is another huge step forward,when do you see a car suddenly get out of shap for no reason? if they are hard in 3rd or 4th gear it doesnt happen,but change gear and all hell can break loose Shocked

As kalle wrote more and more are adding weight to make the cars un VW like in weight distribution,getting nearer to 50/50 weight split which has to help keep the car stable at speed,and maybe we have to accept that the beetle shape we all love may become "ugly" to make it safer with aerodynamic additions but they sure look ugly all scratched up after its gone wrong Sad

Richie

To add to your point, look at the 6 second Latam To#€ta Starlet as a example of a really fast, short wheel based car.
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richie
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« Reply #7 on: July 16, 2012, 11:01:05 am »

Also add in the manual transmission which when you shift allows the car to unload,then the torque as it comes back onto boost and loads the chassis back up trys its hardest to un-settle the car,having watched the video of the 2 cars I know[new beetle from brazil and rotary engined black mamba 1303] that are using sequential or clutchless shifting go down the track so much smoother I think it is another huge step forward,when do you see a car suddenly get out of shap for no reason? if they are hard in 3rd or 4th gear it doesnt happen,but change gear and all hell can break loose Shocked

As kalle wrote more and more are adding weight to make the cars un VW like in weight distribution,getting nearer to 50/50 weight split which has to help keep the car stable at speed,and maybe we have to accept that the beetle shape we all love may become "ugly" to make it safer with aerodynamic additions but they sure look ugly all scratched up after its gone wrong Sad

Richie

To add to your point, look at the 6 second Latam To#€ta Starlet as a example of a really fast, short wheel based car.

Yes another good example of it can be done Smiley
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richie
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« Reply #8 on: July 16, 2012, 11:07:18 am »

Don't know if I count as being an experienced driver any more, but I have put in my fair share of passes over the years in both tube chassis and pan cars, some good, some bad, some plain dangerous.

I know very few people will want to agree but a lot of accidents I've witnessed over the years have been ultimately down to driver error. You have to accept that a SWB car like a Beetle, with the shape it is, is not the most obvious vehicle to build an all-out race car. But as long as you accept the limitations, then fine. The important thing – as Richie demonstrated – is to read your car: don't be a hero, and don't fight it. Many accidents are caused by over-correction or simply holding onto the wheel too tight. Most cars want to move around a little – OK, let them. I usually hold the wheel fairly lightly in one hand, occasionally two, and allow the steering wheel to move as it wishes. If the alignment is correct and there's plenty of caster built in, a car will want to run straight. It's when you feel it move and try to prevent it that things get ugly.

There are situations when external forces come into play, of course: track condition, cross-winds etc, but part of being a good driver is making yourself aware of the situation before you make a pass. If you don't trust a lane, if at all possible, don't run in it. There's nothing worse than staging with the thought in mind that you might crash. Chances are you will because you won't be thinking logically (or 'safely'), and will tend to fight the car.

If the car is properly aligned, there is no binding in the suspension, the corner weights are equal side for side (how many VW racers corner-weight their cars – with a tank of fuel and a the fully-suited driver in place?), tyre pressures are equal – and the circumference of each rear tyre is the same (yes, they do vary...), then you should be OK.

Car prep and driver prep – get them right and you have a fighting chance of making it the finish line in one piece.

OK, I'll go back to the retirement home now... Smiley

I think you have enough passes to qualify or out qualify most of us Wink

it takes a long time to get the mentality of "what if" out of your head after stuff goes wrong.

I bought some scales as I was so aware of what simple changes made to the corner weights,expensive but so is towing a car half way across europe to make a few sh3t passes as the set up is wrong,scaling it  with me in it,then remembering to put my race suit and crash helmet on made a worrying amount of difference.

Also you need to keep checking the corner weights,it will change even after 1 race,wth the work it does towing etc

richie
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Fastbrit
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« Reply #9 on: July 16, 2012, 11:18:11 am »


Also you need to keep checking the corner weights,it will change even after 1 race,wth the work it does towing etc

richie

That is a very good point and one which few people think about. It's especially valid if your car is a chassis car on coils all round. When your car is on a trailer, or in a transporter, you should tie it down with blocks/struts to stop any suspension movement. Otherwise, on a long tow, your car's suspension is doing the equivalent of hundreds of passes, causing springs to soften, rates to change...

I agree – it's no good doing your chassis set-up at the beginning of the season and expecting it to last...
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Berger
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« Reply #10 on: July 16, 2012, 11:29:13 am »

Richie, counting incidents it may not look to bad, but in percent of how many potential 8-sec cars there is in our vw community, it does not look good..
I think you have a very interesting point about the transmission. Keeping the torque from the engine to the wheels as equal as possible all the way, helps to keep the car stable.

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bang
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« Reply #11 on: July 16, 2012, 11:43:37 am »

why not make the scc lules so the limit is 9,00 sec in that way we can run a real final sunday and more racers have the chance to win.. and maby 10,00 for na and 11,00 for na street tyres.. that way it comes up to the driver.


just my 2..
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richie
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« Reply #12 on: July 16, 2012, 12:29:00 pm »

why not make the scc lules so the limit is 9,00 sec in that way we can run a real final sunday and more racers have the chance to win.. and maby 10,00 for na and 11,00 for na street tyres.. that way it comes up to the driver.


just my 2..

I am not sure I understand the logic,this really doesnt have anything to do with the topic does it?confused?

And maybe I am wrong in my conclusion before,but cars dont crash in 4th gear on a perfect pass,they crash becasue of somthing that already happened,which will still happen running 9.0 with the brakes hard on at 1000ft so as not to go to fast,which is way more dangerous than running it flat out

and didnt Johan win last year running 9.0???





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Berger
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« Reply #13 on: July 16, 2012, 12:38:23 pm »

why not make the scc lules so the limit is 9,00 sec in that way we can run a real final sunday and more racers have the chance to win.. and maby 10,00 for na and 11,00 for na street tyres.. that way it comes up to the driver.


just my 2..

I am not sure I understand the logic,this really doesnt have anything to do with the topic does it?confused?

And maybe I am wrong in my conclusion before,but cars dont crash in 4th gear on a perfect pass,they crash becasue of somthing that already happened,which will still happen running 9.0 with the brakes hard on at 1000ft so as not to go to fast,which is way more dangerous than running it flat out

and didnt Johan win last year running 9.0???



Your are right Richie, and what we want, really, is to make the beetle go as fast as we want, without risking the car. That is the goal with this thread (and SCC is the arena to make it happen Wink )
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Jyrki
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« Reply #14 on: July 16, 2012, 13:49:29 pm »

Look at a airplane wing, curved on top and flat underneath. Any similarities with the shape of a beetle? Then listen to the guys with height sensors on their cars and they will tell you that their car is higher at high speed compared to when it stands still and this goes for both the front and the rear. Then I take it for granted that you somewhere on the strip need to either let of the throttle and perhaps even touch the brakes. This will of course also effect the handling. I also find it really interesting that the serious racers have started to add weight at the right places on their cars making them more stable. Not to forget the short wheel base on our cars and the fact that driving a beetle is like trying to throw a hammer and asking it to fly with the handle first.

BB

I had front ride height sensor in my '65 street car. 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. That car has a rear wing, but not any (ugly) front spoilers.

The '65 was horrible the first year with decent power due to a raised gearbox and spring plates at wrong angle. With a raised rear frame it was still unstable at speed; no sudden moves, but felt a little loose and scary all the time. It got a lot better when the bump-steer was corrected (never toe-out, but lots of toe-in in certain situations). Later with the ladder bar rear setup it was really easy to drive and felt safe, but let's put this into perspective; it only ran mid 9s at 230km/h, and running mid 8s or quicker at 250-280km/h is a different game.

For the new car I have tried to do as much as possible to make it safe; lots of weight in front,  clutchless shifting (Finnish dog-ring gears available from Jussi / Kuplapaja + ignition cut) etc, but still no aero mods...

Jyrki

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Fasterbrit
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« Reply #15 on: July 16, 2012, 14:06:48 pm »

One thing I can certainly vouch for from my experience was the fitting of a wing - it made a night and day difference to my car. Before the wing the Oval was so unstable at speeds above 130 mph that it made me not want to drive the car above 125 mph; it was just too dangerous - the back end became so unstable and the car started to 'steer from the rear'.

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. However, I can report that in my case it made all the difference as the car's top speed increased (upping the boost) to over 146 mph and I literally could drive through the top end with one hand on the wheel and not use the chute. That was without any other changes. My rule has always been to make only one change at a time and try it out. That way I always know when a particular mod works. I remember speaking to Fastbrit on this subject a few years back and he confirmed positive results from running a wing on 'No Mercy'. Defo worth a try Wink

Aerodynamics obviously play a great part on VWs, along with the arrow head weight theory etc. so don't rule out trying a wing asomen of your options. A good design such as BigWig's (I based my design on his, but added much taller spill plates into the design) should be considered as part of a 'getting it straight' programme.  Other mods I made include paneling the framehead area under the front axle. That's one huge air trap, which needs consideration and addressing. The flat panel I made runs from the front wings to beneath the axle beam and has cutouts for the front wheel arcs etc. The fake 'crotch coolers' I made for the car allow any pressurised air to escape. Slow mo video shows my car's nose fairly level at the top end, which is good.
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« Reply #16 on: July 16, 2012, 14:16:20 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?

In general when I read about chassis design I see a lot of focus points in a normal V8 race car that you never read about in the VW world.
What I get from that is that our game is different from theirs... but topics like this makes me wonder, does anyone have our "game" figured out?
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richie
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« Reply #17 on: July 16, 2012, 14:17:05 pm »

I have just read that John Troxell crashed his new out Pro/mod - Outlaw/turbo car yesterday at irwindale Drag day,I dont know anything else about what happened,he is ok,the car is not and it was only a 1/8 mile track,no big mph involved so it still happens.

I like Jyrkis idea with the clutchless shifting which should really help keep the car straight if it is already going that way and have sensors to fit to my car,I am in the process of making some major changes to the car and will include the fitting of the sensors while i am making the changes.

Matt why do you think your car was so nervous for want of a better word at only 125-130mph before? I dont doubt the wing made it feel safer but I would want to know what caused it before when so many other bugs have gone 125+mph without those problems
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« Reply #18 on: July 16, 2012, 14:31:28 pm »

 I don't think the beetle is the problem , but a combination of compromises people make to go fast.  Richie has alot more experiance than I do so I hope he chimes in here . I have run 66% rear weight on my tube chassis N/A Ghia and felt pretty good on the top end at about 120 mph, but my turbo pan car at the same weight bias would drift sideways in third.   My point is this, every car is differant and requires differant combinations of shocks, limiter straps , weight bias, ect...  to handle and be safe. The type of rear suspension and the weight of the cars are two critical factors I see in top end crashes. Swing axle cars that are improperly setup roll easier than IRS, light cars are more twitchy than heavier ones especially in cross winds on top end. Richie have you ever taken the time to write an article on how to set up a chassis properly for safety and performance ?  Mike McCarthy
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« Reply #19 on: July 16, 2012, 14:36:11 pm »

Good question Richie, and one which I can't further answer as the wing was the cure and therefore I no longer needed to address the issue.

I guess one possible explanation is that my car has lot of weight in the rear, so was probably more sensitive than lighter cars. The Wasserboxer is a lumpy unit!
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« Reply #20 on: July 16, 2012, 15:00:30 pm »

Good question Richie, and one which I can't further answer as the wing was the cure and therefore I no longer needed to address the issue.

I guess one possible explanation is that my car has lot of weight in the rear, so was probably more sensitive than lighter cars. The Wasserboxer is a lumpy unit!


I did wonder about the extra rear weight,do you know what the corner weights are? I still have mine here somewhere from being weighed at Shakey at its last meeting in the UK,would be interesting to compare


cheers richie

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« Reply #21 on: July 16, 2012, 15:13:47 pm »

I don't think the beetle is the problem , but a combination of compromises people make to go fast.  Richie has alot more experiance than I do so I hope he chimes in here . I have run 66% rear weight on my tube chassis N/A Ghia and felt pretty good on the top end at about 120 mph, but my turbo pan car at the same weight bias would drift sideways in third.   My point is this, every car is differant and requires differant combinations of shocks, limiter straps , weight bias, ect...  to handle and be safe. The type of rear suspension and the weight of the cars are two critical factors I see in top end crashes. Swing axle cars that are improperly setup roll easier than IRS, light cars are more twitchy than heavier ones especially in cross winds on top end. Richie have you ever taken the time to write an article on how to set up a chassis properly for safety and performance ?  Mike McCarthy


Mike I totally agree on most of this,we are stupid enough to make the huge compromise of ignoring most of the infomation available and putting the engine in the wrong end Wink and the more weight the more controlled it seemed to be,proberly right up to the limit and then it is proberly worse as that extra weight makes what happens more violent.

 
I really dont know a great deal about swingaxle set ups,a mid 11s pan car I am fine with after that I would be getting the cutter & welder out and making it IRS Smiley


On my own cars I found the pan car stable and predictable and the chassis car nervous and dangerous,but and this is a big but,I have well over 1000 passes in the pan car and only a few dozen in the chassis car,[for reference they are less than 10lbs difference in weight]
even though I know they are very diferent cars to me  there is something very wrong with the chassis car and I am now changing alot of the "must have" items after they seemed to not be what I was sold,only time will tell
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« Reply #22 on: July 16, 2012, 15:14:18 pm »

On of the problems with the bug design is that there are no truly flat places on the side of the body -- basicially like a turtle shell on wheels -- and when it starts to get out of shape there is no flat side to 'push' it back where it belongs -- a lot of the ProMod guys are going to the notch body for this very reason -- it is also why the Box design for the rear spoiler came into being, it gave something flat for the wind to push against when things get out of hand. And I've always thought that the "rule" that the  spoiler could not be above the rear window really limited it effectiveness.

as far as weight and balance.... When I was playing with my 600, getting it up to speed (130-135 mph) and making it to handle on the road courses, the addition of 60 pounds to the front end made a HUGE difference to stability and handling.

Now, in my latest endevor of going out and playing on the salt, I've talked to everyone that will stand still for a few seconds and they all say that while a wing on the back helps the air leave the car at high speeds and gives  down force to the car at speed, it is the side panels the really gives the car stability at high speed and a lot of thought needs to be given into how they are designed and where they are placed on the car so that they can be effective.
« Last Edit: July 16, 2012, 15:25:27 pm by Fiatdude » Logged

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« Reply #23 on: July 16, 2012, 15:21:44 pm »

I have never driven a bug at high speed but my notch is very stable. I have added 30 kg in the front compared to when i started out. Mostly fo better starts. From what i have read  the notch was the first car that Vw took to the windtunnel and it has a very low CW  i think it is 32, correct me if i am wrong. But this thread is not about T3s, sorry.
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Martin
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« Reply #24 on: July 16, 2012, 17:29:49 pm »


a lot of points have been spoken about in the "wings and aerofoils" thread started by Richie, it makes for interesting reading.

I can only speak from personal experiance, my car is a "back halfed car" and not a chassis car

I learned a lot from the chassis data logging and have had a few scary moments., and when you look into the data for the Scary moments you can see the rear shocks were extending at a greater rate than the fronts.

the single best thing i have fitted to my car is the front air dam, to stop as much air going under the car as posible. the car feels planted and also provided better steering input.

Ive got a rear Keno wing to fit to my car to guide the air over the roof, Im going to try a few runs without it first, log the chassis data then a few runs with it. to see if i can come up with a difinative results


the only proper results are going to be found in a wind tunnel, quite a few bad handeling v8 cars have made the visit to the tunnel and all have come out all better than before.



I'll share any findings with you guys.

To be fair if you take to any Chassis constructors in England they just shake there head and say were crazy for even contimplate going that fast in a beetle ! lol



Martin
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« Reply #25 on: July 16, 2012, 17:32:12 pm »

This is a good and important topic,the cars are getting more and more horsepower and its becoming a problem handling it safe.

I think a huge problem is the design of the rear suspension and ladderbars/springplates IRS or swing,i do belive they are flexing to much.
This a is a huge problem for big hp (700-1000)BMWs and Supras who also run IRS suspension,they are always all over the track.
You dont see the same problem with fourlink and 9" rearend no matter what body they are using.

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

just my 2 cents on the topic

//Patte
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richie
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« Reply #26 on: July 16, 2012, 17:38:02 pm »

I have never driven a bug at high speed but my notch is very stable. I have added 30 kg in the front compared to when i started out. Mostly fo better starts. From what i have read  the notch was the first car that Vw took to the windtunnel and it has a very low CW  i think it is 32, correct me if i am wrong.



I have wondered about the type 3 and the ghia front shape,it is no doubt better than a beetle design,but the front curve under the bumper area must still create soem lift at speed and would be more difficult[ugly] than a beetle to shut that area off to stop the air going underneath,any thoughts?





 But this thread is not about T3s, sorry.


You dont get out of it that easily Cheesy  you still have a lawn dart the same as the rest of us Grin so your input is just as valuable as the bug owners Kiss Smiley and its a strut car Wink

cheers richie
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dragvw2180
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« Reply #27 on: July 16, 2012, 17:46:27 pm »

   I like the swingaxle setup but again I am only racing 1/8th mile and feel comfortable that the car is safe( 8.50 Cert) . Limiting rebound I think is one of the things people overlook, tires tuck in and she rolls over on decelleration, have seen it too many times.  I have limiter straps that stop the axle drop to 1/2 inch before my shocks stop traveling. I never thought about the flat surface , maybe my running boards are helping me, they are wide and high.

     I have been looking at these posts, you guys have some fast cars .  Mike McCarthy
Richie, my Ghia had so much downforce that the top center of the glass tilt front end would cave in on 1/4 mile passes .
« Last Edit: July 16, 2012, 17:58:03 pm by dragvw2180 » Logged
nicolas
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« Reply #28 on: July 16, 2012, 19:40:21 pm »

i am not an expert at all, but i do want to make a comment on the air that gets underneath the car. i think a lot of air can pass underneath and that is a problem, but not the biggest issue. i think the bigger issue is air getting trapped at the rear (in the engine compartment, or behind the valance). but is this is true this would certainly affect the type3 as it has a huge air trap at the back, but it is also very heavy compared to a type 1 body (stock). if i look at Roger Crawfords ghia it has the rear lights that act as air outlets and i think this is a good idea, the wing will help put the car down, but then you get in a situation where two forces act against each other and hopefully cancel each other out. if the  downforce fails or is not sufficient enough (when you shift, unload, accelerate, catch wind, bump,...) things get out of shape at the back.

as a sad note, there was a notch that crashed at SCC a few years back at the topend as well...
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Fasterbrit
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« Reply #29 on: July 16, 2012, 21:27:42 pm »

Good question Richie, and one which I can't further answer as the wing was the cure and therefore I no longer needed to address the issue.

I guess one possible explanation is that my car has lot of weight in the rear, so was probably more sensitive than lighter cars. The Wasserboxer is a lumpy unit!


I did wonder about the extra rear weight,do you know what the corner weights are? I still have mine here somewhere from being weighed at Shakey at its last meeting in the UK,would be interesting to compare


cheers richie



I don't have the corner weight info to hand, but the car weighs 255kg up front and 482kg at the rear. It's got a fat ass! Smiley
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