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Post by scotty 911w on Dec 28, 2010 11:36:53 GMT 12
if youve seen the pics you would of noticed the amount the left rear wheel has moved forward.now ive read the books(well truth be told skimm read)can someone explain it in laymans terms? now if his setup is right hes got alot of "left side bite" and hes got it" up on the bars",but if the left rear is that much forward wouldnt the rear be trying to steer to the outside of the track,? is this a loose set up??? im just amazed at the amout of movement in that left rear  oh wellllllllll guess i better get back in the shed  scotty |
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Post by ajgullery on Dec 28, 2010 12:44:50 GMT 12
Can't tell ya a darn thing about the set up or how it works...other than, 99% of the cars I see running here in the states run that set up.
The whole driving style here is way different than in NZ.
To me, an uneducated couch racer, it appears that here they more use the rear steer to turn the car into the corners under power, verses, the throw it sideways into the corners like the NZ supers.
A lot of cornering up high, riding the cushion.
I know watching Richards, when he was out here running the Summer Nats a few years back, he was trying to drive the latemodel like we do back home, and the set up in it just didn't seem to work for a NZ driving style.
So in essence I doubt I answered a darn thing about how it works or why, but it sure does create a different driving style.
Looks cool as hell too, when that weel moves fwd and jacks the ass end up as the power comes down and it hooks up.
AJ
Illinois, USA.
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Post by Deleted on Dec 28, 2010 13:47:16 GMT 12
I'm not exactly sure how it works.
(I’m not even sure they really know why it works aye, The “theory” is rather vague in the books and internet. I reckon they found it works and things that effect but don’t really understand the full mechanics of it. Ie you don’t see proof of loading diagrams and tyre behaviour in books. They have heaps on elementary static geometry but nothing more.)
A big part of the rear steer is so the car gets turned in easier without the need to chuck the rear in. They don't like doing this as this causes the loss of traction. On 1/2 mile tracks slick tracks this will be a big issue I guess.
The second part is what they call the thrust direction. They assume the car will be sideways. Therefore having the diff steer at mid corner they are driving the car forward even thou the car is sideways. If you have the steering corrected you’re not really turning either are you; the wheels are going straight, but the body is on an angle in relation. Possibly it does let them drive straighter to the track surface and the sideways body is just an illusion to what is really happening.
You might have noticed last night how straight it ran off the corners compared to our saloons.
Further just form my observation because they bring the LR forward and under they must be increasing the LR loading so much. Additionally maybe because the diff steer side bite is increased by having a straighter relative direction between the tire edge and the track direction.
Just remember too, if he was the national USA champion. I pretty sure he is a much better driver than what we have here.
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Post by strx7 on Dec 28, 2010 14:00:28 GMT 12
You might have noticed last night how straight it ran off the corners compared to our saloons. that is because they run very little or no stagger which means the car is more stable in a straight line and can put the power down more effectively because of it. the interesting thing is, they have coil rear suspension not torsion. |
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Post by Deleted on Dec 28, 2010 14:10:16 GMT 12
yeah but he was running straight from mid corner, not following the arc the full way around the corner, then trying to straighten up.
+
Emmerson runs little stagger.
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Post by chris13w on Dec 28, 2010 15:46:58 GMT 12
You might have noticed last night how straight it ran off the corners compared to our saloons. that is because they run very little or no stagger which means the car is more stable in a straight line and can put the power down more effectively because of it. the interesting thing is, they have coil rear suspension not torsion. That's right, they use very little stagger - look at one of the Late Models at Baypark and they will have something like a 92" right rear - which is 12" less than a Super Saloon would use. So, they run a lot more cross weight and are much quicker in a straight line, the extreme rear steer is to turn the car through the corners, rather than having it all sideways and in a drift. Looks ugly but makes sense - a car going sideways isn't going forwards, after all. And of course they use coil overs, they're racing cars, not antique Sprint Cars!!!! "Dirt Late Model Chassis Technology" by Joe Garrison & Steve Smith tells you all about how it works. |
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Post by mod46c on Dec 28, 2010 19:51:41 GMT 12
And of course they use coil overs, they're racing cars, not antique Sprint Cars!!!! Last time I looked F1 used torsion bars. |
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Post by strx7 on Dec 28, 2010 20:04:17 GMT 12
Last time I looked F1 used torsion bars. pretty sure f1 cars run inboard coils over shocks. |
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Post by chris13w on Dec 28, 2010 21:09:26 GMT 12
Nope, F1 cars do use torsion bars... they're JUST like the big assed mother sprintcar bars... Gambler make them for Red Bull and Mclaren... you see them sticking out the side of the cars... NOT!
Slightly different kettle of fish of course, as F1 cars only use them for packaging reasons, and the spring deflection on an F1 car is measured in fractions of a millimeter, so you don't exactly see them running 9" stroke rear shocks like a dirt track car does.
Anyway, everyone in NZ Speedway tends to look to the USA for their parts and technology, so its surprising torsions are so popular, as the only US cars that run them are open wheelers - and I'm pretty sure that's because its in their rules - and innovation just isn't encouraged in Sprintcars. (Plus there is the spring base issue which makes a difference on a Sprint car more so than a big sedan type car).
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Post by strx7 on Dec 28, 2010 21:24:41 GMT 12
innovation just isn't encouraged in Sprintcars. innovation doesn't appear to be encouraged in dirt track racing fullstop. probably why its still on a dirt track, while everything else has progressed to a seal circut. |
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Post by scotty 911w on Dec 28, 2010 21:42:59 GMT 12
innovation just isn't encouraged in Sprintcars. innovation doesn't appear to be encouraged in dirt track racing fullstop. probably why its still on a dirt track, while everything else has progressed to a seal circut. pretty sure rally is mostly still done on loose surfaces,anyone can drive on tarmac,now i think it takes a wee bit of skill to keep several cars on a small patch of dirt out of trouble. ;D ;D thanks for all the answers guys,think ill go cut the rear out of my car and put some coils in  |
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Post by wayne on Dec 28, 2010 22:53:31 GMT 12
,anyone can drive on tarmac,now i think it takes a wee bit of skill to keep several cars on a small patch of dirt out of trouble. ;D ;D lol!!!!!!!!!!!!!!!!!!!!!! |
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Post by chris13w on Dec 28, 2010 22:57:31 GMT 12
But for the last 30 years (since the end of the mighty RS2000 BDA Escorts!) Rallying has pretty much been the domain of 4WD turbo charged "Evo's" of one make or another...
And I'm pretty sure that would be the fastest way around a quarter mile dirt oval as well.... but then you find that Speedway people aren't big fans of high technology rice burners... so our rules say no 4WD - and no active 4 wheel steer either (which is kind of what a Late Model has a low tech version of, ironically enough)!
So - I bet if the rules weren't as they were, the fastest "Super Saloon's" would be EVO X's, WRX STI's, and Godzilla's.
I remember Joe McAndrew running his Subaru rally car against a Super Saloon at Te Marua back in the 90's, and it gave it a good run for its money, so strip all the glass and extra weight out and it would have been a winner.
But fair enough, who wants to see that - its not the same if it doesn't sound like a v8! ;D ;D ;D
And Scott - leave those bars right there, they will work just fine - I talk too much technical rubbish just because it interests me!
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Post by mod46c on Dec 29, 2010 7:26:18 GMT 12
Anyway, everyone in NZ Speedway tends to look to the USA for their parts and technology, so its surprising torsions are so popular, as the only US cars that run them are open wheelers - and I'm pretty sure that's because its in their rules - and innovation just isn't encouraged in Sprintcars. (Plus there is the spring base issue which makes a difference on a Sprint car more so than a big sedan type car). Coil overs have been tried several times in WoO (at least once by Sammy Swindell), torsions just work better on a winged sprintcar  . Incidentally Sammy also tried independent many years ago. |
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Post by chris13w on Dec 29, 2010 7:47:08 GMT 12
Anyway, everyone in NZ Speedway tends to look to the USA for their parts and technology, so its surprising torsions are so popular, as the only US cars that run them are open wheelers - and I'm pretty sure that's because its in their rules - and innovation just isn't encouraged in Sprintcars. (Plus there is the spring base issue which makes a difference on a Sprint car more so than a big sedan type car). Coil overs have been tried several times in WoO (at least once by Sammy Swindell), torsions just work better on a winged sprintcar . Incidentally Sammy also tried independent many years ago. Yes, I've got an old "Circle Track" magazine somewhere that had his independent front Sprinter on it (coil overs and push rods, looked nice) - but then didn't they "Outlaw" it?? But back to the point in hand, just because Sprint Cars make do with them, doesn't make them the most advanced thing to put on a Saloon... |
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Post by Deleted on Dec 29, 2010 11:11:43 GMT 12
Last time I looked F1 used torsion bars. Nope, F1 cars do use torsion bars... they're JUST like the big assed mother sprintcar bars... Gambler make them for Red Bull and Mclaren... you see them sticking out the side of the cars... NOT! Slightly different kettle of fish of course, as F1 cars only use them for packaging reasons, and the spring deflection on an F1 car is measured in fractions of a millimeter, so you don't exactly see them running 9" stroke rear shocks like a dirt track car does. Anyway, everyone in NZ Speedway tends to look to the USA for their parts and technology, so its surprising torsions are so popular, as the only US cars that run them are open wheelers - and I'm pretty sure that's because its in their rules - and innovation just isn't encouraged in Sprintcars. (Plus there is the spring base issue which makes a difference on a Sprint car more so than a big sedan type car). F1 cars use torison bars because they are a better spring! This is mechanical engeering 101. The reason for coilovers is only for ease of maintence or car design. With coil overs they do allsorts of funny deflections due to being a helical shape. A coil is basically a torison bar twisted. But this twisted form is what introduces other forces. One thing that is common for them is to produce side loading on the shock. The problem with torison bars is if not done correctly or rigid enough bearings then friction increases and the suspension reaction can be reduced. Done correctly with both types of springs, Torisons are a fare better spring. |
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Post by Zach11m on Dec 29, 2010 18:27:41 GMT 12
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Post by chris13w on Dec 29, 2010 18:35:10 GMT 12
Nope, F1 cars do use torsion bars... they're JUST like the big assed mother sprintcar bars... Gambler make them for Red Bull and Mclaren... you see them sticking out the side of the cars... NOT! Slightly different kettle of fish of course, as F1 cars only use them for packaging reasons, and the spring deflection on an F1 car is measured in fractions of a millimeter, so you don't exactly see them running 9" stroke rear shocks like a dirt track car does. Anyway, everyone in NZ Speedway tends to look to the USA for their parts and technology, so its surprising torsions are so popular, as the only US cars that run them are open wheelers - and I'm pretty sure that's because its in their rules - and innovation just isn't encouraged in Sprintcars. (Plus there is the spring base issue which makes a difference on a Sprint car more so than a big sedan type car). F1 cars use torison bars because they are a better spring! This is mechanical engeering 101. The reason for coilovers is only for ease of maintence or car design. With coil overs they do allsorts of funny deflections due to being a helical shape. A coil is basically a torison bar twisted. But this twisted form is what introduces other forces. One thing that is common for them is to produce side loading on the shock. The problem with torison bars is if not done correctly or rigid enough bearings then friction increases and the suspension reaction can be reduced. Done correctly with both types of springs, Torisons are a fare better spring. That is all true, but also marginal... And it IS mostly about packaging on an F1 car, as a bar can be fitted into a smaller space - Colin Chapman put them on the Lotus 72 (one of the best F1 cars ever) in 1970 for exactly that reason. (He made them compound as well, to save even further space - clever guy old Colin)! But he also then went back to coils on every Lotus F1 car from the 77 onwards though... And F1 today is another world compared to what we are talking about - there have been times when the tyres were the main suspension medium as the "coils" effectively were solid and just there to hold the car at the optimum aero angle, and because the rules said you had to have them! And note for instance how recent F1 wishbones often use solid mounting blades rather than rod ends - the things flex more than move, so its all now part of the springing medium. But as I said, that has no relevance to a discussion on Coils V's Torsions on a dirt car, as we're talking in the "ox cart" end of the suspension dynamics world! |
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Post by joker9377 on Dec 29, 2010 18:56:53 GMT 12
A lot of the cars over there still use a leaf as well. Pots of travel for the rear steer chassis and most have a chain to the diff to stop the whole shebang rolling over like an "OX Cart" lol
We had 3 cars (modifieds) 2 with coils for 1/4-1/2 mile tracks and 1 leaf car for the 3/8 mile bullrings. All had weird J bars and pull springs etc. Knew what they all did in what combo on what track type but didnt know HOW it all worked lol
It all depends on track, driver, attitude, testicle size on what you use/drive and how you get around the turn
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Post by Brett85p on Dec 30, 2010 10:21:57 GMT 12
I read somewhere a while back that after F1 Latemodels have the most suspension development in motorsport as they are not constrained by any rules for the rear ends. Likely a US article so would have not considered motorsport outside of the US |
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. Incidentally Sammy also tried independent many years ago.
