Chassis stiffness...

[Fran Hall RCR]

Troy we make the seat and its carbon kevlar.

This car has only ever had one seat fitted...we did removed the headrest and add an aluminum Halo restraint

 

[Paul Osborn]

Well, that explains some of the weight difference between the street and track versions.

 

[Ben Whittle]

Wow that's....... extensive.

 

[Fran Hall RCR]

It is a fast car and keeping the drivers safe is concern number one for me....

 

[Dave]

I have cage envy.

Fran, do you still offer the interior footbox caging like Howard and I have as an option?

 

[James]

She is a strong one....now add the race cage (which has 20 points of attachment to the chassis) and you have a very safe...which is the primary goal IMHO...strong and capable chassis...

The ontrack proshop at VIR was kind enough to allow us use of their scales at the 13 hr...I am hoping to get the picture they took of the scales and the accuracy of our set up...without pictures you guys will not believe me....trust me it was awesome.

I know this is an old as heck bump,, but any word on this? (not sure if it showed up on any other thread)

 

[Fran Hall RCR]

I have asked Victor for the picture but he has been unable to find it...he owns the pro shop at VIR and is easily reachable if you want to call him and verify the situation

 

[James]

Wasn't really worried about the picture, just wondering about what the scales said.

 

[Fran Hall RCR]

They were within 1lb and total weight with all of our Endurance race equipment..
two batteries, two alternators, air jacks , heavier DOT tires etc etc and fuel was 2575lbs
In sprint trim we are much lighter obviously and far more powerful.

 

[JustinH]

Troy we make the seat and its carbon kevlar.

This car has only ever had one seat fitted...we did removed the headrest and add an aluminum Halo restraint

Do you have any pictures of the halo modifed seat and the halo restraint?

 

[Kyle]

James there is no Australian SLC with a race cage.....only the two here in the USA with race cages...so far....

The 01 car with the race cage has shown over 35,000 in FEA analysis...this is without any drivetrain components being installed...(engine plate or engine)..which would obviously increase the test figures shown.

That is a huge number, most high end sports cars go about 10,000.

With such a high number what have you built into the car to absorb some evergy in case of a hard impact? Either way that is one rigid chasis.

 

[John Ross]

With such a high number what have you built into the car to absorb some evergy in case of a hard impact?

Ask Dean Lampe...

http://www.gt40s.com/forum/slc-clubhouse/38908-388-views-no-one-asked-obvious.html

JR

 

[Fran Hall RCR]

That is the race car with a full FIA GT1 approved race cage dont forget...which has 20 points of attachment to the chassis....That said the SLC street chassis is no slouch either.
we have a crush box design for frontal impact and the design of the footbox is such that the chassis will deflect the wheel/tire package should the other mechanical fuses in the system fail.

10,000lb/deg is not very stiff for a modern sports car...which ones are you using as an example?

 

[Kyle]

10,000lb/deg is not very stiff for a modern sports car...which ones are you using as an example?

There are lots that are in your Realm but there are many competent cars that are not even over 10,000.

Here is a list I hacked from another web site, many of the numbers for the cars I am familiar with are right in the ball park. AKA the Porsche's

Several low ones, Viper, Corvette, Several lotus's.

I am not sure of the complete accuracy of this list.

(NOTE: 1000Nm/deg = 738ft*lbs/deg)

Alfa 159 - 31.400Nm/degree
Aston Martin DB9 Coupe 27,000 Nm/deg
Aston Martin DB9 Convertible
15,500 Nm/deg
Aston Martin Vanquish 28,500 Nm/deg
Audi TT Coupe 19,000 Nm/deg
Bugatti EB110 - 19,000 Nm/degree
BMW E36 Touring 10,900 Nm/deg
BMW E36 Z3 5,600 Nm/deg
BMW E46 Sedan (w/o folding seats) 18,000 Nm/deg
BMW E46 Sedan (w/folding seats) 13,000 Nm/deg
BMW E46 Wagon (w/folding seats) 14,000 Nm/deg
BMW E46 Coupe (w/folding seats) 12,500 Nm/deg
BMW E46 Convertible 10,500 Nm/deg
BMW X5 (2004) - 23,100 Nm/degree
BMW E90: 22,500 Nm/deg
BMW Z4 Coupe, 32,000Nm/degree
BMW Z4 Roadster: 14,500 Nm/deg
Bugatti Veyron - 60,000 Nm/degree
Chrysler Crossfire 20,140 Nm/deg
Chrysler Durango 6,800 Nm/deg
Chevrolet Corvette C5 9,100 Nm/deg
Dodge Viper Coupe 7,600 Nm/deg
Ferrari 360 Spider 8,500 Nm/deg
Ford GT: 27,100 Nm/deg
Ford GT40 MkI 17,000 Nm/deg
Ford Mustang 2003 16,000 Nm/deg
Ford Mustang 2005 21,000 Nm/deg
Ford Mustang Convertible (2003) 4,800 Nm/deg
Ford Mustang Convertible (2005) 9,500 Nm/deg
Jaguar X-Type Sedan 22,000 Nm/deg
Jaguar X-Type Estate 16,319 Nm/deg
Koenigsegg - 28.100 Nm/degree
Lambo Murcielago 20,000 Nm/deg
Lotus Elan 7,900 Nm/deg
Lotus Elan GRP body 8,900 Nm/deg
Lotus Elise 10,000 Nm/deg
Lotus Elise 111s 11,000 Nm/deg
Lotus Esprit SE Turbo 5,850 Nm/deg
Maserati QP - 18.000 nm/degree
McLaren F1 13,500 Nm/deg
Mercedes SL - With top down 17,000 Nm/deg, with top up 21,000 Nm/deg
Mini (2003) 24,500 Nm/deg
Pagani Zonda C12 S 26,300 Nm/deg
Pagani Zonda F - 27,000 Nm/degree
Porsche 911 Turbo (2000) 13,500 Nm/deg
Porsche 959 12,900 Nm/deg
Porsche Carrera GT - 26,000Nm/degree
Rolls-Royce Phantom - 40,500 Nm/degree
Volvo S60 20,000 Nm/deg
Audi A2: 11,900 Nm/deg
Audi A8: 25,000 Nm/deg
Audi TT: 10,000 Nm/deg (22Hz)
Golf V GTI: 25,000 Nm/deg
Chevrolet Cobalt: 28 Hz
Ferrari 360: 1,474 kgm/degree (bending: 1,032 kg/mm)
Ferrari 355: 1,024 kgm/degree (bending: 727 kg/mm)
Ferrari 430: supposedly 20% higher than 360
Renault Sport Spider: 10,000 Nm/degree
Volvo S80: 18,600 Nm/deg
Koenigsegg CC-8: 28,100 Nm/deg
Porsche 911 Turbo 996: 27,000 Nm/deg
Porsche 911 Turbo 996 Convertible: 11,600 Nm/deg
Porsche 911 Carrera Type 997: 33,000 Nm/deg
Lotus Elise S2 Exige (2004): 10,500 Nm/deg
Volkswagen Fox: 17,941 Nm/deg
VW Phaeton - 37,000 Nm/degree
VW Passat (2006) - 32,400 Nm/degree
Ferrari F50: 34,600 Nm/deg
Lambo Gallardo: 23000 Nm/deg
Mazda Rx-8: 30,000 Nm/deg
Mazda Rx-7: ~15,000 Nm/deg
Mazda RX8 - 30,000 Nm/degree
Saab 9-3 Sportcombi - 21,000 Nm/degree
Opel Astra - 12,000 Nm/degree
Land rover Freelander 2 - 28,000 Nm/degree
Lamborghini Countach 2,600 Nm/deg
Ford Focus 3d 19.600 Nm/deg
Ford Focus 5d 17.900 Nm/deg

 

[Mesa]

One of you frozen tundra guys built a V12 powered Ultima, now to be fair this was some time ago (8 years?) and maybe the chassis are better now. But, the first thing he had to say about it was that the chassis was a little on the flexy side.

 

[Kyle]

One of you frozen tundra guys built a V12 powered Ultima, now to be fair this was some time ago (8 years?) and maybe the chassis are better now. But, the first thing he had to say about it was that the chassis was a little on the flexy side.

That was a guy that was somewhat close to me, He used a BMW 12. Yeah he said the car scored <5000 on his test rig that he built himself. I would not think it is that low but even if it is you can not dispute the cars ability to get around a track and just plain handle.

 

[Jac Mac]

One of you frozen tundra guys built a V12 powered Ultima, now to be fair this was some time ago (8 years?) and maybe the chassis are better now. But, the first thing he had to say about it was that the chassis was a little on the flexy side.

That would probably be Jay E, if so he has had plenty of seat time in F5000/A & Can Am stuff to know if something was not up to par,,

 

[mark b.]

i think the long list above is probably meaningless without the supporting data of how the numbers were arrived at. since i am vested in a jbl cobra, i looked at their website and this is what was given for a very well designed open top chassis using sheer panels.

under design goals--

Produce a very stiff (minimum 24 HZ frequency) chassis with torsional numbers above 4500 lbs per degree.

 

[James]

Looks like the Ultima GTR finally stepped up their game a little bit on their chassis. They used to be at around 4474 Nm/Deg (or around there), but bumped it up 553% to 24741 NM/Deg, So just now as stiff as the street SLC (right Fran?)

New Uprated Ultima Chassis - PistonHeads

 

[Fran Hall RCR]

Well done to Ultima ....customers demands and expectations are far higher in todays market than they have ever been.
The SLC will not be needing a stiffness upgrade anytime soon