Rf 117

[Straight 8 Racing]

RF # 117

Mission Statement:-
Build a car capable of winning in Group 2 Racing in Australia

(That may sound a bit conceited but you have to have a goal !)
(I should mention that my level of technical expertise is around 2 or 3 out of 10 )


A brief history of how this project came about may be of some interest, there again it may not, either way here it is.

After 5 years or racing-developing-racing-developing a local (Australian) Cobra we have reached the end of the development cycle. We knew where the next steps in improving the car lay but it means such enormous and radical alterations to the chassis of the car that we decided to look elsewhere for the next project.

There was always the logical and emotional progression form the Cobra to the GT40, however having stumbled into circuit racing first time around with a car that was never really designed for it we decided to try and be a little more analytical this time around. (The Cobra provided heaps of fun but also heaps of headaches ! Not to mention thousands of new ways to spend money)

The group that we race in here in Australia has an approved list of cars that are eligible for competition in sports car racing “Group 2”

A review of that list compared with the basic principles of where the major components of a race car should be, led to the choice being narrowed to Porsche, Ferrari, GT40.

Any sane man would take his money and bought a GT3 Carrera Cup Porsche, not wildly expensive, proven performance, fully developed (paid for by someone else) good resale value etc etc, no real choice for a man with a cool head.
Then your heart goes and gets in the way….. OK lets cut to the chase, we ended up ordering a car from RF. It may be worth mentioning at this point that Ross Nicol was responsible for doing the hard yards with the relevant authorities (CAMS) to get the car onto the “magic” list some years ago ( I owe you dinner next time I’m in Melbourne Ross)


The car was delivered to the workshop in Sydney in Feb last year and promptly stripped down to bare Chassis.

The rule book that we have to comply with spells out what can be done to the car and we have unashamedly worked every single angle we are allowed to. A full roll cage has been fitted and welded into the car (Once again Ross did the hard yards for the homogulation of the original cage – is that 2 dinners Ross ?) We have added a fair amount of additional bar work to the roll cage which means we have to have it re-inspected and re certified.

We have engaged the services of two race car engineers to provide advice on the suspension geometry. They come from two opposite ends of the spectrum, but interestingly their opinions and advice are strikingly similar.
A gentleman by the name of Ron Touranak who some of you may recognise as the man responsible for designing and building Jack Brabhams race cars ( They were partners in the BT company that produced the GP cars) Ron then went on to form his own engineering company manufacturing Ralt racing cars, I understand he subsequently sold out to a Mr Bernie Ecclestone.
The other end of the spectrum was provided by a young Engineer who has now left for the UK to pursue a career in F1.


The plan was to engineer the car from day one to try and avoid all the issues that I had previously encountered with the Cobra.

In no particular order we have tried to:-

1.Create the strongest, safest, stiffest chassis that is possible within the constraints of the rule book

2. Create the strongest, safest, stiffest hub assemblys to provide a stable platform for, the bearings (as big as practical) the braking system, the steering system and the suspension system.

3. Create the strongest, safest, stiffest suspension components to attach #1 to #2

4. Source the most reliable Transaxle that complies with the rule book
( Must be H pattern, not sequential)

5. Build a really strong engine with the accent on torque rather than outright power.

6. Build a braking system that can provide feed back during the development cycle then also provide telemetry once things have settled down.

7. Try, very carefully, to improve the aerodynamics of the car. This makes me very nervous as I am conscious that fiddling with the front alone may well upset the existing balance of the car.



We have unashamedly used the 2007 Carrera Cup Porsche as an” information Donor”
We have used components where practical and based engineering designs on theirs where we could not use the actual components.
I know --- shock horror--- the only defence I have is the following quote from RT

“Porsche ? ….. A design disaster covered up with brilliant engineering”

For example whilst we could not use their hubs we were able to use
spindles / rotors / top hats / callipers / rims / centre lock systems etc etc as a basis for the four corners of the car.
We basically placed the the wheels where we wanted them to live in the wheel arches dialled in the desired roll centers, scrub radius, camber, caster, toe etc etc and ran a computer generated programme to tell us where the pick up points should be located, wishbone design etc etc. All sounds too simple doesn’t it ? Well it took a year of full time effort from 2 people to sort it all out and here are some of the results.


All I can say is that I hope all this theory actually works.

[Russ Noble]

Wow Iain!!!

A "birdcage" RF! You've certainly raised the bar for spaceframe GT40's. Absolutely stunning workmanship and design. I am sure you will go a long way to achieving your goals.

What are you currently up against? Presumably as mentioned, Porsche, Ferrari, GT40. You'd have to be in with a good chance!

I shall follow your build with interest as the mechanical specification unfolds, don't keep us in too much suspense.

Cheers

[Andrew E]

Hi Iain,

Can't help but to agree with Russ, stunning! I been studying with interest the significant mods and bracing made to the chassis.

Given the noise level regarding RF suspension set ups looking forward to your future build posts to see your approach and solutions to various issues. Noticed you are running a drop floor, do you have any thoughts on air flow under the car between drop floor VS flat floor RF cars?

Truly an exciting build in progress, look forward to seeing more updates and photos Thanks Iain!

Andrew

[Ross Nicol]

Ah virginal white just the right colour for contrast when the C/V boot lets go and sprays it's black greasy contents around the engine bay. Gee you've really gone the hog on the side intrusion Iain. Anyone for a ' T ' Bone. You've put yourself under pressure now mate, after all that name dropping you will just have to perform. It's a lot further on than that now though isn't it? Will someone send Iain a Nigerian scam letter he's got far too much money. Mind you we respect people who don't take the easy route, don't we chaps. Actually Iain and I have had a few good chats and he has passed info on to me and hopefully me to him.Iain and Ross at a card game,I'll swap you some ackerman for some scrub radius and raise you double your camber. (Suspension joke) seemed topical.
Ross

[Straight 8 Racing]

Andrew, The drop floor is to help accomodate my 6'2" frame, unfortunatley the step in the floor goes the wrong way for the '"aerodynamic gurus" a flat floor is definatley better and I am advised that a step going up towards the rear is even better but I have to keep my helmet 50mm below the underside of the roll bar to keep the scrutineers happy,hence no Gurney Bubble and a dropped floor.

I think it is important to note that the standard RF suspension was never designed or itended to be suitable for race conditions, and I dont think that in road trim you should try and emulate race settings.
Ross is staring to push the envelope and as he gets quicker he will continue to uncover shortcomings in the car, I can assure you that he is not alone in this, with the exception of some of the really exotic sports cars they / we all suffer from the same issues

Iain

[Colin Artus]

'A gentleman by the name of Ron Touranak who some of you may recognise as the man responsible for designing and building Jack Brabhams race cars'

Ron Tauranac is the correct spelling surely?

[Russ Noble]

Whatever! Everybody knows who he means.

It's the engineering, not the spelling that we're interested in. There's a guy in the North Island of NZ scratchbuilding a very nice Mk1 mono whose spelling is crap, he is a member but has never posted on here for fear of comments like that! We are the losers! He has put some photos up in the gallery though.

Anyway, when Ron first penned his Ralt RT1, the comment was that Ralt stood for Ron's Absolute Last Try! Acknowledging his many years of innovative design experience. Could be that Iains RF may be his absolute last try?

Keep up the good work Iain.

Cheers,

[Straight 8 Racing]

If you think spelling his name is embarassing you better hear the whole story!
I was instructed by the workshop to drive to Bondi and pick up " an elderly, but very experienced engineer" and bring him out to look at the car. I arrive at the duly appointed hour and we proceed to the workshop, Ron is not the most talkative of individuals and does not suffer fools gladly, so the trip was filled by me prattling on about my racing experience ( a massive 5 yrs !) with him nodding occasionally. It was'nt untill after the visit that the team were kind enough to let me know who he was. Now thats what you call embarassing ! All I can say is that I hope my brain is as sharp as his at his age.

Iain

[Ross Nicol]

Great story Iain I think you've told me that one before but I had forgotten, age is doing that to me. Eric Bana introducing himself to me could almost have gone into the foot in mouth dept, but I came away thinking I'd acted quite cool. I'm a bit prone to that kind of thing though, you are not alone.

Ross

[raca]

what is that pipe for ?

[Peter D]

Iain - superb work !

I was also wondering about that big pipe, (& whether you planned any bracing struts from the roll-hoop back to the tops of the rear suspension mount towers) ?

Keep the pics rolling - its so nice to see that level of perfection.

Kind Regards,

Peter D.

[roaldin]

I was guessing air jacks.

Tim.

[StuM5]

Originally Posted by roaldin

I was guessing air jacks.

Tim.

I must clearly display my L plates here, but to my untrained eyes I can only see 1 big pipe so air jacks would be out, please point out the others I can't see... then again a trained eye would pick up a lot more than someone who has never built a GT40.

...Anyway, Iain I'm sure this will be a thread that people can't put down - just like a good book. Look forward to its progress.

cheers

[Clayton]

I would also say it’s for air jacks. The rear two appear to be where the battery and R/H hopper tank would have been.
Iain, that’s one awesome bit of kit you’ve got happening. Will follow this thread with great delight.
More pics……more pics

Clayton

[Straight 8 Racing]

The tubes are indeed for air jacks, we finally found some units that are made by Harrop Engineering (here in Australia) that give (we think) the right balance between back and front for the car to come up sort of level. They are also quite short by comparison for the amount of lift they provide (which is important especially for the front one. The car does have rear stays to the roll bar, they were not fitted at the time, We have connected them to the top of the rear cradle and the "normal" location (where the battery box normally lives) if I can find a photo I will post.

Iain

[raca]

indeed air jacks... NICE !


one more question, why is the front one positioned to one side and not centered?

[Straight 8 Racing]

Firstly it helps to balance the weight in the car, second we were running out of space in the foot well, hopefully the chassis is sufficiently stiff that it should not make any difference when the jacks are used

Pictures of the rear roll cage struts fitted but not yet painted