Kiwi scratchbuilt

[Russ Noble]

Chris,

As far as I am aware there is no link to the tyres. I ordered my tyres last week through the Motorsport Manager for South Pacific Tyres (that's Dunlop in NZ) they are 430/1160-15 fronts and 530/1500-15 rears. They are being indented from the UK and should arrive about Christmas.They are Dunlop Post Historic series race tyres which, in NZ, are compulsory for classic racing for cars of this period, so that dictated the 15" rims, and also limits the brakes! [img]/ubbthreads/images/graemlins/frown.gif[/img] They are a bias ply, treaded (CR82 pattern), nonroadlegal race tyre. For other racing, where there are no "classic" requirements or class I will probably, later on, run either Avon or Goodyear F5000 slicks. To initially road register it, I will have to fit different wheels with road legal tyres, hopefully I can borrow Lim's (see first post). When I switch back to the CR82's I don't think the enforcement agencies will realise they're not road legal. [img]/ubbthreads/images/graemlins/wink.gif[/img] Time will tell, and if they do notice I would hope to sweettalk my way out of it initially, not that I'm planning many road miles anyway.

Whether you go for 15" or 17" will depend on your personal preference, tyre availability, looks, etc. Brake size will not be an issue as you will be able to get more than adequate calipers and rotors inside the 15" rims for road use or for serious track work if it comes to that. Remember that with a 40 having comparitively wide rear rubber and a lot of weight in the back, your rear brakes can do a lot more work than in a front engined setup and this gives the fronts a comparitively more easy time. I will be using Wilwood 300mm x 32mm discs and forged billet Superlite 4 pot calipers front and rear and I expect them to be more than up to the task for all out racing.

Hope this helps you out.

Regards

[Richard O'Clery]

Hi Russ

I think what you have achieved to date, and the way you are going about it, is exemplary! I can't wait to see some more updates.

Can I ask about your rear uprights? Are you looking to fabricate, cast, or machine from billet?

If either of the latter two, what alloy are you planning to use?

Yes, I am being entirely subversive with these questions - I am trying to decide how best to manufacture the uprights for my own project. There are pros and cons with each and I am trying find the path of least resistance!

I'm currently favouring machining from billet, because I can have my pattern 3D scanned, imported to CAD and then milled from alloy by a local shop. The CAD can mirror it so the left and right side units can have different calliper brackets for each side (ie handbrake calliper vs main calliper), and in my case, can pickup the rear suspension pushrod behind the driveshaft on either side.

For casting, you'd have to make a pattern with attention to draft angles and shrinkage, and would have to liaise with both the foundry and the machining engineers. By the time you've reached an understanding with one, the other will find something to gripe about. I am convinced there are many layers of complexity with this approach (unless you have your own foundry - I ended up blowing chunks out of my concrete path trying this; something about leaked molten aluminium instantly boiling the water bonded in the concrete matrix - and having your own machine shop. I started to make a CNC machine, but didn't finish it because my casting aluminium ended up with too much concrete in it!)

I don't have anything against fabrication except for weight if steel, accuracy due to welding induced distortion, that it may not be pretty to look at, and can be inefficient if you want to build more than a pair or two.

I'd be really keen to hear your point of view, and from anyone else who has given consideration to all this. It's one of the many things that regularly wakes me up at about 4.19am and doesn't let me get back to sleep. Maybe I'm taking it all too seriously, but lack of sleep could be clouding my judgement...

Thanks
Richard

PS The concrete literally blew 8' into the air! The sparks from the burning electrical equipment were pretty though...

[Russ Noble]

Richard, thanks for your encouraging comments.

With regard to the uprights, I am planning on fabricating from steel, which I believe done properly will be not far different in weight to alloy castings, so I don't think there will be a significant downside there. I hear what you are saying about distortion and looks, but done right neither should be too bad. The upside is that they will be much more resilient than castings, they are more likely to bend or tear than break. I would not forsee the sort of failure that Ross experienced a few months ago after being punted by some kamikaze pilot!! With steel uprights any damage from that sort of shunt should be able to be repaired trackside with a gas welder in time for the next race. Mind you if you were really serious you would carry spare corners, I suppose. [img]/ubbthreads/images/graemlins/tongue.gif[/img]

Billet uprights would be a great way to go but I don't have (low cost) access to that sort of technology. However "normal" machining and fabrication is not a problem and this often dictates the solution to a given problem.

Carroll Smith "Engineer to Win" has quite a bit of info about alloys and heat treatments which you may find useful.

[ QUOTE ]
It's one of the many things that regularly wakes me up at about 4.19am and doesn't let me get back to sleep. Maybe I'm taking it all too seriously, but lack of sleep could be clouding my judgement...

[/ QUOTE ]

Yeah, snap!! I dream up some great solutions in the dead of night but in the cold light of day they usually turn out to be either too complex or expensive or ignore some vital consideration. [img]/ubbthreads/images/graemlins/confused.gif[/img] There are two over riding principles that are always at the back of my mind KISS and KILL (Keep It Light & Low) [img]/ubbthreads/images/graemlins/cool.gif[/img] Hence, whenever I am about to use steel I always look to the possibility of substituting aluminium or plastic wherever practicable. The roll cage and 351W block are unfortunately going to contribute a significant proportion of the weight to the finished car and I can't do anything about either if I want to stay within the regs! [img]/ubbthreads/images/graemlins/frown.gif[/img]



I may get to post some body progress pics this weekend since Sunday is going to be a write off . Live Bathurst coverage here from 11am so I will be glued to the set in the hope of seeing Murph make it three in a row. Not because he's in a holden [img]/ubbthreads/images/graemlins/frown.gif[/img] , just because he's a Kiwi!! [img]/ubbthreads/images/graemlins/cool.gif[/img] Also A1GP in Europe this weekend plus F1 at Suzuka. So I can see work on the project being totally non existant!!

How far down the track are you with your T70?

Regards

[Richard O'Clery]

Hi Russ

You are totally right about the pros for fabricating steel uprights. Sleepless nights and the need to build a better mousetrap must be getting to me.

Ultimately cost will be a determining factor for me too, but I would like to go with billet and let the wishbones bend in any impact. I'll meet with the engineers in the next few weeks to discuss cost.

The T70 is my dream car, but despite my avatar it's not what I'm building. I know this all doesn't sound too logical! I'm actually building a prototype for a low volume Australian Design Rule compliant midengined V8 sports car. With luck (lots) and a bit of work (lots) I'll be able to step back and build my dream Lola a few years from now.

If I was building 1 or 2 cars, I would definitely fabricate the uprights. But if we get something going here the economies of scale and the ease of press button manufacture will be an advantage.

Huge day of motor racing and drinking with the boys tomorrow (Sunday). I can't wait! I'm a fan of Murph too, but being from Perth I am very pleased with Tander's recent form. I really enjoyed the opening A1 round, and Suzuka is usually an interesting race. Quite a good track too.

Looking forward to seeing more of your build photos

Regards
Richard

[Ross Nicol]

Russ the upright repair on my car probably highlights the fact that there must be a weak zone somewhere in the suspension and it is better to be an easily replaced and cheap (hopefully) component.If the suspension had been bent, the repairs would have been much more difficult.My concern is that you may make your uprights too strong and in the event of an incident the chassis will take the brunt of it.Just my thoughts.
I'm off to a mates place with my Projector and 8' screen to watch Bathurst all day tomorrow.If Murph or Jason Richards don't win at least Ford has a good chance.

Ross

[Russ Noble]

Ross, I agree with your theory but I would rather go with lighter Heim joints which I would expect to break upon major impact thus saving the chassis AND the upright. Hopefully then merely a matter of replacing the joints and repairing any damaged links! Just my personal viewpoint.

[Ian Anderson]

Guys

I don't know if these will be any good for your applications but the blokes at NF / Car Builder Solutions are pretty good and willing to discuss the applications.etc.

http://www.nfauto.co.uk/cbs_products_new.htm

Scroll all the way to the bottom of their new products.

Might help and save having to re invent the wheel!

Ian

[Russ Noble]

Ian,

An interesting site. The uprights are not in the configuration that I need and if they were I think the price would rule them out anyway. We're not really reinventing the wheel , it's more a case of designing something that will accomodate the bearings, brake calipers, offsets and suspension mounting points that each of us wants to use.Thanks for the link.

After building the molds we had to make some minor mods to the rear clip mold as the plug this was taken off had been shortened at the front which I didn't realise until after we had built the mold. The pic shows Ash,one of my enthusiastic helpers, extending the front of the mold. The mold for the rear clip is the most complex on the car and had to be made in eleven sections to enable the body to come out.

Regards

[Russ Noble]

The rear clip not yet released from the modified mold, photo taken after the air intakes have been glassed in to the main part of the clip. Mounting points and inner panels will be glassed in later.

[Russ Noble]

The inner and outer spider sections need to be bonded together. I used Plexus MA425 for this. It has only 30 minutes working time, it takes about that long going flat stick just to do up all the clamps!! The strong plastic butterfly clips tended to slip on the fibreglass so some W&D paper was taped on to give a bit of grip. The outer spider section is lying in it's mold and the inner is bonded up to it to ensure the correct shape.

[Russ Noble]

Does any one else make stuffups?

Here is the result of glassing up the door inner by mistake before it had had it's six coats of mold release wax!! Fortunately damage to the mold incurred in releasing this inner was able to repaired in a matter of hours. It was a worry when we were trying to release it though. Big hammers, wedges, scrapers, grinders!

[Russ Noble]

This is how it should have been. This one came easily out of the repaired mold. The flanges still have to be trimmed off from around the outside

[Chris_K]

AWESOME! Great work, please keep posting the pics.

THANKS and good luck!

[Richard O'Clery]

Russ

Thanks for the updates. GRP is simple in theory, but the administration is a whole different story! Looking forward to more pictures.

I don't think Murph was in the wrong this afternoon, but (personal feelings aside) it's probably going to be a political call.

Ian

There there is a lot of great suff sold by NF, but as Russ implies, you don't always want to start with someone's uprights and try and reverse-engineer a suspension geometry to suit, particularly if your tyre rolling diameter and/or idealised roll center (static and dynamic) doesn't match the car (P4) the upright was designed around.

Great if you are building an NF car or something with the same rolling diameter tyres, track and wheelbase (to an extent), and are happy with where they put the roll centre. But it is often actually easier to work out exactly what you want in terms camber acquisition and roll centre control, and then calculate the appropriate inboard and outboard pick-up points. Then you can fabricate (or otherwise!) an upright that suits you perfectly.

Russs, sorry if I've hijacked your thread.
What size rose joints are you using? I'm going with heavy 16mm for my lower control arms and 13mm for the UCAs, because I would prefer the wishbones to bend than than risk a rose joint shank to break and lead to something detaching, but I am open to suggestions.

Regards to all
Richard

[Russ Noble]

Richard, I think it's when the links bend that the joints break! As soon as they bend they will lose all strength and then proceed to deform rapidly, the joint then comes to the limit of it's designed angular deflection and snaps through the shank. Using small joints limits forces that can be transmitted into the pickup points as the joint breaks, hopefully saving the chassis and the upright. I will more than likely be using mainly 3/8" joints plus the odd 1/2". In Ross's case I think the hit broke the upright first because I don't think there is a lot of inherent strength in those flanged gussetted type uprights, they may be designed that way to be the weak link as Ross says. However I may be wrong. I also think with a properly designed and fabricated steel upright that you would come out of most situations like that with little or no structural damage and be able to continue. Not so of course when you bury the thing at high speed into guard rails or other solid objects!! At that stage niceties of design are a bit irrelevant.

Bathurst was an interesting race! Neither Murph nor Ambrose could afford to back out of that situation if they were to have a chance at the podium, of course they were both concentrating on the impending conclusion of "the Great Race" and not the championship points situation that they would lose by not finishing. At that stage of the race I don't think any racer worth his salt would have given way. I don't see anyone to blame for it, it's just one of those "racing incidents". The stewards may not take that view though!

Regards

[brianstewart]

You read the Bathurst incident well Russ - both drivers cleared of blame by the stewards!

[Ross Nicol]

Russ Did you note the suspension failures on the V8s.After Lowndes hit the wall and broke the watts linkage they showed the link, broken tube with rose joints intact.They also showed a front steering arm from another car and failed tube again rose joints intact.I think your right, make your uprights strong and let the wishbones/links be the sacrificial part as in most open wheelers as well.I did enjoy your description of how niceties of design go out the window if you bury it in the wall.Very well said.
Even though he's a Kiwi Murph in my mind was to blame.Ambrose had 1/2 his car in front and Murph should have baled out of it.But I sense he was angry after a pass and touch up from Ambrose a moment before, did anyone see that?Now a much better result would have been Jason Richards 1st, I love it when the underdog wins.Bloody Skaife didn't need another one.Go Webber that result will keep you in Frank's good books.Like me he needs a bit more grunt.
I've got one more race meeting this year at Sandown on Cup Day 1st November, lets hope it rains again.

Ross