The Z31 Project - Race Car

[PZG302]

The fibreglass itself will flex around the joints anyway and crack the bog.

 

Probably better to get a nicer finish in the tops of the targa tops, then glue in place, don't use bog and just paint the roof and tops in one hit with the rest of the car.

[260DET]

If these inserts flex then I'm in trouble, in other words if there is sufficient  flexing force in the roof to flex the inserts then ^#+%%#@* 

 

No bog in this car if you please, I'll be making the filler using vinylester resin so it will have structural capacity, the inserts were made using vinylester resin too.

[PZG302]

You might not get flex from the body moving around but you will get flex from the targa tops being separate structures to the roof no matter what you do.

 

Plus race car, only needs a 20 foot paintjob, or wrap....

[260DET]

Oh well it swill be interesting to see if it cracks or not, the whole idea has been to make the inserts part of the roof which would be best as far as structural strength goes.

[dat2kman]

Welded in steel sheet not of sufficient strength or resistant to torsional twist, for you?

An hour or so on a local Warwick steel fabricator workshop's English Wheel, you'd have them shaped quite nicely.

[260DET]

Welded in steel sheet not of sufficient strength or resistant to torsional twist, for you?

An hour or so on a local Warwick steel fabricator workshop's English Wheel, you'd have them shaped quite nicely.

 

No, the inserts I've made are lighter and much stiffer and the job will cost way less than that old fashioned way.

[260DET]

More fibreglassing, oh what joy The bonnet has been laid up but it will be left in the mould for a while, after experiencing composite bonnets that are too heavy and ones that are too flexy light I've done some experimenting using a 3mm core with light woven mat each side, vinylester resin of course. Kevlar patch reinforced for the hinges and latches. Those patches show up yellow in the pic.

 

Next the front bumper/spoiler which looks good and is nice and smooth to reduce drag but rubbish as far as generating downforce goes, probably does lift better. So what to do? None available in AU at all, nothing. After throwing ideas around, avoiding the problem and so on it's been decided to take a mould of the original and chop that up to suit. But the original is soft floppy plasitc that is partly held in shape when attached to the car. So it's been braced to hopefully hold it's complex shape correctly, particularly in regard to the attachment points and guard matching outline. Exciting pics of the bracing.

 

 

[260DET]

At the X roads with this, as the Bathurst debacle showed I need regular track time but am being held up with the roll cage while the other car, the 280ZX auto V8, is a goer but needs some suspension and aero work. Going to try to get a firm time today for the cage, wish me luck.

[260DET]

The project will continue, the idea is to get some MP sprints track time in the 280ZX and when the project is ready drop the 280ZX's powertrain into it and do some testing at MP. If it comes up to scratch and gets log booked then it will go to Bathurst in 2018.

[260DET]

Cage is supposed to be done this week, in the meantime I took on something best avoided, redesigning the whole front of the car which consists of a big lump of plastic which goes back to the bonnet front edge. The redesign is simply to improve front down force by getting rid of the bumper protrusion and extending the lower part at the front forward for a better spoiler and add on splitter. Pics are a before and after of stage one of the process, taking a mould which will modified and then used to produce the final item. There has to be a better way, fibreglassing that big lump of plastic was a awful job that has not turned out well.

 

Irrelevant sunset pic included, second pic includes the 280ZX's undertray that was smashed at Bathurst.

[260DET]

Finally the beast has been caged, pretty basic and not international spec. Nothing exceptional, a taxi bar for the seat belts and a X bar where the dash was to brace the sides of the A pillar bars. Am going to tag the cage to the body as much as possible to combine the strengths of both parts.

 

[260DET]

This is an unusual post but from posts in other topics apparently a couple of  those who prefer not to be straight forward and comment here have issues with my welding. Yep, they need to find fault. To 'reassure' them I am going to put some extra tags on the cage which was mentioned to the cage bloke. He said, look, I can see that your welds are sound but some consider only appearance so best to avoid any welding on the cage that's visible. Tack them in place and I'll finish the welding off he said.

 

Happy everybody?

[1600dave]

Whilst appearance can sometimes be an indication on the quality of a weld, I have seen "pretty" welds with no penetration and "ugly" welds that are perfectly sound.

 

Having said that, the CAMS manual does say something along the lines of "welds that look bad may be an indication of poor quality welds".

 

If you're at all unsure, grab a few offcuts, weld them up and then test / cut them up to see how much penetration you're getting. Or pay someone to do it.........

Edited December 27, 2017 by 1600dave

[C.A.R.]

This is an unusual post but from posts in other topics apparently a couple of  those who prefer not to be straight forward and comment here have issues with my welding. Yep, they need to find fault. To 'reassure' them I am going to put some extra tags on the cage which was mentioned to the cage bloke. He said, look, I can see that your welds are sound but some consider only appearance so best to avoid any welding on the cage that's visible. Tack them in place and I'll finish the welding off he said.

 

Happy everybody?

 

I am more than happy to tell you, most of your welds look shite!

[dat2kman]

Cocky Kack, is a more apt description.

But, wait,,,,, it will still be the fastest Z tractor on the hole wild wurld!

 

Surely the local Warwick TAFE offer a daytime course in creative origami welding for the Octogenerians?

 

As a CAMS Technical Machine Examiner, ( yes they used to run a course, over 3 days, very hands on, with a few crash damaged race cars, where you were final tested on how to look for non-obvious items), upon presentation of any cars that were not built correctly, the owners would be told to rectify and re-present.

Today, there is a distinct "Dont hurt their preciuos feelings, after all, we just want their money, give it a logbook, no-one inspects cars anymore" attitude.

Edited December 28, 2017 by dat2kman

[260DET]

Well that's sorted then, it's pretty obvious that my welds are not the most photogenic but penetration baby, it's all about penetration as Dave said. 

[1600dave]

At the end of the day, YOU have to be comfortable that in a big incident the cage will do its job.

 

I built mine to the letter of CAM schedule J (although I didn't use their "preferable" method of welding......). Before starting on the cage I welded up quite a few sample pieces and tested them / cut them up to make sure I was happy with my abilities. Took the sample pieces along with me at inspection time in case questions arose from my welding method (none did). Inspection guy even got his tape measure out at one point, I was within a mm or two of failing due to the roof diagonal meeting the main hoop too far in from the "bend" in the hoop (my fault, I got the fishmouth slightly wrong on the diagonal so re-cut it without thinking of the effect this would have due to shortening the diagonal a little).

 

The direct quote from the CAMS manual that may trip you up is :

 

Although good external appearance of a weld does not necessarily guarantee its quality, a weld of poor appearance may indicate that it is unsatisfactory.

[260DET]

Why only partial fill of the tank with foam???

 

I would have filled all the tank as a safety thing. Especially after I had a fairly big shunt at Oran Park where the fuel tank was ripped from the mounts, and even with a full tank of fuel foam a few litres were still sprayed over the back of the car as the filler neck was ripped from the tank. Having the foam in the tank in that crash certainly prevented a much worse incident from happening.

 

Just in case someone is interested in fuel tank foam, ran across the Jaz instructions. They say that the foam expands with fuel and to to dry fill only 75% of the tank's capacity with it.

[PZG302]

Fuel system is done at last and it's a bit different to the usual race car setup. The cell is partly filled with foam which sits on top of a silly expensive Holley fuel mat, from there fuel runs by gravity to the EFI pump and from there to the engine bay fuel filter via a new aluminium fuel line. The pump outlet is T pieced to a pressure regulator which returns excess fuel to the tank. And that's it. In the pic, fuel cell at the extreme left, pressure regulator on the extreme right with the braided return hose running along the top back to the fuel cell. Really needs a close up pic of the EFI pump and regulator too (edit: done)

 

So now the car can come off the rotisserie, yay, another mile stone.

But is the partly filled with foam tank filled at 30, 50 or 75% of the capacity? This wasn't specified in the original post.

 

With my old car the foam was in blocks that we just shoved in through the filler hole until we couldn't get more in, not neatly packed to make sure there were no voids.

[260DET]

Cage has been massaged with extra tags and bits including a interior rear vision/camera bracket. All painted inside, messy job but it's turned out OK. Big brake kit is on it's way so the next big job will be either electrics or brakes including new lines, the targa top infills can go in now too. Pretty pics just for you dear reader.

[1600dave]

Not 100% sure if it is applicable to your cage or your timeframe but thought I'd mention this so you don't get caught out - CAMS have changed a few section of Schedule J, you may need a few extra gussets if you don't get it logbooked before July. I only noticed as I'm looking at building a rollbar for my MX5 and was reading up on the rollbar requirements for open cars.

[260DET]

It better be logbooked by July otherwise much frustration and tantrum throwing.

[260DET]

More work, bugger you hot weather. Fitting the new nose and bonnet, this nose job has taken hours and hours to get to the present stage but if it's not done now it never will be. It's up to the fitting stage which firstly involves making and installng flanges where it mates with the guards so the two can be bolted together. Additional support will come later. Overall I'm pleased with the result, it certainly will help generate a lot more frontal down force. Oh and note the bonnet shut line, is this a race or show car?

 

 

[d3c0y]

Get the file out! Race cars don't have to look shit and the top running guys seem to have nice cars!

[260DET]

Yeh, the outside of the nose with be smoothed off, with glass ball and polyester resin filler, no bog. There's quite a bit more work to do on it yet.