Sam's build thread

[sambb]

Well I just did the last round of the nsw state hillclimb championship. I did a 48.11 which was 1 second under my previous best and placed me 3rd in class. For a brief moment after run 3 I was up into second (in an upcoming vid you may see that I was a tad pumped with that run) but 4 cars later the GTS topped it and put me back into a clear 3rd.
The track was very slippery/dusty in the morning with loads of aborted runs due to roos jumping across the track. I was taking it relatively easy doing my own thing because I was trying to get a gauge on a different setup to what I normally do on this track - less front wheel offset and less front bar and the strut bars first outing too. I was confident it would make me quicker. In all honesty looking at last years time I think I should have gone quicker than I did considering the diff and soft compounds this time, but the car was down on power compared to the last one and it so hard to compare a track from a year ago with what I was on this time. The car did feel very good. I can now honestly say that the strut brace does make a massive difference. The biggest effect it had was the down hill braking area where you turn it in after nailing the brakes. It just felt like the wheels were pointed where you wanted them and it felt very consistent whereas before you'd be turning it in with the front end would wandering around under brakes. I had the front anti roll bar on soft and it almost felt the same handling wise as when I had the front bar on hard without the strut brace. I wanted to try the front bar on hard but I can't add anymore rear roll stiffness and I think it would have just created understeer, and a few cars had run wide and one went right off into a pile of timber where I went wide last year and I erred on the side of safety on that one, and didn't change the setup.
I had the fastest 20m and 1st split times of all the cars in my class but the problem is the straight going up the hill where they would make up 3 lengths on me that I just can't get back. I could have gone quicker and cracked the 47's because I ran wide at the top of the hill on my fastest run, but that's hillclimbing you just can't make one mistake, so I'll take it.

Here's the time sheet: http://entry.sdmahillclimb.com/WebDi...p?d=2017-09-10

pics and vid to come.

[sambb]

My car with the Enkei RP01's fitted. A tasty little Mk2 Golf Gti which had a 1.8T with jabbasport VF23? Subaru wrx turbo and 300+hp apparently. It was the schmickest track prepped road reg retro VW I've seen and had me salivating. A dallara with a Kawasaki 2.4L V8 rocking some serious down force and a bloody quick Mk7 golf R.

[sambb]

Picked up the rear beam out of the old car this afternoon. After much thinking the educated guess by the engineer was that a 3mm plate stitch welded across the beam should be in the ball park RE the torsional stiffness I want without going over board. The plan is for it to be stiff enough to be able run without the rear anti roll bar so saving many KG of dead weight and cut down on unsprung weight too. If its too stiff I'll take it out again and nick off a couple of welds, if its not stiff enough then I can throw the RARB back on at the softest setting as a short term measure and then next time it comes out seam weld the whole plate and try again.
What I have to do now is sort some proper bushes and also order the Eibach toe correction shims. On the first point I thought I was onto a winner when I was told that Mk4 Golf bushes would fit and that I might be able to use 034 sphericals. Well it turns out the Polo beam uses <72.5mm OD bushes so it'll probably be some slightly different poly's that Gav put me onto instead. Regarding the shims I have to go this way because whileline don't seem to make their solid wedge shims anymore - IF ANYONE HAS THE WHITELINE SHIMS ON A SHELF please let me know!

[metalhead]

We'll done mate, car looks good too. Any more news on class changes for next year? Seriously considering running the series next year, was considering the supersprint series instead but there's not really any suitable classes for me to run my car in there.

I like the stiffer torsion beam. Wouldn't the 3mm plate weigh more than the ARB though?

[sambb]

No I don't think so, the bar is pretty dam heavy. I'm not certain of it but it doesn't look like it it'll be heavier. I'll weigh everything when I do the swap over bar, beam + bar vs boxed beam. Just painting it now and when its fitted you wouldn't even know it was done because that plate faces the fuel tank.
They addressed us at the drivers briefing about the classes and it seems that hillclimbing will remain a bit of a law unto itself and retain the classes that exist now. They did say there may be a couple of re jigs to other classes, but road reg will be staying the same. Keep an eye on hillclimbnsw.com because they said they'd have next years calender up soon and were encouraging everyone to register for the series early and get the Bathurst entries in as soon as they open next year. Hope you can do it because everyone was saying they'd be running again next year so the >2.5L should be massive at Bathurst - probably 30+ cars.
If you're interested in the tarmac rallysprints goto nsscc.com for the info. All you'll need extra to what you already have is a medical kit, breakdown triangles and a summer licence for that club which is 25 bucks. Liam in the black GTS seems keen to do it so we may have 4 or 5 hillclimbers there this year from road reg.

[metalhead]

How big is your rear bar? My rear 7/16" (11mm) bar isn't very heavy at all really, but I guess 3mm plate isn't very heavy either.

Thanks, good to know about the classes, and I will have to keep an eye out for entries for next year. I'll be interested to see the calendar too.

I'd enter the series of rallysprints now if not for the drama with the car. I'm not sure when I'll get it back from being repaired - it's booked in to drop off for repairs in the first week of October - but who knows how long it will take if they need to source some additional parts. Gonna put a bit of a hole in my budget too - I'm going to pay a bit more to get the rest of the paint done so that it doesn't look like a patchwork of new and old, but that will impact my wheel/tyre/entry fee budget quite a bit.

[sambb]

My rear bar is a 20mm and runs the width of the torsion beam and then out to each lower damper mounting point. The advantage of the beam stiffening is that its located within the torsion part of the beam which has virtually a zero amount of movement in space relative to wheel movement, so for a given weight won't be affecting the unsprung mass by much. Yeah it'll be interesting when I weigh them to see where its at. I've just received these rear beam poly bushes: Polo Mk4 Type 9N - VW - Polybush (the 44AX rear beam bushes) so i'll get them in asap. The rear calipers are at European Autotech getting a kit run through them and I should have them back tomorrow.
Sorry to hear the car is dragging on a bit. Just keep aiming for Bathurst cos I definitely want to hear it roaring up the hill.

[sambb]

"I will have to keep an eye out for entries for next year"


An inspirational pic for you as you try to get your car sorted- the view from the start line of the mountain straight hillclimb. You'll be sitting there waiting for the light to go green thinking 'I can't believe I am about to do this'. Seriously if you have any struggles getting your car sorted or if you want to overnight it in Sydney (we are half an hour off the freeway) before doing the rest of the leg to Bathurst or need to hijack Pete's trailer, don't hesitate to ask.

[metalhead]

You run a 20mm rear bar, and needed more? Bloody hell! Does it have really long arms (not much leverage) or do I really need to rethink my ideas on swaybar size...? My cars a lot heavier than yours too, though centre of gravity is probably quite a bit better. How much bar do you have up front? I've got a 1 1/8" (~28.6mm) up front.

I plan pretty firmly to run the whole series next year, and am definitely keen for Bathurst.

[sambb]

Its actually adjustable and on its stiffest is equivalent to 21mm. Yeah the arms are long relative to the width of the bar and generate a bit of leverage. Our rear beam is a torsion beam so the bar is only there to add torsion to an existing torsion beam - it doesn't tie each wheel to the other via the chassis, so any bar has to be pretty big to do anything at all. The beam in the Polo is pretty soggy. Pete's Clio (which has a torsion beam rear end too) can be parked on his driveway with just a bit of fall in it and his inside rear will be sitting in the air and will have hardly any droop. In contrast my car needs to be literally thrown up turn one at Ringwood and the inside rear will be drooping 50mm and the tyre will only just be leaving the ground so on my car I think you need to add quite a bit of stiffness for what we do. I have square spring rates. The wheel rate on the back end would be a bit below 1:1 though so the car is front biased, but relative to the weight it carries the rear is much much stiffer. My front bar is a 22mm whitleline adjustable too. I generally run that on soft for the best handling so the hope is that I can stiffen the rear to the point where I can go up a notch at the front and be stiffer all round in roll but keep the same balance.
Good news re the series. We'll be there.