Sam's build thread

[metalhead]

Awesome! Wish I could've been there with you. Slightly different compared to a hillclimb isn't it! I had a far less successful day than you (believe it or not), and still had a great time and really want to go again when I get the brakes and a couple of other things sorted. I want to make it to one of the days in Feb, probably the 24th, you interested?

[sambb]

Oh man I'd love to. We'll go down again this year for sure but probably in spring. Can you do mid week days there? Yeah it's a different animal to hillclimbs. There's no pressure, it's not as intense or risky. Both are a major rush when you nail a good lap though. I definitely needed that seat time to learn the new suspension though. If I'd waited until griffons bend at panorama to work out how it turned in I'd have hit the wall! Very taily. Pete said it looked like I was in a rwd but once I got to grips with it it was insane. Still not sure about cold tyres with low pressures in the hillclimbs but I basically have a new car. We're still deciding what we'll run before Bathurst but I'll let you know either wAy.

[metalhead]

That's actually why I want to get down there again soonish myself. I'd really like some more seat time to get a better handle on how my car reacts at higher speeds, preferably before heading to Bathurst which is rather less forgiving... Yes, there is an event on Tues 13th Feb also, I could probably do that instead.

[sambb]

The car was running a F:R track of 1470:1451. That's with ET40 7in rims and 12mm spacers on the front and 20mm spacers on the rear. The rear tyres were 10mm outside of the guards but never touched, but the guards will have to be rolled for me to avoid a possible protest from a certain d**k at the hillclimbs. The front track was wider again because with 3 degrees neg camber on the front, the tuck at the top of the wheels allowed the wider spacers to fit.
Front alignment was 4mm toe out, 3 degrees neg both sides, 5/1/4 pos castor. Rear camber was a rear beam dictated 1/1/2 neg camber and 2.5mm toe in on each side so 5mm total toe in. I'd run out of time to refit eibach shims and having experienced the car with that much toe in I'd be a little nervous to go more than zero toe to be honest especially considering Bathurst. This setup worked beautifully. My A050's medium had really uniform wear and weren't chundering the sidewalls like what was happening previously, although you do deliberately run underpressure in hillclimbs to find more cold grip which wouldn't help that.
The front suspension was 7kg/mm springs, whiteline front bar on soft and rear was 8kg/mm springs with whiteline bar on medium. Even given the rear toe in I don't think I could have put the rear bar on hard unless the front went up a notch with it. It was my plan to change all this but the linkage drama took up every second of my time between sessions so I couldn't play. Even the dampers remained unchanged from the mca recommended settings which were probably more street centric too but may have been spot on for curb riding. But it was riding the curbs well and the front grip was very good so I left it alone as all the time was either in me or just getting clear track.
Again I have to say a massive thanks to Sydneykid - Gary. I was hesitant to go that stiff on the rear springs and run that much bar simultaneously without his assurance, and really wouldn't have known what front springs to spec. It was so unreal to finally drive a car that did what I wanted it to do. It was on rails when I needed it to be but a little lift or a dab of the brakes and it would move around just the way I needed - it was actually adjustable rather than me being the passenger like before. If you do end up going to Bathurst Gary there will be drinks for you.

remaining jobs on the suspension are finding front springs that have less coils. The front of the car is so high (basically stock) that the springs are preloaded to the point where the coils were coil binding before the damper was into the bump stop. I had to wind the dampers shafts up to prevent this but ate into lots of my travel to make it safe. The new springs will cure that. I'll also sort the rear toe. Shims are in the garage so just need a night in the garage to attack it - again! I'll also look at fitting the UR 4 point brace. Its not going to be possible without mods to get it to fit around the subframe Eddy sleeves on the back of it, so that'll be a bit of a fab job but worth doing I think. Oh and roll the rear guards.

Oh and the wavetrac was flawless. Despite curb jumping it seemed to stay locked. The only place I struggled for drive was the left hander after coming down the hill. I was told after that I should probably have been throwing it in there in 3rd which would have cured that but as it was, in 2nd I had to short shift up to 3rd to get a good run towards the back straight and really concentrate on feeding in the throttle progressively.

[Stuwey]

nigg

I'll also look at fitting the UR 4 point brace. Its not going to be possible without mods to get it to fit around the subframe Eddy sleeves on the back of it, so that'll be a bit of a fab job

Hi mate - great writeup, sounds like you had a blast and it's always nice when the car largely plays along - even if there's some niggling issues.

FYI, I had the UR brace and Eddy's spacers in mine - no interference.


Cheers,

[sambb]

Hey Stuwey - yeah - I couldn't picture the 1in adjusters head fitting in the socket. sweet! I'll get that fitted sooner rather than later then. thx

[sambb]

tonight I had a little look into the linkage problem. First up, when I compared the position of the sliders channels between the forge quickshift (bottom) and stock shifter, it can be seen that the slider channel extends further clockwise on the stocker. This was when the keyway in their splines were lined up.

The other difference is that the forge and also another audi shifter I have both have a bevel on the lower edge, whereas the stocker doesn't. The bevel is not at the end of the shifter that was the problem ( not where mine was jumping out) but suggests maybe that these quicksifts are tailored more for the audi fitments? The forge units channels are just that little bit shorter on the right edge too - the edge that was the problem.

The linkage on the left is off a later model box (seans that was an '08 box). On the right is the one I was running on my '06 HWY. Differences are that one is resin and one is steel. The resin one doesn't use plastic bushes on its main shaft. Its resin shaft is the bushing. Also the resin versions slider is shorter lengthways but is very stiff - it has limited range if you twist it, whereas the HWY version tilts to nearly 30 degrees and can be spun around like that and feels very sloppy in comparison. I decided to swap to the later model resin version because it was a much tighter fit into the gearbox with less play in its pivot/main shaft and because although shorter, its slider feels much stronger and the slider on the linkage I've been using/breaking has been damaged.

So here is the main source of the problem I think. On the left is the forge quickshift in 3rd gear and on the right is the stocker. Both linkages were given a fresh cable setup after instal so the only variation in where the slider is sitting is due to variation in where each shifters channels extend to. Both shifters have exactly the same channel length but the whole channel is rotated further CCW on the forge unit allowing the slider to nearly come out the back. So I'm back to the stock shifter coupled with a later model resin linkage. What i'll do this week is modify the stock shifter and turn it into a quickshift by modifying the pin position. I may be able to just drill and tap the pin that came with the forge quickshift into it 5mm further in. That way i'll get the best channel position and have a short shift again.

[sambb]

Ok so I just went down to Eibach, Sydney in Warriewood and had a chat to them regarding a change of spring spec on my fronts. My issue stems maybe from the way the first Polo that got measured up for MCA's was expected to be set up. If the car was to be run low then all is good. For the track though, with the front of the car 325+mm up (hub centre to guard lip) which gives the geometry I need - it could go higher actually - the 180mm free length springs end up being preloaded to a captive height of less than 150mm. This meant that the distance between the coils was reduced to the extent that the coils could coil bind before the damper body was even into the bump stop which = crash. To remedy that, the damper body was wound up - you can do this with MCA's, adjust the damper stroke and ride height independently - so that it would be into the stop before coil bind, but the result is that I have minimised the travel by like 30mm. Like Gary suggested I put cable ties around the damper shafts and sure enough even with street driving the cable ties were finding there way 1/2 way into the 20mm bump stops without any really memorable pot holes, so yeah the travel is too small and a good hit when its already compressed under a cornering load would be a problem. The inside wheel never felt like it bottomed out going over the kerbs at Wakefield but it does concern me for doing the esses hillclimb at Bathurst. For example when you throw the car right straight up the face of the dipper, the compression in the front would be pretty full on on both the fronts.
So I explained all this to the guy at Eibach and we crunched some numbers. He said that if I was to go to a 200mm spring rather than a 180mm spring then the spring would only need to be preloaded by 10mm to achieve the same ride height. I could then drop the damper body down by a corresponding amount which is also incidently about the width of the bump stop and get back to an ideal compression:droop ratio. The problem is though, this will put the adjustment collars right next to the tyre sidewall so i'll need to get under there and see if it'll clear. If not my options are to change to different offset street rims because I'm sure the track rims with spacers will clear, or as Gary has said to me go to a higher quality spring that achieves the same spring rate for the same free length that presently fits (150mm) but does it with fewer coils - obviously thinner coils would be needed which would need some high quality steel ($$) and I'm not sure where I could source something like that but that may be the last option.

[sambb]

actually scratch that. I just jacked the front of the car so that I could extract the cable tie tell tales from the bump stops before they get damaged and found that the left side spring (the light side of the car) is actually a few mm un-captive when the car is jacked. To my thinking that means that fitting a 200mm spring of the same rate/load would achieve nothing at least on that side. The right side is different - being heavier, it is well and truly preloaded at full droop to achieve the same ride height. Surely that means that the spring has insufficient spring load doesn't it? If it has to be really preloaded to just support the standing weight of the car at the desired ride height that is unsufficient spring load? Sure I may then need helper springs to keep it captive at full droop but I'm thinking maybe that is the answer??

[sambb]

Attachment 32394Hey Stuwey. From memory when you fitted the 4 point brace, did you have to remove these black plates that link the chassis to the subframes ie did the brace just go over the top of the plates or did you have to remove them altogether. Can you remember if the hex adjustment for the eccentrics was on the outside of the braces tube with the bolt to tighten on the inside OR was the hex adjuster AND the bolt both inside the braces tube?