Sam's build thread

[sambb]

Fitted this Mk5 Golf GTI steering wheel. To do so you just have to remove the DSG mini paddles on the back of the wheel (or you can leave them on there if you're into fooling people), the front button cluster (mine were broken anyway when this wheels airbag had gone off and then do a little trick to get the Polo thumb panels to fit in their place. It slides straight on and our airbag is a direct fit back into the centre. When I'm pushing it I generally drive with hands at 9 and 3 oclock and the difference in feel is amazing. It also has the squared off bottom which looks alright I suppose. Pretty happy for 90 bucks. Selling a standard Polo Gti wheel now!

[sambb]

A proper few hours work and all the suspension and steering is out of the car. Once I finish on the dash/interior then the doors will come off, Ill have to beat out the rear hatch and salvage a few bits off that and then she'll be gone.

[sambb]

I decided that while all the car stripping/organising of parts is going on I needed to have something going on in the background to get excited about, so I dropped my spare rear beam off at the engineer that I'd been in touch with lately. He's going to weld in a plate that boxes in the rear beam from end to end. Being a spare I'm prepared to take a bit of a risk with it which is why we're going to box the whole width initially. It won't be fully seam welded the whole length top and bottom just yet - basically if I drive it and its too stiff I can take it out again and get the plate hole sawed or sections removed from the plate. If its too soft then we can continue towards full seam weld.

[sambb]

I went through all the front end bits that will be going into the new car just to give everything the once over. The Audi TT ball joints were aok and still rock solid from when I'd done that mod nearly a year ago. The 'eddy sleeves' although nearly an interference fit were still nice and mobile inside the routed subframe bolt holes and were like the day they went in. I repacked all the superpro offset LCA bushes and FARB bushes too.
I also had a good look at where the dogbone bolts into the crossmember. My superpro insert was actually spinning over time and there were still some good thunk sounds from the front end that I'd put down to dogbone slop at the crossmember end. I know Eddy had found some slop here and it was pretty bad. The OEM bolt has an 8mm thread but nearly an 11mm shoulder that feeds through nearly a 13mm hole. This means that the dogbone can basically lever the dogbone bolt back and forth pivoting it at its threaded end. I considered drilling and taping the crossmember out to 10mm and just going to a bigger bolt, but in the end decided to retain the OEM bolt as it had a snug fit inside the superpro dogbone bushes sleeve. What I did was take a thick enough washer that could be welded and drilled/reamed it to exactly the bolts diameter and then got it welded to the crossmember. Now the OE dogbone bolt has zero slop and it can't be levered as the motor thrashes back and forth on every gear change. Now it'll only be the bush that flexes so hopefully it all feels super tight when its back on the road.

here's the back story on the modified wishbones/audi TT ball joints: DIY adjustable camber ball joints mod

[sambb]

8 hour day on the car today. It basically has an entirely refurbed front end out of the old car including:
- Bilstein B8's with Weitec 28 N/mm 20mm drop springs
- Whiteline 22mm 2 way adjustable bar
- whiteline adjustable drop links
- modified sub frames with eccentric adjusters and superpro offset rear LCA's (castor position)
- crossmember modified at the dogbone locating bolt
- superpro'd dogbone
- modified wishbones with Audi TT ball joints for roll centre correction and adjustable camber/caster, and modified superpro front LCA's
- new tie rods and tie rod ends

The only original things that stayed in there was the hubs and the steering rack. Otherwise its all redone. Buggered and don't want to think about it anymore but tomorrow am going to have to do a tape measure toe adjustment that'll last until I can get a proper alignment.

[guile]

some great work and engineering going on here mate, well done and keep it up...

[sambb]

Thanks mate. Appreciate it. The car was tight as a drum today on the way to work. It has a lot of castor now. The wheels are visibly forward in the guards and as you start to wind on lock, it produces a tonne of negative camber. I think i'll back the static negative camber off from 2/1/4 degrees to 1.5 degrees. The control arm pivots are dead level now too with the ride height change and different ball joints fitted and the difference is enormous to drive.
Happy that's out of the way and I can spend a night shift at work without having any foreign orders to do and can catch up on indy 500 qualy.

[sambb]

Did a bit of measuring of the deflection of the rear beam in the car, with and without the RARB connected.
I set the rear of the car up on stands with the rear beam at full droop. I measured the starting heights of each side of the suspension and then placed a jack under one side and started jacking it up and measuring to see what the other side did in response.
The aim was to see how much difference the RARB made to torsional stiffness of the rear beam.
First up I started jacking one side until I could just measure a change in the other. With no RARB, one side of the suspension had to move 45mm before the other started to move. With the RARB on full stiff, it moved 40mm before the other side started to lift. Basically not much in it.
I then continued to jack till the beam was nearly double that height again ie closer to it operating position. This was where there was a bit more of a measurable difference. With no RARB connected the unjacked side was lagging by 65mm but with the RARB connected by 50mm.
In conclusion what does it all mean - dunno really! It was strange to me that close to full droop there was virtually no difference between them yet the differences got bigger as the beam moved up into its operating position - something to do with the angled bushes causing a binding effect when the suspension is extended but not when its in its normal operating range? Also I thought there'd be a really pronounced difference between no RARB and with RARB but there wasn't. The difference between driving no RARB and a whiteline RARB on stiff is huge but it was max differences only in the order of 15mm between the two that were measured. I thought it would have looked more obvious than that.
The reason why I did this was to get a baseline on what numbers are produced by changes in the torsional rigidity of the rear beam. That way when I get my boxed rear beam back off the guy who's welding it, when I fit it up i'll be able to see what order of change the boxing of the beam has made to its torsional rigidity. ie if it suddenly jumps from 50mm lag to only 20mm then i'll know the front bar needs to go up a notch and that I better do my testing in the dry!

[sambb]

first vid ive seen that shows a back to back comparison of the same car (VW mk2 GTI), same corner, same speed with two different diffs - wavetrac versus quaife. Pick the wavetrac before reading the comments.

https://www.youtube.com/watch?v=E4wY2NoJ6f8

and here's another vid that shows the two main differences between quaife and wavetrac. The 'wave' camed gear that side loads the pinion when a wheel lifts and the carbon end shims that the side gears run against. In a quaife from what I can gather (and I could be wrong) apparently the side gears run against the side of the housing itself.

https://www.youtube.com/watch?v=QEhLGe_M6XU

[sambb]

Argghh found a drama with the turbo. Was giving it the once over before reinstalling it over the next couple of days and all looked fluffy until I checked the compressor side play. There's lots of lateral play in it. It was never noisy and hasn't gotten to the point where it ever touched the housing as there are no score marks but it can't go back in like that.
So now I'm in the process of getting a price from GCG in Sydney for a new core. Staying with my K03s is the main option because the exhaust housing has already been modified pretty extensively and I don't think there'd be much advantage going to a k04-001 es[pecial;ly considering that I'd then need a tune, FPR maybe injectors etc etc. Probably will all come down to price.
If anyone has a mint proper german borg warner K03s core in a drawer that they want to move, let me know!