Sam's build thread

[sambb]

hhmm good thinking. righto I'll check that out. thx

[sambb]

Bad Day. Started off well - slept most of it for upcoming night shifts, opened up my box full of MCA goodies, went around to a mates house to pay him for my new Full river HC20 battery and debate how to tackle cutting off the strut top domes for fitment of the MCA's - all nice optimistic stuff. It was wet on the way home for the first time in 2 months so I thought I'd push the Toyo's a bit and see how they felt in the wet. Well the car just didn't feel right. A bit dull and not as nimble as I'd felt. I had heard a few little clangs in the back over the last week and it kind of clicked that maybe the beam welds were letting go. I drove straight into the garage when I got home and put it up on ramps and with a torch and mirror was not surprised to see that the first welds I looked at had cracks in them. The more I looked it was evident that all the welds along the bottom side had cracked while all the ones along the top were intact. I wasn't surprised based on how the handling of the car had changed but knowing how much work is needed to swap it back it was definitely one of those FARK! deflated moments that only working on/modifying cars can give you.
At the end of the day I gave it a shot. It worked brilliantly (for a brief moment in time) but ultimately proved to be turd. I now have a very noisy standard rear beam which has to come out if I want to be ready in time for the first rally sprint. So as the guinea pig on this one, don't do it unless there's something glaring that I/we missed. Obviously the forces in torsion are pretty mega, which might make me re do my rose jointed droplinks that I'd had too and go for slightly bigger ones. I'm just glad that I didn't jump the gun and sell the other beam/RARB and its all there ready to go back in once I swap the bushes over.
anyway bugger but I'll get it sorted quick enough.

[HaydEn]

Instead of the plate.

Try a 25mm or whatever really square tube inside of the beam and weld in 2 spots at each end.

This is the method most popular with all the beam equipped cars in Europe.

Sent from my Moto C using Tapatalk

[sambb]

I know Julian edgar bolted strips across the beam in 2 or 3 places, sort of like trailer axle clamps and got good results. I didn't have the clearance against the fuel tank to do that. Thinking about it now the strips would be forced to flex themselves and the clamps could move slightly. Maybe the problem with the continuous plate welded in so many spots is that all the force gets put through the weld when the plate can't flex. I know that's what the engineer was most worried about, the way torsion would try to tear at the weld along its length. No blame whatsoever though - it was all very experimental. I did it the plate way though because I didn't want it to be heavier and I wonder if the other ways wont just be as heavy as having an adjustable bar on there. I think the fall back will be what you suggested though. I've seen lots of pics of that and it might be the go. In the mean time though the old beam with bar will have to go back in and i'll see how that goes in conjunction with the MCA's. It might be that the bushes and the way they bind allow the car to pick up the inside wheel with less roll stiffness coming from torsional stiffness and it mightn't even be necessary once the bilsteins/h&R's are out. Just about to get my work gear on and stack hacking out the standard bushes out of the other beam before the kids get hungry. fun fun not.

[simon k]

when I started reading "day started off well", then "push the toyos in the wet" I was expecting "then crashed into blah blah" - the welds cracking were just the result of your experiment, that's scientific method for you - hypothesise, implement, test, revise.... still a good experiment

I didn't know that torsion beam rear suspension was a thing till I saw your modification - I'm used to the full independent setup on a mini...

[simon k]

In the case of using aluminium vs phenolic, yeah as a heatsink material aluminium works best but not in the setting of the engine bay bolted to the rocker cover where even finned aluminium would heatsoak immediately and just become a heat source maybe even worse than the standard set up. I think phenolic would act as an insulator and might not pass all the rocker covers heat onto the neck of the coil.
If I was to make a one off for myself the single piece adapter that takes in all 4 coils would be the easiest to make and I'd do it out of aluminium. But if I'm to do it out of phenolic where the cost of the material is higher, then doing the individual coil adapters would squeeze more units out of a sheet and be more $ efficient + I could buy 1 single coil adapter as a template for not much coin whereas the long quad adapters cost bigtime for what they are. Phenolic is just a different material that if anything may have some slight advantages to aluminium and no real disadvantages that I can see.
At work we have these small heatsink squares. If you were really anal you could glue them onto the tops of the coil themselves with conductive paste which would probably cool them slightly but whether that's even necessary I don't know.
At the end of the day I'll be running water injection which demands a reliable ignition system which is why I went for the R8's. anyway enough thread jacking from me. Louis seems sorted in that regard.

cross-thread-jack... what's an R8 coil? literally from an Audi R8? this one? Audi R8 Ignition Coil Pack Set (set of 4) - 06E905115F | V-tech Australia | Engineered Performance

I don't think you need to buy one of the aluminium adapters to copy, if I had a coil I could draw one up... the threads are there on the rocker cover so that bit's easy, it's just the size of the hole for the coil and the little cutouts that I assume are for locating lugs?

[sambb]

ha ha I had a mate call me saying the same thing - 'I thought you were going to say you stacked it'. Been sitting here at work debating what went wrong with a fitter/engineer. I may not even try it again, although it might be nice to have it redone (but differently!) and at least have it sitting under the house ready to go in case I ever hit anything.
Yep used in the audi R8 V8 and V10 and 2.0TFSI. From what I can gather more or less electrically the same as OE 1.8T but there's always progress in construction/materials so if I was going to replace what I had it made sense to get these. Yeah its the little cutouts which would be the tricky bit.

[simon k]

ha ha I had a mate call me saying the same thing - 'I thought you were going to say you stacked it'. Been sitting here at work debating what went wrong with a fitter/engineer. I may not even try it again, although it might be nice to have it redone (but differently!) and at least have it sitting under the house ready to go in case I ever hit anything.

bolting it in with spreader plates probably would've worked better - you're right about the welds taking the stress in a small area, and the welds would be brittle (depending on what it was welded with) but either the welds, and/or the metal around it would fracture eventually

Yep used in the audi R8 V8 and V10 and 2.0TFSI. From what I can gather more or less electrically the same as OE 1.8T but there's always progress in construction/materials so if I was going to replace what I had it made sense to get these. Yeah its the little cutouts which would be the tricky bit.

thanks... some techie crap you've probably seen: HSTuning - R8 Coil Pack and NGK Spark Plug Sale - VW GTI MKVI Forum / VW Golf R Forum / VW Golf MKVI Forum / VW GTI Forum - Golfmk6.com

I assume they don't fit under the vacuum reservoir etc.? my SAI is going because it screams, but I'm reading mixed things about getting rid of the other bits, I guess they'd have to be lifted up, but then the engine cover wouldn't fit on, and I like the engine cover!

[sambb]

Doing the SAI will get rid of 1. and 5. Doing the N249 will get rid of 2. and 3. You cant get rid of the former unless you have it ticked off in a tune so that the ECU is not looking for a particular mixture change at start up. You can get rid of the latter right away. I'd recommend doing it. Its there as an extra safety net for the ECU to be able to dump boost (even not associated with throttle plate closure apparently). The car drives better without it in my opinion cos the ECU interferes quite a bit. With that gone you'll be able to simplify the pipe work enough to fit the coils.
Haven't metered mine personally (but will now) had read that there wasn't much variation electrically but the link disputes that. The high rpm stuff wouldn't affect us but its the stronger spark especially in the presence of water that I was after. I can notice zero difference on the street but I suspect it'll be when running WI that the benefits will kick in if any.

[Sydneykid]

I did warn you about checking for cracks regularly, it's called a twist beam for very good reason, it twists. As I suggested in a previous post, for minimum unsprung weight increase I'd be looking at a chassis mounted rear swaybar with drop links to the shock mounting points. Until then the clamp on Whiteline bar is the go.

Running sans rear bar is a big compromise as the much higher rear spring and damper rates required reduce the available traction. So not something that I would suggest.

Cheers
Gary