Sam's build thread

[Sydneykid]

yeah thinking about it the clutch/PP will come balanced together but they are not part of a kit with a flywheel so how they'lll balance out with the flywheel is an unknown. Thats good enough reason for me to remove the flywheel and do it right. Given that, instead of emery i'll get it refaced which'd be the right way to go yeah? Just a super light skim should be fine.
Of course the other option is to just retain what I've got. A oneyear old clutch that's done 40,000km which should last longer than the diff plates anyway...….its tempting!

A decision best made with the evidence in front of you, no pre judging.

Cheers
Gary

[sambb]

indeed.

I can get another ECS 14lb flywheel for a good price. Thinking I might grab that and get everything pre balanced and ready to go in. Then if the existing fly/clutch/pressure plate comes out in good nick I can either sell it as a single mass flywheel conversion kit or at the least have a spare flywheel to look at potentially lightening further down the track.

[simon k]

I can either sell it as a single mass flywheel conversion kit

*cough* dibs *cough*

[metalhead]

You can get it done Sam! I'm working on my diff at the moment, it had picked up a little play so I decided to rebuild it while it was still ok, and improve a couple of things while I'm there (stress relieve some parts, solid pinion spacer, improved bearing cap fit etc). What may be of interest to you is that I bought a new set of clutch plates as they're cheap and I figured while I had it apart anyway I should replace them - but after ~50,000km the plates look like new, and measure the same as the new plates - I think I'll just put them back in and leave the new plates on the shelf!

[sambb]

Yeah I'm kicking myself now that I never measured the old vs new plates. Once cleaned up they looked pretty schmick so they are definitely going to be kept as spares. Yeah I am starting to think i'll give it a crack before Bathurst. Sounds like we both have been busy. Its always worth giving the car a once over before the next season - I had to replace a tie rod that's was shagged, found a not so tight subframe bolt, and one of the aero fittings for the oil cooler was weeping. She's good to go as is - just maybe with a new box for Bathurst.
How's your power steering belt issue - that thing staying on now? I'd hate to be counting down to turn-in at Griffins and find I didnt have power steering like you did!

[metalhead]

Haven't done all the things I had planned for the power steering yet - but (touch wood) it hasn't thrown the belt since I fitted the underdrive pulley. I'm still waiting on my new clutch to arrive, but other than that no major jobs need doing, and I'll run on the current clutch if need be.

[sambb]

You should see Pete's car now. He's gone berserk. I'll get some pics of it up. He won't be ready for Bathurst but he's aiming for some pretty quick Wakefield times. bit worried he'll beat me actually

[sambb]

Ok I think I'm going to do the harness thing for tracking. Need harness bar advice though. I have 2 options. Fit one of those harness bars that bridges between the top seat belt bolt positions OR run off a bar welded or bolted in the strut brace position.
So does anyone know of a harness bar that fits our car and would you trust them? If I do the strut brace option, what diameter/thickness/grade of steel do I need? Can it be a bolt in if flanged correctly or must it be welded?

[Sydneykid]

CDS (or CDW) 38 mm OD x 2.5 mm wall thickness or 40 mm x 2.0 mm. The harness bolt minimum is M12 x 8.8, so that's what I'd be using for the bar mounting. Also can be welded of course.

I'm not a fan of harness (taxi) bars, get a decent hit in the B pillar that bends the taxi bar and the seat belt cuts you in half.

Is the angle not suitable for using the rear seat belt mounts?

Cheers
Gary

[sambb]

Ok that confirmed what I'd thought. I was thinking the harness bar could sheer off in a side impact and go through the back of your head in a multi impact crash. I'll cross that off.
When talking about the rear sea belt mounts did you mean the ones on the rear seat bases? Those are too steep I think. They have to be within 45 degrees yeah. That might be ok with a one piece bucket but it worries me what that angle could do to the oem seats' recliner/latching mech. The upper rear seat belt mounts are inside the seat backs.
Thinking of it I have seen rear harness bars that have spigots either end that slot into where the rear seats click into place and then bolt into the floor: YouTube

[Sydneykid]

I've had 30 plus track day, hillclimb, race cars that I have worked on and not one had a problem with the rear seat belt angle using the lower seat belt mounting points. Some of them were much smaller than a Polo, so I'd be very surprised if it's any different.

The reason for the angle limitation is to avoid vertebra compression. They don't want the seat belt compressing your spine when you get thrown forward in an accident. Before that reg we used to see cars with the seat belt shoulder straps mounted straight down to the floor directly behind the seat. That's where the minimum 45 degrees comes from. I've never actually seen anyone measure it, we just look and if it's at a "reasonable" angle then we move on.

If your shoulders are higher than the seat back (or level with it) where the shoulder straps go, then the seat itself should be fine.

OEM seats/recliners are OK in forward accidents (the seat belt does its job), but in any decent rearwards or angular accident they break surprisingly easily. My son went LHS rear into the wall at Eastern Creek turn 1 (around 160 kph) and the hit destroyed the OEM Recaro in the Evo.

Cheers
Gary

[sambb]

stoked.... I measured the angles properly off the seat down to the rear seat belt anchor points. Measuring from the angle of my spine its only a 30 degree divergence from the ideal 90 degrees down to those points ie well within the 45 degree rules.
So I can just bung eye bolts into those points and also the front bolt of the slider rail. I'm not sure if there's room to put one in on the seats buckle mounting point against the centre console. With kids getting in and out and the seat sliding fwd/back on its rails it might tear up the carpet, so it may be that I need to drill into the tunnel furtherback. But either way it looks like a 4 point is just a plug and play and a 6 point looks east enough too once I can find someone to upholster the seat once I hack a slit into it for a crotch strap.

I've seen pull through bezels sold - ones where you can reinforce/dress holes cut in your seat back for harness shoulder straps. Anyone seen something similar to these sold so that you can line a hole cut in a seat base for a crotch strap?

[sambb]

Ok Ive had a really good look at the base of the factory seat in the Polo and I'm pretty well resigned to the fact that the seat cant be modified for a 5/6point harness. It took forever to get the seat base cuddy removed (64 screws and clips holding it in in typical teutonic fashion) so that I could get a good look underneath. With the seat unbolted it was clear that there is far too much steel plating under the seat cushion to be able to get a 5/6 point crotch strap through. There is a bit of a void but the problem is there is a nest of bars and adjusters etc under there that run pretty flush to the floor that would prevent a crotch strap getting cleanly through even if you could enlarge the hole in the steel base which I don't think you could without a grinder that would burn everything.

There are two plugs under there. One is a two wire which is for recognition that a seat belt is plugged in. I might bridge that so I dont get the annoying seat belt alarm. The other 3 wire plug is for the airbag. It would need to have been resistered out if a new seat was to be fitted. But I have neither the $ for a nice 1 piece.

So I've made the decision. After watching/hearing a felloe hillclimber nearly kill himself last year I'm not going to hold off anymore. Better to get something in even if its not the whole seat/harness etc caboodle. I'm going to go for a 4 pointer. Not a run of the mill one but one of the proper ones with anti submarine strapping on the inside shoulder to combat the normal 4 point harnesses biggest vice - the fact that in a head on you can submarine/slide underneath the waist strap. That's why 6 pointers are the go for racing. The crotch strap acts to prevent submarining and allows you to get the ideal shoulder strap tension without the shoulder straps lifting the waist strap which can cause submarining with 4 pointers.
So from what I can find, a 4 point harness will be safer than a lap sash provided the waist strap fixing points are in the ideal positions AND the inside shoulder strap has anti submarining tech built into it. ASM basically allows your inside shoulder to move a squidge more before it is arrested than the door side shoulder. This twist in the torso causes the waist belt to dig into the waist (same deal as a lap sash) to prevent you sliding under it. So its safer than a lap sash because it wont let you submarine yet holds you much closer to the seat during the crash - the lap sash lets you move miles before it arrests you, and in other collision angles is apparently much safer than a lap sash.
The only two brands I could find that have ASM 4 pointers are Takata and Scroth. This is the one i'll probably get because it has a proper latch mech (the takata has a normal seat belt kind of latch) and it has a 2 inch waist belt (apparently digs in more than a 3 inch to prevent submarining). Both have 3 in shoulder belts as I wont be using a HANS:

Schroth Clubman II-ASM-4 Black | HARNESSES | Revolution Racegear


All I need are 2 x eye hooks M10 fine for the rear seat belt positions, another for the side of the centre console tunnel and another to screw in on the front bolt hole of the seat belt slider rail. So 3 of the 4 bolts are plug and play and only the inside waist belt one will need to be drilled. An alternative to that is screwing a spec strap on underneath the existing seat belt latch mech that the harness can clip on to but I'm not sure I'll get the right angles on the waist belt if I use that.

anyway. that's the plan. I'd have loved to use a 6 pointer but I only have enough money for a seat OR a harness not both, and as the seat cant be modded for a 6 pointer, then a 4 pointer will have to get me through this year until I get afford some more safety down the track.

[metalhead]

Sounds good to me.

I've had some dramas over the weekend with the car. I might be pushing it to make Bathurst now, though you can bet I'll do all I can.

[simon k]

good plan, take pictures so I have something to copy... I love the Polo seat, but would like to be held more securely

I wouldn't be concerned about the Takata latch, just the looks and comments you'd get about airbags... How long are the shoulder straps on that Schroth? will it need extensions?

I already have the 4x M10 eye bolts, they were rattling around on the floor of that Honda I worked on and happened to land on my bench.