633 replies to this topic

[76lxhatch]

Signs of me getting old, minor vibrations that used to part of the car's character are now just annoying. Used a phone app to measure frequencies, the worst of it seems to be a resonance between the driveshaft and the exhaust. With the 3.9 diff the driveshaft is approaching 3000rpm at open road speeds so any small issue is magnified.

 

The rear section had iffy replacement weights that were drilled and riveted on instead of welded, but being completely stock VN I just replaced it with the besting looking one from the stockpile, installed a new solid Spicer uni joint and painted it.

 

The original front section is so short now I managed to get mounted in my little lathe with the slip yoke removed, runout was around 0.015" and it didn't seem to be perfectly straight. Back to the stockpile for a better piece, machined the yoke and tacked in place on the lathe. For some reason this one gave me far more grief than usual, tacks would move it 0.005" or more and I ended up having to take runout measurements on the car then set up the lathe to mirror these as something about the flange yoke or uni I used was misaligned, but eventually got it down to around 0.002" runout.

(Before final weld and paint)

 

New front uni as well, replaced the centre bearing and CV joint, reassembled and reinstalled. Much better!

[axistr]

Well done SS hatch, there is nothing better than doing it you self to make sure its done right.

[76lxhatch]

So I've been mucking around with the breather systems on and off to fix all the little issues to my liking. The main thing is minimal maintenance, I don't want to be draining excess oil or replacing filters too often.

 

The catch can filter just filled up with moisture and didn't work well with PCV vacuum running through it, so that is now atmospheric only. To maximise the flow and cater for repeated high rpm I stepped up the hose size. This required a bigger fitting for the rocker cover:

 

There's also a nipple for the air cleaner housing which I don't seem to have a photo of, and a couple of custom-made large flange nuts to retain the fittings:

 

 

The fittings are 6061 aluminium and the nuts are 4140 steel.

 

Along with some black cloth braided hose gives this on the atmospheric side:

 

I'd like to change the cable ties on the ends to some of those heat shrink clamps at some stage to tidy it up. Seems to work well, the filter in the can no longer clogs up but it does avoid smelly fumes. The fresh air hose to the air filter housing is always clean.

[76lxhatch]

Next part is the PCV, it works fine but occasionally depending on what sort of driving I'm doing it can start pulling some oil. A big part of this is the lack of baffling in the rocker covers but I want to keep them. I've tried making a few different internal baffles in the past but they never really work, I don't think there's enough room in there for an effective solution which means I need something external. I could run a suitable catch can, and you can get small inline oil separators, but as mentioned previously I don't want to be emptying oil out of something like this all the time.

 

The ideal solution for me is a separator that sits on top of the rocker cover and stops oil from tracking out and/or allows it to drain straight back in. This is what I came up with:

 

It has a lower section that is angled to match the rocker cover so the whole unit basically sits upright making for easy drain back. This bottom section has stainless perforated plates (cheese grater) top and bottom, and is filled with open stainless filter media (pot scrub). The top section is open and is where the PCV goes.

 

The pieces bolt together allowing servicing if that is ever necessary, and the whole thing seals and bolts to the rocker cover. I added a small baffle under the cover to avoid oil tracking along the top being sucked up (one of the things that has caused a re-think of the system is replacing the rockers a while ago - the new ones direct oil straight up to the inside of the cover where the old ones were drilled to push it to the valve stems).

 

This seems to have worked very well, there is ample flow and never seems to be any oil in the top chamber or around the PCV.

[76lxhatch]

Lastly I've never managed to find an oil cap that seals fully and wanted to fix that. With the proper breather system the cap can be sealed which makes it easier too. This is the best I'd come up with which at least stayed in place and mostly sealed but it needed two rubber gaskets and still weeped a little (plus its too shiny and we can't have that):

 

The last piece of 6061 on hand was just enough but I needed to get creative to have enough for all the necessary work holding:

 

This is the cap itself, the stub sticking out is the hole-sawed area and is needed for indexing the part in the mill:

 

 

The remaining piece is the boss that it threads into. I set it up with a nice coarse thread that is a slightly loose fit, and suitable shoulders for an o-ring seal.

 

It looks kind of small but the hole is exactly the same size as the cover. The boss bolts on with three small stainless button head screws and seals against the original sealing face on the cover.

 

All done.

[Hatchback13]

Fantastic engineering. Cheers

[Heath]

Exemplary work.

[kudu]

Great stuff.

Reading this thread from start to finish has been a great way to spend a work day!

Scott

[christolx]

Re-Visited this thread tonight. So much great work 

[Heath]

Damnit Christo, I thought there was going to be a fresh update waiting for us!

 

Not sure if we can forgive you for this thread bump, haha.

[76lxhatch]

Sorry no updates as I've been distracted by boring things like work, also got a new daily/toy:

 

 

Probably not much interest here but its a bit of fun with a naturally aspirated V8 that does over 8,000rpm

Way, way better value than an HSV these days.

 

I do have some minor updates on the taxi, will make a post on that thread.

[axistr]

Nice sparing partner for the E90 M3. Very nice 76lxhatch, a wolf in sheep clothing. The Germans do make some very exciting and well engineered cars. 

[Shiney005]

Way, way better value than an HSV these days.

Can't agree with you there.  Almost everything else is better I'm sure, but it can't be better value than a car that is worth more each year. Any Audi that isn't a rally spec Quattro or an old V10 R8 is only going down down down..........

[76lxhatch]

For some reason the RS5s are cheaper than RS4s (which are basically the same vehicle but a wagon) which helps. Neither seem to be losing much value being the 'last of the (naturally aspirated) V8s' but I was thinking more of bang-for-buck in the purchase price rather than resale value.

 

I was interested in say an E2 Senator of similar year. It would have cost at least half as much again for less power, less capable handling, fewer creature comforts and features, and higher kms. The maintenance costs may well be another matter, we will see.

[76lxhatch]

Previously I had hacked up a VN throttle body linkage to get the progressive lever. This was definitely better than the original lever which was too touchy to be driveable.

 

However I was still looking to tidy that up a little and improve progression, so I made a new one. You can see how much closer to the throttle shaft the cable is at the anchor end.

 

Just clears everything and allows full throttle just as it hits the secondary lever:

[76lxhatch]

Took the car for a WOF inspection one of the days we had some major flooding a few months back, turns out driving through the water uncovered some hidden issues and failed on some rust inside the guards both sides.

 

Turns out a previous repair to the inner structure of the guards had been left with the bottom part of the flange missing, which has just packed full of dirt over the years. The water washed some of that out leaving a hole. On the driver side this was still only the guard itself, so I just had to rebuild the flange that sits against the pillar.

 

On the passenger side, the mud packed in there had started eating away at the base of the A pillar.

 

Fresh metal required.

 

Rebuild the inner structure and seal it up.

[76lxhatch]

The fit of the front guards has never been very good, as it turns out the previous repair to the inner structure was also responsible for this. The passenger side had a big shim to get even close to reasonable position, notice the gap between the flange and the pillar.

 

But even the shimming didn't give a particularly good result on the outside.

 

Removing the part of the flange that needed replacing allowed moving things around to get a slightly better fit.

 

While mucking around with gaps something that had always annoyed me was the passenger side window frame. According to my measurements there's no significant difference between the openings left and right, so resorted to a bit of brute force and ignorance.

Now I can no longer get my finger in between the window frame and body, and the seal sits in the right place. Good enough.

[76lxhatch]

Of course all that required removing the front guards to get access, and a through cleaning of the inner guard area. So, while I was there...

Cleaned up the wiring under the driver side and made some brackets for the cable ties so they sit straight instead of just through the speed nuts.


Tidier and hopefully doesn't trap dirt quite as much.

 

Keen eyes will also notice the clean speed nuts and bolts; they were filthy and generally looked pretty bad. Came up well with a lot of cleaning and a coat of black zinc though.

[76lxhatch]

Another long-standing fitment issue was the driver side flare position. It was OK at the back, but pointed down with the front sitting nearly half an inch too low. Doesn't sound like much but if you hit a driveway too fast with too much right hand down the tyre actually touches the flare and had cracked the paint. Moved this to match the passenger side.


Somehow this also lead to re-finishing both flares, which have had a few modifications in their lifetime.

 

And while I was at it, may as well replace the last few bolts that didn't match with stainless hardware and rivet nuts. This included the front spoiler, so that ended up being re-finished too.

 

Spent more time cleaning the paint gun than painting. One day I'm going to buy a decent one...

 

I have no idea what weird shade of off-white this car is. The paint I have was colour-matched years ago, but still isn't a very good match. If I ever get around to re-painting the whole car it will be straight white. But I think the flare looks a lot better now - it's straight, matches the passenger side, and I have a few extra mm of clearance.

[76lxhatch]

Another thing I couldn't leave alone was the front anti-roll bar brackets.

 

The bracket for the links on the lower arm is a fairly long piece of angle to clear the steering. This flexes itself, as well as having the fasteners in a position where the lower arm does the same. Over time this has accumulated quite a bit of dirt packed in between the arm and the top of the angle bracket.

 

Resolved with some additional bracing of the bracket, including a third bolt at the top.

 

Along with a threaded doubler plate that all three bolts screw into, instead of just individual nuts. The thread does actually go all the way through, just can't see from this angle. There are split washers under the bolt heads.

This should reduce flexing stress on the arm and make the bar more effective.

 

The original U bolts that hold the main bar are also not ideal. These are the only thing holding the side brackets and the bracing bar together, but they can't be bolted up solid because that would squash the bushings. The bushings are distorted somewhat regardless.

 

 

The factory style clamps are a lot better idea. They bolt up tight to the mounting surface without squashing the bushing, and support it better for minimum distortion. To make them work I had to widen the bolt spacing slightly.

 

Made some threaded bosses and welded them on, upgraded to 3/8" hardware. The side brackets and centre brace are a solid assembly.

Edited by 76lxhatch, 27 November 2022 - 08:50 AM.

[Heath]

Some expert re-working there. Super nice job.

You've been busy!

[Shiney005]

The site must be playing up again. No pictures for me.

[claysummers]

Nice work. That patch panel shaped up well, just shrink and stretch?


Sent from my iPad using Tapatalk

[76lxhatch]

The site must be playing up again. No pictures for me.

Probably your web browser (Chrome?), they are a pain in the neck these days refusing to load anything over HTTP. Can't edit the posts now but will try to remember to post HTTPS next time. You might find some way of telling it explicitly to load them?

 

Nice work. That patch panel shaped up well, just shrink and stretch?

Yes just hammer and dolly until it fits.

[76lxhatch]

Actually if you're really interested and can't see the photos, they're all here:

https://img.v8comp.c.../Torana?page=24