Roman

More VVTI related WTFs. Today I replaced the VVTI pulley with a brand new one. Now it follows orders perfectly and drops to zero degrees as it should. So it wasnt a problem with cam offset, and it wasnt a problem with minimum duty cycle on the solenoid. The problem was some crud stuck inside the old VVTI pulley or something like that. Soooooo this is interesting news as gaining 12 degrees more cam angle retard should help with top end power. If it makes more power, it should run a little leaner... Previously it has been +- 13:1 all the way to redline. Results: wtf! Mega lean now. Either I've just unlocked a shitload more power (skeptical) or this 12 degrees difference has now made injector timing critical at that sort of RPM range. Or maybe a bit of both. Interesting results anyway though, look forward to fixing up the fuel tomorrow and then seeing how it goes by comparison. Would be awesome to have unlocked some more doorts for trackday at that rpm.

I think I've managed to bodge it. I think the trick here though, is to never undo the pulley ever again, ever.

Does cross threading the thread in the end of your crankshaft, for the pulley, count as a form of masturbation? Because I think I just fucked myself

If you look to the right of the yellow vertical line on the time plot. When it applies 5% dc cam angle does drop to zero instead of 12 deg.

Thanks Dwlee, no I havent considered a custom PID as I've considered it beyond the scope of my abilities (especially since theres a VVTI preset already there) I think the high derivative gain is on account of that the pulley naturally tries to pull itself back to the most retarded position when the cambelt pulls on it? However, the plot thickens! Check this out: When my RPM drops below the minimum threshold that VVTI operates at, the cam angle does drop to zero. But when it comes to the VVTI operation rpm range, if I look at custom PID settings. The minimum duty cycle for the oil solenoid is currently set to 20%. Which causes... 12 degrees advance. Mind blown, have been driving the car for years like this and never bothered to check, just assumed 12 degrees was zero haha. It likely means more power up top by retarding the cam that extra 12 degrees. Will be interesting to see if my fuel map changes by much. Tomorrow I will reduce the minimum DC for the oil solenoid and see how it goes.

Oh god how have I managed to miss that cam angle offset haha. Thanks I'll get that done.

"Zero" degrees on that map is actually 12 degrees. Because I'm using the PID for VVTI control from an Altezza that has a different offset on the cam angle sensor I think (12 degrees different I'd imagine...) So it's maybe not as sharper transition as it would seem. However yes this is a good suggestion, thanks. Thinking about it, I've had a rattle at idle for frigging ages, and I've always thought it relates to valve clearances even though I've checked several times and they're all within spec. So I might have a good listen and see if it sounds like its coming from the pulley. If so I'll just replace it.

Phil is now one of those blokes, Who's quite sick of my mitsi jokes. He saw no potential, in fully sequential, As fuel isnt why his car smokes.

Went for a drive Previously my VVTI map looked like this: So I tried setting it all to zero between 2000 and 4000rpm except for full load area.... Seemed to sound the same once car had warmed up. So I went the other way, and set it all to 25 degrees including the low down areas where I'd always had zero. It looks as though this may have sorted it. Maybe the time that it clatters, is when its just coming off its base position, or is just above it. So set to stay well above it and so far so good. Will need to go for a longer drive to confirm though. Maybe this type of oil is contributing, recently started using a Penrite 5w30 when I've previously been using magnatec 5w30. I've noticed that oil pressure goes a fair bit lower at idle now, possibly running hotter oil temps or something. Sheesh I think I owe you a few beers by now Downtrail! And a few others here too. Thanks for the point in the right direction

Hmmm yep this could be it. 12 degrees is the position when there's no advance applied. Then its bumping a few degrees ahead, just as rpm and throttle goes up that slight amount.

Hmmm okay thanks... Yes it's happening just around the rpm region where VVTI first turns on, so it could be a rattly pulley. I've tried adjusting the angles but I dont think I've tried shutting it off completely. Unfortunately I cant listen directly with my knock sensor anymore as it's wired into the ECU and there's no audio output from it. But I can definitely hear knock (or something knocking!)

The earlier versions of these engines were very much prone to BEB failure. But these ones not so much. It's still a possibility though. I think it's definitely engine knock rather than gearbox/engine mounts etc. As its very repeatable, it's only in that specific rpm and load region. Maybe I just need to go back to basics a bit and do a compression test, check for manifold leaks, etc etc.

Well, it wouldnt exactly be a precedent for a 3SGE to have big end bearing issues haha!

Got a bit of a head scratcher guys. I've found that my engine is knocking, between say 2500rpm and 3500rpm at motorway cruising sort of load. At the region it's knocking it's currently running ~20-25 deg timing, and has done for quite some time without issues. In fact I even advanced it a shitload further than this a bit prior, without any issues. I recently found a problem with one of my coilpacks and fixed that, and changed the plugs as well. But it's still knocking in that region, if I let the knock control pull timing it out pulls timing right back to almost nothing. Yet at the rpms just above and below that range, it doesnt knock with the normal amount of timing. Any thoughts? I'm thinking it sounds like I've probably got some physical problems with the motor. But I cant think what it could be, or why it would only knock around that rpm range. A partially blocked injector perhaps? Or hopefully not a broken ringland or something from a few over revs haha. This is around the rpm range that VVTI turns on, I've normally had it set to roughly 20 degrees advance at that load/rpm combo. But I've tried adjusting it up and down and doesnt seem to help. Maybe I should get a compression test done. The car otherwise runs fine. I will pull plugs again after work today and see if there's any evidence of anything weird going on, maybe double check valve clearances. Any other suggestions?

Haha oh man, what a read! http://www.formulapacific.nz/?p=44 I would just rip that old piece of crap out. (unless racing rules dictated otherwise of course... Which they probably do)

That little carb tuning board thingy is awesome! Top work.

Yeah you stop to take a piss and you've just "lost" all of the advantage of driving like a fucken moron overtaking on blind corners etc. Drives me insane seeing some of the crazy driving around Coromandel etc. The ignition timing strategy at cruise on my engine from factory is to advance the bejesus out of the timing until it knocks, then dial it back a tad. So I reckon maxxing out timing as much as possible around cruise region is probably pretty good for economy too.

With an AFR target of 15.5:1 and travelling at 100kph all the way I got 7.8l per 100km. Not a particularly scientific comparison though, as it wasnt the same stretch of road etc. I reckon the speed you're going, and how you're driving makes more of a difference than leaning out the AFR does. Yet leaning out the AFR makes a horrid amount of extra poisonous chemicals coming out of your exhaust. (and a little into the cabin) I think I'd rather just take the penalty of 0.1 L per 100km and the reduced chance of dissolving my brain any quicker than necessary.

Maybe it's because anyone who bought the diesel version had already given up on life.

There were a few episodes of 8000rpm in there haha

I ran a trip back the other way with a little less stop and start, didnt make too much of a difference though at 7.9l per 100km (36MPG instead of 35) Travelling between 80-100kph most of the way. Might try same both ways again tomorrow or Friday but with a leaner goal AFR.

MY previous coils were part number 90919-02227, however the new ones I bought have a new part number 90919-02275 which is a slightly different shape, they now look like the Altezza ones with the flat top. But the instructions in the packet say they perform identically to the 27s, the old ones were superceded. I've found that my ECU does have dwell times set, but it would be dwell times for the Altezza coils.

I drove a dual shift box thingy Mirage once, that a friend owned. This thing had the worst tires known to man. The steering had more play in its box than Paris Hilton, and the alignment was about as straight as owen wilsons nose. I think it had taken a punt to the rear so it would sort of crab down the road. The headlights, one shined down at the road about a meter ahead and I can only assume the other was trying to signal batman. I had to drive it from A to B on some West Auckland backroads at night in the pissing down rain, and it was terrifying. I've never felt so unsafe driving a car at like 35kph. It still holds a fond place in my heart as being the absolute worst car I have ever driven. (Not really on account of being a Mirage though, to be fair) More a story of the perils of neglect than anything else!

Oh man good to know! I will go buy a bucket of beads and place in them in various cars I've got stored at various relatives houses haha. In thread relevant news, Looking forward to seeing the new and improved VH next nats! Rust work aaaaabsolutely sucks haha. There's an exponential decay of motivation, you'll get as much done in the first week as you will in the last 9 months. I begrudgingly admit that your wagon is pretty cool Ugh I feel dirty now, off to look at pictures of coupes