VX220 2.4L VVT ITB conversion

alanoo

My safe, not optimal tune that I use at the moment before finishing the exhaust and last dyno tweaks
(Remember it is for a 12:1 CR too)
It is MAPxRPM, I have an unfinished TPSxRPM tune somewhere, I'll try to find it

rabidh

That's great, thanks!
I'm running TPS/RPM at the moment (It's easy enough to change, but I heard that most performance-oriented ECU's did that, so that's what I stuck with).
I added some code to look at the knock sensor on Saturday (currently it's taking 60 samples over the course of a rev), so if I can use it to properly detect knock then I'm sorted (although maybe i should be looking for a certain frequency of 'ring' rather than a spike at a certain point in the rev). I figure I can just advance the timing until it knocks and then back it off a bit, and it'll be close to correct.

And then the cam phasings... I just found:
http://www.localcobalt.net/forum/techni ... sheet.html
2.4 VVT Ecotec - LE5
INTAKE: lift=10.54, timing=135, duration (@1mm)=210
EXHAUST: lift=10.03, timing=-125, duration (@1mm)=195
I'm guessing the durations are measured differently to the way I've seen it done commonly? The Z22SE is 198 inlet and 193 exhaust by this measurement...

No idea what the timing really means here, as obviously it's variable. It would be nice if they were the peak power timings, but I doubt it 🙂 The cams have 0-60 degrees of adjustable retardation, and currently they are being held at the default 'startup' retardation, which is -30 (inlet) and -0 (exhaust) - I need to work out the absolute peak lift timings really 🙂 Still... I reckon I can retard the exhaust by a load, and advance the inlet, which I'd hope would give me quite a bit more power (assuming I don't overdo it 🙂. 60 degrees is a hell of a lot, so i'd guess there's a lot of fiddling to get something that's really good.

It would be nice to get some full lift timings from a range of different performance cams, and I might be able to work out roughly what my full lift timings should be at different RPMs from them. Unfortunately it looks like most manufacturers don't tend to like giving them out. Mark's got a great list here, but no timing info either 🙁
http://www.verboom.net/projects/speedster/cams.html

Otherwise it's just going to be a matter of trying different things with the butt dyno really 🙂

alanoo

on the comp cams site, they give the infos for all ecotec grinds.
I must have the full data from the Schricks too somewhere

rabidh

Thanks, just looked at the catalog though, and while there is lobe separation and duration, there is no angle given for peak lift 🙁

Looking at the pictures I took of the LE5 camshafts, the trigger wheel on them isn't actually aligned with the lobe on the cam - which just makes life that little bit more difficult 🙁 It looks like at 0 degrees retardation the trigger wheel triggers at 90 and 270 degrees on the crank... but then I have no clue what angle the lobe is relative to that!

alanoo

http://www.gmtunersource.com/media/race ... HEET-2.pdf

do you know this pdf too ?

rabidh

Interesting... I'd seen a PDF with just the first page in it, but hadn't seen the other 3 🙂

You can see what I mean from the picture of the LE5 cams there... The trigger wheel has a pattern that means that you really need to base your timing on the falling edge, as that always happens every 90 degrees of cam rotation... and the falling edges don't appear to line up with the cam lobes...

rabidh

http://www.pur3.co.uk/tmp/VX220%20ITBs%20-%20Accelerate.mp3

It's only mobile phone sound so you don't really get the full effect. You can hear how quiet it is by comparison when I lift off though 🙂
There's a bit of a wobble from the engine on the 3rd gear change, I didn't quite get the revs matched right, and the ECU is still learning so some areas of the map aren't quite right yet. Could be engine mounts too.

Bit of a shame about the engine braking, but I have to have the ITBs open quite wide to get a decent idle. Does yours deal ok with that vocky, or is there some magic for automatic idle adjustment on your TBs?

Alanoo: Thanks for the mappings, I roughly stuck them in (not using a map, but just "advance = 15 + rpm*6/6000" and it's a definite improvement - the engine really picks up at 5000rpm, so a bit more tweaking should see it better through the whole rev range. I do need to use a proper map though as it idles really badly now 😉

How did you set your map up out of interest? On a rolling road, or just doing power runs and tweaking?

alanoo

the injection map is done via road normal driving + power runs logs and the wideband lambda (which is logged by the ECU too).
We log something like 5 min of normal driving with various load levels + 5 power runs (mid and full throttle) then analyze these logs with an Excel sheet and hop, done.

the ignition map was done on a RR for its first version, but the engine has changed since that moment. The one I gave you is a degraded and simplified version of that last one.

You'll need much less ignition advance than I do at idle, my stronger springs and most importantly high CR makes it quite hard to turn with no load.

For cold starts, you'll need approx 40% more injection time and 30% more ign advance to get a good idle

rabidh

The 40% more injection and 30% advance are very useful figures - I have been putting in 100% more fuel on startup to be safe, but it'll be good to be able to tune that down a bit 🙂

I'm getting knock and firing early even though my timing isn't set to be very advanced at all. It's becoming obvious that I have the positions for the trigger wheel wrong. I just assumed that the 2 tooth gap (58 tooth trigger wheel) was right before TDC, but that looks wrong (and I can't find the answer anywhere). Anyone have any ideas where it lies?

Either that or I'm going to have to attach a light to the tacho signal and figure it out the old fashioned way 😃

Otherwise stuff is going well though, I have the knock readings coming in, and the VVT is working great (although I blew the first set of drivers up by leaving the solenoids on when the engine was off 🙂. I'm going to have to have a few more entries in my fuel map table though (and work off MAP rather than TPS) as my part-throttle response is rubbish at the moment.

vocky

it should be set to 9 teeth after the 'missing' tooth will align with the sensor - at tdc

rabidh

jesus. No wonder it seemed to be knocking a bit on WOT - 9 teeth = 54 degrees before 😃

So basically there's the missing teeth, then the 9th 'rising edge' of the tooth after that is directly on TDC?

Where did you find that out from? That's so amazingly helpful - I made a little timing light to work off the teeth, but to be honest I wasn't looking forwards to ripping out the wheelarch + undertray right after I'd put them back - and then jamming my head right under the engine with it running 😃

vocky

the middle of the sensor should sit with the middle of the tooth above it.

I asked webcon :lol:

rabidh

vocky said:
the middle of the sensor should sit with the middle of the tooth above it.

I asked webcon :lol:

Oh, great. That really works well with my integer 'teeth past TDC' counter. I might just ignore it, as it's 'only' 1.5 degrees I guess 🙂
I'm amazed that nowhere else on the internet actually seems to have that written down anywhere. Vocky is officially more knowledgeable than google :thumbup:

I just changed my mapping to an 8x8 map, and made it work off of MAP rather than the TPS. It's starting to feel a hell of a lot better already. I hope that when I stop sparking so damn early it'll really get exciting 🙂

vocky

I couldn't find the info either, so I rang webcon

alanoo

vocky said:
the middle of the sensor should sit with the middle of the tooth above it.

I asked webcon :lol:

Beh, Why would they use the same pattern as the OE 2.4 ECU ?

Rik, you'll have to measure it, it is too dangerous otherwise

rabidh

I just tweaked it to take account of the tooth position (using 9 'whole' teeth for now), and a very rough estimate of the Lotus Excel timings I had before.
Took it for a drive, and I have the biggest smile on my face EVER.

There's still a load of tweaking to do, mainly because currently the software screws up over 4500rpm and it forgets about the odd spark, but it's still pretty damn good. Way more responsive, the idle is now smooth as silk at 800rpm, and most importantly there's enough torque to unstick the rear wheels, so I'm quite near the old engine's power already.

I can't help feeling a bit bad about the massively advanced timing though. I hope the engine's ok... The knocking was only really apparent at hard throttle, and as soon as I realised I eased off it a load.

alanoo: as you say though, it'll be worth me getting under the car and sorting the timing out so I'm 100% sure. I'd just assumed the gap would be aligned at TDC - seemed sensible really 🙂 Who the hell would choose 55.5 degrees (which is what I think it is for the first rising edge after the gap?).

rabidh

Just saw this actually... Some very useful info about cam timings... It looks like while I was advancing the cam timings linearly with RPM, I should actually be retarding them a bit at higher RPMs.

http://forums.vwvortex.com/zerothread?id=4051402&page=1

alanoo

rabidh said:

Does anyone have any info on the oil pressure/water temp/MAP sensors in the block of the Z22SE, so I can get stuff calibrated properly?
Like what resistances/voltages they are at different temperatures/pressures?

http://www.bmotorsports.com/shop/produc ... ts_id/1598

Maybe worth the try for the temperature calibration ?

rabidh

Thanks. Looks great! Am on holiday at the mo, but when I get back I'll try with those values

siztenboots

ha ha , found you all over here ( from vx220.org.uk ) , basically my interest in this is doing a similar thing to a VX220 currently with Z20LET and swapping to a 2.0L LNF Ecotec

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