The 16V G60 thread.

1.9 KR, and oil cooler housing.

 

cool thanks

 

If anyone is interested when i ordered my BBM kit i had to pay 130 quid for import duty and vat.

 

I didn't have to pay much in the way of import duty at all, as BBM put small figures on the waybill

 

lucky you, guess i should have asked them to do likewise

 

Right, update.

At last, after all this time, the car is in a state where I can drive it over for its MOT. There are a number of small simple things remaining, such as fitting front wipers, fit rear brake compensator spring and lever, fit horn, and so on.

I've got the brakes sorted out at long last. I fitted some different seals underneath the fluid tank which are a lot tighter. I went around and tightened a couple of new brake line nuts that were possibly leaky. Then pressure bled the system using a tyre at about 30psi. They now work!

I had a horrible noise when driving around which for a long time I thought was clutch or transmission related. I even ended up replacing one whole driveshaft as I was so desperate to work out what it was. I felt a bit red-faced when I realised it was a bolt head on the BBM tensioner idler bracket rattling against the chassis arm when the engine tilted back under load. It made such a loud, horrible noise that I just assumed from the start it was something far worse. So glad to have solved that one now.

Something I have already covered in another thread is the work I've been doing to provide improved Bosch ISV control from MegaSquirt. I reverse engineered the ISV control circuit in the Digifant I and II ECUs and discovered that the ISV is actually PWMed by a ramped current. Designed a retro-fit circuit for MegaSquirt. It controls the ISV nicely now. I can do things like turning the PAS from lock to lock when stationary and it idles reasonably well.



I'm not relying on the ISV to rescue the engine from hunting, and to force the engine to idle. The ISV is there to just ensure stable idle under all load conditions, such as when using PAS, and that kind of thing. Prior to using an ISV, I think you have to have an engine that is able to idle at a reasonably constant RPM on its own. The trick I used in the end was to have very, very rich VE bin values for about 500 or 700 RPM at idle kPa; this well-known method stops the engine from 'hunting' by providing a wider squirt of fuel whenever the engine tries to fall below your idle RPM. Using a bit of spark advance in the same way was found to work also, but I just used the fuel table. Now, I can have idle at an AFR of something not far off 14.7, without having to make it really rich all the time just to stop it hunting. I still have yet to try my Gunson Gastester to see what the CO really is like out the back!

I reckon this is why people sometimes can't get a Digifant engine to stop hunting even though the ISV is in good order. If the mixture is totally crap and the engine wants to hunt like buggery, the ISV won't save it.

So yeah, a few things to sort out and then hopefully it's MOT time. Christ, it has been a long time. When did I start this thread? I have total strangers walk past and comment to me that the car is finally back together!

 

Good work Trev, I like the board mod, spot on

 

Actually drove it to the MOT station today!

The MOT has not been done yet, but the fact that I've driven it on a public road for ten minutes without it catching fire or breaking down is good enough for me.

The engine is going to be tuned and run in within the standard MK2 it's currently in, and then once it's all good, it'll come out and go into the Syncro.

When I dropped the car off I did have to ask them to keep the battery disconnected in case it catches fire overnight, avoid revving it past 2K because the oil warning buzzer will come on because it isn't connected up, that they might get it started if they are very lucky, etc...

 

Now has MOT!

But the starter motor has died, so I have to take another one with me when I pick it up from the garage. Or maybe I'll just take a hammer along and belt the solenoid...

 

Just don't belt the motor if you want to re-use it, you'll only end up killing the magnets.

 

Cars...Luv em or Loathe them you cannot do without them!

 

Any update's Trev?

 

Hello mate!

Not really, except right now I happen to be fitting a knock sensor circuit into the Megasquirt unit...

How are you? Fancy a curry one eve?

 

Sounds good, Not had a curry for ages. I need to come and see you car sometime too

 

I've not touched the car much at all since it passed the MOT (more important issues in the way such as my wife being seriously ill, and doing up the house) but over the weekend just gone I decided to really get my finger out and work on the VE map.

At first I was very nervous about giving the car any welly at all, but after a number of datalogs made from runs around the block and several analysis sessions using MegaLogViewer, I've got to the stage where I can boot it up to about 4,000rpm in first gear, second gear etc. and the car accelerates reasonably well without jerking back or anything, and the AFR remains reasonably on target. I'm trying to be gentle and gradual with it because it's a freshly rebuilt engine, using a charger with a small pulley! If I was tuning MegaSquirt on a N/A run-in engine, I may be a little braver...

I'm personally finding that tuning using datalogs and MegaLogViewer works best for me. I have not tried using MegaTune's autotune function.

I have been running about 10% of EGO correction. I need to work on the EGO closed-loop values a lot more. I understand from the documentation that running EGO during datalogging is a good idea because it creates lots of crossover points which are useful for MegaLogViewer's VE analysis function; however next time I go out in the car I'm tempted to turn EGO correction off completely as it gets quite unstable sometimes. Those of you who are using MegaSquirt, did you find it helpful to use EGO correction during tuning or did you only use it once you had a VE map that was pretty much spot-on? Furthermore, once my VE map is 'tuned', is there any reason why one HAS to use a small degree of EGO correction? Is it always advised to run a small amount of EGO authority (say, +/-5%) just to compensate for the fact that changes in ambient temperature, humidity, fuel quality etc. can change the fuel mixture?

Anyway, I am more confident now that I'm getting the right 'feel' for tweaking the VE map (certainly a lot more confident than I was at the start of the weekend), and once that is done, the next challenge is to have both a good VE map and advance map.

After such a long time of being on a bit of a downer with the car and engine, I'm now really chuffed to have been able to have it drive quite nicely and to be able to give it some stick. I'm looking forward to more tuning next weekend.

Another electronics project I have been working on recently is a really good knock sensor circuit design. Might stick another thread up about it at some point. Basically I went out with a mate in his Polo, which can be made to ping quite easily. We made many audio recordings of the pinging noise from a knock sensor and I'm using the recordings to design a circuit that'll filter and identify knocking really well. I need something like this because my hearing is pretty crap (yep, even at just under 30) and I can't really hear engine pinging just by ear. We found pinging occurs between 6.5kHz and 7.5kHz, so really I'll be having a very narrow 7kHz bandpass filter and then feeding the output into a little speaker or headphones. I know knock sensor boxes already exist but I believe they can be improved upon.

Anyway I'm tying loads of crap because I'm drinking; I'll stop typing now.

 

nice one trev, its good to see the car progressing further.

 

Right, I am really quite sure I have coolant going out of the exhaust now.

Last weekend I drove around and did quite a bit of fuel table mapping. Drove the car harder than I have done in the past (but not silly with it). At no time was I ever aware of excessive steam coming out of the exhaust.

But when I've used the car today, absolutely LOADS of white smoke / steam has come out of the exhaust at idle. When the car is first started, there's nothing visible out of the exhaust at all; once the coolant warms up, it gets worse and worse and worse. Water drips out of the tailpipe and there is LOADS of steam. Yes, I know about condensation and all that, but this is loads. When I actually drive the car I can't see any smoke / steam in the rear view mirror.

Basically it looks like a car that has just had some Red-Ex plopped into each cylinder.

So I used my Block Tester on the coolant header tank. After a few minutes the fluid went greeny yellow, indicating that there is gas getting into the coolant.

I've started putting marks on the header tank to determine whether the coolant level really is going down.

The head (and block) were freshly skimmed as shown at the start of this thread. The one thing that's worrying me now is the fact that when I fitted the ABF head gasket, I removed one of the two alignment dowels due to the head gasket not having one of the holes in the right place (yep, maybe I should have just drilled it). If can remember being a bit concerned about the head gasket alignment and I was adjusting it slightly by eye.

I took the spark plugs out expecting one of them to have been steam cleaned, but they all look the same.

Hmm.

 

The Block Tester result is a concern, but until you see the coolant level definitely falling, and no leaks elsewhere; still blame the weather.

Misty as a misty thing in a cloud today wasn't/isn't it? That means the H2O content of your exhaust gases has nowhere to go as the air is well and truly saturated.

Go out for a curry and a pint or something to take your mind off it.

 

Hi,

I built myself just the thing with sealed DJ type headphones which are by far the best thing i've found for listening as they provide superb isolation. If you are going to be using a listening device, from my experience I would recommend not making the bandpass filter too narrow as it causes too much attenuation of the knock signal, (centre frequency/2.6 is a good bandwideth with a moderate roll off) and if possible make it so that you can adjust the centre frequency. The problem is that the knock frequency can change with engine speed and very often, 7khz as you mention can typically be the same frequency as valve closing events.

For my device in the end I set up the bandpass filter for 5 to 20 KHz and used 2 knock sensors. This way I could better use my ears to determine knock from other engine noises as you can listen for all the knock harmonics.

Copper tube bolted to the block is obviously another tried and tested method

 

Thanks for sharing your experience and advice, it's extremely useful.

A Q of 2.6 is pretty gentle and broad. I agree about the knock frequency moving about with RPM (we found it to shift across 1kHz in one particular session) and I agree also that having it too narrow will throw away a lot of useful information. The recordings showed that the knock also manifests itself at around 15 or 16kHz also with various other harmonics, and some quick FFT analysis in Audacity suggested that keeping that higher frequency information is also quite important when you're trying to pick out the knock by ear; so based upon that together with your advice I'll keep it broad.

The filter I have ready to test at the moment is an Akerberg Mossberg 2nd-order BPF idea passed to me by a guy on the MS-extra forum, which is a rather nifty topology that enables independent control of bandwidth and centre frequency by altering resistor pairs; therefore a couple of dual-gang potentiometers gives you tuneable frequency and width.

I like your idea of using two knock sensors. Whereabouts did you locate each one? Did you have each one run through a separate filter to the L / R of your headphones? Did this make the knock more distinguishable because you could hear it from both sensors?

Good to discuss ideas like this anyhow as I'm determined to put together a good system. I went out in the car the other day and my passenger said it pinked like buggery for definite at one point, but I personally couldn't have said whether it was just the clattery gearbox or what.

On another note, going back to the subject of the exhaust steam... in another thread I posted about the Block Tester, I've reported that a re-torque of the ARP head studs appears to have resulted in the Block Tester fluid staying completely blue, and has also raised the cylinder compression, too. I think maybe I just didn't re-check the torques enough times when I originally did it. It'll probably after Christmas before I can play a bit more. But fingers crossed I'll be able to properly run the bloody thing in now - once I have sorted out the brakes...

Trev