Sandgroper

Okay. If I use the values from the ABUT which has a Spark Reference Angle of 6* should the BLCF Spark Reference Angle be changed to match it at 6* as well, or will it be okay so long as it matches the physical setting at the crankshaft?

Currently SRA is 9.84* in the binary and at the crankshaft (mark on the balancer).

The stock SRA (in ABUT) is 6*, but I understand it will be okay at 10*?

RBob

iTrader: (1)

The spark reference angle (initial SA) needs to match where the distributor is set. Stock for TPI being 6* BTDC.

RBob.

Sandgroper

At the moment SRA is set at 10* BTDC, that's what the people on the delcohacking suggested. I'm not sure if it was suggested because it is best for the tune of the car, or if it's best suited to the $12P software with my style of engine, or if it's just a standard response i.e. using a standard value that they know and are familiar with?

I've arranged to take the car to a dyno tuner for an assessment in the next few days. I am wondering whether I should set it at 6* BTDC or at 10* BTDC.
--
The engine has 11:1 compression, so I tried putting 1 litre of E85 Ethanol into 1/4 tank of fuel - it seems to make a bit of a difference but hard to tell if it's that or something else since the tune changes so much at the moment.

I wonder whether it might be good to swap in a slightly thicker head gasket to reduce the compression to an acceptable 'pump gas level'?

syntax terror

If you have a healthy cam you should be able to tune it to run on 11to 1 cr

Sandgroper

Cool :-) the cam is Comp Cams 08-502-8 Grind#XR269HR, will that do it?
--
Now that I have $12P running I want to also put $8D Super_AUJP onto the NVRAM. The Aussie board has a jumper to hard switch to extend the address space in the module - like having two EPROMS I suppose.

I've got the code into TP5 and set it up roughly to start, but I'm not sure how to go about burning it into the NVRAM through the USB cable. Maybe it needs to come out and flash it in a programmer?

I'm familiar with that process, but not too sure what address offset to write the 32K $8D bin, is it 0x8000.

Sandgroper

Thanks tunedperformanc, here's a picture of the computer. I ended up using the '808 that I bought as a spare. Mainly because of it's small form factor and the way it mounts under the dash. The USB board provides fast communications (8192 baud).

I'm hoping to get Super_AUJP ($8D) code running on it in conjunction with OSE $12P. The wire on the bottom right of the pic splits the address space into 2x64K spaces (0x0-0xffff & 0x10000-0x1ffff).

Tuned Performance

iTrader: (92)

Thats cool stuff right there, Im staying tuned

Sandgroper

The knock sensor hasn't been working properly... While looking for ways to run $8D code on my '808 (aka 1227165) I stumbled across this note about '165 external ESC Knock Sensor Module 100 K ohm signal.

It may require a 3.9K ohm resistor to bias the 100 K ohm signal so I'm going to try and jumper pins A12, and B11 (was B7 before $12P) with a resistor.

[Edit] I tried this and it works - I'm stoked man!

I was getting constant knock at around the 200 count mark, and of course constant spark retard with that. Not anymore... woo hoo!

junkcltr

iTrader: (1)

Some of the $8D I/O in the bin need to be changed to the 165 appropriate pin or address. These are code changes.

Sandgroper

Yes... I am running the OSE $12P software and a Speed Density MAP setup instead of MAF. So the pins have been wired to suit that. It's similar wiring as the 1227165 to 1227730 conversion except B7 moves to B11. I have a (temporary?) jumper wire from B11 back to B7.

It just crossed my mind, that I am still running the external ESC Knock Sensor module with a 4K ohm resistor across pins A12 and B11 to bias the 100K ohm signal.

Maybe that has something to do with it?

It did start at some point but stops after a couple of seconds pass. Similarly if you touch the throttle it will stop. Hmmm?

Sandgroper

Did you say code changes? Is there a list of the pin-outs for an $8D ECU like 1227165 preferably (or 1227730 I can translate)?

Lucky I read your post again. Thanks junkcltr.

syntax terror

Take a look at this http://www.exatorq.com/ludis_obd1/p4xref.html
I suggest that you get it tuned first then work on the other fun projects as I have found that they can get you side tracked. Make sure that your distributor setting maches whats in tunnerpro so things read right.

Sandgroper

Does this also apply to AUJP and Super_AUJP, those tables show advance cells greater than 42*, where does the -3.5* - 42* limitation come from?

Sandgroper

How does this work, can you set it up with parameters of a modified engine and use it to (theoretically) test your calibrations on the bench?

Is there a computer modelling tool that can simulate a modified engine?

RBob

iTrader: (1)

It is the limits of the distributor, not the calibration.

RBob.

junkcltr

iTrader: (1)

Yes, 165 ECM and $12P or MAF code is a go.

No, $12P and 730 ECM is a no go even if you re-pin the ECM connector. Look at the Microprocessor schematic and you will see MUXC and others need control on the 730 ECM that the $12P code does not do. Again, you need code changes to the $12P to run on a 730 ECM.

Sandgroper

Cool. Straight to the point... I appreciate that junkcltr, thank you. I'll look into that when I get some more time. Just got distracted again at the moment...

Sandgroper

Thanks RBob. You are being a great help. I'll come back to this soon...

Sandgroper

Check out this thread on delcohacking http://delcohacking.net/forums/viewtopic.php?f=9&t=2543 it's made of the same stuff...

Sandgroper

If that's a mechanical limitation... Then I think it might be possible to shift it by changing the Spark Reference Angle. Only if necessary to get more advance. E.g set SRA to 10' (from 6) would that then give a range of between -0.5' and 46'?

RBob

iTrader: (1)

The physical base setting and the calibration always need to match. With an initial SA of 10* BTDC, the range of at-crank timing is from 6.5* to 52* BTDC.

RBob.

Sandgroper

Thank you RBob, but I must say you've lost me somewhere. May I try to clarify....

Assuming (below) that the Spark Ref Angle (SRA) always matches between the calibration and at the crank...

When the SRA is set to stock at 6* - I understand the Max Retard is -3.5* and Max Advance is 42*.

So when SRA moves +4* i.e. to an SRA of 10* would that not shift the range by 4*?

I don't get how you've derived a range of 6.5* to 52* - or am I misunderstanding - not too sure. What did I miss?

RBob

iTrader: (1)

Recall that it is the limits of the distributor, not the calibration. Being able to program a maximum of 42* advance into the distributor, the base setting gets added to that. Which is 48* BTDC at the crankshaft with an initial of 6*.

Same for the maximum retard allowed in the distributor.

RBob.

Sandgroper

Thanks RBob

The distributor range limits are added to the base, which is the SRA. I understand that part...

I would be grateful if you could look at the attached XDF ($12P) and advise which are the relevant settings.

http://delcohacking.net/forums/downl...le.php?id=4323

This is a link to a recent bin if it it helps too.

http://delcohacking.net/forums/downl...le.php?id=4321

Sandgroper

Yes you would need writeable memory for the learn functions to update. $12P also has flexible (flex) tables and inputs (on the ECU pins), that can be configured to do whatever in the TP5 ADX - I think.

RBob

iTrader: (1)

The titles are not entirely correct, but it is these two:

EST params - Maximum Spark Advance from TDC
EST params - Maximum Spark Retard from TDC

It is really from the SRA, not TDC.

Note that in the Tuning Guide Book sticky, chapter 5, the 8063/7747/8746 ECM section there is a write up on the SA logic.

RBob.

Sandgroper

So if the SRA if 10* BTDC, and the distributor has a movement range of 45.5* then I would initially guess that these variables ought to have the following values...

EST params - Maximum Spark Advance from TDC = 42*
EST params - Maximum Spark Retard from TDC = -3.5*

and, the above values are still correct if it's from the SRA instead of TDC as you say.

Would it be correct to think of it as the SRA is at zero on the distributor?

So that being the case SRA at 10* crank, and zero on dizzy would give an effective timing range between 6.5* and 52* - is that right?

I searched these forums and Google for the Tuning Guide Book sticky, chapter 5, the 8063/7747/8746 ECM section to see the write up on the SA logic.

All I found was other references to it but no links to it. I would like to read it, have you got a link to it?

Tuned Performance

iTrader: (92)

https://www.thirdgen.org/forums/diy-...cs-anyone.html

RBob

iTrader: (1)

Go back to the main page for this forum (DIY_PROM forum). Up top are the Stickied links. One of them is the Tuning Guide Book. Can spend days on end reading the links in that thread.

Your other questions have already been answered. Go through this thread again and re-read the stuff.

RBob.

Tuned Performance

iTrader: (92)

how the progress going

antuss

Digging up an old thread, but ive joined 3rd gen for a visit from delcohacking land and have been having a look around. I just wanted to clarify here - it sounds like your other codes are differnt - but in 12P the spark reference angle refers to the timing input to the ECU. That is when the ecu gets the electrical signal from the reluctor, so 10 degrees BTDC means that the ecu is triggered when the engine is at 10 degrees BTDC. That part of the system is isolated from the rest and should be configured to match your trigger hardware. The 10 comes from the default setting used by GM in most of their reluctor ignition modules. They fire when they see the trigger (no delay) when they are cranking, so the 10 degrees BTDC offset gives you a 10 degree BTDC spark when cranking before the ecu has synced up and takes over. The GM spec is 10 degrees and should match your distributor.

Everything else spark related shows real world spark timings - you do not need to take your reference angle in to account. Thats the main spark tables, limit tables, the displayed timings, they should all match exactly what you see on your timing light regardless of the reference angle of your trigger system.

Also, beware converting MAF load tables to MAP. Your engine might run, but they are different relationships. The MAP VE table shows how well your engine is breathing based on pressure not airflow. Typical VE tables drop back down again at higher RPM and past the point of max torque, and when the ecu calculates the air and then fuel, the rpm makes up for more than the amount the VE is decreasing. Thus the result is still more fuel overall. In a MAF table your measuring airflow so the tables wont back down, they will be lowest at lowest load and highest at highest load. So it is not a 1:1 relationship to the MAP tables with different scaling.

Probably a better approach would be to get one of the default commodore tunes for an engine with the same number of cylinders, adjust the injector rate if needed, then adjust the whole VE table by the % difference in engine capacity. This way, even though the VE wont be perfect, it'll at least have the right kind of shape. Hope that clears things up!

Sandgroper

bump