Warmed engine, no knock; what controls timing

Delox · Post by **Delox** » Wed Apr 27, 2011 8:37 am

I'm combating some high end knock currently, and I've noticed that even when the car is up to temp and the knock system is disabled (resistor in ECU path, sees no knock for tuning purposes) I am running more timing than I am trying to dictate the car to have. Notice the position on the map vs the datalog'd timing at that given time.

What exactly controls the timing when warmed up besides this timing map??

Eric · Post by **Eric** » Wed Apr 27, 2011 5:57 pm

There are still quite a few tables that can influence the timing.

the main one is TADVC(warmup timing advance)
Also a faulty neutral switch can advance timing in some cases, but usually only at idle.

Delox · Post by **Delox** » Thu Apr 28, 2011 3:04 am

I'll admit I haven't scoured nistune completely, but I will ask, in addition to the "warm up" advance (even at operating temp?) what else could be causing this timing? Does that timing not seem high for full boost/load? It was nearly 30 when I first data-logged it!

Delox · Post by **Delox** » Sat Apr 30, 2011 2:36 am

Any input? I'm concerned to even drive the car until I can pinpoint why I'm having such advanced timing. I'd actually have to go negative on the timing map to bring it within reason...

Eric · Post by **Eric** » Sat Apr 30, 2011 4:44 pm

25-30 BTDC under full load is very high.

can you post (or send) the bin to have a look ?

a screenshot alone won't tell that much.

Delox · Post by **Delox** » Sun May 01, 2011 3:13 am

I've attached one of my bin's that I've been messing with to figure out this timing. I totally understand and agree that there is way too much timing top end and I cant figure out why.

Eric · Post by **Eric** » Mon May 02, 2011 1:50 am

I can't find anything weird that might be causing the over advanced timing...

Although I noticed you are using a 48P01 base image ?
Is this also what has been programmed into your Nistune board ?
(you can see the the base image file in your Nistune board once connected to it with the software)

I have never dissassembled this particular 48P01 ROM, but maybe this ROM has some additional tables or variables messing around with the timing...

To be on the safe side, use the 47P10 base image

Also copy regular ignition map to knock map, as it may be reading from the knock map, which in your current ROM has more advanced timing under full load then the regular map

-Eric

Delox · Post by **Delox** » Mon May 02, 2011 8:24 am

hm, thanks for catching the base image, i'll have to double check that. Also about the knock map, I have my knock sensor disabled (resistor), but from what I've heard, the car can still access the knock map occasionally, so I'll do the knock copy.

I found a melted ground strap on one of my spark plugs today

so its taken its toll on the system. Once I get a new set of plugs in I'll take your advice and give it another try.

-Rich.

PL · Post by PL » Mon May 02, 2011 11:04 am

Please let us know the outcome of this one. I don't do much Z32 tuning but these ECU's are widely used for tuning R33 RB25 engines here in Oz.

I've never had an ECU add timing over what's in the main timing map. I know they'll pull timing for any number of reasons. But to add timing scares me more than a bit.

Thanks
Pete L

Matt · Post by **Matt** » Mon May 02, 2011 2:46 pm

Would like a log file to see your input parameters and resulting timing so I can repeat here with that base image

Delox · Post by **Delox** » Tue May 03, 2011 1:29 pm

Here are a few recent pulls

Delox · Post by **Delox** » Sat May 07, 2011 3:33 am

input? Received new spark plugs today and I'm ready to get back at it. Not sure how to approach it though.

Also, I'd like to add that I'm having trouble loading up the correct base file. While hooked up to the ECU I see this as my ECU type (I believe thats what this is)

So i am using the wrong base file for my *.bin... How can I change this to the correct one? I have the correct base file in my ROM pack (for the 41P60), but my current tune is using the wrong (48XXX) base file. Can I merge my tune file with the correct base file, even though it's already merged with the wrong one?

Eric · Post by **Eric** » Sat May 07, 2011 4:58 pm

Not sure what's going on, but it looks like it sort of uses the values in TP row 34 as the last row in the ignition map.
Once TP gets over ~ 35 it looks like it is still reading this particular row in the ignition map to calculate the timing and is ignoring the values in the TP corresponding rows.
You could try a 41P60 ROM and copy your maps into this base ROM and see if it behaves the same ..to be on the safe side mechanically retard the ignition about 5 degrees (by turning the CAS) and don't go full boost but just enough to reach approx. 40-42 TP and see if the timing as shown in the logfiles is corresponding with the values in the map.
If it does, gradually increase boost (and TP) and check again.

regarding the merging of 2 bins, I'm not sure how to do this in Nistune..
Maybe Matt can explain if or how it can be done.

but personally, to avoid any '48Pxx' specific tables and variables to be copied to the 41P60 base-rom, I would just do it manually by opening 2 instances of Nistune and manually copy the main maps/variables and tables into the 41P60 rom.

Delox · Post by **Delox** » Sun May 08, 2011 3:30 am

Not sure what's going on, but it looks like it sort of uses the values in TP row 34 as the last row in the ignition map.
Once TP gets over ~ 35 it looks like it is still reading this particular row in the ignition map to calculate the timing and is ignoring the values in the TP corresponding rows.[/quote]
Unfortunately I think my understanding of TP is less than it should be.. Time to re-read some materials.

Eric wrote: but personally, to avoid any '48Pxx' specific tables and variables to be copied to the 41P60 base-rom, I would just do it manually by opening 2 instances of Nistune and manually copy the main maps/variables and tables into the 41P60 rom.

This is what I was thinking of doing for the same like of reasoning. I want to steer clear of any and all carry/over from 48PXX.

I thought I had a handle on this finally, this is making me feel

...

Also, does it make sense that my ECU is 41P60 and not 47P10? This is not my original ECU, my car is a '91. It looks like 41P60 was for a 1992.

Eric · Post by **Eric** » Mon May 09, 2011 3:13 am

I would use the 41Pxx base image to start with... also to rule out the problem isn't caused by any ROM compatibility issues.

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Warmed engine, no knock; what controls timing

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