Increasing idle timing (stock IX engine) from 5 to 17 degrees pulls a stronger vac, sounds better, is more responsive, run fewer ISCV steps.

I didn't go beyond 17 degrees, must be getting near to MBT? Every extra degree did pull a stronger vac. Surprised I didn't get to the point where vac got weaker again. Couldn't hear any detonation.

Downsides? Cat warm up time? NOx emission?

 

I have done this on my VIII....for the open loop during warmup. Increased to 12 degrees from 5. Much less stumbling and better driveability

The timing is retarded by the factory to light the cat off quicker, so be aware of that. I have a wrapped DP to help it light off tfaster though.

Probably does mess with the HC and NOx, but my car passes all check very handily

Milburn

 

My last 4G63 (Twincam Staz) was set to idle in a "well" at 14/15*.
That was where it was happy!
Came as a bit of a shock to see the typical evo idle timing.

jcs, have you found anything resembling cranking timing v temp yet?

 

Surprised you haven't thrown a CEL. That's a LOT of idle timing.

 

I have my base idle at 8* it seems to do pretty well. I may try increasing it a bit although I don't think it will matter much since the idle timing jumps around a lot because of open loop, er closed loop.....which ever it is.

 

i also have my Idle to 17* and never had any issues with it, if i go 2* more then it start to get a PO300 code....

 

He probably has the P0300 code disabled?

Did you have to retune your IVSC tables to prevent a high idle speed? Also, are you just adjusting the base ignition table to acomplish this or is there some idle ignition timing tables?

I adjusted the coolant temp based ignition trim to to reduce the amount it was pulling out by about 5 degrees. It made a huge difference in how well it ran, but it also wants to high idle on cold start now.

Also, are you IX guys running a lot of cam retard at idle?

 

[QUOTE=03whitegsr;6815353]


I adjusted the coolant temp based ignition trim to to reduce the amount it was pulling out by about 5 degrees. It made a huge difference in how well it ran, but it also wants to high idle on cold start now.
[QUOTE]

Could you please show an example?

 

I'll have to post up tonight with the revised tables.

 

JDMs don't seem to throw P0300.

Not touched the ISCV, but it was maybe idling about 50 RPM higher.

I'm running stock MIVEC at idle.

 

any reason to go so far! what use is extra vac?
the smoother tickover is a plus it just seems wildly increased from most.
maybe half that would be a nice inbetween?

 

I was intending to stop if it became rough, knocked or the vacuum weakened, but I didn't reach that point and stopped at 17 for no particular reason other than I got the hint I might be nearing MBT.

We could rephrase the "use of the extra vac" question, and ask what is the point in the extra air and fuel you need to make it idle with less timing? I can only think of NOx. Uncertainty was the reason I posted.

12 would probably be good, since many use that and it was enough to make it smoother and crisper off idle.

I was happy with the idle before, I just thought I would play with the live mapping, I wouldn't have wasted flashes on it otherwise since I was happy, although having tried more I prefer it.

 

fairy muff
john what will you do with your self when every parameter is concoured

 

John,

The live mapping was something I was definitely looking forward to as a major mod to various ROMs, since I was so used to it with DSMLink. I wonder why it never caught on. If I were good enough to implement it, I would have already.

I think that is part of the reason why I don't tune or mess around with my car that much...I just hate the hassle of reflashing for every little change.


Eric

 

The trouble is it is so complex! I've simplified the programming so now all the assembly is in one file, the routines are mainly interrupt driven and the vectors are the same between all the SH2 ECUs, it is really just putting in the variable locations for different ROM, and there are about a dozen instruction changes and hooks which are not too bad now. But now with map tracing and SD, and a plethora of xmls floating about, version control and support are the biggest issues.

Even a guy who managed to do a 2.3 GT35R on SD without too much trouble and has mapped over a hundred Evos on the stock ECU is going to leave playing with it until he comes to see me this week so I can demonstrate it in person. It really isn't difficult once you know how, but in adding features and flexibility I think it has scared people off. Now you can map trace the max knock over the ignition map and adjust the ignition map on the fly, all in one application. Not done the same for fuelling as I don't run a permanent WB that is ECU logged, but it could be added. Maybe this guy will help me work out how to explain things better when we see how he takes to it.