Ecotec Negative Ignition Timing Values

Dylan · Post by **Dylan** » Mon Sep 14, 2015 8:59 pm

I'm doing a tune for a mates VX Ecotec. So sourced a new ECU and downloaded The1'a enhanced files to suit. Got the new bin flashed no worries.

Looking at the tune in tuner pro and noticed there's some ignition timing values in the negatives (by a few degree's)
Is that real or is there some offset table at play? This is my first attempt at an ecotec and looks to be some gains to be had over stock.
Very lean under load and not much ignition advance?

Looked over VS VT VX VY and they all look relatively similar. Hopefully someone can shed some light on it or has a modified tune from there own car to look over?

All help appreciated,

Post by **Jayme** » Mon Sep 14, 2015 9:11 pm

yes ecotec's require a lot less timing than their predecessors, due to a number of factors including head design, compression, chamber design, etc. the goal of timing is to get peak pressure in the chamber to happen ad 12 deg after TDC (-12) combustion is faster in ecotecs and so needs less advance. some of the numbers are lower than they need to be, to tame it down low, but dont get too excited, even a few degrees and the knock retard will rear its ugly head. if the engine has extractors, it will need more timing. if not, you wont get much gain up top in the spark table.
the negative values just mean to fire after TDC instead of before...

now imagine mandating that an ecotec MUST run on a VN ecu (speedway) its no wonder why some of those engines dont last running 15 deg more advance than they should

Dylan · Post by **Dylan** » Mon Sep 14, 2015 9:29 pm

Thanks mate at least I know I'm looking at real values then.
Have you tuned an ecotec before? I'll post up the bin I done.

Main thing he's after is some more fuel economy as he previously ran a VY snd thinks it had way more.
Probably down to O2 condition as the tunes are near identical.

But the quick one I've done made bugger all difference to economy and performance.
I haven't got a log yet but I will get the wideband on it soon.

Post by **vlad01** » Mon Sep 14, 2015 10:27 pm

There is a lot of performance to be gained in the ecotec, As Jayme says, be careful of detonation from too much timing, which isn't much compared to the pre ecotec.

Also the ecotec pistons are very brittle likely from high silicon content and do shatter easy even in NA.

One guy on FB who got The1's tune blew up 4 engines in a row in minutes of driving them. He had a walbro (fakebro) pump causing it to lean out. All 4 engines shattered pistons and it was just stock NA engines.

Dylan · Post by **Dylan** » Mon Sep 14, 2015 10:37 pm

Gee they're touchy things, I cant find the tune but I have the ECU here. I put a couple degree timing in up top and naybe 3 down low to bring the curve on a bit quicker.
And in the higher load area took it from 14.7/ 13 afr to 12.8 in every rpm.
Not sure how well set up the MAF is from factory guess ill find out soon.

Post by **vlad01** » Mon Sep 14, 2015 10:40 pm

maybe take a look at 202's ecotec tune for 808. Should give you some idea.

They really get up and go with a good tune. 0-100 high 5s when put in a VN/VP. Not sure about in a VX, they are pretty heavy so maybe 8-9 sec?

Dylan · Post by **Dylan** » Mon Sep 14, 2015 10:51 pm

I did take alook at that. Low rpm is at least in positive values (single digits lol) and peak is around 13 but I think the stock ecotec was low 20's?
Good to see it taking some low end timing at least.

Post by **Jayme** » Tue Sep 15, 2015 9:23 am

yeah some of the ecotec models were pretty lean in low rpm high load areas too... I never stuff with the maf or maf tables other than cleaning the element with carby cleaner. ... only touch PE commanded AFR and open loop values. never done a cammed ecotec with a MAF... they all go 808 by then.

as the MAF gets dirty, it leans out and uses more timing from what it thinks it less airflow... good combination

Post by **Holden202T** » Tue Sep 15, 2015 9:24 am

my 808 tune is not going to be that useful if your using a MAF tune though .... but if it helps then all good

also bear in mind im pretty sure that tune was for 98 octane fuel and the second map was 91 ?!?! you'll be able to see cause one map clearly has less timing.

Dylan · Post by **Dylan** » Tue Sep 15, 2015 9:49 am

Your 808 tune is what made me think if there's another table involved in the later PCM's from memory you're about 7 degree up down low.

Thanks for everyone's input though good to see other's have played with ecotecs. Sounds like we should get some gains out of it for sure.

I'll check the O2 readings when I get a log and clean the MAF. As he keeps saying how thirsty it is compared to his old VY. But that wont be tune related as the VX VY tunes are near on the same from what I can see.
Maybe there's something there I'm missing?

Ecotec Negative Ignition Timing Values

Ecotec Negative Ignition Timing Values

Re: Ecotec Negative Ignition Timing Values

Re: Ecotec Negative Ignition Timing Values

Re: Ecotec Negative Ignition Timing Values

Re: Ecotec Negative Ignition Timing Values

Re: Ecotec Negative Ignition Timing Values

Re: Ecotec Negative Ignition Timing Values

Re: Ecotec Negative Ignition Timing Values

Re: Ecotec Negative Ignition Timing Values

Re: Ecotec Negative Ignition Timing Values