Rex4Life

Thought I'd post this up for discussion. I decided I wanted to generate a stock ECU ignition map, so I hooked up the ole timing light and made some marks on the pulley. After the stock leading yellow mark, I made black marks (on whiteout) every 15 degrees and silver marks every five. This enables me to read the ignition advance with a timing light. Here's what I came up with:



A few interesting things:

1) Stock ECU does nothing with ignition advance based upon boost pressure--huh, I always thought it did. But the Rtek kicked in on the 13 psi point and did reduce the advance, but up to 8.6 psi no retard due to boost.

2) The AFM has a HUGE effect on timing--that's why I altered my test plan and included data for lo and hi load conditions (albeit very unscientific). Aside from rpm, the AFM signal is probably the next biggest factor. This should be a big warning for guys using SAFC and fuel only ECUs. This means don't remove the AFM if you have a fuel only ECU in addition to stock ECU providing ignition.

3) I still don't fully understand why the vacuum values are retarded so much???

I tried to put all the caveats on the image but surely you guys will have some questions. If you know about #3 above let me know.

Scott

p.s. Oh yea, the ususal disclaimer, if you use this data do it at your own risk.

Node

iTrader: (1)

awesome, thanks

Wankel7

Very intresting...

Any way you can figure out the trailing split?

James

Turblown

iTrader: (12)

What does it do at higher rpms?
Gosh why are they pulling away timing?

Rex4Life

I kinda assume that by that by 3500 rpm the timing is flatlined. I checked up around 4500 rpm and it was the same.

Yes this method could be used for trailing also, but I didn't see much need, that's been beat to death already. If I had a setup that was out of the car I would test the trailing.

RETed

How did you simulate the air temp and water temps?

I have a chart that Henrik posted of the stock ignition timing maps for a Zenki turbo a while ago...


-Ted

Rex4Life

I'd like to see that chart, do you have a copy or link?

I didn't need to simulate air or water temps since this was done on a running engine. I would think that for a warmed up engine the water temps would remain relatively constant. So that shouldn't be a big player.

The air temp is something that I realize is not quite right. Under higher loads the air temp would increase and cause a little more retard of the ignition. I do know from datalogging on street driving the air temp doesn't go up that high--even under heavy boost--perhaps cause of the FMIC I'm running. Believe it or not, it seems one of the bigger factors on the air temp is from heat soak.

Scott

RETed

I have it on my puter at home.
I'll drop the file when I get home.


-Ted

Wankel7

Thanks man I just spent 20 minutes searching and could not find that thread.

James

HAILERS

http://www.teamfc3s.org/forum/showth...5&pagenumber=1

Rex4Life

Ok, so just how do we read this? I know the colors are ignition advance from 0 degrees. Ted, is yours any different?

What are the load values and S## rpm values--how do these relate to real word parameters?

RETed

I think it's the same data.
Here's the raw numbers.


-Ted

Rex4Life

Thanks Ted, that's good stuff there.

I see the ignition advance data in columns for RPM; do you know what the row variable is?

Scott

RETed

Yeah, it's not explicitly defined, but it's easy to spot the "0" is.
Also, since the boost sensor is a "2-bar" MAP, you can estimate what the load ranges are.
I would go +15psi and -15psi?


-Ted