your right, i wrote it backwards, i admit that

 

man this thread has so much potential for helping out people, but its cluttered with nonsense. anyhow...

i think i know what you guys are talking about with flat curves, ramping up timing to a certain value then carrying that through to the rev limiter. ive seen a bunch of tunes (especially crome bins for some reason) that do this. personally, i pull some timing around peak tq, or at least dont ramp up substantially till after that.

ive been doing a lot of monitoring with my b20 and neptune over the past few months, and noticed that the actual ignition while at wot can be as much as 10 degrees over table ignition. the ecu on its own seems to want to ramp it up consistently. by pulling a bit of timing around maximum tq i can keep the actual ignition value relatively consistent through that rpm then it advances itself again with rpm past max tq.

what i really struggle with and is in my opinion causing slight detonation in my engine is that the ecu adjustments seem to try and run the high load columns (on an n/a engine) with much more advance over table ignition compared to low load like 18" vacuum. ie - my table timing at .8" and 3800 rpm is about 26*, but the ecu is running it at roughly 33*, with an advance of around 7*. now at the same rpm my table value for 18" is 38* and the ecu only runs the actual timing at about 40*, only 2 degrees of advance. imo this negates pulling timing under load, as the ecu is very disobedient lol.

 

I wish someone had really good dyno plots of timing curves that were flat, ramped, and had the timing pulled around peak torque. When i initially got my tune done it was done with a flat timing curve from 4000rpm to the rev limit, i changed it based on suggestions made by muckman's dyno's to raise a half a degree every 500 rpm and the car seemed to respond much better.

 

You can disable these ignition adjustments in Neptune, if you want complete control over ignition timing.

'Parameters' window -> Main Settings -> Options

Just uncheck the box for ignition adjustments completely, or disable it above a certain load.

Just be aware that if you do this, prepare to completely reshape the ignition curve.

 

to figure out everything you wanted to know about ignition timing about your specific engine, just plop down $10gs on one of these

http://www.tfxengine.com/

 

I know a bunch of r35 guys monitor combustion pressures.

You can get an in car system for cheap... the sensors are actually really cheap, its the software that people charge an arm and a leg for, however the sensors will connect to a standalone and if you know the scalars for your particular sensor, your ems can log the pressure

 

You could also look into ion sensing...

 

yah i did that too for the hell of it as i was struggling for whatever reason to have my plugs stay "speckle free". it really turned into progressively ramping up timing with rpm. it took a few hours driving around but i was able to pretty closely replicate the "actual ignition" for what it would be with adjustments on. from there i pulled about 2 degrees under load.


spawne, the ecu ramps that timing up automatically. by adding it in the table you are just increasing the amount it ramps up. im probably wrong but id say that some engines that have excellent ve can get away with it, but other motors that dont flow as well might run into issues.

 

My bad. Read that part wrong.

 

If i had a vtec motor i would be inclined to agree with you, problem i was having was that it wasnt ramping at all. Actual timing was exactly the same as table timing, we are still confused about this to this day.

 

damn man ill trade you lol! im working with a nonvtec b20 and an rtp installed in an obd1 pr4 ecu.

if it wasnt ramping with the adjustments, i think u did the right thing by ramping it up. i do remember reading through most of your thread at various points, and i think its possible your skirt wear was due to not enough timing increasing egt causing piston expansion more than your ptw was set up for. in addition to the ramp up, i think the timing would have started at 3-5* more than you had in it from watching how my ecu was reacting.


to all contributors in this thread, is there a way i can get my ecu to adjust less aggressively like if i start with base code from a different ecu then import my tables?

 

well when writing the tables manually, my concern was where to know where the limit was without a knock sensor, muckman had thought that i probably could have pushed it to somewhere around 30* without it ramping the timing, but i just wasnt sure of that.

 

hey thanks man. im pretty excited about it! will be easier for people to say it reads high, rather than trying to explain for hours on end that the mustang dyno we are using reads low haha. our dynojet was pretty standard, but now the other local tuning shops that use dynojets are jacking with the corrections to skyrocket the numbers. its all such a game haha. i wish you could educate people and they would understand, but in the end everybody just seems to want the highest number, even if it means their car is going to blow up in the parking lot afterwords lol some of the stories we hear about some of the other local shops would blow your mind, and somehow they still have business. i dont get it

 

Thanks for those who are contributing to the thread, Gaining some knowledge. keep it up.


So reguardless of the ignition value in the table the ecu has its own correction factor that the end user cannot change? SO its all sort of a "by feel" type thing?

 

my current answer is both yes and no. the ecu does have its own correction factor. you can either disable it if your software allows for this or you can decrease your table ignition which in turn will pull down the actual ignition a bit.

example, if your table is 29 degrees and you see 36 degrees actual, you can get the actual down to say 34 if you bring your table ignition down to 27. i dont think its totally linear like that but its along those lines....

its not a by feel thing though, its a by spark plug reading and knock detection thing

 

Makes sense, i am also running Neptune RTP. great software. guess Im going to go for a drive and log some Isht.

 

so for example does a p75 ecu try do run more/less correction on the ignition timing than say a p72 ecu?

 

I don't think enough of the original honda code has been unlocked enough to know for sure how much it is correcting.

 

But that is aside the point, Either way it DOES change the timining.

Now is the "Actual TIming Value" displayed within the program the actual outputted timing number or is this Phantom correction factor applied afterwards?

 

"Actual" is actual, after all corrections.

 

Actual is only actual with the Honda base ECU. Use any other EMS and the "actual" goes out the window.

 

Which is what we've been referring to for the last several posts, no?

 

Maybe, I didn't read all the fine print. lol

 

So when running an aem ems whatever you have your ignition table set to will be your "actual" ignition as long as you don't have any other maps adjusting your ignition?

 

If there are no other correction factors, yes.