The point for me is that after all the BS it still seems that no-one (including MM)actually knows what the numbers in the table mean .

 

You don't need to know.... hell they could be stored in Hexdec or Binary for all we know (and I'm too lazy to find out) - if it makes the translation easier for the PCM.... kinda irrelevant.

 

True . I guess if MM has scoped the changes and got the results he expected then it is irrelevant .

 

Quote of the DECADE.

No, if everyone would just apply this to everything, we would be in much better shape.

I know this is an Internet forum and, therefore, way over-stocked with geeks, nerds and math-tards, but we are talking about a car and all the incredible approximations that go into making it what it is.

Figuring out the math is not about coming to conclusions. Its about setting a baseline upon which you can build. It doesn't matter what the actual numbers are as long as you can repeat the effect.

 

I like this one personally.

 

I agree completely . But from the very start you threw a whole lot of red herrings out there that gave me the IMPRESSION that you knew what the numbers meant and how they related to rpm etc . This is why your final revelation did not go down well with me ...

 

I do know what the numbers mean. Absolutely. There were NO red herrings.
But it is totally useless information, apparently. Because, when I explained it, all I got was puzzled looks from everyone involved.
It wasn't that they were being misled. Its just that they were being led to somewhere they hadn't seen before and couldn't make believe they understood the path.

People don't want to understand things. They want the things they don't understand to be changed and conformed into things that they do understand.


This is the real reason I don't like explaining things to people - all they will do is argue until the thing that was explained is made to look like something else that they can explain away.

 

I ,for one, DO like to understand things . You could accuse me of being too lazy to go and get dwell scoped for myself which would be fair .
But I did not really have any compelling reason to do that other than - I might need the info one day if I go for higher boost etc.
Could you point me to your previous explanation and I'll try see if it makes more sense to me now ...

 

I will second that Brettus. I absolutely want to understand things. I tried a while ago to understand a few things but got shot down for it... wrong question in the wrong thread!

The problem I see is that not everyone understands the same things in the same way. Simple as it is, I had never thought of this problem in this way "deviation from a known standard"

 

Deviation from a known standard would not have worked if the theory put forward earlier in the thread were correct ( about a 2ms Base with a modifier table) . That is why it is dangerous to assume that theory unless you have evidence to back it up . IE scoping the results before and after .

 

As a senior software developer and mentor I have always followed and always teach the you should never leave something saying "That works but I have no idea why". With the RX-8 and flash tuning I have no access to the ECU source code and have zero experience with engine tuning. I am reliant on others experience and my own experience in what seems right.

I had never seen or read about the 2ms base theory until post #34 from atl8. But I have to say that it doesn't sound right to me as its way to variable for something that is very precise. On the other hand, a_ahlan's post makes very good sense, seems very logical, is backed by experience and findings from MM.

Reading back on a_ahlan's post I now have a question about spark duration

Cheers

Andrew

 

I did a little test on that theory a few months back (but forgot about it when alt8 brought it up again) . Set dwell to 0 at 2000 rpm just to see if the engine would run ................. It died as rpms approached that rpm so I dismissed the theory .

 

Would love to know what it was based on.

 

Which is why you and your apprentices will be sitting around, fiddling with minutiae while I'm out blasting around town in my car, enjoying the power.

I often leave things that work alone. There are plenty of things that don't work that you can geek about.

 

I'll even go one further -

If a man-made device works, why spend extra machine cycles trying to reverse-engineer it if you can just ask the guy that built it how it works?

But - be prepared for him to give you an answer like "It just does".

There are a surprising many things in this world, built by experts, that just work because they do.

Sure, you can dissect the physics, but you will be no closer to any true understanding once you have.
Much of it is incidental.

 

Well a Known standard would be information that was not a educated guess... like the field service manual that lists what the dwell time is; I know I have posted that picture more than once.

"Perfect is the enemy of good" and all that jazz.

 

There are also a great many things in this world that we take for granted purely because people have said why does something do what it does.

I can sleep at night knowing that when I have understood something, there is a much lower chance that what I did wont result in unexpected outcomes.

 

Amen to that .

I also see merit in what MM is saying about the "just do it" attitude because if we always had to know the answers before we did stuff then we would never do it in the first place .

 

Sure...sometimes before you can actually figure something out you need to find what works...then you can start to theorise, etc. Been through one engine already...would now rather ask questions first

 

Sorry if I'm being a total ignoramus (I'm trying hard not to be!), but I'm really trying to figure out where my math is wrong..

According to the factory NA dwell map posted by auzoom in the first post, the value in all the fields at 9k rpm is 395. I divided 395/9000 = .04, then add 2, and it's 2.04ms dwell at 9k, not 2.4.

 

alt8 was saying it's 2 + 0.395 = 2.4

from the above discussion it would seem that this theory is incorrect however ........

 

In his example if you take the line of 12.75v, at idle the table shows 1208. He then believes there is a base dwell of 2000.

So you have:
1208 + 2000 = 3208 (3.2ms)

For 9000rpm By that logic it would be

395+2000 = 2395 (2.395ms).

I think its wrong though. Kane has shown the manual stating the base dwell is 3ms for the OEM coils.

I am running strong now using the "deviation from a known standard" calculation. Not that its hard to figure but I will post up the Dwell map I am running when I get home tonight.

EDIT: Geez I am slow at responding! ^^ what Brettus said.

Cheers

Andrew

 

In his example, he cites 1208/1000 (1208 is derived from the map value of 12V @ 1k rpm). This gives you 1.2ms, which is then added to the base value. Right? Ugh. Nevermind.

Is there any evidence of this 2ms base dwell time, or is it just an assumption?

 

seemed liked a pretty logical theory at the time but there is no evidence i know of to support it

 

As promised. Dwell I am now running using HEC715's.

Cheers

Andrew