M50B25 - Spark Map

[No name user 379]

it has nothing to do with trade secrets

ring your doctor and tell him you have sore finger and see what he tells you

you cant do that over the phone nor email you have to see it to know

theres many different ways to tune and you dont always get the same result

i tune for torque not peak hp,torque makes you move

also when tuning you need to have some way to measure temps on intake and exhaust to insure what your reading both in det and af is correct.

you also looking for a rate of gain which works for both na and turbo eg:if you gain 5hp from 1 deg timing thats the gain factor,when you do so again but pickup 2hp your getting close to peak before det and egt goes up thus peak cly presure.

at that point you add more fuel and the gain may go up again and if not your reached the max based on the fuels BTU's against compression,if your intuned with the eng you can pick this up if not then the dyno is very helpful.

you get the idea to why its not that simple and this isnt a piss take?

i dont even tell people this much cause it normaly ends in tears,you say its a cheap eng that great but your still the one to take it in and out each time it turns to custard not an option that i want to spend my time doing.

i see you run a rotax? cool i run a 250 shifter

Edited March 21, 2010 by crunchy

[rds 0]

it has nothing to do with trade secrets

ring your doctor and tell him you have sore finger and see what he tells you

you cant do that over the phone nor email you have to see it to know

theres many different ways to tune and you dont always get the same result

i tune for torque not peak hp,torque makes you move

also when tuning you need to have some way to measure temps on intake and exhaust to insure what your reading both in det and af is correct.

you also looking for a rate of gain which works for both na and turbo eg:if you gain 5hp from 1 deg timing thats the gain factor,when you do so again but pickup 2hp your getting close to peak before det and egt goes up thus peak cly presure.

at that point you add more fuel and the gain may go up again and if not your reached the max based on the fuels BTU's against compression,if your intuned with the eng you can pick this up if not then the dyno is very helpful.

you get the idea to why its not that simple and this isnt a piss take?

i dont even tell people this much cause it normaly ends in tears,you say its a cheap eng that great but your still the one to take it in and out each time it turns to custard not an option that i want to spend my time doing.

i see you run a rotax? cool i run a 250 shifter

I understand its not super simple, thats why I want to do it.

Yea i run a rotax. Shifter classes down here are very small, not really worth the effort if there is no competition. Im guessing you run in Open, whats your thoughts on the KZ2 vs the 250?

Good points about the "rate of gain", I can see why a dyno is handy when tuning a spark map.

Ok so your point about adding more fuel, this is to slow the flame front down so det doesnt occur?

If your wideband o2 is reading stoich or 14.7 then surely the burn is clean and your fuel is correct. Unless under high load when it is benefical to "richn" up the mixture.

Also is your peak HP normally close to where det occurs? Or can it vary engine to engine?

Tell people the information its their choice what they do with it!! Its not your bad if there sh*t blows up at least you told them good information. Im no idiot and i know the risks.

[rds 0]

And the point is that you should never just trust someone else's fuel and ignition maps (point number 1), and that it should be tuned by someone who knows what they're doing (point number 2).

It is possible that "someone who knows what they're doing" is an amateur, so point number 3 is simply that if you want to know for certain, get it done / tidied up / checked by a pro.

I'm going to have a go at getting my turbo M10 to run, but only because the engine that's gone into it cost $80. I don't expect to do a good job but if I can get it started and idling ok that will (hopefully) assist the tuning process.

Goodshit Cam, someone else who is willing to give it ago.

Idle is the first barrier! gl

[CamB 48]

For the record I wouldn't try on an M50 - in my case the engine has to come out again anyway (for the "proper" engine), so the one going in is solely there so first startup with an untuned computer isn't with a newly rebuilt engine (including new cam, which will need running in).

[rds 0]

For the record I wouldn't try on an M50 - in my case the engine has to come out again anyway (for the "proper" engine), so the one going in is solely there so first startup with an untuned computer isn't with a newly rebuilt engine (including new cam, which will need running in).

Wheres your sense of adventure, my M50 has done 1000kms in current form with no problems thus far.

I posted in the hope that I could eek abit more out of it

[CamB 48]

My pioneering spirit is a little weak today!

Speaking as someone's who's only researched and hasn't tried yet. There's plenty of information floating around the web about DIY tuning, its just really hard to sort out the good from the bad.

The one common factor I've seen is that its hard to get ignition timing right without a dyno (ie tuning to MBT like crunchy's talking about). MBT makes sense to me as a theory.

[barf 0]

here are some links on tuning theory i found:

http://www.daytona-sensors.com/tech_tuning.html

http://www.honda-tech.com/showthread.php?t=1060267 (LOL people tune Hondas?)

http://www.innovatemotorsports.com/forums/...ead.php?t=10210

http://books.google.co.nz/books?id=ze_w0i3...;q=&f=false

with regard to MBT; there is only one ideal time to launch the ignition event, for any given combination of variables. im not as experienced as some here, but afaik if you are adjusting timing to extract more power, then rather than increasing the power output, you have just yet to find the ideal or correct timing.

the reason ignition is advanced in the first place is that the peak energy conversion (deflagration) occurs latent to the ignition event, the piston should be on the power stroke in otto engines at this time (advance majorly considers time to reach peak energy conversion) otherwise should the fabled detonation (an explosion; which is the opposite of a deflagration aka 'burn') occur, the piston could be forced in reverse direction.

* detonation is detonation

* combustion is a deflagration (subsonic)

http://en.wikipedia.org/wiki/Deflagration

Edited March 22, 2010 by barf

[barf 0]

more tuning theory links:

http://www.streetrodstuff.com/Articles/Engine/Detonation/

http://www.gami.com/articles/bttfpart1.php

http://www.magnecor.com/magnecor1/truth.htm

http://www.motorsport-developments.co.uk/stus.html

http://innovatemotorsports.com/resources/rich.php

http://www.max-boost.co.uk/max-boost/ignition_deeper.htm

[rds 0]

awrsme posts barf

thanks!

[nastnas 9]

My advice to you would be to spend less time on bimmersport and more time on the megasquirt forums but don't ask questions like these as the answers will be short.

Goodluck.

[barf 0]

this whole concept of tuning for 'most-advance-with-least-knock' irks me. surely ideal combustion is the goal not minimum-acceptable-risk of detonation? what balance do you strike?

welp, fuel has to be my next question, how many degrees of ignition timing difference is there between using different RONs? are there any rules of thumb? eg; does 95/98 RON offer 2 or 3 more degrees safely over 91?

[rds 0]

My advice to you would be to spend less time on bimmersport and more time on the megasquirt forums but don't ask questions like these as the answers will be short.

Goodluck.

Telling me not to ask questions about performance tuning in the Performace tuning forum.....

Edited March 22, 2010 by rds

[Forrest 35]

^ I think he means you won't get much help on a forum like this, with many having not run with it, better to go to a better suited forum like a mega squirt focused one.

[rds 0]

^ I think he means you won't get much help on a forum like this, with many having not run with it, better to go to a better suited forum like a mega squirt focused one.

Yea true true, initally i thought the bimmersporters would be interested!! I was also hoping for a spark map for a M50 that I could steal the gradients off. I didnt think bimmersport was going to be the tuning gospel ;D

Edited March 22, 2010 by rds

[nastnas 9]

also try msruns... its the site for various project cars... so get onto megasquirt forums

[No name user 379]

Yea true true, initally i thought the bimmersporters would be interested!! I was also hoping for a spark map for a M50 that I could steal the gradients off. I didnt think bimmersport was going to be the tuning gospel ;D

thats pretty unfair,we have given you good advise its just not what you want to hear

im not about to teach someone how to tune with what ive learnt over the years in afew posts on a forum!!!

there alot more to it than meets the eye and ive told you a very basic way to start it so dont bag those who have tried to help, and as someone has already said why would people like my self be bothered to waste the time to help.

but hay what the hell would i know

[nastnas 9]

thats pretty unfair,we have given you good advise its just not what you want to hear

im not about to teach someone how to tune with what ive learnt over the years in afew posts on a forum!!!

there alot more to it than meets the eye and ive told you a very basic way to start it so dont bag those who have tried to help, and as someone has already said why would people like my self be bothered to waste the time to help.

but hay what the hell would i know

a bit harsh, but i do agree as well... What i have learned over the years with megasquirt is hard to write on a forum...

[*Glenn* 854]

My car is running well with the LC-1 o2 all hooked in and tuning to AFR table. The car runs well currently it has got good pickup reponse etc.. but I was hoping to get the most out of the engine.

Seeing youve got this far, I would now suggest you get on a dyno and have an experienced person (tuner) give you the right advice. Its either right, wrong or close. Every car is different as suggested, even different air filters will change things...there are so many variables between motors, even if they are the same. You cant use someone elses map long term. For start up and driving to a tuner...yes you can use someone elses map. And you cant teach experience, or learn experience on a forum. The tuner might also be prepared to let you watch and teach you a thing or two. Maps from tuner sites may not work well either. Altitude also has alot to do with tuning as well... ask any tuner. Maps get changed on serious race cars virtually every meeting due to atmospherics, air temperature changes and track conditions.

[mr E34 11]

Tuning is an art! Crunchy has 'natural' ability to understand what each engine design likes.

Thread closed.

[*Glenn* 854]

Thread closed.

I'm tempted... one more straw will do it.

I got 2 straws

Edited March 23, 2010 by *Glenn*