Street tuning with a narrowband and stock sensors

[MD323]

Well now the MS bug has bit me and I have already spent 2 hours just learning how to navigate the megatune menus. my next big hurdle is learning to actually tune it to make the same or greater power than i am on the stock ECU.

I have some dyno time coming up in which i will give it a full wideband logged tune but i want to "street" tune it and see where i get. I am constantly at the drag strip so i can data log a run and make adjustments afterwards but i need some guidance here on where to stock on an internally stock BP in N/A trim. I have a narrowband and the standard gauges and thats it at the moment.

no im not asking for maps but some example one would be nice, i m asking for those who have done it to point me on what to change first and answer a few questions.

like what is a safe a/f ratio on an N/A BP with 89 octane?

im currently running 16 degress base advance on the dissy, should i bring that back down to 10 deg and tune it on the MS?

any other pointers would be nice

[smoke187]

i think you should get your own wideband before attempting to tune

not sure what the best af would be on an n/a bp but idle would be good between 14-15

[MD323]

getting a wideband in 2 months or so, gotta make due after dropping the cash on this and a new place with a garage

[smoke187]

just wait till you have the money for the wideband then worry about tuning

[Lex]

Glad you're enjoying the MS

I would set the base timing so that it is in line with what the MS thinks it is. That way you can adjust timing reliably and accurately as desired in the spark tables.

It will be tough to tune using a narrowband and no knock sensor. Essentially you'll only know you're running rich or lean but not much else and timing will still be a gamble.

How is VICS working out?

[MD323]

Glad you're enjoying the MS

I would set the base timing so that it is in line with what the MS thinks it is. That way you can adjust timing reliably and accurately as desired in the spark tables.

It will be tough to tune using a narrowband and no knock sensor. Essentially you'll only know you're running rich or lean but not much else and timing will still be a gamble.

How is VICS working out?

Yeah its fun, the VICS is setup to the default values but do to it being late i didnt rev it up while under the hood to check it.

[Lex]

You can switch it to any RPM to check. Let me know when you get a chance

[MD323]

will do, since it came up I know aftermarket Knock sensors are either expensive or horrible to use but whats needed for the MS to add one?

i found a timing that matt was using that i might give a try, and adjust fuel to be in the 15:1 range? the dyno im going to has a wideband so that no issue, but this basemap is godawful slow, no offense

[smoke187]

not sure how much this will help i found this http://www.bristoldyno.com/tech/airfuel.htm

[Lex]

A/F cruising should be around that, but for WOT I would look for something 12.5-13 AFR.

The knock sensor can be hit and miss. I would get on a dyno and make a "knock sensor" for your ears while you're doing a pull and adjusting timing.

Have you set timing so that it matches what the MS is targeting?

By no means do I take offense, if you come up with a better/ more aggressive map we can all benefit.

[323driver]

Don't bother tuning without a wideband, just wait. The narrow band is uselles for tuning, it is only good when your tables are close to good. A base map is a base map, it's meant to be slow and conservative to avoid blowing things up.

Also, I wouldn't bother using knocksense unless you find a good aftermarket module that can handle it properly. AFR at WOT should be 12.5 at 100 KPA and decrease slowly to 14.7 towards 60 kpa, roughly speaking.

For the disty, you have to set timing to fixed timing at 10 deg let's say and then using a timing gun, set the disty to the same angle. This way, your timing is actually what MS thinks it is. Once that is done, you can go to your table and set timing to 16 deg at idle if you wish so, it's really up to you.

Hope that helps

[MD323]

well ill be tuning on a dyno week after next hopefully, I found some N/A miata maps im going to try to use as a "guide". plus a friend and local MS guru has volunteered to help me