Any tips for tuning ignition timing maps?

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Oct 11, 2012 | 05:05 AM

#21

Gernby

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Quote:

Originally Posted by blade954

Quote:

Originally Posted by Gernby' timestamp='1264810817' post='18025787

Thanks for searching, and sharing that info too. I thought about starting with one of the timing maps included with the FlashPro, but they seem odd to me. What is obvious is that the stock maps MUST BE ADJUSTED if you are going to lower VTEC, since the timing below 6K is WAY too advanced. Retarding the timing is what allowed me to make more power with VTEC lower.

BTW, I just emailed the spreadsheet to you.

Sorry to revive such an old thread but the info here is really usefull.

Gernby,
I just wanted to confirm that the above statement is correct or not because it sounds really strange to me. I thought that lowering the vtec required the trimming to be advanced, which is the opposite of what you say here.

Also in this later post:
https://www.s2ki.com/...st__p__18560844
you appear to be advancing timming to suit the lower vtec engagement.

I too have advanced timing and added fuel in the range 4-6k as I have lowered the vtec engagement and it appears to be making more power. Unfortunately I have no way of reliable logging knock retard or actual ignition maps as my car is F20c powered with the slow obd port.

Additionally advancing timing lower in the range seems to have improved mpg greatly. Not to mention the nicer throttle response and improved pull. Unfortunately I'm probably relying on knock retard to save me from trouble as I'm on stock ecu... Which is probably not very much different from how Honda does it anyway (I just hope that all the theory about increased knock sensitivity at suspect rpm range applies to the f20c ecu too).

Oct 19, 2012 | 01:36 AM

#22

liquid_helix136

Joined: Dec 2007

Posts: 4,289

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Quote:

Originally Posted by Gernby

Quote:

Originally Posted by blade954' timestamp='1349899476' post='22073189

[quote name='Gernby' timestamp='1264810817' post='18025787']
Thanks for searching, and sharing that info too. I thought about starting with one of the timing maps included with the FlashPro, but they seem odd to me. What is obvious is that the stock maps MUST BE ADJUSTED if you are going to lower VTEC, since the timing below 6K is WAY too advanced. Retarding the timing is what allowed me to make more power with VTEC lower.

BTW, I just emailed the spreadsheet to you.

I was definitely wrong about ignition timing when lowering VTEC. I made incorrect assumptions back then about why the OEM tune had ignition retarded briefly below 6K, then advanced above 6K. I thought it was because the engine needed it retarded, but I realized later that they did that to take the "edge" off the VTEC kick. Without ramping up ignition advance with a 6K engagement, the kick is way too abrupt.
[/quote]

So what your saying is that if you were to retard the timing after 6k on a stock engine, you would make more power? As in Honda was restricting the engine in this area for safety purposes?

Oct 19, 2012 | 10:54 AM

#23

Gernby

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Quote:

Originally Posted by liquid_helix136

So what your saying is that if you were to retard the timing after 6k on a stock engine, you would make more power? As in Honda was restricting the engine in this area for safety purposes?

No, I'm saying that if you were to advance ignition timing right at 6K, the VTEC kick would be stronger. They retarded timing briefly after VTEC in order to smooth out the transition a tiny bit.