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-   -   99-00 Spark table problem finally fixed! (https://www.miataturbo.net/megasquirt-18/99-00-spark-table-problem-finally-fixed-42998/)

CRAIGO 01-17-2010 03:48 PM

99-00 Spark table problem finally fixed!
 
2 Attachment(s)
I'm pretty happy at the minute, I've finally sorted out a tuning issue I've had since fitting the MS and it was all in the spark table. The problem was that at cruise and light, slow acceleration the car would bog slightly and throttle would would seem stiff and clicky making the car hesitant to cruise (spiking lean at points). I always though since I was running a slightly more advanced spark map based on the PnP map and that my spark table was very similar to most mk1 cars that it couldn't be that at fault and was determined it was the VE tune and AE that was off. How wrong I was - It was spark!

Here is my old map
Attachment 201191

And here is the new more vacuum aggressive map
Attachment 201192

Roughly adding in approx 10deg advance to my 2000rpm/50kpa region and shifting the rest of the curve in earlier to match this has resulting in making the throttle so responsive now that the car just pulls instantly and my AFRs are much more solid.
My MPG was so shitty too at around 20MPG (city driving) and the revised spark map has already shown my city consumption go up a fair bit. I guess it's a safe bet to say Im getting much more torque at lower loads now to factor in my MPG increase.

I've seen some of you guys running similar advance at low load on built and stock mk1 engines but most of you running around 10deg less than me at slow cruising loads which is nearer to the PnP values, I can only asume that my compression ratio in the NB has alot to do with it?

I also want to ask if this amount of advance at such low load areas of the map could be detrimental in any way to the life of my stock engine? I have some det-cans and will do some tuning on them but wanted some of your opinions on it too. (The boost regions are purposefully safe shall we say ;) )

Cheers,
Craig

thirdgen 01-18-2010 12:45 AM

Here's my opinion: Try running a turbo at 14psi, then tell me what your spark should be set at.

Zaphod 01-18-2010 02:26 AM

Have a look at the DIYPNP spark maps for the 99/00 they are way more advanced than the MSPNP ones.

Though they are not that much advanced in the lower regions, more at boost and high rpm.

http://www.ingenieure-reichel.de/upl...iypnp_9900.jpg

CRAIGO 01-18-2010 07:18 AM


Originally Posted by Zaphod (Post 509546)
Have a look at the DIYPNP spark maps for the 99/00 they are way more advanced than the MSPNP ones.

Though they are not that much advanced in the lower regions, more at boost and high rpm.

http://www.ingenieure-reichel.de/upl...iypnp_9900.jpg

Wow! If I put those figures in im adding ~10deg of advance in boost over my current map!
This must be a "safe" map too if it's a base directly from DIY to use. Still, I'll put some cans on and check for det.

I didn't even know such a map existed, that's why I roughed out my conservative map from those that I'd seen on here and starting with the DIYPNP base designed for earlier cars.

Thanks Zaphoid :)

Zaphod 01-18-2010 08:22 AM

I had a chat with Matt at DIY about the map and he told me this is still supposed to be a safe map. The MSPNP would be something like - übersafe... ;)

CRAIGO 01-18-2010 04:44 PM

I've found the zip file where that spark table came from and it was tuned for a customers car. They do state that it's only to be used to get your car running and I would asume that the spark and fuel and pretty well dialled in for that particular engine. I won't be using the boost regions of the map and Ill still with my current cells. Driveability and throttle response in the vacuum areas has improved a lot by bringing in the advance earlier on at low load areas, that'll be the charger helped by the dual throttles.

Ben 01-18-2010 05:11 PM

I'll note that the test mule was a supercharged car. SC car will hold more timing w/o knock than a car with a turbo in the exhaust path. Use your due diligence.

CRAIGO 01-18-2010 05:24 PM

So it was a SC car? that's good to know. It's also obvious now when looking back at the fuel and spark maps and seeing how linear the curves are.

I'll be sure to det-can a few runs on the road and probably call it a day with my spark map. I'm running modest intercooled boost and putting down nowhere near the amount of torque even a mild turbo set-up could offer (like my old MX-5).

richyvrlimited 01-18-2010 05:27 PM

Hrmmm intriguing! I couldn't get near that level of timing with my old engine... Maybe with the new one I can!


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