MicroSquirt.com read only forum (Jan.15,2018)

Setup includes v2.2 MSnSe utilizing MSD6a, 370cc nissan injectors, fuel pressure at 32psi idle & 39psi @ atmospheric. The engine is a 2.5L 24-valve V6 mazda engine running ~10psi max with a T04E 60trim. Here is a link to the datalog I recorded earlier this week:
http://www.designbydan.com/pt/datalog7-24-06.xls

Im looking for some general tuning advice. I got a decent tune from a friend with a very similar setup so the fuel VE table was close to start dabbling in boost. I have a AEM wbo2 and it was reading in the high 11's to mid 12's all the time I was into boost. I tried to do a few gears in each MAP range. I ran through a few gears around 65kPa(10in/vac), a few pulls at atmospheric, 5-6psi and then again at 8-10psi. I babied it as much as possible while trying to get the boost up. This will all be obvious in the log.

1) My duty cycle runs around 66-69% @ WOT at max boost(165kPa or ~10psi). I dont really know where I should try to finish with the duty cycle numbers. I've been told to never go above 75% while boosting just to be safe with the nissan injectors. I spiked 71% at max boost, will that be alright or should I raise the fuel pressure and drop the VE? Im thinking its never bad to be safe, especially for when I start running more boost down the road. The pulse widths under full boost were also around 16 which was a lot higher than I ever expected, but Im a newb still.

2) Im not sure I understand the spark angle readings. Under more load the spark angle goes up as well. This isnt the actual amount of total timing Im running is it? I have it set for 10* before top dead center for my base and my trigger angle is set at 60. I havent even thought about timing yet, Ive just went along with what I was given by my buddy. So if something in the log appears to be way off please let me know.

So in general am I off to a good start or should I light my car on fire? haha
Any comments or advice would be very appreciated. Thanks in advance!

I ran 90% duty cycle before MSII for a few years. Same injectors with MSII I went up to 114%. I swapped them to larger and am now in the 80% range. Based on that I would say you are fine at 71%.

You want the timing to increase with revs till around 3k or so where it will be all in. Then as boost comes on you'll reduce timing.

I wouldn't run in the mid 12's. A small fluctuation and you are in the high 12's.I would shoot for real low 12's preferably high 11's.

Clifton wrote:You want the timing to increase with revs till around 3k or so where it will be all in. Then as boost comes on you'll reduce timing.

I wouldn't run in the mid 12's. A small fluctuation and you are in the high 12's.I would shoot for real low 12's preferably high 11's.

Let me make sure I understood correctly...

You are saying that while under full throttle and the car is starting to build boost it needs more timing until the point where the boost climbs past a few psi to make it a bit safer, right? Luckily for me the tune I borrowed/stole was pretty accurate to start. But when Im looking at my log how can I tell what my total timing was at a given point? That would really aid in my tuning adventures.

As for A/F I see what you're saying about high 12's being a bit lean. But for my amount of boost with my fully built motor it should be fine if it does spike that high. Though I agree for now I need to play it safe. I can always try to inch out a little more power down the road when I hit the dyno. My pistons were thermal coated specifically for reducing detonation. Oh well we'll see what happens.

You will want to pull timing when entering boost. A few psi at full advance won't hurt but you don't want to run 38* at 7 psi unless you have really low compression. On your log, spark angle looks to be your timing based on the numbers.

Peak power is around 12.5. A little richer doesn't cost much hp. Thermal coating will help protect the piston but it won't reduce detonation if you have too much timing. If your timing is good (low enough to avoid deto) you can run 14's and not knock. I've done it tunning. Piston would develop a hole pretty quick from the heat if run for any length of time though:D.