Re: Squirt Squirt: The "How To MegaSquirt your SyTy" Thread
Re: Squirt Squirt: The "How To MegaSquirt your SyTy" Thread
TYTILIDIE said:
Ive read all the info on the links and have a few ?'s. If you get your A/F R to a perfect tune, wouldnt this leave you reason to ditch the KS? I knwo that when I do DM runs I assume that if my O2 mv are where they are supposed to be then whatedver Knock I get is BS. Is this safe to assume? As soon as this progresses to a perfect tune I am going to do it for sure. I am very good with the soldering and wiring and what not. Even have a great appearing solution for the other Coolant sensor. My other ? is this, Im not too sure I like the idea of being limited to 21lbs of boost. Even though I dont plan on upgrading turbos for a year or two, I would feel very comfortable knowing that I cvan and run 25-30 lbs of boost. Are there options for a 3bar MAP? This is very interesting and I cant wait to start building mine. One last question. If my ultimate goal was to ahve this set up AND a dist-less IGN, would I be better off doing the Dist-less first or the MS?
I?m no tuning expert, but from talking with those that are, in race and HIPO applications, knock sensors aren?t really used. Excessive mechanical noise (valve train, blowers, etc) along with custom parts combinations that knock sensors aren?t tuned for make their use problematic to say the least.
Assuming everything else is up to snuff (IC is working perfectly and IA temps are normal) and your AFs are safe, I would think one could get away without one. The tricky part is finding a safe enough amount of timing incase IA temps rise (say it?s a really hot day and you hammer it).
But keep in mind that other things that may very from truck to truck such as true compression ratio or combustion chamber deposits can effect how sensitive an engine is to detonation. A truck with badly worn rings might take plenty more boost before it pings because it isn?t squeezing as hard as another one. My Dodge Spirit (163k miles on the rings) was like this. I could run 23psi on pump gas, though I would blow the dipstick out under boost.
Fortunately for me, my truck has 55k miles on an unmolested motor. Aside from the crappy false knock problems it is tip top mechanically. I think it will provide a reliable baseline tune.
With MS, you can run more than 21psi. The internal MAP only reads that high, but you can also use a GM style 3-Bar MAP instead.
That said, Scott has done more than one car higher than that even with the 2.5-Bar MAP. I know of a DSM here in town Scott tuned to 35psi using the 2.5-Bar MAP. He just set a conservative amount of timing and tuned the AF ratios all the way up. That DSM (stock long block, save for head studs) ran
11.94@120 on pizza cutter wheels.
I think the proper way to do it would be with a 3-Bar (or 4-Bar in his case) MAP. When I get to that point, that's what I'll do.
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