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Street Tuner n00b Tuning Primer
Street Tuner n00b Tuning Primer
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Old 07-22-05, 10:15 AM   #11
STirish
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Wolf,

I'm curious about the tuners who choose to push the timing further and run less boost. Some tuners here have talked about running less boost at peak torque (~17.5 max). The question is are these guys the ones running more timing in the peak torque area?

The reason I'm interested is my S4 used to respond very well to timing in the mid range (Always had to run good fuel). Timing gave the car a much more "responsive" feel out of boost. This was a great feel and seemed to help with spool up times, not that the S4 has problems in that area

This is a tuning school would like to try (I'm still logging the AP like crazy and trying to learn before the ST is installed), I'm was curious what you thought of this route and if you had been down this tuning route?

There is one more question about MBT. The theory that I understand at this point is you want the peak reaction to happen right at TDC or slightly after and this is why we create the spark before TDC. Given this MBT depends on the stroke of the particular engine or time it takes for the piston to travel that stroke correct? This is why when you push beyond MBT, no more power is gained correct?

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Rob
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Old 07-23-05, 03:41 PM   #12
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Quick question,

Quote:
You modify the MAF table (Intake Calibration). You basically look at what the A/F learning is at a particular MAF Voltage. Look up that MAF voltage in the Intake Calibration table. Take the value for that voltage and multiply it by the A/F learning. Examples ...

+5% A/F learning at 1.20 MAF Volts
Let's Assume the value for 1.20 MAF Volts is 3.1 g/s.
The new value will be 3.1 + (0.05 * 3.1) = 3.255 = 3.26.
Are the values logged for intake learning the percentages (0-100) or the decimal equivalents (0.0-1.0)? That is, given the above example, what number is in actual the "A/F Trim Learned" log column? Is it 5.0 or 0.05?

Thanks...
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Old 07-24-05, 01:07 PM   #13
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Quote:
Originally Posted by WolfPlayer
I've had no luck in truly figuring these out. What I have determined is that the knock advance most clearly follows KC A and that KC B appears almost to be a max limit that the ECM can try to achieve given the right gas.
Just from my little bit of logging, etc... it almost appears to me that the ECU is interpolating (or maybe just hard-switching) between KC A and KC B based on IAT (or IAT + other factors). On the same tank of gas I have seen what appear to be changes in the timing that look like going from B to A without any sign of knock, running plenty rich, and the only real difference I can tell is the IAT. If that's the case, then increasing A could be dangerous depending on climate and whether you have a short ram, etc. And, of course how you are tuning in general would decide that ultimately. But IMHO, I'd keep the danger zones in A lower than in B. But what do I know. Admittedly very little at this point.
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Old 07-26-05, 04:52 AM   #14
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Daemon,

I think I recorded IAT in my tests that I did. I'll have to post those logs when I get a chance so that others can review.

If timing is changed based on IAT then that shows just how well short rams are

t
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Old 07-26-05, 05:26 AM   #15
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Looking at it some more, timing definitely seems to be reduced, but it seems to be happening in a stage after knock correction is applied. Subtract my logged knock correction values from my logged ignition when IATs are very high, then it seems very apparent that something else is also reducing the final ignition values. The knock correction values are lower (closer to A map), but still positive. And the total ignition is lower than what my ignition map + knock correction should be.

I have been playing around with a short ram out of curiousity. Definitely of no real power value on stock turbo/stock IC. No surprise.
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Old 07-26-05, 05:35 AM   #16
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The section on intake tuning helped me, thanks.

For my injen limited (wrinkle red) CAI, I had to add +12.5% on the low end and +6.25% on the high end, it feels much better now and idles like normal.
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Old 07-26-05, 06:54 AM   #17
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Quote:
Originally Posted by jaygoesfast
The section on intake tuning helped me, thanks.

For my injen limited (wrinkle red) CAI, I had to add +12.5% on the low end and +6.25% on the high end, it feels much better now and idles like normal.
... and people say that the injen uses the proper MAF size

t
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Old 07-26-05, 07:03 PM   #18
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My A/F learning was at +15 at idle a day (75 miles, multiple drives) after installing the injen CAI, and my LC-1 readings at WOT had jumped from 10.9:1 to 11.7:1.
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Old 07-26-05, 08:57 PM   #19
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Anyone have any ideas on the proper hi and low % for the K&N Typhoon?
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Old 07-27-05, 06:09 AM   #20
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Quote:
Originally Posted by shilvan
Anyone have any ideas on the proper hi and low % for the K&N Typhoon?
have not done much tuning yet, but my a/f ratios are all pretty close with the stock box and the typhoon.
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