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      09-24-2011, 09:16 PM   #34

Drives: X1, 335i
Join Date: Sep 2006
Location: SF Bay, CA

iTrader: (0)

Originally Posted by pbonsalb View Post
For forced induction, where you have a tune that changes AFR and/or timing when the meth is flowing and increasing octane like race gas would, it is nice to have the tune operate only when the meth is operating. This is almost more important with the supercharger than with the turbo. You can set up an Aquamist failsafe to drop boost on an electronic boost controller regulating boost on a turbo. However, you cannot set up an Aquamist failsafe to change ths supercharger pulley for lower boost if the meth goes out. The Procede is nicely integrated.

On the other hand, the stock ECU will take some advantage of race gas, so simply adding an Aquamist on a naturally aspirated car should provide some gains. Ideally, you would take full advantage of whatever extra octane you have, and that may be beyond the range of the stock ECU when meth is flowing -- which would make the integrated meth and tune the best way to go. I am also not sure how immediately the stock ECU adapts to the higher octane of meth or race gas.
The ECU adapts to octane pretty quickly in terms of ignition advance. But a good tune should already be running close to max timing numbers if its calibration properly. Which wouldn't leave much room on the table for power gains when running race gas. But no doubt you would see some passive gains from the lower temps if/when meth is injected. You are completely correct about the importance of an integrated tune/meth kit when running an NA or SC'd car that doesn't have the ability to drop boost when/if meth runs out or fails.

To clarify, the Procede actually holds a nearly infinite number map calibrations. This is because I calibrate two maps. One to represent the least aggressive tune I ever want to see active. And the second to represent the most aggressive tune I want to see active. The Procede will then "slide" smoothly between the two settings as a function of average knock retard and/or methanol flow. Essentially making it a feed-forward system that is adaptive to current conditions.

What this means in simple terms (on an NA car) is that when meth isn't flowing, it runs a basic pump-gas only tune which means slightly leaner up top with a couple degrees more advance (worth about 15-20whp). And as meth starts to flow and reach the max flow rate (as dictated in the meth flow map), the Procede transitions to the aggressive side of the range.

Of course, there is also a completely stock "pass-through" mode that you can select that applies no tuning changes if the need arises.

Maps are switched through the cruise control stalk and displayed on the tachometer