Thread: Weather changes
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Old 03-14-2006, 10:52 AM   #4
Scooby Guru
Member#: 32792
Join Date: Feb 2003
Chapter/Region: NESIC
Location: lincoln, ri
2003 GGA MBP
12.9 / 105+


Originally Posted by MidRex
I'm running a VF34 with a TXS Topmount

I'm tuned for 18psi on 93.

In the colder temps my boost would climb to ~20psi.

Running map1 on 94 in the cold almost feels like running my race gas map5 in the hot weather on C16.
i'll bet it was a lot more torque than you were used to! you got a little more boost and a lot more mass air flow than you had been getting before.

you could get away with a bit more boost with that vf34 and big tmic. 20 psi is not out of the range of reasonable for 93 octane. just make sure you have loggers going when you try to tune in the extra boost for warmer weather. if you're using an abc it might just be easier to use that to up the boost a tad. go slow, 1/2 turn at a time.

I haven't changed any settings on my tune other than moving the MAP value from 7 to 10.
which MAP value did you change specifically from 7 to 10?

How do I determine MBT?
ahhhh... the best question yet! without a dyno this becomes a difficult endeavor.

since i don't have one, i have to essentially rely on two things: butt dyno (prone to subjectivity, but always on) and logs from the same sections of road (requires a high attention to detail).

in the long run we are limited by octane in terms of power output, so the idea of running as much advance as we can get away with without knock nets us our effective MBT.

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