| Captain Insano |
03-15-2014 09:41 AM |
Quote:
Originally Posted by steve99
(Post 1569685)
These "canned" tunes are good value and ok if you stick to the standard "mods" they cater for, even then an individual tailored tune is better, that's why they cost more. If its done on a dyno and not an e-tune then it more again.
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Bolded part is key. jamesm, all due respect, I appreciate your knowledge in the forum, but you make it sound like running an OTS tune is bad (I don't think you meant it that way, but it reads that way). I understand (and agree with you) jamesm that a custom tune is always best, but you cannot expect an OTS tune to work optimally or even at all when somebody is not running the modifications the OTS map was tuned for - the release notes specifically indicate not to run an aftermarket intake (like Perrin intake here) and you should use the stock intake for these maps/tunes. If you are running the modifications the OTS tunes are designed for they should be perfectly fine/safe for daily driving a car without custom tweaks. If you are not running the modifications they are tuned for, well expect that you WILL have to make tweaks or get a complete custom tune depending on the modifications. Pretty simple and straight forward.
If you tune somebody's car using a stock intake, and they throw on a different aftermarket intake after you have the tune dialed in, should your customer expect their tune to run OK or perfect after that?
The OFT OTS tunes are pretty good "generic" tunes IMHO if you are running the exact modifications they are tuned for. Even on a wide range of fuel (91-93+ octane & E60-E90).
Quote:
Originally Posted by jamesm
(Post 1563412)
your car should not need learning time after a tune, imho. that log is off-the-scale rich and pulling timing. by 'giving it time to learn', you mean allowing time for fuel and timing corrections to be written in, both of which shouldn't be there in the first place.
just my .02, but one of the primary goals of tuning a car is eliminating fuel trims and knock correction. this whole idea of relying on fuel trims and knock correction to tune your car for you is just not a great idea.
the reason is because it leads to inconsistency in the tune. on the timing side, even the smallest bit of flkc can seriously impact how much power you're making. we were seeing losses of 10hp or more (on a turbo car) from just -1deg flkc on the dyno. the ecu is far too aggressive in pulling timing, and will almost always pull more than is necessary. this is why tuning up to the point of correction and not beyond it is so important. it allows you to run the most timing possible, as tuning into correction just results in the ecu pulling more than you could've gotten away with without it.
on the fueling side, relying on trims is a bandaid for inaccurate calibration. it results in inconsistent open loop AFRs (which is exactly what you're seeing here), and in cars with modified fuel systems (injectors and maf size, mainly) significant drivability issues. obviously running off-the-scale rich is not the way to make power.
though the computer is smart enough to correct the afr back to something near target fueling (given enough time to adjust), it's still far less than ideal particularly on the timing side and should be optimized if possible.
it can be argued that these issues exist in the stock tune (high trims, timing corrections) and they do, but the entire point of tuning is to improve upon it. i don't think it should be accepted that high trims and consistent knock correction are 'ok', and certainly not optimal on a tuned vehicle.
these are the natural downsides of an ots tune. they're generic, and need to suit a range of configurations operating under a wide variety of conditions. they're basically well-developed base maps. the beauty of these particular roms is that they're open and editable, and those looking to get the most out of them should certainly look to take advantage of that rather than just accepting mediocrity as 'the way it is'. if it can be ideal it should be, because that's what we're tuning for in the first place. most of this stuff is so easy to optimize (especially given a solid base) that there just isn't any good reason not to.
ok rant over lol.
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