californiacuda said:I'm not a tuner, but here goes. Most of the time when an engine is modified to make substantially more hp than stock, the computer is asked to run the car far beyond its intended purpose.
Most of the tuners who I have worked with move away from a maf application to speed density. Putting more than twice as much air down the throat of the engine, metering it accurately, and have the computer make sense out of it is a challenge. I know that there are oversized mafs and maf extenders, but they are patches to try to work with what's there.
A speed density system such as Fast or Motec doesn't meter air but uses throttle possion sensor, engine load, rpms, etc, and the tuner builds tables of data for the computer to use for injector duty cyle, etc.
My observation has been that it's much easier to control the engine functions for high hp application using speed density method.
I'm open to anybody else's thoughts or observation.
EasyEric said:The question still remains: Does anyone have first hand experience with the Kenne Bell flash tuner sold on their site?
Specifically, has anyone used the Kenne Bell tune on a bone stock GT and if so, what are your observations? Note I said "bone stock". Tunes done as part of pulley and other mods are not relevant to me at this time (maybe later though).
Eric
californiacuda said:I'm not a tuner, but here goes. Most of the time when an engine is modified to make substantially more hp than stock, the computer is asked to run the car far beyond its intended purpose.
Most of the tuners who I have worked with move away from a maf application to speed density. Putting more than twice as much air down the throat of the engine, metering it accurately, and have the computer make sense out of it is a challenge. I know that there are oversized mafs and maf extenders, but they are patches to try to work with what's there.
A speed density system such as Fast or Motec doesn't meter air but uses throttle possion sensor, engine load, rpms, etc, and the tuner builds tables of data for the computer to use for injector duty cyle, etc.
My observation has been that it's much easier to control the engine functions for high hp application using speed density method.
I'm open to anybody else's thoughts or observation.
analogdesigner said:'cuda,
I had purchased an SCT control unit by a tuner back east. I had specified all of the updates to my engine setup, along with use of 91 octane fuel. I had also asked to set the timing "conservative," meaning about 2 degrees less than his recommended tune for my setup. The problem is that my friend and I could hear detonation at maximum engine load while driving on the highway. I reloaded (reflashed) the factory "stock" setup and it was fine, no more detonation. In my opinion, when you can hear the engine rattling, then the detonation is severe...
I don't understand how a tuner can come up with a recipe that keeps everything operating safely under adverse conditions, such as high engine temperatures? Doesn't he tune things under whatever the engine temp is at that moment, such as 180 F? What happens when the engine is at 230 F? Is his recipe still valid???
Thanks all,
Jay
http://www.fordgtforum.com/forums/forumdisplay.php?f=34
tmcphail said:If detonation is audible that is a really bad thing and you should have lifted, contacted your tuner immediately and given him the rpm range that it was occurring in and had him reduce timing and resend you a file to upload to the vehicle. There is spark retard based on both ECT and ACT to make timing reductions based on both temperatures. In fact there are a lot of tables used before final spark output is calculated.
Mr. Torrie R. McPhail
2005 Black Twin Turbo Ford GT 924rwhp / 787rwtq
2005 Silver Viper 610 rwhp / 760 rwtq
2006 Silver Jeep SRT-8 [email protected]
tmcphail said:Competency again is key here. You can make very good calculated guesses tune wise for a mail order tune if you know what you’re doing. Obviously having the car on the Dyno or on hand for a wide band street tune is the absolute best way to go. The GT is so over engineered far more than any other car I have ever dealt with its pretty crazy. Also the stock calibration is extremely conservative and you can make substantial HP gains by the tune alone based on this fact without any long or short term detrimental effects.
__________________
Mr. Torrie R. McPhail
2005 Black Twin Turbo Ford GT 924rwhp / 787rwtq
2005 Silver Viper 610 rwhp / 760 rwtq
2006 Silver Jeep SRT-8 [email protected]