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Old 05-18-2010, 11:35 PM   #41
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Just reading through, boost by gear seems like the way to go. You already have the AEM and a ton of time into this thing. Boost by gear is known effective and if you are considering putting all this in a 99 flares and all on the current chassis is just one more of many headaches to deal with at that time. IDK if flares would even transfer from a NA to a NB. I doubt it.

The great thing is that boost by gear on a MAP setup is stupid simple. IIRC Brain runs a switch with a solenoid to an MBC that changes boost, while running the same tune. This is because from your engine and EMS POV, 10 psig at 6000 RPM and 120 F IAT is what it is, regardless of throttle position.


So lets say right now you are tuned for 15 psig max boost. You do a WOT run, and at a given RPM (lets say 7500) you are at 15psig boost, 120 F IAT. Your EMS does its job, somebody gets smoked, life is good.

Now lets say you are on track, coming off a increasing radius corner. You are getting into the throttle pretty hard, but not all the way because you are still in that corner and you dont want to leave the track right at the exit. So you are at 7500RPM, 120F IAT, and 10psig boost. Your EMS will have 0 trouble with that. The lower MAP means it uses the mapping for that lower pressure combined with the mapping for the 120F (or whatever the case may be) IAT and provides fuel and spark accordingly.


Boost by gear is pretty similar. Your EMS will provide fuel and spark based on your IAT ad boost level. So if you only hit 10psig in 1st and second, it will see that and provide you a bit less fuel than if you hit 15psig. It will in fact do about the same amount as it would in the 10 psig example above.

In fact, as I think about this, this wpould work even in a MAF based EMS. Lower boost means you will not have the same amount of flow through the MAF and thus you will get the proper amount of fuel there too. Though the MAP based system is probably much easier to dial in in that regard.
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Old 05-18-2010, 11:48 PM   #42
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Originally Posted by 1slowna View Post
you seem like you dont wana have to redo things and your kinda just doin it how u want it right away. So why not throw some flares on it now and stick the 275s back there. The stock f20c motor is good for over 500whp so why not set things up to run at there maximum potential? Seems like you will prolly end up doing it later anyway and the extra set of tires you would buy could offset a huge chunk from the cost of flares.
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