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Remapping

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Another post by Doc 1

So many times I get the question do I have to remap ? Well here is some facts that will help you answer that question your self.

First off every engine is an air pump....if you built two identical motors side by side they would breathe differently taking on their own flow characteristic plus ignition timing would also be different in each motor to optimize the performance. VE in these engines is an indication of Air movement through the motor so if the identical motors had their own flow characteristics the VE would be different. They might put out the same hp and tq but, at a given rpm and throttle position the engines will differ. Now if this is true we can break it down even further, if every engine is an air pump then each cylinder is it's own air pump too....so the flow characteristic (VE) of the front cylinder is going to be different than the (VE) of the rear cylinder. ie the rear cylinder is going to breathe differently from the front. A lot of this comes from the firing order of 315 degrees for the rear and 405 degrees for the front...so the air movement through the same motor differs.
Cams, like pipes will make a big difference in the air movement through the motor too...a cam that comes in late will have better air flow numbers in the higher rpms and throttle positions, like wise a cam that gives more torque and power on the bottom end will have larger VE numbers in the lower rpm area and lower throttle position or vice versa. This air movement from cams and pipes can be seen on the VE tables and their effect on the motor. (Is this making since to you yet...I hope so.) Ant time the motor has something installed like pipes, cams, air filter, displacement and such the VEs increase and they move up or down the rpm and throttle position range. So for a good example; a set of SE pipes are installed...the VE tables are altered by the tuner to fit the flow characteristics of these pipes (we do this through a process of Synchronization which takes up to four to five hours some times).....now the guy wants to put on Reinhardt Tru Duals.....do you think the VE is going to be the same of these pipes....absolutely not. Like cams pipes flow differently so the VE changes again and again with ever change. Now how many times have you seen questions out there like " Do I need to remap just because I installed my new Fat Cats''? If you understand what I just explained, what would your answer be? Yes he does need to remap. Better yet...watch this. If you notice all the down loads (canned maps) on the Race Tuner are for Screamin' Eagle parts....if you had all SE parts but decided to install a V&H Pro Pipe will that down load work? ........NO !!!!!..... Because the Pro Pipe has different flow characteristics...... So how many times have you heard dealers just installing a down load in bikes that don't have all, or any, SE parts on them and out the door they go? Bottom Line....any time you change the air movement in an engine configuration the ECM needs to know, so a remap is necessary for the bike to have optimum performance.

In my opinion the Race Tuner is by far the best tool to manage the ECM out there if you have the knowledge of the program and how to use it correctly....it doesn't get any better or more complete Gentleman.
 
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