I'm trying to figure out how to convert a 450's tune to a 720's tune...does anyone know a formula or a percentage to lean out the 450's tune that will work?

It's on a ZDYNE but maybe some hondata or ems guys would know the answer.

(ZDYNE guys - know that the base and gamma figures only work when converting a stock tune to 720's)

 

best estimate to remap is using math = multiply entire table map by 62.5%

greg

 

that's excellent, how did you get the 62.5 figure and 81.8 should be correct for 550's, right?

 

450 is 62.5% of 720

greg

 

mathematics 101

 

Math 101 does not reflect the response of the injectors. you can start adjusting overall fuel trim as mentioned but in reality the low rpm with bigger injectors will deliver less fuel but will be spot on at high rpm. this is because injectors don't have a linear response. remember the weight o the pintles are heavier when you have bigger injectors. read hondata's injector tech.

i have verified this when I replace rom 440 to 550.

 

Will this work for any size injector.Im planning on using some 1000cc msd injectors with a speed pro.

 

So at idle you had to richen the fuel maps a bit? In your case, what defines low rpm 0-3000?

 

you have to experiment really. depends on the actual engine. but hondata has made a good research on this matter. You also have to consider air flow nut just injector response. take a peek at their article on their website.

 

Speed Pro fuel map is based upon volumetric efficiency, so what these guys are trying to do doesn't apply. If your motor is mapped out well the map doesn't need much changing when going to different size injectors. The biggest adjustments will be the cells controlling idle. But like anything your results may vary.

In general going by these equations is a very rough way of doing it. I wouldn't place any bets on a map made in this manner. unless your really a master tuner, going with a wide band is the only solution that makes sense.


[Modified by SEFI8LOxCivic, 4:41 PM 12/28/2002]