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thundermax question

Started by itsafatboy, September 04, 2021, 08:18:05 AM

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itsafatboy

So i was wondering why are the  Throttle by wire twin-cam maps setup for same engine say a 124 or a 117" , with much richer AFR , than the throttle by cable ,

Same as the M8 maps all much richer setups , this might be because they can burn fuel better i dont know ,

also on the TBW they have small cruise area and all are set at 13.5 ,  and slopping down the 12.6 rapidly  ,  i thought 13.5 for cruise is to rich ,  maybe im thinking wrong,  when is it too rich and can cause damage like fuel in oil and washed cylinders,  i dont care about mpg just want safe and good running AFR   


q1svt

September 30, 2021, 08:32:40 AM #1 Last Edit: September 30, 2021, 08:58:55 AM by q1svt
Late to your questions, but...
There are too many reasons why TM Maps are different, like when written, by whom [Zipper's], performance level, etc   [if your motor build is like one by Zipper's, use one of their maps]  :smiled:

Re:AFR
AFR is different based on fuel type & quality
air to fuel ratio, @ 14.7:1 lean cruse being the value determined for PURE gasoline;  91-3 Octane with <= 10% oxygenation value is 14.08... values for rich range are all lower too ... 

"when is it too rich "  generally excess carbon, performance/power falls off... again too many things to consider, like performance level, build, compression, etc, etc, etc

fuel vapor burns ... droplets not so much   so quality of fuel delivery is very important.

good luck

edited: found one of my charts..

Fuel   A/F   Lambda ()
Pure Gasoline Stoichiometric   14.7   1.000
Pure Gasoline Max Power Rich   12.5   0.8503
Pure Gasoline Max Power Lean   13.23   0.900
E10 Stoichiometric   14.08   1.000
E10 Max Power Rich   12.0   0.8523
E10 Max Power Lean   12.7008   0.9020
E15 Stoichiometric   13.79   1.000
E15 Max Power Rich   11.75   0.8521
E15 Max Power Lean   12.4362   0.9018
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