Thread: Stock motor, e85 how small of a pulley can be ran assuming custom tune

Originally Posted by revin24

Im just thinking more fuel lower combustion temperatures I just don't want to run out of injector pulse I know cars I just don't know how to tune them yet I'm trying to learn

stop looking for people to give you the answers you want and really think about what they are saying to you. so lets think about it for a minute. ive done a couple e85 cars and the consesus seems to be either scale the injectors or scale the maf and change the stiochmetric fueling and PE accordingly. since you cant tune the only option you have really is to scale the injectors physically (ie intall bigger ones) 42's are roughly 30% bigger then stock so all other things held the same just changing injectors fueling should be fairly close. going to 60's or 80's gives you either 100% more fuel or 140% more fuel the maf curve is setup for the 33# stock injectors and regardless of pulley size you are bound by the curve (with a smaller pulley you are just going to reach higher in the curve). adding bigger injectors at this point is just going to throw idle tuning and cruising ability way off. sure the LTFT's will account for some of the error but its not even close to "right".