Hello i just picked up a Fc with microtech lt10s. And when i go into settings. I see decel set to "off". I was wondering if i should turn on? But im new to turbo and rotaries in general. So, after countless hours reading. I seen that the decel feature is there to save gas on cruising under light load. My understanding is it cut fuel at set manifold presure or under light or no vaccum. U can set it at -5mm Hg to 0mm Hg to cut fuel. To save gas. But wont that mess up the rotor? Because no omp. My oiling is coming from premix in gas? There must be reason why the tuner turned off..decel. the tuner is eddy renown. Thanks.

 

Some will argue its necessary. The reality is, it doesn't matter. Compared to factory omp operation, the short time during engine braking with no injector makes it negligible. Premixing is so much better than the oil injectors it doesn't matter.

if you turn off the fuel cut then you run the possibility of shooting some sick nasty hot boi flames at high rpm driving. If it was me, I would leave it off to conserve what little mpg gains there are to be had.

 

Ah ic so leave it off. Because there is no gains for fuel savings. But ,if i leave off i get cool flames at highway speeds. If anything it shoots fire *****. I guess miliseconds of having fuel cut , ie no fuel at no load at high crusing speed wont affect my rotors while it spinning around the housing. So , i could leave it on decel. And,it wont affect the health of my rotors. Ill be back on throttle due to passing cars or having to use accelerator in split seconds anyways.

 

In your case, since you have no OMP, leave the ECU's decel/overrun fuel cut feature turned OFF. And yes, lack of apex seal lube during deceleration/overrun conditions is exactly why your tuner turned it off. Regardless of what anyone else might tell you, I'd keep it off, especially if you do ANY driving in the mountains or hilly areas. Looking at my ECU logs from last year's trip to Deals Gap, I can see that I spent maybe 50% of the 30 minute downhill part of the skyway drive in decel/overrun fuel cut, at RPMs mostly above 4K. Do the math... running an engine at high revs with zero premix lube coming in for that period of time won't do it any favors, even if it's running under low load/high vacuum conditions..