Hi guys... im ready to part out my old car and i was wondering if the SAFC makes any difference on our cars. SC300...

If not, im just going to get rid of it. I searched but couldn't really find much info on them.

 

it does apprently. ppl use it to get better gas mileage. if anything u could sell it to someone on this forum, or just give it to me, lmao.

Peace out

 

I had this same question and posed it here and here is what I understood...A SAFC is a piggy back fuel computer that allows you to adjust your fuel mapping depending on the driving conditions during different driving conditions. These are mainly used for modded engines up to a certain point. you can also use an SAFC on a stock car to improve your cars tune.
Lexus likes to let their cars run rich from the factory because its safer for the engine. If you re-tune your car to a lower A/F ratio (by removing a % of gas from being injected) in certain cases you can gain extra hp/tq and improve gas economy slightly.

the gain is not that significant and most poeple use it for turbo, or if they run larger cams, full header->exhaust system, larger injectors, and such...

A little bit of the negative too...You can damage the engine if you use it improperly, which is why you should get it tuned by a professional unless you have experience with it. Most people who have an idea of what they are doing use a wideband O2 sensor to tune the SAFC and as long as you stay within your engines acceptable Air/Fuel ratio range you should be fine (The O2 sensor tells you the A/F ratio in real-time). Some more experienced persons can tune on what you call a "butt dyno", which is just them playing around with it till the engine "feels right".

With a wideband sensor the risk is reduced, because its safe to have a ratio too high (like factory), but when its too low (dangerous) it will show you on the gauge and you will feel your engine stumbling (detonation and such), when this occurs, you just raise it back up a notch. quickly.

After hearing all that I passed...lol. I hosted a wrench session and someone installed one I personally dont this the risk is worth the reward...and his car was completely stock. Jus my .02!