i am curious to hear about the fuel delivery issues with the DI in sleds as cars (like my Audi 2.0 TFSI motored A4) runs like a raped ape for a little turbo 4-cylinder. Its chipped as well, and with just the chip is making 292lbs/ft of torque at low engine speeds. of course weight isn't as much of an issue with cars, but i do know that the advancement of DI on cars works extremely well with turbos as the fuel can be shot in at the very last moment (no detonation issues) so much higher compression ratios and boost levels can be used with no ill effects, which allows for the throttle response and snappiness of a naturally aspirated motor w/ ability to handle the same or even increased boost levels. in addition, crusing fuel usage is way down as well. Explain how an Audi RS4 w/ its DI 4.2L V8 can make 420HP, spin to 8000rpm and still get 23mpg on the freeway, and still rip off 0-60 runs in 4.2sec? The car weighs 3650lbs!? Impressive.
I think DI kicks ***, but perhaps it has a tough time combined with 2-stroke technology (fires twice as many times at a given RPM) and the necessity for lightweight-ness?
All this being said, Cat's had EFI on sleds for 15 years now and they keep getting better every year, but they still aren't any better performing than the carbs on our 800r - the difference between a 2005 cat EFI system and the 2010s is pretty impressive though, as they continue to add more and more advancements in programming even without the addition of sensors (well, it has pipe temp sensor now). EFI is the future on all sleds (like it or not) and though the 800r combined with carbs is awesome and overall performs better than most EFI setups. Unfortunately, it has a shelf life and has probably run its course. It is the last carb left in a sea of EFI.
