Man, it's amazing what a few years of research (breaking shit) has taught me!
Gaz is on point, as always. My 10psi on pump gas, stock compression, no intercooling/water meth was really only doable with the supercharger. Many different things are going on there, as you don't have that peak boost (cylinder pressure) value at peak VE (NA peak torque) or anywhere near the backpressure/high EGT's.... you can get away with a lot more timing/boost on pump fuel compared to a turbo/N20. Once you put a snail in the exhaust there ARE SO MANY MORE THINGS that go into the equation of making a good strong motor that is reliable for a given fuel. Everyone gets wrapped up in compressor sizing, but what's going on on the turbine side is just as important, if not more. Header design and turbine size/AR are going to determine how much backpressure you have ant any given flow... and with people running extra fat mixtures to be "safe" on a turbo set up you end up with pretty high EGTs.... backpressure puts that 1000+ degree exhaust heat back into the cylinder and causes uncontrolled combustion....so people pull timing and throw more fuel at it (which creates higher EGTs...). At some point the dog catches its own tail and bites down. Long story short: you have to have well matched parts in the entire system to get the sort of professional results we all see from happy dynos & message boards across the land
And as far as timing & turbos go, I'll update with a little more I've picked up: You need good fuel. Assuming your hardware is A+, you have to have good fuel (or some sort of water injection) to take advantage of timing. There will be a magic number 'plateau' for ignition timing ( +/- a degree or two) that makes the best power, but I promise that you will not be able to get it there on pump gas.... that really applies for any boost level above a couple PSI. Knowing that, it takes a lot of effort & equipment to properly develop timing maps beyond what the OEM offers. If you're not logging knock, EGT, IAT, and AFR at the same time (dyno or track), you're really just guessing. Some people are really good at 'guessing'. Some wizards can still read plugs instead of looking at knock, but I'll be damned if I'm taking my plugs out that often on my set-up.
I don't like giving numbers to people anymore, as you can't just say to someone "pull X degrees per psi" quite like you can with nitrous or other mods.... the turbo set-up causes a lot of variables that you really have be 'Hands On' to predict. And someone telling me "I use X turbo on so-and-so's stage 3.5 kit" really doesn't tell me dick about backpressure ratios, EGT's, IAT's, etc. Honestly, unless you've previously worked with a production copy of EXACTLY what another guy is trying to set-up, I feel the best advice I can give is: "Get ye to a dyno with an experienced forced induction tuner at the controls.". If you don't like that answer, then start reading every damn book about engines, turbos, timing, fuels that you can find.... and prepare your wallet for a beating; it's going to be a long, hard, expensive, and wonderful road to knowledge.
Funny that you mention Cycle Logic, because a have a few melted pistons on a C14 using that guy's parts when I first started out.... but before the fuel system parts started failing that bike was a real animal... any 880lb amateur rider/bike combo that goes 9's with saddle bags at stock height with a shaft drive and 40psi of air in the tires is a good time. Mine lasted a bit longer than most (about 10K miles with nothing more than scavenge pump problems), but I used my own header/turbo choice. The garbage ass fuel system killed it in the end.
Attack life... it's going to kill you anyway.
Last edited by SpazOnaZX; 12-20-2016 at 10:21 AM.