Quote:
Originally Posted by Xtina
I do have a flash tune kit at my disposal. But do you suggest anything else? I'm fairly new to engine stuff, but am decently well versed in all other aspects lol
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you can alter camshaft timing or even better get a pair with more duration and lift... I designed my own and it showed +5 on the dyno but my design is quite radical and demands stiffer valve springs... stock cams work better when inlet one is at 105-106 degrees lobe center(stock position 100), exhaust at stock position, on 250 EFI model but they are exactly the same on the 300... but you have to increase base CR to at least 12,5:1 for that setup (I worked mine at 13,9:1)and/or more advanced ignition timing so as not to lose the bottom end...
porting gave an extra 3 hp (without polishing) but it was NOT about getting ports bigger, but better shaped for less turbulenced flow...in fact the only points reshaped were around valve guides and just a tiny bit behind the seats...
it is imperative to use some tuning kit like PC V because any of that will change a lot your A/F ratio...
porting and camshaft tuning does not increase heat production but both advanced timing and incrased CR do.... it's up to you to decide how far you want to go...
the hp figures mentioned are a result of these mods combined with the already existing full yoshi exhaust system, larger throttle bodies and a bunch of other stuff (but stock 250 ccs...)