not a lot of Sea-Doo traffic through here, but I'm hoping more forum contributions change that.
I am also interested in bumping my 2008 Challenger from 215 to 255 ...hopefully over the coming winter?
from my research and understanding, the IC, 255 SC, and 255 injector combo are the best bang for your buck. this will get you on plane quicker and a little more top speed. I'm not expecting much, but if it gets me halfway to the performance of my 2005 AR230HO, I'll be happy.
IIRC: by comparison, my stock AR230HO with refurbed pumps would GPS to about 50-52mph WOT with me and a full tank, then 47-50mph with 4-5 adults and gear on the lake - the twin engines do make a huge difference in hooking-up to plane and also help maintain "traction" in the turns (I liken it to 4WD). my stock C180 does 46-47mph on GPS and I was shocked it couldn't hold the g-force in the corners anywhere near as well as my AR
* - I was disappointed because I assumed a smaller boat would be more "aggressive." with 3 adults in the boat and pulling an adult on a tube, my C180 tops-out around 35-40mph (takes longer to get to top-out than the AR230HO). granted, I loved the power of the AR230HO, but the increased cleaning on 5 more feet and double engine maintenance on a boat that costs $10k more just wasn't worth the 5mph difference.
do I miss my AR230? oh yes, I put a lot of work into it getting it where I wanted it and it was way better in the Gulf swells, but I don't spend so much time working on this boat, which is what I wanted. another positive, the C180's separate throttle & shifter set-up along with the reverse bucket design is much easier to maneuver at the dock (stock Sea Doo vs Yamaha with latest Cobra Steering).
- does the ET wheel need tuned? the three items I mention work fine with the stock system by increasing injector output. you might just need a fuel pressure regulator (I think?) and that's it.
- I'm not sure what a CAI is?
- I've not seen anything compelling for through hull exhaust - my impression is this is for marginal top end on competition PWCs and is very loud.
- once you finish all engine mods, that is the best time to call an aftermarket impeller shop. for now, I would stick with a refurb exchange (SBT) if yours is worn.
* I've done some research on the turning issue. the Sea Doo nozzle (the part that swivels on the pump) is oval, narrowing-out at the sides. this "step" seems to disrupt the water flow, causing a drop in acceleration as it is turned further. it's kind of subtle, so I did not notice it until I went looking for it. the forum theory is Sea Doo did this as a restriction to improve turning safety. I've seen a couple guys on PWCs alter these with a cylinder hone tool like
this, but haven't seen any posted results. I am planning on doing this soon. just be careful not to make the diameter any bigger than it is, because different diameter nozzles change holeshot and top speed.
