Solas New Saturn prop
5/19/14 @ 5:59 PM
I thought I'd throw this out there hoping someone has tried this prop with a similar boat. I have an Alumacraft Competitor 175 tiller with a f75 Yamaha four stroke. Running wide open, I'm currently at the top of the rpm window (6000 rpms) with a stock 13.5 x 15 pitch aluminum prop. I'm assuming switching to a stainless prop of the same diameter and pitch would lower my rpms (less flex and cupping), but how much? Any recommendations on pitch when switching from aluminum to stainless and does anyone have any experience with this prop? Thanks!
5/25/14 @ 1:32 PM
5/25/14 @ 12:29 PM
It's interesting to hear peoples perspectives. After doing research on other forums and reading the comments on here, I'd say it was 50/50 on weather switching to stainless would raise or lower rpms. I suppose a lot of it depends on individual prop design. The problem is this makes it hard to make the 300 dollar gamble. I decided to call some of the so called experts. Two were tech support from iboats and Dan's discount props, and the other was an engineer directly from Solas. The guy at iboats didn't give me a whole lot of confidence, but his opinion was that my rpms wouldn't change. Both the guys at Dan's and the engineer at Solas said my rpms will lower slightly (100-200 rpms). They said even running a 75hp outboard, aluminum will flex so a 15 pitch actually runs more like a 14. Stainless won't flex so it will run like a true 15 and reduce the rpms slightly. They also said the more aggressive cupping would slightly lower rpms. The mass of both are supposedly very similar. All three of them recommended I stay with the 15 inch pitch.
5/25/14 @ 8:47 AM
5/20/14 @ 5:37 AM
I've seen it posted on outdoor forums that gains are fairly minimal at 90hp with SS props and that is where you start to consider them. (because the aluminum is strong enough to not flex much on the <100 hp motors)
That said, I'd check iboats for props, they usually have good prices on props:
If you keeps the box you might be able to return or ebay it if your gains don't justify the expense.
5/19/14 @ 6:26 PM
Typically you will increase rpm's if running stainless at the same pitch as aluminum. A stainless prop blade is thinner creating less drag, and the cupping allows the prop to run at higher trim. A stainless prop is more efficient. Try a 17", it should run close to the same rpm's at WOT.