RacerxV6 Posted August 31, 2021 Report Share Posted August 31, 2021 So, last year Geeviam and I had a conversation about upgrading from aluminum to stainless. Based on the weight of my boat and the motor 1700+/- lbs he recommends the Yamaha Talon SS 13.125X16. Current prop is the factory aluminum 13.125X17. I spoke to the dealer where i bought my boat and he mentioned when going from aluminum to stainless you go either up or down in pitch. I do not doubt Geeviams suggestion. I was just curious if anyone here has heard of that. He also mentioned Ken from PropGods. Super excited about getting this new prop. One other thing, boat at WOT is only hitting 6000 fully trimmed when motor should be at 6300, not sure I should try to squeak out the remaining 300 roms, but I would think i should hit the numbers specifie d by manufacturer. Agree or disagree? Quote Link to comment Share on other sites More sharing options...
FROZEN Posted August 31, 2021 Report Share Posted August 31, 2021 Disagree.....switching between aluminum and SS, assuming same diameter, cup, and pitch, will not produce much difference. At least in the real world. In a lab, there is a slight difference, but mainly due to blade thickness. SS props tend to be thicker. Picture an airplane wing. SS props also tend to have more sophisticated geometric shapes (ie progressive pitches) of blades. This is where a huge performance difference between an aluminum v SS may be. The motor should be propped in the 5300 to 6300 band to manage valve train and other internal engine loads. Over-propped and underpropped motors usually don't last as long over the long term. You do not "have" to prop it at 6300. One inch of pitch is about 200 rpm, so your new SS should give you about 6200. Might be perfect for you, might not. Propped near 5300 gives more speed, propped nearer to 6300 gives max out of the hole. This is where HP to weight ratios comes in. Get demo props and try both, get what works best for you, but keep it in the band. Hope this helps 2 Quote Link to comment Share on other sites More sharing options...
geeviam Posted August 31, 2021 Report Share Posted August 31, 2021 Matt, Frozen's advice sounds good to me. There are so many different opinions, and mixed information out there on whether you should go up or down in pitch when changing from aluminum to stainless. Even the performance bulletins from Yamaha defy physics sometimes. As many will say - picking the right size prop for your setup is a crap-shoot, and not likely to be just right on the first try. My take on it so far, is to start with the same pitch you're running in aluminum. Reason being: The polished SS blades leading edges are thinner for less drag. Yes there is more cupping, but that allows more trim to balance it out for higher RPM at WOT. Your highest RPMs are in the good range now, IMO I like the Michigan Wheel Apollo XHS 17 pitch (part # 993144, Hub Kit # 203), as an option to try on your rig. Inexpensive, and I like the geometry better than the Talon SS for grip in turns, and hole-shot with vented ports standard. Here are a couple Yamaha performance bulletins that I thought were questionable, on prop size - compared to your numbers: https://yamahaoutboards.com/en-us/home/outboards/v-max-sho/in-line-4/vf115/pb_xpr_h20bay_vf115la_2016-06-02_alm https://yamahaoutboards.com/en-us/home/outboards/v-max-sho/in-line-4/vf115/pb_g3b_20ccdlx_vf115la_2017-07-09_alm 1 Quote Link to comment Share on other sites More sharing options...
dabear Posted August 31, 2021 Report Share Posted August 31, 2021 Getting the right prop is black magic what one boat owner loves about a prop another may not like . Some boat hull designs and owners like a hull to have a smooth of a ride as possible with a hull that is designed to cut through the water like a battle ship . Some hulls and owners enjoy getting the hull completely out of the water dancing on top . Owners likes. Boat hull design , the way you drive , the way the boat is balanced all are things to consider to get the ultimate prop for you . What RPM range with in the factory’s suggestion also is something that has many different opinions. Most prop guys will suggest getting it as close to the hi end as possible without going past the factory redline . Really depends on the power curve of your engine no sense teaching the motor beyond the maximum torque curve . There is not a one size fits all prop for a person that is looking for the ultimate all round performance in his ride . It’s very easy to reprop a boat that is way off but the closer it get to what your looking for the harder it is to find a large performance gain . Another thing that is neglected when looking for the best prop for your ride is if your engine isn’t in doing what it should and is weak it won’t pull the same prop as a motor in good condition will . One or more weak cylinders won’t be able to turn a prop the same RPM as a motor that is performing correct will . The pickier you are the more time and money you will spend in search of the ultimate prop for you . It should be hard seeing a major performance gain going from a aluminum prop that won’t cup and don’t have thin sharp leading edges that cuts water better or squared off 90 degree sharp trailing edges that releases water better . Caution searching for every last bit of performance from your prop can will take a lot of time and a lot of money . You have to be able to say the boat is performing really good and I need to stop think maybe this new design prop will give me a tiny bit more performance thinking what if looking at prop slip charts for hours sending a prop out to be blueprinted twice to get it perfect is habit forming and very expensive. Have fun . 1 1 Quote Link to comment Share on other sites More sharing options...
geeviam Posted August 31, 2021 Report Share Posted August 31, 2021 4 hours ago, dabear said: Getting the right prop is black magic what one boat owner loves about a prop another may not like . Some boat hull designs and owners like a hull to have a smooth of a ride as possible with a hull that is designed to cut through the water like a battle ship . Some hulls and owners enjoy getting the hull completely out of the water dancing on top . Owners likes. Boat hull design , the way you drive , the way the boat is balanced all are things to consider to get the ultimate prop for you . What RPM range with in the factory’s suggestion also is something that has many different opinions. Most prop guys will suggest getting it as close to the hi end as possible without going past the factory redline . Really depends on the power curve of your engine no sense teaching the motor beyond the maximum torque curve . There is not a one size fits all prop for a person that is looking for the ultimate all round performance in his ride . It’s very easy to reprop a boat that is way off but the closer it get to what your looking for the harder it is to find a large performance gain . Another thing that is neglected when looking for the best prop for your ride is if your engine isn’t in doing what it should and is weak it won’t pull the same prop as a motor in good condition will . One or more weak cylinders won’t be able to turn a prop the same RPM as a motor that is performing correct will . The pickier you are the more time and money you will spend in search of the ultimate prop for you . It should be hard seeing a major performance gain going from a aluminum prop that won’t cup and don’t have thin sharp leading edges that cuts water better or squared off 90 degree sharp trailing edges that releases water better . Caution searching for every last bit of performance from your prop can will take a lot of time and a lot of money . You have to be able to say the boat is performing really good and I need to stop think maybe this new design prop will give me a tiny bit more performance thinking what if looking at prop slip charts for hours sending a prop out to be blueprinted twice to get it perfect is habit forming and very expensive. Have fun . Well said Joe. Great advice as always, Coach! Quote Link to comment Share on other sites More sharing options...
dabear Posted August 31, 2021 Report Share Posted August 31, 2021 Geevism , that’s a nice shot of that new skiff . Are you turning that hard right with that motor trimmed up ad far as it seems to be ? Quote Link to comment Share on other sites More sharing options...
geeviam Posted August 31, 2021 Report Share Posted August 31, 2021 1 hour ago, dabear said: Geevism , that’s a nice shot of that new skiff . Are you turning that hard right with that motor trimmed up ad far as it seems to be ? Yes Sir. Corners like a Ninja bike! Thanks Joe Quote Link to comment Share on other sites More sharing options...
RacerxV6 Posted September 1, 2021 Author Report Share Posted September 1, 2021 Thank everyone for the advice. It is greatly appreciated. I got in touch with Ken and he really helped me understand what I need to be looking for. some of the things he got me to think of is the porposing at causing speeds. I run her at 5000 and above most days on the water because I don't like the porposing. So I told him that is the most annoying thing I would like to get rid of. I am waiting for his response to see what he thinks will be the best fit for her. I will keep ya'll informed and let ya'll know how she runs. I mainly want to get a SS because everything I hear about hem is they out perform aluminum, plus I need a spare and the aluminum will become that. Gary, skiff looks really sharp..... 1 Quote Link to comment Share on other sites More sharing options...
RacerxV6 Posted September 2, 2021 Author Report Share Posted September 2, 2021 After my conversation with Ken Reeves from Propgods, I decided to purchase the Powertech SCD4 13X17 which will give me more sternlift to help with the porposing and also give me a better bite on cornering. Price was not bad at $390 and if I am not happy with the performance, pay shipping plus $35 restock and he will ship another one based on how I want to go. So all in all, I could basically go through say 3 props before I even come close to the price of a Talon SS. Ken was very helpful in getting me to really understand what I was looking for in the outcome of changing props and the performance I wanted. 1 Quote Link to comment Share on other sites More sharing options...
SouthernWake Posted September 3, 2021 Report Share Posted September 3, 2021 Talking with Ken has worked for me as well. You are making the right move upgrading from aluminum. 1 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.