throttleup

Will do Anthony, call us when you are ready to test.

Matt

US1 Fountain

iTrader: (1)

As far as ideal propping for best prop from the HP/Torque/RPM factors....

Even though say best RPM is at 5800, but a customer prefers 5200 as his WOT, do you still ideally prop for the 5800 factor and just not use the full potential?

nordic95

Yeah what he asked.

throttleup

One of the things that you need to keep in mind is at what RPM the peak torque is produced. You DO NOT want to run at or near your peak torque as this can lead to early drive failure and behavioral issues that can be associated with torque loading. So in nordic95's case you don't want to run at 4800 RPM or near it according to the dyno sheet posted, in post #1. In my opinion running at 5200 is to low, and you are not utilizing all that HP you just purchased!

Julie

Julie

bbladesprops

Like I stated earlier, 55-5600 will be fine. You do not need to prop at the highest hp # on the dyno sheet. In fact, in some instances this will hurt the overall performance. Especially when the last few hp come over a 3-500 rpm increment. You do need to get close to the max and the dyno sheet tells me where that point is. To answer your question, If you over prop and keep the rpm too low, you risk engine failure from detonation. It's like running your SUV around town all day in overdrive.There is a window to keep the rpm max at. It depends on the customers boating habits and desires and the design of the engine. Once the engine is propped correctly, you can run at any rpm you wish.

nordic95

OK,


I am finally ready to start testing some props.I have posted my dyno sheets and since my last post I have added new XR drives with the 1:50 ratio and with Imco prop shafts.Pictured is the hub system that came with the drives.I will need props to fit this hub,please make sure its not too much pitch as to kill my planing time with four or five people aboard.I am not to concerned about getting every last MPH out of it.Let me know what kind of loaner programs are available also.I would like to also keep my old props for spares but this hub does not fit them.Can they be machined to accept the hubs or no?

nordic95

ttt

throttleup

Your old props have rubber bushings in them. A large shaft hub can be welded into the old props which will allow you to use the old props with the new drives.


You will not be able to use the old props on a standard prop shaft once the larger hub is welded in.

bbladesprops

You can contact us at the phone number below when you are ready to test propellers.

nordic95

OK Here are some preliminary test results.I have broken in the motors and drives the last couple of weekends.Since I have installed new motors,drives with different ratios,and new transoms its like a completely different boat.I ran stock power 415 hp 502 with 1:36 ratio bravo one and a 23 pitch 3 blade Mirage.5200 rpm gps at 75 MPH in stock configuration.Now running 600 hp per side,1:50 bravo XRs and 30 pitch 4 blade Bravo ones.Mid range 3600 rpm 60 mph and could only turn to 5000 rpm at 80 mph gps.Boat has a ton of stern lift.I am trimmed almost double as the stock set up and it still feels like it is running to flat,nose down.I'm not sure if its where I have the celery stick located on the new drives or if its the prop,but I should be able to spin to at least 5600 rpms with this set up I would think.Where should I start with a different prop or what should I look to do with the set up I have?I love the hole shot and mid range but I feel like I am dragging the bow through the water.Is there a happy medium prop I should try?

Thanks
Nordic95