Nocoast

I just picked up a 85 38kv it has twin EFI500’s and TRS drives, I took it to a local lake and ran it around to see what I need to do for props. She ran 55mph on gps and wouldn’t push past 4,300rpm at 5,300ft elevation 3 people on the boat and 3/4 of a tank. I have Bravo1 4 blade 26p props on it now, so I figured I needed to drop to a 22p. Over memorial weekend I went to a different lake at 6,100ft elevation same props 3/4 tank but 10 people on the boat this time and exact same numbers and no noticeable difference in plane time or power... I’m not great with how much props change the performance overall other than changing rmp‘s but this seems like it’s maybe some other issue holding the boat back. Any advice?

jeff32

never had a 38 scarab but i would think 26 are too big props... i had a 357 formula twin 485 dyno hp and 23 was the biggest prop i could swing max wot. so your hull is not lighter than my 357 was, similar hp, same TRS...
i would start 21 and go up if needed

jeff32

i would think a stepped 38 could swing those 26, or 25

Nocoast

I probably need to go to a 22 it just doesn’t make sense to me that with an extra 1700lbs worth of people it didn’t change anything. It jumps on plane fast and doesn’t seem to power out just hits a wall. Just looking for more experienced opinions before I drop 2k on props

82FlatDeck

I had an 82 KV - the notched transom model - running 23 p three blades at 5000 rpm it would just crack 60 mph. That was the best performance I could get out of the boat; that was with 450 hp a side. I found the boat liked the older three blade Mirage better than a Bravo 1.

Team Archer

I would run a 3 blade Mirage instead of the 4 blades because your TRS drives are mounted very low and it will be hard to make a 4 blade work properly. Regards Dan

Nocoast

Thank you Team Archer!

flashgordon

i am running 4 blade quad 4 hydro motives, 26 pitch,
was mentioned to me , i should be running a bravo prop, but ..
running 82mph, 5600 rpm, 10% prop shipage ,"" hard to argue with.""
i talked to bbblades and that was there comment.
straight vee bottom here

Team Archer

That's because the Hydromotive props have smaller blade area than a bravo prop. They try to lift the back of the boat to much with a low X

resurrected

How much HP does it take to make a 38KV run 82?