shagndaddy

I'm running a 91 357 with 425hp with trs drives, 21p mirage props and only getting 57 mph. Just wondering what other people with this boat are running and what kind of set up you are running?

jeff32

gps?

shagndaddy

57 on gps

jeff32

depending on the rpm you are spinning, you are not too far from truth... 4800 rpm? 5000 ? 5200? maybe a little difference there... spinning props in, or out? might change a little bit also... on a river with current or lake? number of hours on engines?

original spec sheet from formula claim 61 mph. not sure they had gps back then... they are not fast boat but really crushes the big waves...

again you are not far off... just couple minor stuff to check

shagndaddy

rpm are 5100 and 5000 with prop spinning out.

Previous owner said he got 62- 65 on gps, just not seeing that yet

jeff32

65? down wind with the current no gas and one driver no gear....

I have 480 hp per side and run 5200 - 5400 rpm and get max 63- 64, never seen higher in the best condition...

Prater

I have an 85 357 with aprox 600HP per side(used BAM's calculator to figure HP). Last time I ran with 26P Hydromotive QIV props spinning out I saw 72GPS at 4800 RPM. That was a few years ago and what I remember on speed. I have not ran since getting the props labbed. I am also cleaning up the boat and doing repairs now. I hope to run later this season.

Full Force

iTrader: (5)

Seems right on to me with that power and hull, give or take 2 mph...

ctuck0659

My '86 357 w/ 502 mpi's, 22P prop was running 60-61 mph @5000 rpm on GPS. I spent around 10K on parts and head work to rebuild the top end and had the ECU's remapped. I'm now running 25P props and getting 68.5 mph @ 5100 rpm. Lot of money and time but it feels like a monster!