I know this is old as can be, but did you ever get it sorted? What was your final numbers? Looking for more in my Vyper, not alot of info of people running more than 600 hp per side in a vyper that I can find. Thanks

I think I maybe the only Vyper with big HP that I have seen here. Put some Bravo 30’s on years ago and funny thing I really didn’t notice much change. I have always threatened to try a 5 blade just never pulled the trigger. But if you want to go fast turn them out and change your linkage, takes about 5 minutes. I noticed no change around the dock or planning, but once over 70 here comes the roost and control, but don’t get me wrong in the high 80’s you’re paying attention with a big smile on your face. (plus I have the 280k planes that we modified to fit) Wish PQ would have put them a little bit more out away from the props.

HP 770 or so per beast at sea leave, here in Utah up in the nose bleeds the loss is just over 100hp per side☹ Not cool earth.

What elevation are you running/motors/props/WOT are you seeing now?

Thanks for the reply. I am pretty open to sea level in Michigan. I currently have 454 MPI mags in it and 26P props. It's a solid 63/64 everyday boat even loaded. I am planning on a motor swap and have some power options, I would like to run in the high 80s consistently, is the goal. Say low fuel and w 2 people maybe a low 90. I was estimating 700 hp per side should do it.... looking for others experience with this boat.

700hp full of fuel and 6 people no worries hitting 90's but the chime walk different story. Is your PQ 2001 or newer with the updated hull design? FYI https://www.boats.com/reviews/coiled-and-ready/ with the HP500EFI during their test 86mph. I went from 496 HO's 425HP 77 gps to 770HP 88 gps tattle-tail. I know I can easily get into the 90's but the chime and wife's eyes tell me something different.
Has anybody else got lucky hitting over 90 in your 340 vyper?

Mine is a late 2000 build, November says the build sheet, with updated hull. No Chine walk yet,.... maybe have gone fast enough either ;). Do you have k planes or equivalent?

Did you loose any speed when you started turning props "out"?
I have a 2000 380 with modified bottom and stock-ish but tired 502 mpi. Can run 70gps with 30p Bravo I's but slip is horrible. Been planning bigger power and rebuilds for a long time but life has gotten in the way. Tempted to try any little setup changes I can now to improve handling. I run pretty good at 70 but will chine walk if gets upset, easy to settle with wheel input though, at least at 70 mph, but i came from a single 730 hp 25' pad bottom checkmate before that so pretty good at balancing haha.

mid 80's you may start seeing a little, all depends on the water conditions. Yep the K Planes 280's

My Vyper is sold in the 70's, not till the mid 80's where I see a little movement.

I was curious to this as well. I am planning on building mine over the winter. Should be seeing a little over 600 a side. Was unsure if I should try spinning out or keeping it in.

did you have your hull done?