Problem is that you are loosing power up top. This my Zz572s/620 engine in 99 38 Avs. 30 pitch 5400/5500, 84/86 mph. Wouldn't pull passed that rpm. Your numbers are about the same.

My sheet shows horsepower climbing all the way through 5800.

Yes so did my Zz572s . 5hp increments with torque falling quickly, u probably need 700 at 5400 to notice a difference . That's not going to keep spinning prop faster it's not a car on flat ground. You had 19hp increase in 400 rpm engine might be making 700 but it only has 680 usable hp at 5400.

Hmm.... looking at the numbers you guys have posted here... I'm a little dissapointed in what this AVS I just built some 725hp NA engines for is going to run for top speed. I was hoping closer to 90mph but it seems like mid 80's is where it will be.

Baja226sport, is this Paul F.? Looking at your peak torque, I'm wondering more cam duration might be better for your setup. Looks like it plateau's around 4200. If you're spinning 5500/5600 WOT and even though the HP number are climbing (they usually do with blowers) I usually want to cam it so the peak torque range will be a little higher (say 4500-4800) from the setups I've put together.

yeah I don’t think u have enough to get to next barrier, either need more cam or possible retard cam 2 to 4 degrees and move torque higher up in rpm to push the prop some more. Probably 30 pitch 5500 as u are now.

I usually prop something like this 800-1000 rpm above peak torque so figure 5700-6000. It has bravo's so I can't lug it either.

What have you guys needed to do with the fuel system on your AVS's from the tank to the engines?

The boat ran 87mph with a small chop, 6 people on board and full of fuel. 28" Bravo 1, -2 Sportmaster, ITS steering/extension box, 5600 rpm. AFR is also rich (12:1) and air temp was around 90 with high humidity. 90 mph should be possible after some fine tuning with better weather and water conditions.

Saw this article the other day. I really like the 38 AVS setups

https://www.boats.com/reviews/speed-merchant/

Panther, how would you compare the ride and handling to a Top Gun or your 36 Apache? Never been on a 38avs

Tough Question.

I'd say it's very comparable to my Apache however, I haven't been on the AVS in any "really" rough water like I've been on in mine over the years. I've run with a few in rough water and they seem to keep up just fine but I also have a lot more power than any of the ones I've run with.

I will say that the AVS rides better in calm water than mine (no hull rocker). It's a bigger boat, both wider and longer as well as heavier than my 36'. This boat came in at like 13K lbs or something like that. It was weighed this winter while getting a new transom. Like an Apache, they need a lot of power to go fast.

Mid range on the AVS's isn't stellar. it has like 18% slip in the mid range and 11-12% on top (rough numbers). I attribute the mid range slip to not being "on the step" yet. Once you hit 4200 rpm the boat hooks up and really digs in and moves.

Of the TG and Flat Decks that I've been on, they all seem to ride very different. It could be differences in weight, balance and cabin configurations. Surprisingly, I haven't been enamored by them. I'd probably skip the 38' and go to a 39'.

We tried some 5 blades last weekend and they were a little tall so the RPM's were short and as such the speed was down considerably on top. Mid-range picked up a lot though. We're going try the next size down 5 blade and see if it finds a happy medium. We might even try a 1" spacer so the 4 blade works better mid-range. Other than that, the way it sits now, it'll be an 84-87 mph boat every day of the week with 90 mph on a glory run is my expectation.