[ColoradoDiablo]

Got the serial number on the drive Eric?
It'll be bad to the bone for top end , if you can wind her up that far.
Holeshots' gunna sux I bet.
Hope you don't want to pull anything.
You really need to stay in the "powerband" , for the 7.4 that you have.
You're gonna burn fuel like no tomarrow!

JMO

[EricG]

Where is the serial number located on the outdrive? I checked the lower today and could't find the serial#'s. I didn't look to awfully hard though.
Right now with the 26p props that thing shoots out of the hole and on plane like a rocket, I'm know I will lose that but I'm hoping it won't be that bad. I don't pull anything right now with it. My buddy has a nautique wakeboard boat that we use for watersports so I'm not too concerned with pulling. If my son wants to get into that stuff I will swap the props back.

[voodoo]

Originally Posted by EricG

Where is the serial number located on the outdrive? I checked the lower today and could't find the serial#'s. I didn't look to awfully hard though.
Right now with the 26p props that thing shoots out of the hole and on plane like a rocket, I'm know I will lose that but I'm hoping it won't be that bad. I don't pull anything right now with it. My buddy has a nautique wakeboard boat that we use for watersports so I'm not too concerned with pulling. If my son wants to get into that stuff I will swap the props back.

26P props and you are a rocket...I could only wish.

Upper drive, decal for the numbers.
There should be another plate on the top intake cover that has all the serial numbers on it.

I can hit 48-50 MPH with a 3 blade 19p stainless, 2 people plus a fat hairy dog on a flat water scenario.
225 Davanti with a 350 alpha one.

[warner0308]

It should be stamped on the port side of upper of out drive,

[JRCustomCar]

The last bravo III I checked the gear ratio was on the starboard side of the leg.
I'm running a 1.62 Alpha One that used to have a 2bbl 4.3 V6 in front of it in my 98 Shabah 202. The 4.3 V6 would hit about 48-50 (about 4800rpm) with a 19p 4 blade stainless and get up on plane nice and quick.
I'm now running a fresh rebuilt MPI 5.7 and the only thing it's done is decreased my time to plane and increased rev-ability by about 200rpm. I've only run it with an aluminum 19p 4 blade (50mph@5000rpm) and a 23p 3 blade AL (54 mph @4600 and sluggish to plane)
My stainless 19 is at the prop shop, picking that up this week to give it a shot.
I honestly expected a lot more performance increase from the 190hp v6 up to the 300hp v8...I don't know why I barely gained a couple MPH. I can say that the v6 had about as much trouble turning a 21p 3 blade as this does turning the 23, so there is SOME performance gain, I couldn't rev past 4600 with either motor running respective props.

[EricG]

Originally Posted by JRCustomCar

The last bravo III I checked the gear ratio was on the starboard side of the leg.
I'm running a 1.62 Alpha One that used to have a 2bbl 4.3 V6 in front of it in my 98 Shabah 202. The 4.3 V6 would hit about 48-50 (about 4800rpm) with a 19p 4 blade stainless and get up on plane nice and quick.
I'm now running a fresh rebuilt MPI 5.7 and the only thing it's done is decreased my time to plane and increased rev-ability by about 200rpm. I've only run it with an aluminum 19p 4 blade (50mph@5000rpm) and a 23p 3 blade AL (54 mph @4600 and sluggish to plane)
My stainless 19 is at the prop shop, picking that up this week to give it a shot.
I honestly expected a lot more performance increase from the 190hp v6 up to the 300hp v8...I don't know why I barely gained a couple MPH. I can say that the v6 had about as much trouble turning a 21p 3 blade as this does turning the 23, so there is SOME performance gain, I couldn't rev past 4600 with either motor running respective props.

I can't believe you gained 110hp and mpi and only gained a few miles an hour. I'm wondering if your alpha drive is what is limiting you on the top end. I've seen other 20ft boats run 60-65 with a 5.7mpi anf bravo I combo. But then again I've found the mariah hull design isn't made to be overly speedy on top end but they ride like cadillacs! I was at a party at a sandbar on Saturday with the Z255 and when I left I past 3 boats and was jumping over 4ft rollers and it was like landing on a pile of pillows. Very smooth. I'd say 95% or more of the boat was out of the water. I did check my RPMs and they would hit 5000 so I had to back it off to about 4500. I'm hoping the 28p props help out with that.

[ShabahZ280]

A 5.7L with 300hp? Just to make sure we're all on the same page here, is it the 350 Mag MPI version? Because the fuel injected 5.7L is EFI, and is only 260hp.

The standard equation I've always heard the high performance racing guys say is that once you get above 40 it takes about 10hp for every 1MPH gain.

[JRCustomCar]

The motor is a horizon 5.7L mpi, 330 crank hp, 300 at the prop. Fresh rebuild with good compression new plugs running 92 and then 89 octane to see if there was any difference. Gonna pull the plugs this week and see how it's burning. I honestly expected about 60mph from this setup and I'm a little disappointed...
Now, I've seen this same motor in larger boats running the same gear ratio and getting 60s, I've seen it with 1.5 gear ratio running similar speeds.

[EricG]

Well I got the new 28p props on the Z255. The boat now runs WOT at 4600 rpm and 52mph. Before it would go 50 mph at 5000rpm. There is really no noticeable loss on take off. It still launches like a rocket out of the hole. The speed was on a gps with 3 people and a full tank of gas. I'm pretty happy with it now that the RPMs are back down to a safe range.

[rodneytx]

Originally Posted by mikeyt

If you install a damm hydrofoil on a Mariah you will be disowned here! You might as well wear a pair of Mickey Mouse ears while you are driving the boat around too.

Install a pair of Smart Tabs with 60lb actuators at a cost of $125 or less and do the job right!

So what, I have made it 75 years and 12 ski rigs long before MARIAH was ever thought of.