dyno

Bill, dave and I were talking last night about asking to barrow your light.......well I'll call you in the spring.....The gauges are some cheap **** that came in the boat!

KAAMA

iTrader: (1)

I'm not trying to be a smartbutt here, but if a GPS says 74 or 75mph is it wrong? Myabe his tacks or props are off, but from what I have always known about GPS's, they are known for their accuracy----at least that's what I have always thought!

audacity

who knows...the data does not add up. now you need the answer why it does not if you want to make changed to the boat.

dyno

well the Numbers arent that important to me........at least the attack angle,slip,....... whatever I'm no engineer or racer just some poor smuck who likes to go fast on the weekends!....the important one is the top speed and like I said its 74.? on gps if that # is accurate thats all thats imporatant to me. the goal is to get to 80+ I need to pick up about 5mph Ken gave me a pretty good Idea about how much HP it would take to get to where He's running (85+) very simular boats ,so I'm making a guess that without changing the X demension around 600 hp would get me close....But again I'd like to keep my combination as bullet proof as possible so If I can raise the X and gain a significant ammount speed thats something I should consider....so If anyone knows of an older Sonic that has raised the X with shorter lowers please let me know!!!
Don

audacity

"well the Numbers arent that important to me"...if you want to go faster that those numers are THE MOST important thing! if going fast with reliable power was that easy everyone would have a 93mph 30 foot plus boat with 500's in it!

cougarman

Audacity,

I don't quite under stand what you mean
by making water out the otherside of the
prop. But I respectfully believe you
know allot more than allot of us
pleasure boaters.

Now to add to the confusion, I don't
understand why dyno isn't running faster
with the said power. I realize it takes
allot for a few mph, just seems he should
be faster.

A few years back I used to run a
1990 31' Sonic (OLD SONIC)
23 pitch Mirage aswell
74mph at 5200rpm on Sonic's Faria gauges.
I never had GPS so I figured 3mph to 4mph
slower.

My friend that I run with has a
36'ss Sonic with 468's that were
run on the dyno at 500hp.
Not sure of his prop size or pitch,
but they are mecury's and merury
labbed finished them for his set up.

The 36'ss runs a 25 degree deadrise
and I believe the 31' runs a 23 degree
deadrise with a pad. He uses gaffrigs
liquid filled speedo with a tattle tail.
Best speed ever recorded is 68mph at 5100rpm.

On calm Lake Michigan water I could run
by him with ease. Quite frankly pissed him
off. Nothing mind blowing, but a desent clip.

In 3 to 4 footer's we were dead even.
neither one of us could ever shake each
other. Just dead even running HARD.

I had a few ask me here or there if it was
ever worked over, answer is NO. For
365 magnums it ran well. So Old 31' or
new 31' I don't believe Sonic made new plugs.

They may have corrected there existing molds,
if there was anything to correct. I guess
Jay Ross would be the best one to ask.
X-dimension changed since 1990, I don't know
she ran pretty good with 365 magnums.

So Dyno, I don't know if any of this helps
or makes sence, But I feel you should be
running faster. I agree with Audacity
that if you want to do anything the numbers
are very important.

I didn't take the time to go back and re-read
these post. But Didn't Audacity offer to call
and help? Could Quite possibly be the best
Nickle ever spent. He has more exposer than
any of us on a daily basis. And how many
racers are willing to lend a hand.

Good luck with your project, Take your
time and spend your money Once.

Cougarman

audacity

ok brother...here we go...the numbers game...if you have X RPM going into a gear box...with a given gear ratio you can calculate a rpm out...every time...your prop,,,,lets say a 23 will pull(not push) 23" forward for every RPM . thus giving you a speed for X engine rpm,,,,but then you have to calculate losses...kinda like spin'n your tires....the math can never be so that the prop is pulling you forward 25" with the same given rpms...it like saying the engine has 500hp at the crank and 525 at the wheels...that would require out side forces or inccorect math...it's all math you know! as you know energy can not be created nor destroyed!

dyno

Cougar according to Jay at the factory the X is higher (about 2") on the Sonics that they are building now then when my boat was built.....the mold is the same.

Pure Energy

Cougarman,

My 1990 30SS with stock power, 365s, ran 67 on GPS in 4' ers

dyno

Cougar that sound about right mine ran 64 with 330's....