Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   Dyno Day! Question for engine builders - A/F correction factor for dry dyno headers? (https://www.offshoreonly.com/forums/general-q/312970-dyno-day-question-engine-builders-f-correction-factor-dry-dyno-headers.html)

Knot 4 Me 05-30-2014 09:28 AM


Originally Posted by buck35 (Post 4129702)
:boat::boat::boat::boat::boat:Great build!
Now you can worry about your bravo......
Congrats and happy boating! I

Lol! That's what I was thinking. Next thread from BUDMAN II, My Bravo Build!

Congrats!

Budman II 05-30-2014 09:52 AM


Originally Posted by Knot 4 Me (Post 4130019)
Lol! That's what I was thinking. Next thread from BUDMAN II, My Bravo Build!

Congrats!

Man, I hope not. There's a reason I didn't go for a 540. ;) I'm surprised there aren't more OSO guys on here rebuilding their own drives.

the deep 05-30-2014 10:00 AM


Originally Posted by Budman II (Post 4130029)
Man, I hope not. There's a reason I didn't go for a 540. ;) I'm surprised there aren't more OSO guys on here rebuilding their own drives.

I know for a fact that the blower I bought from Mike is definitely scaring the living chit out of my B1 . Hopefully being a 1:36 diesel drive on a light cat will help .

Budman II 05-30-2014 10:22 AM


Originally Posted by the deep (Post 4130036)
I know for a fact that the blower I bought from Mike is definitely scaring the living chit out of my B1 . Hopefully being a 1:36 diesel drive on a light cat will help .

Is the 1:36 ratio inherently stronger than a 1.5:1 ratio? I have a 1.36 in my Bravo. Next step is to figure out what prop I need. Had a 23 Mirage Plus for it, which roughly corresponds to a 25 on a 1.5 drive, but with these numbers I'm afraid I may have to step up to a 25.

hadleycat 05-30-2014 10:28 AM

I think it was Mr. Gadgets who said the 1.36 gears were a little stronger because of their size

the deep 05-30-2014 10:28 AM


Originally Posted by Budman II (Post 4130046)
Is the 1:36 ratio inherently stronger than a 1.5:1 ratio? I have a 1.36 in my Bravo. Next step is to figure out what prop I need. Had a 23 Mirage Plus for it, which roughly corresponds to a 25 on a 1.5 drive, but with these numbers I'm afraid I may have to step up to a 25.

I believe you will like what you read here . http://www.offshoreonly.com/forums/g...vs-1-36-a.html

Budman II 05-30-2014 11:21 AM


Originally Posted by the deep (Post 4130050)
I believe you will like what you read here . http://www.offshoreonly.com/forums/g...vs-1-36-a.html

Good read, deep - thanks for the link!

Black Baja 05-30-2014 03:04 PM

Bud, you are probably going to need a 24 b1 should put you in the upper 70's with your boat and chine walk very nicely. Congrats on the motor sounds like a runner.

Budman II 05-30-2014 04:03 PM


Originally Posted by Black Baja (Post 4130194)
Bud, you are probably going to need a 24 b1 should put you in the upper 70's with your boat and chine walk very nicely. Congrats on the motor sounds like a runner.

BB, I was thinking about trying one of those. Friend of mine has the identical hull to mine, 235 Force, and was running low 80's with a blown 502 a few years ago. He tried a 4-blade on his and found that it gave him too much stern lift and not enough bow lift, which is what these boats need. They have the helm and driver's seat pushed further forward than a lot of other go-fasts for more cockpit room. Also has fridge, head, etc in cabin, which makes them nose-heavy. He found that a 3-blade with a lot of cup helped to lift the bow and cut down on drag. My boat tends to be very nose-heavy. Always had a hard time lifting the bow with the 454 that was in there before. I have a 23 Mirage Plus that belongs to a friend that I am going to use as a starting point. I know it is probably not enough prop, but I want to see how it carries the bow. I will also be looking for a 25 three-blade and probably a Bravo 1 like you described to try.

At this point it will just be nice to have it moving without a paddle!

Budman II 05-30-2014 04:26 PM

Here are the sheets from the final dyno run. Fought my scanner all day before I gave up and just took pictures with my phone.

http://i1224.photobucket.com/albums/...e69/dyno-2.jpg

http://i1224.photobucket.com/albums/...e69/dyno-1.jpg

Sorry for the neck strain on the graph. I rotated it in the photo editor and saved it that way, but for some reason it has it sideways again.


All times are GMT -5. The time now is 08:19 PM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.