New prop

[lesman01]

how do you tell what the ratio is? Is it on the tranny label?

[Bitzco]

My first SX had a tag wired onto it that said 1.46:1 ratio. My new boat does not and I can't find anywhere where it says the ratio. Hence my question for the Cap'n

[toyotafreak]

Seems like we've heard that the SX was given a shorter ratio than the S22 because it was intended to be haul ballast. The S22 was intended to haul PB&J sandwiches and Sponge Bob floaties through a slalom course, so it retained the taller gearing. The label in this pic shows that my engine is gonna turn like 1.2 revs per propshaft rotation. Your SX will turn 1.5 engine revs per prop turn. For an equivalent prop, the SX will be both slower and quicker.

That is to say that the SX is downshifted as far as gearing goes.

[festivus]

so a 3 blade prop on an SX would give a better hole shot the same prop on an S22, right? 

[toyotafreak]

Yes, so long as the SX has the final configuration gearbox (1.5:1).

[Bitzco]

GREAT DNA BATMAN! I've got to find that label on my boat. Someone always comes through.

[Bitzco]

Has anyone with an SX gotten an ACME prop yet? I just talked to ACME and they suggested a 13 by 12 5/8 three blade. Part number 449.

[cyclone]

I would do what Bitzy did, talk directly to Acme. As for the gear ratio, put the boat in neutral, turn the driveshaft by hand and have someone watch the prop. 1.46 (1.5) turns on the driveshaft should be 1 revolution on the prop.

[toyotafreak]

Sorry to repeat this, but is still applies...When you call ACME, they're gonna primarily replace your current prop. This means that they assume their 13x12 5/8 prop is the quivalent to the stock prop. Kinda like us 1.26:1 guys that were told to replace 13x13 with 13x11.5 ACME. To that they might adjust a little based on your stated preferences regarding ballast or skiing, etc.

My first step will be to say, "my WOT throttle RPM is 5800, so the current 13x13 4-blade OJ Stainless is a little tall to start with." Let's say that 200 rpm equals 1/2" of pitch, and that the prop specialized for all-around runabout stuff would become 13x12.5. I ask him which ACME prop would be the quivalent to the theoretical 13x12.5 OJ stainless 4-blade. He tells me "that's the ACME XXX, a 13x11.5 three-blade."

To this, I ask for like 500 rpm (or more, just a guess right now) to improve hole shot with weight and improve throttle response at 22 mph. He says, "alrighty then, you're now in for an ACME 3-blade 13x11." I put down the visa and go wait for the UPS guy.

That might change me from 5800 RPM and 43 MPH GPS to like 6000 RPM and 37 MPH GPS. Pretty heavy hit to top speed, but the extra 500 rpm at wakeboarding speed would probably make the thing into a different boat.

There's an article in the latest WBM that talks about propping your boat and that just because you have Perfect Pass, there are still benefits to downshifting your prop. Besides quicker time to plane and better speed control, they claimed that thequick hole shot will end up saving you gas. I've always wondered how the scale tips in the 'quicker hole shot vs. higher rpms all day' battle. The article did say thatt he higher rpms increase wear on the drivetrain.

[Bitzco]

Thanks, that is the conversation I had with ACME. On my SX 6000 rpm's was about 34 mph and I don't carry a lot of ballast usually (except when the babes are on board), so the recommendation for me was the three blade 13 X 12 5/8. They thought it would give 3-4 mph to top speed and keep rpm at about the same they are now. He said the hole shot would be about the same as what I have now and that if I wanted a better hole shot, I should do the same size and cup ACME but in a 4 blade. He said the 4 blade would do a little better on the hole shot, but be less efficient and lose a couple mph. Since we are not pros or ballast kings I'm gonna go with his recommendation. It will be better for sightseeing at Powell and Mead. I'll let you know how it comes out.

[toyotafreak]

Sweet. I thought your crew weighed a little more than that.

[brad]

I have the same tag as posted in the archive pics on my 2002 SX.

Any help in interpreting it as far as gear ratio?

[Bitzco]

I have that same tag but don't know what it means.

[Bitzco]

  I also don't know if this is on the transmission or Vdrive (which is which) it is on the part closest to the engine. The part under the rear middle seat is a different part and is the one that my old boat had a label on with the 1.46:1 ratio. That label was just wired onto it not on an affixed label.

[toyotafreak]

Hey Mickey you're so fine, you're so fine you blow my mind, hey Mickey.


The tag you've shown is the transmission, which is attached directly to the bell housing on the engine. The tranny in our v-drives does a little ratio changing, but mainly controls fowrard, reverse and neutral. It connects to the thing under the seat, which is the 'v-drive'. The v-drive changes the direction of the driveline, but also the ratio pretty significantly (1.5:1 in your case).