Gear ratio 1:5:1 vs 1:36
 

What are the pros and cons of the 1:5:1 vs.1:36 XR ,as far as dependability and longevity ? Purchased a Cig that originally had a 1:5:1 ratio, then the ratio was changed to the 1:36 with the Hp increase! Thank u

Normally the gear change is beacuse your running out of props to use with an increase HP. If your already running 34s w the 136 then you should leave it alone. So I hate to answer your question with a question but how big are your props?

Around here this is like asking what is the best brand of engine oil . Personally I have a single engine cat with a 1:36 drive and have seen no disadvantage , even in holeshot mode , against any boat with a 1:51 . Most times I plane quicker . I also believe that spinning a smaller prop faster is easier on the drive . I know without a doubt this will change along with the size and weight of the boat . I know there are many opines on this subject and that you must decide what works best for your particular application . Good luck .

I believe one of the biggest pro's is the taller gear allows you to drop back below a thirty pitch B1 and get slip numbers back down. B1's above thirty become inefficient and have higher slip numbers. (learned all this in the tech section on here but at the present i got nothin that runs more then a twenty eight so maybe someone else will chime in on the validity of all this :D)

There's something I didn't know . Good info Dave .

Dr.pete, the boat was running 1:5:1 with 4 blade bravo 1 -32s with stock 575s, the motors were rebuilt- and Dynoed at 683hp @5600, they re geared the drives to 1:36 and spinning the same wheels but 30 pitch- boat GPSs at 96 mph- twin step, so it's set up right I believe, I was just concerned with longevity and dependability of the 1:36 gear ratio?

Id know if this applies to bravos also but with the aplhas the 1.32 drive is stronger that the 1.5.

My understanding is that while you can achieve the same overall top speed & or cruise by manipulating the the drive ratio & prop size the larger the prop turning less RPM results in a greater efficiency b/c less blades slapping the water means less parasitic loss.

This is why when I retrofitted my Skater w/ ILMOR Indy drives we ditched the 1.36 Bravo ratio for a 1.50 ratio which allowed for better acceleration & better use of the speed range I intended on operating in.

At the end of the day you have to determine what your end game is, Top Speed, Cruising, Acceleration or somewhere in the middle for a best of all worlds.

I had both 1.50 and 1.36 on my T/S Gun. The 1.36 gears seemed to hold up better. Also seemed to like the lab'ed 30 Bravos A lot better with the 1.36 Vs the 1.50 and 32's.
That was with both stock 575s and after rebuild with about 650 hp. Now I am over 725 and need to try some 34's

All around the 1.36 worked the best for me.

I like the sounds of that Quinlan!