What out drive to use with 600 HP?
 

The new 502 engine is making around 600 HP and about the same in torque.

The boat is a 1998 Cobalt 252 that weighs 4500 lbs dry. Let's say full load and fuel 6,000 lbs.

Main use will be congested inland lake, so not many WOT runs. Mostly cruising and some tubing with the kids.

If I'm easy on the throttle, will a Bravo ! handle it? (already have a Halo max cooler)

https://www.driveshowers.com/

Will an upgraded Bravo I be sufficient? (Already have a Teague billet top cap) Maybe get the steel tower installed.

Will an XR or XZ be much better?

Don't think I'm anywhere close to needing an IMCO

Maybe just keep a spare Bravo I on hand for a quick swap in case of failure?

What's your thought?

I simply would not hole shot it neither catch air without managing throttle... spare bravo 1 are cheap. BUT !
id dont dont use it with respect, one simple week end could be enough to break it!

Im way more power than you through XR uppers and IMCO bottoms, three yrs no trouble.

Don’t over prop it. That causes too much throttle for planing (and everywhere else in rpm range) which loads drives way too hard. Single engine boats even more susceptible to this since weight changes (people, fuel) can more likely change the need for a prop swap. What planed fine yesterday may not with more people and fuel on board today. This is a real thing.

Keep it in 'low gear'. Your max.speed RPM will be higher, as well as your cruise rpm a bit as well. But the drive gears won't have as much tq on them.

I have an assortment of props already.

Factory 502 (black engine) came with Mirage Plus 23p. Still have this

Have a Mirage plus 25p

Bravo I 24p

Bravo I 26p

Rev 4 22p

4 blades are prob not going to be my friend from what I'm reading.

XR or Imco SC

XR will be efficient and fast and handle the power. I crossed 210 hour this weekend and I run my boat very hard. I'm 5500 rpm all the time and always coming out of the water trying to keep up with my friends. I am either idle or full throttle literally. My fluid always looks perfect.

Thank you

When going from B1 to XR, I assume it will need a HD transom assembly?

Why do u s a y 4 blades r not gonna b e good for u

My understanding is more blades is more prop surface area in the water. Less prop slip.

Finally you take an answer from someone ? I have the same question.

At that means more pain for the drive. If the torque is not slipped away, something between propeller blade and connecting rod will be the weakest link.

I would think that the XZ gears would be a help. Less expensive to upgrade and not have a failure than to have the internals polluted with metal.
Have you considered doubling up on drive coolers? This aims a pretty good stream of water a top cap and to a degree, a lot will go down the sides. More is always better!
Pretty reasonable price, my son put one on his B3. Observing it at speed there is a chit ton of water splashing around back there.
https://www.ebay.com/itm/28221628448...saAug3EALw_wcB

I've never seen anything quite like this before. pretty cool.

It does the same thing functionally as this, possibly not as effectively but for the price. On my Son's B3 he will be using the Halo and this. B3's get hot!
https://imcomarine.com/cal_store/bravo-shower-cap.html

I have not. Still waiting to get my engine first. Looking like I will have all winter to figure this one out unfortunately...

Excatly. More prop in the water has less slip.

Less slip means more stress on the drive.

More stress on the drive means better chance to break drive components.

OK, lets try this.

Rebuilt XR or brand new XZ?

4500 lb boat.

502 cu in with 600 HP/ 600 TQ

Recreational use with occasional WOT runs.

I would go with an XZ or even just an X. XR gears may be slightly stronger, but probably have half the longevity of X gears.
New XZ's are not sold anymore. You would have to buy a Bravo X upper and XR lower to make an XZ.

Thanks Griff.

There were a few new XZ's for sale locally. (in the box)