Props for 292 with 6.2
 

All,
Maybe I seem to be too picky..but I have to say that the 292 with 6.2s just seems to be pretty tempermental with props. I have 28p Bravo 1s that have been labbed by merc(stock from Formula) and with the exception of polishing and vent holes they are stock. My concern is that while I do not have a lot of time in the boat in a lot of different conditions, it seems that there is a lot of slip...and top end is not so good.

Here is a quick summary of the speeds and RPM with tabs and drives neutral(parallel with hull). Boat was also full of fuel, water, and two people on board.
4000 rpm. 45mpg...all gps mph
4200rpm. 48 mph
4600rpm. 53 mph
4900rpm. 58.5 mph

with the drive optimized for speed, and the tabs all the way up and out of the way with the full fuel and water load, I saw 64mpg at 5100rmp

Now...with the load of water and fuel lightened, this would take out 1100 pounds...but I am not sure if this would simply get me to the rev limiter quicker. Honestly, I can bounce the rev limiters very easily if you start to trim up a little....not a lot.

Should I be patient and get a lighter load and run again? Seems like a lot of RMP to hold even the midrange speed...like there is a lot of slip.

Any recommendations from people with this boat and power? I think I may need to do something with the props...but am not sure.

PS...I have contacted Brett at BBlades, and he thinks he would need to look at the props. Of course he could tune them...just want to know if my expectations are higher than what the boat should/can deliver.

Thanks!!

You have the props vented? I would not run any vent holes they add slip on purpose.

How high are you trimming the drives? Other owners can tell you the best setting for top speed.

64 with full fuel and water and how much other gear may be a tad low but not terrible. We just need to get your slip down a bit

Also, do you have KPlanes or smaller tabs? You do not want to run them "all the way up" at high speed, you want them neutral with the hull or slightly up so they help keep the boat stable but do not scrub speed

I would get your props checked. I have an 04 with 6.2's running box stock 28's and see 5000-5100 rpm at 73 gps with 1/2 tank of fuel and 4 people.

THEY ARE A PIG OUT OF HOLE.

I don't even bother with the tabs I think it hurts more than helps. It is just the only real penalty for having small blocks and lacking low end torque of a big block.

Roll the throttles up and let her get over the hump. It doesn't need a ton of trim.

And the best and by far cheapest upgrade was ditching those 3/4 inch high arrestors. I picked up 2 mph gps with back to back runs.

I have 3 inch tall now it just took a little fabing

The 28s would blow out every time getting on plane. It was a constant finesse job with the throttles before they would bite. I made the decision since I come off and on plane more than going full throttle, that I'd give 26P bravo's a go. I'm finally about to put my 28s up for sale cause I won't go back. The 26s grab moment I hit the throttles. I lost maybe 1mph on cruise, its really not noticeable unless your watching your speed, and I believe probably 2mph on the top end going to the 26s, I really don't know cause I haven't really tested them wide open.

That slip does seem excessive. Here are my numbers from several years ago running labbed 28" pitch Bravo 1's as is from Formula. These do not have the vent holes.

The slip numbers were me running by myself with 1/2 tank of fuel. The all time best top speed was with perfect water conditions and a big tail wind.

I would get some of these plugs and see if closing off those vent holes significantly reduces slip. I believe they will fit your props. Brett at BBlades will know. Good luck Kai! You will be much happier with how the boat runs once you get the slip reduced.

http://bblades.com/product-category/...es/vent-plugs/

Split - You may want to consider getting those 28's worked on. Mine do not blow out and pull smoothly on plane. That is with the tabs all the way up.

Can anyone let me know the best trim angle for this hull? Should it simply be neutral/parallel to the hull, or up a little for best performance? I am wondering if over trimming could be an issue.

Also, I will get some plugs and see if there is an impact in top speed....thanks Dave.

Pardon my ignorance, as I am new 292 owner, 08 w/6.2's, I have a lot of slip out of the hole. Could someone define "labbed" props? Thanks.

A little up from neutral for top speed. Water conditions and boat load will dictate the ideal trim setting. I will accelerate with trim neutral and once over 60 mph or so start bumping it up a tad while watching the gps. It will slowly climb to 70 mph and if you over trim it will be quickly noticed by the drop in speed on the gps.

Labbed means careful balancing and thinning the blades in effort to increase high speed performance. In general you can lose midrange cruise efficiency if the lab job is only focused on increasing top speed.

Last year I finally hit something and dinged one of my labbed props enough to require rework. I sent both to BBlades and had a long talk with Brett on what I was looking for. There is a trade off between top speed and cruise efficiency. I told him I wanted a balance off both. He did a great job. I have the same top speed as the Mercury lab job but better cruise efficiency and planing. He added a little cup to the blade tips which he said will hold the water better and help efficiency but this does not help top speed and can hurt that slightly. Remember, it's a balance...

They are also much better balanced and run so smooth with less vibration that I thought was simply normal with the original set.

Prop work is an art and Brett really knows what he is doing.

Thanks for the education, I will give Brett a call Monday.

Anyone ever run a straight up stock Bravo 28p? Thinking of getting a set and then sending the labbed props to blades for fine tuning. Simply want to know what to expect with the stock 28p. Any advice would be great.

I ran stock 28p for 5 seasons on my 292, I have 350 mags and best I saw was 70.3. on GPS but was a solid 68mph boat everyday all day. Getting on plane was an art form for me with the 28s, trim down tabs down and had to ease into the throttles just right in order for them not to slip and bite immediately. I got a set of 26p bravo's just to test with and first test run with them I just hit the throttles and it came up right out of the hole with no hesitation and bit immediately. I still have the 28s with hubs, PM me if interested.

What did this do to your top end?

I lost about 1-2 mph I believe. Maybe 1mph in my mid-range, its definitely not noticeable. I don't really know. I'm definitely not one to beat on my boat, and its so rare that we get the perfect conditions to do any accurate testing. It's either a lot of boat traffic or its blowing 15-20 it seems. I did have her up to 66mph last season, but only once for a few seconds. That was with 4 adults 3/4 tank and fully loaded. So I'm assuming perfect conditions 2 people loaded light with light fuel I'm sure I could hit 67-68 if I really wanted to. Still have never hit rev limiter.

REVSPAN your inbox was full but here is the link I tried to send you.

http://www.formulaboatsforum.com/VBF...L-amp-R-w-Hubs

I run box stock 28's on 6.2's at 5k and a best of 72 but everyday 69/70 hot days and a heavy load it will turn 4900. just had cutting edge labb and add some pitch they should be a 29.5 pitch. will let you know the results when she goes back in the water next week. hoping for a everyday of 72 and perfect conditions 74+

I just got my 2009 Formula 292 with 6.2's, it has the 28 pitch Bravo 1's, I've noticed that the props start blowing out right at the point where the bow starts to come down and then they hook up. I read on here where someone else with that problem went to 26 pitch props and their happy now. I'm debating do I get my props labbed or just buy 26 pitch props? Opinions?

Ditto on my situation, everything is the same for me. I talked to Brad at BBlades, and he said I need to give him a few numbers before proceeding. First, top speed and the corresponding RPM's. This will give him the slip at the top end as a starting point. I will also note when the props start to blow out coming up on plane. I thought maybe he would have a generic answer as to what I needed, but it looks like every boat is a little different.

I have only had mine out a couple of times, so the learning curve is still steep. The only modification that I am aware that has been done to my boat, is the baffles have been removed from the exhaust. It is a well built boat, and I believe we made the right choice for our needs, but there definitely is some tweaking that could make things better. I am leaning towards labbed props before dropping pitch, but then, I know just enough to be dangerous!

Some results from the weekend with the labbed 28's... So cutting edge added an inch of pitch and and labbed my stock 28's I gained 2mph at cruise and top end is where they shined. I went from 5k at 70 mph with a perfect storm 72 too 72 with full fuel and four on board including coolers and beach gear and dead flat water. When the wind picked up I ran 70 into the wind with 6" chop. 1 footers with wind at my back 74.5! all turning 5200 rpm. Low fuel and a single occupant speed run could be 75+!!! Thank you Auggie @ cutting edge!!!

How is the performance out the hole?

Comes out of the hole great. Same as stock if not better

I have a question about your baffles being removed, so they are stock corsa's but you had the baffles removed? I called corsa about the baffles after reading that some people had the baffles chiseled out, and they of course wanted to sell me new tips, I asked about just having the baffles removed and he said I risked reversion, water getting into the manifolds and even the engine.

I will have to check it out. This is info I got from the previous person, whom I have not met face to face. I will look and get back to you. You have given me information that I was not aware of. I believe the valves close to the transom position and return to the hub exhaust position when you cut the power, thus eliminating risk of reverse water flow.

I imagine many that read this are already aware of how the captain's call works. First off, I have rubber flaps on the exhaust tips, so that is the first check valve. Secondly, the valve that switches the exhaust will only open when the key is on. If you are running your system in the open position and shut the engines off, the valves close, making reverse flow difficult.