Should I get the prop's labbed??
 

I am running a Scarab Panther (twin 502's, 550hp, TRS) on Mirage Plus 25's at about 4800 - 4900 WOT with full load of fuel, and 4 passengers. I can get 5000 rpm's with less fuel and less people. I want to be turning about 5200 - 5300 rpms.

I also have a set of 25p Mirage props that have given a best of 76 mph but cruise speed was only 45 mph. The RPM's with the Mirage' was slightly higher at 5300 rpm's WOT. With the 25 Mirage "Plus" the cruise speed is 51 mph with a top speed of 74-75 mph. I really like the Mirage Plus better though. They bite better, and the cruise speed is better.

Cruise speed with the Mirage Plus is about 51 mph at 3600 rpms. I don't want that to change, but would like it to get better if possible? Will labing make me loose any cruise speed?

What would the dammage be??? $$$$

What are you're opinions?


__________________

I had a Panther in 1987, that boat didn't run well with any of the Props you are running. I ran Lazers, and a pair of Vipers. The mirages didn't give me enough bow lift. Call Dennis Cavanaugh at Mercury Racing. He will me glad to give you some recomendations. Nobody is better then the "Top Man" at Mercury's Prop Lab. If you need his number let me know.

Philip

Philip,

Can you email me his number.

[email protected]

Thanks

Panther

I know there must be some other opinions out there as well??

Philip,

To overcome the tendency to bury the nose I switched the drives to change the prop rotation. Now I have a lot of bow lift.

Panther

I tried to e-mail you the Info. but it came back, address N/G. here it is,Frank,
Dennis Cavanaugh Mercury Racing this number is his number at his
desk. 920.924.2037 Dennis is the man to
talk to. . If you want to call my # is
973.214.9686

Philip

Phil,

Thanks for giving me Dennis' phone number. I just got off the phone with him.

He confirmed my thoughts of loosing cruise speed with a labbed prop. He said that I will definetely loose some cruise speed, and thats not what I want.

Although what he did recommend was that I test a 27P Mirage Plus and see what the rpms are, which should be about 4700 rpms. Then he recommended getting the 27P Mirage Plus props labbed and I wont loose any cruise speed and gain a little top end.

Thanks againk,

Frank

the biggest problem when you lab finish a 3 blade prop it tends to give you a lot more slip out of the hole and can cause you to blow the props when trying to come on plane

I have a Panther as well. Original equipment was 365hp mags running 25 pitch Mirages at 5000. This was before I owned the boat, but I believe the prior owner when he said he got low seventies with the boat. For various reasons, the boat now has mid three hundred horse power engines and with the same props gets 66-68mph GPS at 4700rpm. Am working some engine changes over the winter that I hope will get me in the low four hundred horse power range. With that I expect to go to a 26 four blade or a 27p 3 blade. Target speed is 75mph. Can't really understand why at 550hp you are not at 80+. Only diff between you and I is trs vs bravo.

When I contacted a prop labber (can't remember who) they said older heavy boats like the Panther were not good candidates for labbing due to prop flex from the thinning. I left it at that.

I guess that fact that you have trs drives makes you need bow lift, which I alway thought a mirage 3 blade was good for. Me with the bravo, well I have plenty of bow lift already with the bravos and the need stern lift of a four blade (I think).

BT :cool:

Sounds like the Rev4 prop might be a good choice. They seem to have similar top end to the Mirage but much better cruise. Lots of lift stern and bow as they will hold more trim. Might be worth a test drive.

I labbed my quad 4s this summer. Got nothing on the top end, but picked up subtantaliy in the cruse dept.

Guys,
Just my .02 all Prop Lab's are certainly not the same. The whole concept is too bring the prop as perfectly into spec. as it can be, and then tuning the rake, pitch, and Dia. To get what you need out of set of props. Mercury developed these props, and they have the expertise to turn out a stellar product. I have never broken a prop blade, except by striking something. Mercury Lab is the best. Dennis Cavanaugh will never steer you wrong.

Philip

Sangercat,

You have one of the 32' Sangers that have the Skater bottom? right. Can you post a Pic. of the boat? or a link to a Pic. I would love to see it. I had a 30' Sanger. Ran Choppers on that boat. It loved the bow lift of the choppers. My 32' Skater runs best with 3 blade Cleavers of course. I tried choppers, 4 blade cleavers, most every prop, and the 3 blade cleavers are the best. what are the specs on your boat? engines, drives props etc. Peter discussed the Jack Davidson boat last year at Skaterfest. When my boat was built in fresno, I went there and stayed for 10 days, went to the Factory and hung out with Jack while the boat was being laid up. lots of fun.

DENNIS IS ONE OF THE BEST AND SO IS Darin!!!!!!!!!!

Dennis steared me away from a 4 bladded prob becuase of the tendency to lift the stern. He said they don't work very well with a TRS and a non-airated (stepped) bottom.

I can attest to this because I was involved in setting up a 42 Fountain a few years ago. Everyone was saying that the hydromotives, or the bravo ones will run the best on that boat. Yes they run great on a fountain with steps, but not to well with a regular bottom. With the hydro's the cruise speed was about 60mph, with a top end of 81. With the Mirage Plus the cruise was 55mph, but top end was 86.

Bluethunder,
The bravos are worth a lot in top end speed at least 5 mph or more. First is the loss of weight with the Bravo. you don't have a transmission, or a really heavy drive setup. Next the center of gravity is shifted farther rearward because the engines are farther back. It seems that the Panthers with TRS's were not balanced all that well from what I am hearing lately.

also the loss of propshaft horsepower turning the trans and the drive.

If I recall, bravo consume ~ 30hp, trs about 50hp. That would be about 1 mile an hour. The rest of the trs inefficiency must be in the center of gravity issue which is requiring props with bow lift. You have the in the mirage. Next move for me would be to figure out how to move the cg back some... not sure what the opportunities are for that, but things like batteries and stowing extra things toward the rear come to mind.

I'd like to see a picture of your panther sometime. Don't tell anyone, but I am getting my wife a digital camera for Christamas so maybe I can reciprocate. Hope she likes that as well as the new boat upholstrey I got her last year :D :D :D

BT :cool:

bluethunder,

Here is a pic from a few years ago, before I replaced the upholstry and re-painted the boat.

I have another picture in the 2002 NYC poker run section here on the board.

Here's a more recent pic.

Love your panther!! Is it a 1987? I'll look for the other pics. I'll put some up as soon as Santa Claus arrives. Mine is mostly white with blue stripes. Do you ever make it to the Chesepeake Bay?

BT :cool:

It is actualy an 86'

I have never been to the Chesepeake, but I hear it is some of the best boating on the east coast. If I can get the trailer up to snuff I may go to the Poker run down there next summer.

Look forward to seeing the pics bro!

later!

A friend of mine had one with blower motors. He always complained he couldn't get enough bow lift with the 4 blades he tried, hydros and bravos. He also tried both rotations. The mirage plus worked best for him. The boat also had Bravos. Eddie down at Smitty's Marine will know the boat. Anyway here it is.

http://home.att.net/~firststepp/John.jpg

Whooohooo!! Love that pic. ;) ;) ;)

BT :cool: