Cant wait to see it :D
We will be riding w/ Dennis (BajaPit) if you know him.

We know BP and Nancy. See you guys this wknd. Its gonna be a heck of a party.

Sounds like she is coming along real well. Very interested in what you final speed is. I am haveing the hardest time trying to find a set of 32 to try. anybody around me have a set?

I have a set of labbed 32" 4-bladed Bravo Ones you could try, but I live way over here on the west side of the state. Do you plan on going to Hardy Dam this year for Hot Boat Weekend (weekend after Labor Day)?
How about you Tibbs? You planning on being at Hardy this year for the Hot Boat weekend?

I plan on being there along with a friend of mine with his 32' A/T with 556cid supercharge engines called "Severe Turbulance".

how does that one run 100 plus??

Yeah, inquiring minds want to know!!

If you guys are asking about my friend's (Ken) 32' A/T with the newly rebuilt this past winter supercharged dyno tested 556cid 815hp engines....uh well, actually his boat can NOT pull away from me.

A couple weekends ago in South Haven we hung around together and we raced each other about 5 times and every time we were dead even---he can't pull me and I can't pull him either. Even in the midrange he cannot pull away from me---I'm right there with him. The best we saw that day in South Haven was 91mph with the humidity.....and the best he said he has seen so far this year is 94mph at 5400rpm with labbed 32" 4-bladed Bravo One props.

Naturally, I would expect his supercharged engines to kick my arss with the same boat, but that isn't the case here.

I will tell you that my naturally aspirated 565cid engines are NOT anywhere near the power output of his engines so, the only thing I can attribute it to is my engine combination as well as the set-up I have hanging off the transom of my boat----extension boxes, -2 IMCO shorties w/built-in nose cones and 5-bladed P5X's props.

I have to say the Ken's drives do NOT have nose cones and I feel that with his power output that he would walk away from me if he had the nosecones and I told him that. We both turned 5400rpm @WOT with our engines that day in South Haven.

Kaama,

Not sure if I will make it over to that side of the state this year. Been so busy with work and not fun time on the water. We have a poker run on the 7-9. I will let you know. Maybe I can make the drive over there and borrow them for the week and then drive them back to you. Thanks for the offer

KAAMA - I'm planning on hot boat weekend! Question is, are the Hardy police going to be busting us if I run loud exhaust :) These Holland/Grand Haven police have had me on best behavior for a while, I'd love to pull the mufflers so that the Active Thunder name makes sense - I sound like a sail boat in the channels right now :) Goodness knows that's not good.

I DO have 32p Bravo I's - not labbed that you can borrow... so if you're at Hot boat weekend - that would be a great place to try them out :) I need to try some combos myself. 32's are my best speed prop so far, but too much (perhaps nose cones will make these necessary). I'm not going to do nose cones until this winter I've decided.

All I know so far is that the fastest I've gone is 85 and I'm getting a prop slip around 18-20%... I have not been in "good" speed conditions and have not had the time to mess with breaking the boat loose. No control issues whatsoever with the Bravo I's... I am a little light in the bow in rough water, I think a stern lifting prop is worth a try.

Maybe you could try a set of Hydromotives from Throttle up. They labbed a set for me and the 4 blade is a stern lifter.

I have been going up to Hardy now for several years in the past and have not had any problems with the water police concerning exhaust noise. I was up at Hardy at the end of July this year and it was very busy....no problems. I do not have mufflers....just open dry Stellings tubular headers. :cool-smiley-011:

That's what I was hoping you'd say KAAMA :) - I knew you were the guinea pig in this case :) I still haven't forgotten the day I put my old Baja in at Brower park and let it kill backing up from the dock due to hearing loss after you fired up your Thunder :D ...

I'm not totally dry either... CMI's - dry to the tip, close enough I guess.

Prop wise, if I run a Bravo - a bone stock 30p, or a labbed 32... better yet if some cup is removed.

I agree with spilman - a set of hydromotive 4 blades may be a good start... I'd rather try them out before buying though - as my experience with hydromotives has been shaky. And unless I'm mistaken, the majority of the 32 AT guys like Bravo I's.

My current thinking is that if KAAMA is having a lot of success with P5X's - I may want to go down that path... however, I do not have a shorty right now, or nose cones, or extension boxes... and I also have no idea what Mark's X-dimension is - that's a lot of variables :) Supposedly my 540's put out a little more power than his... but my engines aren't yellow either :D

I'm looking forward to heading to Hardy in a couple weeks - it would be great to have a bunch of 32 AT's up there!

Try the Mercury Labbed 32s. Not much luck in testing the Hydromotives on the 32 V. However if it's free it can't hurt to explore all the avenues. Just don't spend any money.

Your X-dimension is very conservative so if you want to go 5-bladers you need to get shortees.

When using a 4-bladed prop I always liked the Merc Bravo One and mine were labbed. Never tried a Hydro 4-bladed prop---I few years back I heard some guys were throwing blades after being labbed.

I guess Hydromotive redesigned the P5X blades to a more rounded shape vs their past designs and was told by some of the prop people that they liked the design of the Hydro P5X vs the Merc Maximus 5-blade. The blades on Hydro's P5X's are very identical to the blades on a Bravo One prop.

My propshaft centerlines sit about 1.5 inches below the hull and the 5-blades props are the only ones that can pop me up on plane now---throws a nice rooster tail as well...kinda fun. :)

I do have to "feather it" when coming over on plane with the Hydromotives, but @ higher rpm's the Bravo 1's do not perform like the Hydromotives. Mid-range is slightly better, but top end there's no comparison w/ B1's. The Hydromotives give me more stern lift, rpm's & 7 or 8 more mph! BUT, this is a rare set up; 28 w/twins......
Also, I believe if I had more power, say 400-425hp per side, I'd be able to turn B1 props and get the "holeshot" advantage as well as the top end I need....who knows.
Maybe next year I'll experiment!

BTW...my propshafts sit 5-1/2" below the hull; 1-1/2" spacers were added before I owned the boat and I was strongly advised not to remove....maybe next year.

Keep in mind that my boat does NOT have a notched transom!

Good point, mine does...well sorta. It has a keel plane that pretty much makes the notch irrelevent....I'm guessing. The plane extends the keel approx. 18" back & is about 14"wide@ the widest point, tapering back to maybe 10". This is why the spacers are needed; again just an assumption.
Well good luck with the props, & Throttle Up will let you try them for free.

Man that keel plain is just the strangest thing I've ever seen. Have you ever talked to Pat about that? I hope he sees those pics. There must be a huge amount of pressure on that.:confused:

Yes, I'm sure there is a good bit of weight on it, but it has been there for 250 hours of operation. Before the keel plane, the boat would porpoise uncontrollably and had a top speed of 64. Now the keel is just a few inches short of a true 30' & rides like a DREAM @ 70; just needs the spacers due to the x-dimension.
Pat has seen the pics and did question me about it....but he never gave me any feedback about the "original set-up" of this boat; best he could recall it was fine. The props did turn in when new, that has been switched to outward. Being that this boat is stern heavy, the outward rot. & Hydromotive props seem best.
Any feedback is wanted.

Thanks for the input on the propellers!

I don't have a notched transom (97 hull)... I'm curious what the gains are there.

Kaama, do you know the prop slip you're getting at WOT? I think Thunderstruck was getting around 9.5% with nose-cones and a notched transom... Mines been a crazy 18-20%... there's some improvement to be had :)

Looks like we need some cones!!! :cool-smiley-011:

I'm measuring around 6-6.5" prop shaft centerline below the bottom of the transom in-line with the prop CL. That's pretty conservative indeed... From a handling standpoint, I have 0 issues up to 85 mph, feels like I'm still not breaking free - given the difference in x-dimensions, I'm not surprised.

I'm getting the feeling that I may be wasting my time looking at nose cones (although I know I need them one way or another). I may want to go with a 3" shorty IMCO... that would give me the most adjustment if I really needed say a 2" shorty...

I'm thinking a drive checkup over the winter may be a good idea to see what a year does - good opportunity to switch lower cases.

Take a look at this thread. http://www.offshoreonly.com/forums/s...d.php?t=166893 Your notch looks to be about the same size and causing a similar problem. If a notch is close to or below the water when on plane, it creates a suction that hurts performance instead of helping.

Posted some pics of Thunderstruck here: http://www.offshoreonly.com/forums/s...14#post2254614

Had a nice little rooster tail when he got on it. :cool-smiley-011:

Attaboy Tom!!!

Need to get permission to put those pictures up on the MarineKinetics website. Between Kaama and yourself, we have about 186 MPH of Active Thunder to post up!

Best regards,
Bob

Those are resized, let me know if you want the full size versions to put on the website.

Thunderstruck was looking GOod yesterday in the Galveston Bay poker run. Blew past the Donzi stores 38'525 boat.
That 32 airs out nice in the rough.
Great meeting you guys. K.W. run should be a blast.

Hey Chuck,

We had a good time. Great meeting you guys.

Punching off with the Donzi was fun fun, the guy driving that boat was a good sport too!!! :cool:

I have some pics of Clark's boat I will get off of the camera and post. That boat looks absolutely awesome running, great paint job. Your 65 mph cruise speed was impressive to say the least and hard to keep up with even with 30" B1 props.

I would say AT made a good showing at the run. The AT godfather should be proud.

BTW, that's the hardest I've run the boat since I upgraded the motors. We ran from Top Water to Kemah at 4000 rpm (65-70 mph) plus after we rounded redfish sucking up most of the other vbottoms on the way. The 32 AT rides better than most, even in the nasty boat wakes/chop/prop wash that were common on Saturday. Also, no significant motor issues. Bob Madara of Marine Kinetics is the daddy.

OK guys, here's where I'm at right now... (crossroads I guess)

Boat: 1997 Active Thunder (no notch)
1.5:1 Bravo XZ drives with no nose cones or spacers
Prop shaft to bottom of the boat distance = 6"
540ci - NA engines around 700hp
Target RPM range for engines is 5600+ rpm

With 2 guys in the boat on near full tanks on a flat river:
1. 28p stock Bravo I's - 5600rpm @ 83mph GPS - 18% slip
2. 32p stock Bravo I's - 5100rpm @83 mph GPS - 19% slip

Btw, I have run several times with 5 people this summer 82 mph on 3/4-full tanks with both the 32 B1 and 28 B1s. So I really am hitting a wall.

I've heard a lot of guys say that the 4-6" propshaft to transom dimension is pretty common.

Pat, - with my propshaft currently at 6" below the transom, would a 2" imco shorty help significantly while still working with a Bravo I style prop? Is that still conservative, or would I be looking at 5 blades to get on plane?

Here's what I'm thinking, I need to get prop slip down first... (I could run with less fuel and never let anyone ride with me again... but there are alternatives :) )

1. I need labbed props... but don't know what one yet because my slip is too high. (Too much drag)
2. I could try a nose cone, if I do, I may still be too conservative in the X-dimension to gain the most out of my situation.
3. IMCO shorty...???? I'd get to 4" on the prop shaft dimension to the transom and would have a better bullet... the nose cone is much more efficient.

Any advice you guys have would be much appreciated!!!

where's the 30's??
 

I was just wondering what happened to the 30p prop test numbers? I would think a labbed set of 30's with the sportmaster shorties will get you to 87 @ 5400-5500, just a guess. slip approx. 15%???

Tibb, personally I like option 3 for you. No notch, normal drive height for driveability, etc. I believe that your boat would respond well to shortys. But, I don't have practical experience with them. Try posting a question in the tech section. Call BBlades props and Throttleup for opinions.

BTW I think now that you have accurate data on slip, speed, rpm that you have taken the first step in getting your numbers up to where you want them.

Thanks for your opinions!

I have not tried 30's - the reason being that I have so much drag that the 28's are getting me to the RPM's I need.

My feeling is that when I change to a nose cone/shorty - I should reduce my slip enough to start getting closer to running a labbed 32 - (like a stock 30) - I should be able to run a labbed 30 right now and get enough RPM's. Once I reduce the drag, I should be able to pick up RPM's just from breaking free a little more.

Any one else have opinions on the prop shaft height? How conservative would 4" below the transom be? Right now, that's about all I can get without major changes... if I'm not gaining a lot, then I should stay at 6" and just do nose cones.

Helicopter scared the crap out of me at TPA but neat pic. Should've plucked my eyebrows. :D

Another.

BTW clark crb76 was about 800 yards off my port bow when these were taken. I was trying to catch him to get an old/new thunder combo pic. However, Clark was running some kind of super cruising props that produced 65 mph at 1500 rpm and I couldn't catch him in time. Stared at his azz all day. :D :D

Yea right!!!

Wife just said you have a nice azz! You must've made an impression. :cool: