Super drive decisions...
 

Well, turns out the 21 Super I have is the only one that was made with the Blackhawk drive. Hearing about it from those that have rode/drove it, I guess it was a rocket with the stock 502 and bh.

Currently it has a built 509 with a stock bravo drive behind it. The propshaft is around 5-5.5" below the pad. I'm planning on replacing the lower with a imco -3 and modding the upper for prop clearance. The prop would be 2-2.5" below the pad. I think this should be a great setup, but have no ideal how it would compare to going back to a bh?

From what I've seen the blackhawks are around 12mph faster than a stock bravo- I don't think the speed difference would be that much compared to a -3lower on this boat? There are a bunch of things I don't like about the BH, like idling at 6+mph, no props, and worse rough water handling. I have no first hand experience with one... just what I've read. It would be a really cool drive, but I'm not so sure it'll be practical for the type of boating I do... and its quite a bit more than switching out the lower.

So, lets hear your opinions or thoughts on my drive dilemma? Or if you have a story about the boat, share it.:drink:

Thanks!

I dont think it can compare to the black hawk in any shape or form. The only down side will be the fast idle speed.

Thanks Zuper...
I posted this over on S&F and hearing about how the boat ran, sounds like it was realy flat... according to The Hoser who drove the boat- It wouldn't lift the bow and anything over 80 became uncontrolable.... on SB website there is a claim of 96, which falls right in line with the speed differences I've seen compared to a stock bravo- but that was on cats/pod tunnels...

It sounds like you have a good plan to me.
Start with the -3" lower and you can space it down if need be.
I would not raise the gimble and engine up and screw with the CG of the boat.

I have absolutely no hatch clearance in the 21, in fact its toucing it. I agree with keeping the COG as low as possible, espically with this boat (it already has aluminum heads, so thats a big plus). I figure drive depth should be just about right, but was looking for some opinions on it before dropping $s on the shorty case.

Thanks, Pat.

You could call up grumpy old John and asks him where he set the prop shaft on the new 21 I/O he built a few years ago.
I remember talking to him about how the newer 21 deck and engine hatch allowed for the "X" dim being higher.
Pesonally, I think you'll be good at 2-2-1/2" below but I'm not basing that on any more than a guess compared to some 22' Velocities I've read about. The Velocity has a much larger pad and a notch so some have run well with the prop even with the bottom.
As for the Blackhawk drive, I believe they only ran well on boats that had a rocker built into the bottom or boat that don't require any bow lift at all. The 22' Donzi Blackhawk had/has a lot of rocker cut into the bottom. The 22' Donzi Blackhawk does not run well in the rough compared to a stock 22' Donzi. Think about it, two props are going to lift the heck out of the stern and can create a lot of bow steer.

One of the first things I looked at when I picked up the boat was the bottom- its straight. I read alot about the dozi bh editions and rocker they added to em... had no idea what to expect when it came to the bottom on this sb.

I was thinking that the prop depth should be about perfect with the -3 lower. 2-2.5" should still allow for alot of leverage and hopefully reduce drag... could always add a neutral xtension box if its a little too high- that'd be really trick...

I'm kinda tempted to wait untill the middle of the season or next fall to do it, so I can get a good base line with the current setup... but know that I'd be better off catching Mr.Gadgets earlier than later.

Thats what stinks about buying a new boat going into the winter... I've never even run the damn thing, but have been kicking around ways to make it faster/better handling. Just looking at the drive depth, it looks way too deep to me- for such a small boat, and I can imagine thats going to be a problem as far as handling goes... wish it was spring already!:grinser010:

I drove that 21 with the blackhawk in original form.... 502 Mag 415HP.... at the time it had the biggest blackhawk props, cleaver style, available.. 30's maybe? and it would bump the rev limiter.....

Anyway... with 4 adults it ran mid 80's effortlessly on the speedo... and you could take your hands off the wheel it drove like it was on railroad tracks.... I can;t imagine why anyone would have changed that drive?

If you can find another blackhawk... put it back.... I would have owned that boat if the guy had been the least bit reasonable about selling it....

I bought the 24 you have Nick instead.... seems we have the same taste in boats & its great that they both ended up with the same owner!


Enjoy & have fun with them.....

Gary....

Hey Gary... man, you have great taste in boats!!!!:grinser010:

Its pretty funny that you looked at the 21- I'm guessing it was owned by the guy in CT when you saw it? If so, he is the one that replaced the drive with the bravo. I've heard mixed reviews about the Blackhawk. I'd love to have one to give it a try and see how I like it. There is one up for sale right now, but its $pendy. I don't like how hard props are to come by on the BH. Guess I'll keep thinking about it.

I was going to send you an email this spring to see whats been going on... still have the Y2K? Hows it been treating you?

While at the shop with Sean, George and myself, I asked Coen about your boat. He said it did a solid 92 on the rev limiter. And it was set up perfect. At least thats what he said.

Thank you Rick...
Any idea if that was gps or speedo?
Its very tempting to buy a BH if thats the case, sounds like it was a hell of a boat with that drive!

I was there, and thats exactly what he said. JC said it was dialed in great at the time

Speed is not everything. If it handles like crap you will never see a real top end. I bet with the blackhawk the boat will be like on rails. I bet Lightspeed would give an honest outside opinion.

I know... looking for the best overall balance.

I'm still kinda leaning in the direction of the -3 lower... I think the overall performance should be great and speeds respectable as well... the prop availibility really sucks for the BH- it'd be trick, though.

I don't see how it could be a bad setup with the -3 and propshaft 2-2.5 below the pad on this boat- I'm not really worried about the propshaft being too high, since it worked with the BH in the past?

I like hearing different veiws on it and appreciate any input I can get from everyone. So feel free to chime in...

Thanks, guys!

If the Blackhawk drive parts and props were more available, then maybe that would be the way to go.
Bolt a -2 or -3 lower onto your B1 and you'll be happy.

Hi Nick -

Still have the Y2K.... and still enjoying it.... the guy from Ct was the owner when I looked at it... he was afraid of the boat.... he drove it trim in to about 75mph and backed out... he let me drive & with 4 of us it ran as I said into the 80's easily... it handled perfect imo... no chine walk... no wheel torque... felt more like an STV then a V-Bottom... it was on rails.... only reason I can think he would change it was he broke the BH and didn;t want to spend the $ to fix it?

That BH Drive worked better on the 21 then on any other boat I ever saw one on... PUT IT BACK!

OH yeah.... and it threw an AWESOME rooster tail!

Hey GORT, What motor do you have in the Y2K?

If I remember right... a 496 with forced induction:eek:

Good Memory.... 496 MAG with a procharger.... 3.5lbs of boost...

Thought the Y2K was going to get a Boyd's upgrade? :D

I Gary's shoes, I'd run that engine until it blew. I ran with SB30 (Scott) many times and the boat ran perfectly. I believe that she topped out around 80mph too.

I had planned on having Jack build a motor and we may sometime soon..... but as Pat said the 496 runs great... I was very skeptical of the pro charger when I bought the boat.... but after running it last year I like it... alot...

Nick - here's alink to a thread about BH drives... interesting & educational I thought....

http://forums.screamandfly.com/forum...d.php?t=111970

Tanks Gary, I've read thru it before- lots of good info in it. I even pm'd back and fourth with raceman a while back about the drive, since he switched over to one from a bravo.

Looks like any drive modifications/changes will have to wait for another year... going to go to school for the next year and learn some new skills. I just couldn't pass it up and the timing works out pretty good...

If my Checkmate sells this sping I might be able to do something with the drive... for now, the only plans I have is to check the ecu with a wideband O2 and tune it with the help of Precison Marine if it needs it. Then get some baseline #s with the stock bravo. Next winter, I'll do somthing about the drive.

Good luck with school Nick....

Best of luck in school

Thanks guys, it'll be worth it to give myself another option.

What are you going for? Options....always good!

HVAC... there is a good school here in Lima.