388 with 750hp,What speed ??
 

If I add 250 hp per motor to my boat :D what speed increase should I expect?
15?
20?

I figure someone already has a 388 with some 750 hp motors w/ bravos already in it , I am trying to get a Idea what to expect.

I am not looking for guesses

Thanks :D

Rob

Re: 388 with 750hp,What speed ??
 

95-96mph :drink:

Re: 388 with 750hp,What speed ??
 

I have tired out 500efi with whipples and teague drives and i am seeing 95 consistantly. The motors are going to be rebuilt this winter. With 750's you should see 105+.

Re: 388 with 750hp,What speed ??
 

Do it strip!!! that blower wine is cool!!

Re: 388 with 750hp,What speed ??
 

Is it the old style Whipples???

105 I think may be pushing it ?it would be nice though :D

I think Lmarth has 800hp w/ speedmasters and does around 108mph???

Re: 388 with 750hp,What speed ??
 

I have never heard the Whipples run before .I was use to the wine though :D On my Old Scarab I built a little Blower motor for it , Now it had some wine :eek: 8% over

Re: 388 with 750hp,What speed ??
 

Rob- 104 with a hair under 800hp. Lou

Re: 388 with 750hp,What speed ??
 

That with which speedmasters? Whats your gear ratio and prop pitch?

.I figure they slow it down some but the reliability is there.

Re: 388 with 750hp,What speed ??
 

Don't forget there is a limitation of hp to that particular drive set up, certain drives are more effecient, you might be pushing the envelope on a bravo style drive vs a stern surface drive. Good luck, it's a great winter project, I'm allready looking forward to the next boating season. 98-101mph

Re: 388 with 750hp,What speed ??
 

Whats up Jeff :D I figure with the B-Max and my driving habits I should be OK ,but on the edge. On my old Scarab after learning how to build drives :D . The Imco lasted pretty good on it at 828hp

I figure the boat may be 500lbs heaver than most 388's with Bravos and the B-Max may hurt a little bit .But I think the old motors where a little down on power also. i wish I dynoes them just to see, but wasted money.

Jeff Dean and Karen's new web site is coming along , might be a good local site for all of us to get together.I guess our first trip next year will be the oss race in Bolixi

Re: 388 with 750hp,What speed ??
 

Rob- As you finalize your plans for your motors and drives which may get you to the Century mark, you may want to get Hustler's latest bottom tweaks for your setup from Chip. Don't want to get into it here, but the inboard strakes at the stern may need to be let's say 'modified'. Lou

Re: 388 with 750hp,What speed ??
 

Rob,

109 GPS
K/E 750's
XR's w/IMCO Shorties
1:35 ratio
Give me a shout if you want to talk about it.

Dean
502-249-1646

Re: 388 with 750hp,What speed ??
 

Thanks Lou,Ill call him see whats to it.

Dean thats some pretty strong #'s.Thanks for the # ill give ya a call :D


Rob

Re: 388 with 750hp,What speed ??
 

That's a fact! :D

Re: 388 with 750hp,What speed ??
 

L is right that hull was not set up for those speeds

Strip have a friend that had a 388 with power and B Max's and had issues with them
you may want to try a different approach

Chris

Re: 388 with 750hp,What speed ??
 

Rob,
Mine runs great above the century mark.
It seems to run best with 1/2-3/4 tank of fuel and a little tab.
I think the hull is fine up to 105-110. May need strake mods above that but don't know for sure. I will probably find out this spring. I'm planning to up the ante a little this winter.
Later,
Dean

Re: 388 with 750hp,What speed ??
 

Rob- Number 5's with a high 'x' dimension (like in roostertail). Don't know ratio, but labbed Merc cleavers are 17 1/2 x 29 as I recall. Remember the PM where you and I discussed how well our boats run when the gas tanks are empty? Looks like Dean has had the same impression. After I fill the tank, I subconsciously check the tabs until I burn off the gas and the boat frees up. Lou

Re: 388 with 750hp,What speed ??
 

How does the boat feel at 100mph compared to 80?

Whats the difference ?

I figure a little lighter feeling.

Rob

Re: 388 with 750hp,What speed ??
 

Rob,
It definitely feels a little lighter because there isn't much boat in water :D
Like I said earlier, mine runs great with about 3/4 fuel and little tab.

Give me a call when you get a chance or send me an e-mail. I sent my address to you in a PM.

Dean

Re: 388 with 750hp,What speed ??
 

Rob,
I'm a friend of Linster I have a 388 I'm still trying to work out. I have 565's with 10-71's xr's spinning 30's with 1.25 gears.I run a little tab drives up just a touch 102 at 5,000 4 1/2 lbs. of boost 3/4's full fuel 6 adults 2 cooler of beer. Winter plan is to do a little engine ajustment & try 8lbs. of boost. I only got 7.78 in the compression department so I think it should like the boost.

Re: 388 with 750hp,What speed ??
 

Yea on my Scarab it was 1 to 1 on the blower at 7psi at 8.1 cr . Then went to 6 % over 11 psi still on pump gas did ok .gained 156 hp ,tryed 8% lost power ,found the limits on the 8.71blower .started building too much inlet heat :eek: Should of went with the 10/71 blower . hine sight :D

Thanks for the info :D

Rob

Re: 388 with 750hp,What speed ??
 

When we first got our 388, it had 500efi's with m-1sc prochargers(approx 700hp) and Bmax drives. Worked perfect...mid 90's all day long. So of course I had to fix it (lucky for me the wife likes to go fast). I sold the engines with everything and started new. We bought some new Paul Pfaff 1000's(went for the 14-71's, same price as 10-71's). Shannon found it a little tough to shift without it stalling(and since she takes it on and off the trailer that's important). We started to pit the lower unit gears and they said it was because of the amount of torque. So instead of playing the drive game we sold our Bmax's and broke down and put some #6's on it(now Shannon says it shifts fine).

I guess what I'm saying is watch what you start.....But it's worth it

Tom

Re: 388 with 750hp,What speed ??
 

Tom- I already had this conversation with Rob. Your boat sounds impressive. Pictures? What are you running for transmissions? Lou

Re: 388 with 750hp,What speed ??
 

Lou we are running BAM super cyborg tranny's...I'll try to post some pic's tonight(if I can figure out how). A friend of mine has a new 388 with 875hp Pfaff's and imco 4x4 drives, he has BAM tranny's too. He has the strake mod done, but I didn't feel much difference. We put the 380 tabs on ours and that made a huge difference, definitely a recommendation.
Our boat is the one on the peggedmovie.com trailer...Of course they show us when Shannons driving, but who would want to see me drive anyways. Tom

Re: 388 with 750hp,What speed ??
 

Here is a picture of the drives...

Re: 388 with 750hp,What speed ??
 

Tom whats the bracing under the swim platform?? Where the ladder usually goes.

Do I see a tab in the center between the drives?

Do you remember your BMax drive ratio? prop pitch? and top rpm w/ the 500's??


What was involved in redoing the transom for the speedmasters :eek: ??

How many hours did ya put on the BMaxes? and did you get the shifting to ever get better ? Dean has mine now redoing them.

Tom very Impressive boat .

Thanks for any Info you can give me.

Rob

Re: 388 with 750hp,What speed ??
 

Tom-Thanks for the quick feedback. Ol Rob has a keen eye (for boats/women) doesn't he? At the risk of asking the obvious, what specifically did the 380 tabs buy you? You wouldn't know the lengths of the tab actuating cables would you? Rob and I need to know. Tell us more about the motors and what do you tow with? We've been swapping info so we all don't recreate the wheel. Got my pegged video and immediately recognized the boat...regardless of who's driving! Looks great! Lou

Re: 388 with 750hp,What speed ??
 

Hey Rob, That's the tie bar for the #6's under the swimstep...We moved the tie bar under the mount now so there is more clearance(that's why you don't see too many 6's on 388s)..We also made it so the drives can only be raised up so far, so we don't have any problems.
The drives were put on at Archer Marine over here on the left coast...I bought them used from Dan. He is buddies with Pat Weismann who went through them and helped with the rigging. We took the motors out, filled all the holes in the bilge and started over...we even filled the transom, so it looks like it was always a #6 boat...never cut for bravos. The nose on the lower units are 1 1/2in above the bottom of the boat when neutral...like Lou's #5's...There is no center tab, that's just the cavitation plate from the drive in the photo.
Our Bmax drives had the 1.30 gears with the procharged 500s(rev limit at 5200)...shifted great...we only had a problem shifting with the big motors because Shannon had a hard time with the blower cycle...We must have had 200 hrs on the Bmax's..worked great. When we put the big motors in we switched the lower unit gears to 1.19 so we could keep the same props.. 31 labbed bravos. We started pitting the lower gears so we did the deal on the #6's.
Hi Lou, We put the 380 tabs on and it basically eliminated all the chine walk. They mount on the 280 mounts, so I never had to change the cable..sorry I don't know the length. We tow it with a 4x diesel excursion. We haven't gotten our pegged video from Chris yet, so I didn't know how much footage was cut...
Sorry so long..tried to get most of the answers... Tom

Re: 388 with 750hp,What speed ??
 

Tom- thanks for the response. Very sanitary rigging. It's hard to estimate how long your boat was on the video but enough for me to fully appreciate it. Just my opinion, but in the helicopter shots, you've got the boat very nicely trimmed out. Only the last 4-6 feet are in the water yet the bow doesn't bobble at all-classic Sligshot! Care to comment on any modifications to the bottom/strakes? Lou

Re: 388 with 750hp,What speed ??
 

Hustle This, very nice!

Re: 388 with 750hp,What speed ??
 

Thanks Tom thats very Impresive .What year is the boat? Thats a lot of work to put the 6's on it..Post some more picks :cool:

The suports I was looking at are where the swim ladder screws to. I just never seen one without it. I figure the drive would have hit it anyway.


It looks like with 750 hp and B Max's . Its going to be around 99 on the low side and maybe 105-6 on a good day? That might be pushing it ?

I allready have the 1.30 gears .Dean is at 750hp w/ xr's turning 32 pitch 109 and Tom was 700hp 1.30 w/ B max mids 90's. Maybe Ill be in the middle?Maybe the motors will make more than 750hp?. I am doing a little more that there standard 750 hp Whipple package they usally do.

I know theres allways going to be faster out there , the main thing is we are going to have Fun :D

I know there has to be more Hustler owners out there , so post up

Rob

Re: 388 with 750hp,What speed ??
 

Hey Lou, When my friend was having his engines rigged at Pfaff's, I wanted to see the 875's and check out the new boat. So my friend that works down there called me when it got there, so I just happened to show up :rolleyes: . What they did on the center strakes is smoothed them out for approx 13-15 in from the transom(I don't remember the exact distance now). From what I hear, that is supposed to help the boat ride on the pad better. After talking to my buddy and riding in his boat, he has the same riding characteristics as ours....I think to really make a difference you would have to smooth more than that short distance of strake. As of now I don't see myself doing it, especially since I put the 380 tabs on....just my .02 Tom

Re: 388 with 750hp,What speed ??
 

Tom- That's good feedback. A friend of mine was crewchief for a F2 Slingshot. Chip @ Hustler told him to grind off the last 18" of the inside strakes. I'm really intrigued by the 380's especially if you don't have to drill new mounting holes. Canyou just change the tab or do you have to change the transom mounting bracket also? Cost? Lou

Re: 388 with 750hp,What speed ??
 

Lou, We paid 550 for our 380 tabs(used)...It takes 5 min to change one. It uses the same mount as the 280...you just remove the stud that they hinge on and unbolt the ram from the plate and switch them....We had to trim ours so the wouldn't hit the drives...I'll take some pics and post them. If you can find a used set, it's the way to go... Tom

Re: 388 with 750hp,What speed ??
 

I found this boat is the for sale section. claims 103 with 720hp

http://secure.offshoreonly.com/geocl...hp?a=15&b=3252

Re: 388 with 750hp,What speed ??
 

Rob - I definitely believe 103 on this boat. He is running a very similar setup to mine with just a little less HP.

Tom - Sweet boat. What kind of speeds?

Dean

Re: 388 with 750hp,What speed ??
 

yeap :D

Re: 388 with 750hp,What speed ??
 

Dean, What did you get by going to the shorter lowers speed wise. MIKE

Re: 388 with 750hp,What speed ??
 

The shorties were on the boat when I bought it. My guess is 2-3 mph. I don't have any trouble at all getting on plane either. In case you were wondering :D
Dean