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!