Team Tanglefoot

larby · 03-04-2010, 10:08 AM

Anyone got any knowledge of this boat?
I've noticed it ran a pair of Lancing/Bellamy surface drives. Does anyone have any photos of these at all, or does anyone know how it ran?

I'm still concerned about the concept of running 500hp through my bravo drive, and i'm at an ideal stage to be considering a change, rather than rigging with a bravo, just to de-rig again!

Does it make a huge difference that the LM's are fixed shaft, not trimmable, especially as I've got tabs too?

If anyone's got anything to add, please go ahead, I'm just thinking out loud here...

Cheers, James

Jon Fuller · 03-04-2010, 10:43 AM

http://boatmad.com/gallery/main.php?g2_itemId=17381

Originally owned & raced by Will Haycock in National Production class as I think 'Sherry & Haycock' / 'Ambassador Communications'

Then I think Stan Ford & Tony Cordial as 'Superluminal', then Tony 'smooth' Donald bought it to race in Touring class as 'Team Tanglefoot' from around '96. (co driver Dave Barham had dealings with, or worked for Tanglefoot beer)

Ran well in a head sea with the surface drives, but harmonic issues with the large cleavers used to shread gearboxes like they were going out of fashion. By the end of Tony's term with the boat it had some pretty hairy chested small blocks in it and was running upper 70s. That speed was achieved by brute force in my opinion, as it ran with it's nose firmly planted in the drink and must have had enough power to overcome the enormous resultant wetted area drag. When Tony first took the boat on, it struggled to get into the 60's.

I think a single LM drive would be disasterous, as no doubt, you'll find out.

larby · 03-04-2010, 04:10 PM

Nope, think that says it all for me! Looks like I'm sticking with the bravo then!
I remember discussing surface drives a while back and deciding they wouldn't work, it was just having seen the pic of tanglefoot with them got me wondering. That description says it all though, thanks Jon

James

lain · 03-04-2010, 05:26 PM

home made hull, supercharger, and surface drive, harmonic issues! What could go wrong

larby · 03-04-2010, 06:53 PM

Oh ye of little faith, I've already scared you out of my class and I haven't even finished it yet!

Lets just hope that the comparatively light weight of the hull will give the bravo an easy time. I'm only hoping to put 500hp through it so it should be fine. At least I've got a spare!

James

lain · 03-04-2010, 07:18 PM

I was told by Raylar who I purchased the 496HO bits off that I shouldn't go for his 525 prop hp upgrade if racing because of the constant popping out of the water, unless i upgrade my bravo1X, to something like an imco upper. Also told me not to put more than 450 racing hp through it, but maybe he was just covering himself?

You haven't scared me off, it's more of a been there, 'ruled', done that sort of thing and want to give you lot a chance

You going for the; home built hull, supercharger, home build engine, surface drive route is for some reason reminding me of that game 'Jenga'

larby · 03-04-2010, 08:20 PM

Ha ha! Well I'm not going for the surface drive any more. Come and have a look at the hull, it'll dispell any worry about it being a home build, It's definately better done than 99% of original stuff I've seen. I don't have a price to build it to, just a quality, so I can take my time getting every little bit right!

Racing with the bravo is a worry for me, but there really isn't another option it'd seem. I've got all the info I could need to rebuild it much stronger, but I'm gonna start off with the stock one and see how long it takes to break first. Never know, it could be fine!
Even replacing it with a ssm 5 seemed like a good idea, but it's an obsolete drive, and I've been advised against it. I know nothing in this area so can only go by advice from people who know!
The bravo ratings are for when it's pushing quite a lot of boat. You're extreme is fairly small, yet it looks massive compared to the revenger. This lack of size/weight should have a big bearing on how much the drive can handle, in the same way a lighter car's drivetrain will last longer than a heavy one with the same hp doing heavy launches etc. We'll see

James

lain · 03-04-2010, 11:32 PM

Well it's about time you changed that avatar from 'bits' to a moving boat

larby · 04-04-2010, 07:33 AM

Fingers crossed for June or July mate

Burty · 04-04-2010, 11:26 AM

Quote:

Originally Posted by larby

Racing with the bravo is a worry for me, but there really isn't another option it'd seem. I've got all the info I could need to rebuild it much stronger, but I'm gonna start off with the stock one and see how long it takes to break first. Never know, it could be fine!

James

yeah, or it could let go and take your engine with it!!

larby · 04-04-2010, 12:33 PM

Oh god, don't say that!! It's a good point actually, if it does let go when I'm hard on it, which it most likely will, it could over rev a touch. Ruddy 'ell.
What else am I gonna do?! Revisit the speedmaster option running as a submersed drive?

Jon Fuller · 04-04-2010, 12:39 PM

Or spend 50 quid on a rev limiter.

Anyway, with 500hp, you'll only break a good bravo if you're crap at throttling.

larby · 04-04-2010, 05:26 PM

Would the intertia of the engine not still take it above the limit though, in the same kinda way as shifting into 1st in a car at 60?
I'm gonna be running MSD ignition anyhoo, so have a rev limiter in there. I've been told by several people the bravo should be fine and I like to think I'm reasonably good on the throttle, never blown a box on anything else before. It will be getting raced pretty hard though. Blowing a box racing isn't an issue, it's more if it decides to let go half way to jersey!
Maybe I need a bracket for my 4 horse!

James

peterunwin · 04-04-2010, 07:15 PM

Quote:

Originally Posted by larby

Would the intertia of the engine not still take it above the limit though, in the same kinda way as shifting into 1st in a car at 60?
I'm gonna be running MSD ignition anyhoo, so have a rev limiter in there. I've been told by several people the bravo should be fine and I like to think I'm reasonably good on the throttle, never blown a box on anything else before. It will be getting raced pretty hard though. Blowing a box racing isn't an issue, it's more if it decides to let go half way to jersey!
Maybe I need a bracket for my 4 horse!

James

Hi James,
Your absolutely correct a mechanical or electronic rev limiter will only hold the engine revs to it's preset limit if you approach the limit relatively slowly in which circumstances it will work fine,if however you have a relatively high performance engine accelerating hard & you jump out of the water just before the rev limiter would cut in the rpm achieved would probably be in the region of 2-3000rpm over the preset limit.Having seen lot's of race car data logging particularly on the porsche 911 GT2'S with a fuel shut-off rev limit of 6500rpm it was not uncommon to see well over 9000rpm on missed upshifts usually resulting in at best in bent valves, so until somebody comes up with an intelligent rev limiter that can anticipate when you are about to jump out of the water the best protection is a very good throttleman

Peter

Jon Fuller · 04-04-2010, 07:30 PM

I don't really get that, but I don't think i have the energy to disagree tonight.

larby · 04-04-2010, 07:42 PM

I guess with fuel cut, which mine wouldn't be being carb, there is a certain amount of time between it sensing an over-rev, and it actually taking effect on the engine due to various reasons. Under normal conditions it'd catch it in plenty of time, but if the engine is under no load and rocketing up, that amount of time (a tenth of a second ish?) will equate to quite a few revs.

What I was meaning in my case, is that the engine has a lot of inertia, so even if it's spark is cut, could it continue to rev itself higher? That said, the simple laws of physics suggest that if the spark is cut, there is no force acting on the engine, therefore it would stay at the same revs at best, unable to accelerate as there is no external force acting upon it. Unless it could detonate it's way up there? Not sure on that one, Jon, you'd know much, much more about this than me!

It's of particular relevence actually as I was thinking of a gadget (amongst a thousand other things!) which could sense a sudden rise in revs, or a drop in water pressure etc, due to jumping, and cut the revs at the point they were at when you left the water and hold it there, effectively allowing you to drive with your foot to the floor...

James

Jon Fuller · 04-04-2010, 09:23 PM

Quote:

Originally Posted by larby

What I was meaning in my case, is that the engine has a lot of inertia, so even if it's spark is cut, could it continue to rev itself higher?
James

That's the bit I don't get.

The limiter on our 502 for example, came in at 5150rpm, and I never saw the needle go above that figure under any circumstances, not even the shortest spike. It's hard to imagine it spiking to 50% more than its max limited rpm. As I see it, when you stop pushing on the crank journals (5151rpm = no spark) rotational speed will stop increasing. I can't see how it could be any other way.

Anyways, we ran IRO 460hp through a bog std non 'X' Bravo ('95 vintage) for three seasons racing, testing, fun, cross channel dashes and windermere records, and never once had a breakage or problem. All it got was regular lube changes.
Roger Severy had 300hp small blocks and managed to break 3 transom assy's, so I think, it's all in the amount of mechanical sympathy applied by the operator.

lain · 04-04-2010, 10:10 PM

I get the feeling the GT2 engine is quite light and will rev quite free compared to your V8, and maybe as you said the fuel cut off rev limiter on it isn't that fast acting where an ignition system should act instantaneously preventing the problem.

And what's the next idea? An auto rev cut system. Personally I'd just get it in the water. Once you start using it you'll probably be quite satisfied manually throttling off, and it's just another thing to go wrong.

steve h · 04-04-2010, 10:41 PM

Quote:

Originally Posted by Jon Fuller

That's the bit I don't get.

The limiter on our 502 for example, came in at 5150rpm, and I never saw the needle go above that figure under any circumstances, not even the shortest spike. It's hard to imagine it spiking to 50% more than its max )limited) rpm. As I see it, when you stop pushing on the crank journals (5151rpm = no spark) rotational speed will stop increasing. I can't see how it could be any other way.

Anyways, we ran IRO 460hp through a bog std non 'X' Bravo ('95 vintage) for three seasons racing, testing, fun, cross channel dashes and windermere records, and never once had a breakage or problem. All it got was regular lube changes.
Roger Severy had 300hp small blocks and managed to break 3 transom assy's, so I think, it's all in the amount of mechanical sympathy applied by the operator.

nice one john i ran pair opf bravo ones with supercharged bulldog for 4 years on same drives like you say down to throttle man god help the new breed of racers