502, 5psi, power?? - Page 4

larby · 03-09-2009, 10:30 PM

I'll second all of that Richard. I'm aiming for 550hp by the way, so should be about the same speed as you. By then I'll also have a fully fitted cabin, no loo though!

Paul E - Currently the class you're looking at is 2litre to 4 litre, so yes, you would be in the same class as Jacques and the other 21ft boats.
I believe the current class structure is...
up to 2 litre
2 litre to 4 litre
4 litre plus
I'd like to see a cruiser class added to that for boats with a fitted cabin you can sleep in such as mine/richards/formulas etc. Yes, we've got big engines, but we're not that much faster, and we're at a disadvantage with the small tight courses. When it roughs up enough for us to have an advantage, the course would be moved for the sake of the smaller boats, putting us at more of a disadvantage, it's a no-win situation if we've got to do a load more laps.

James

Big V · 03-09-2009, 10:41 PM

I personally want to do the same amount of laps as the V8 boats. In the last North Beach race everyone saw Chief was close behind me in his 8 litre V8 and that is exactly the kind of racing we all want next year and what I will be pushing for.

Haha Richard, you enjoyed those pot-shots didn't you mate! All I'm going to say is I look forward to racing with you again next year.

Hi Paul, you will be in the same class as all of us next year mate, all doing the same amount of laps

The committee will be liasing with the RYA over our plans for all of next years races.

'Round Sark' sounds brilliant Hugh, great idea mate.

Tony Le P also wants to do 'The Round Herm Race' - as with the Herm Race this year, he will be sitting down with The Harbour-Master plotting all our race courses so they are challenging but at the same time very safe.

Jacques.

Matt · 03-09-2009, 11:08 PM

Does that put more load on the drive than when you accidentally land after "wanging" it in the air?

Quote:

Originally Posted by larby

...but i don't really plan any heavy launches which would strain it the most....

larby · 03-09-2009, 11:15 PM

Quote:

Originally Posted by Matt

Does that put more load on the drive than when you accidentally land after "wanging" it in the air?

That's a very fine point, and likely to be my drive's undoing!
I'm gonna have to be pretty careful with the throttles eh!
I guess that's just a downside i'll have to get used to until i can afford some amazing drive designed for the use. I'm gonna have a look into the imco uppers for now, they seem to be a cost effective upgrade?

James

Matt · 03-09-2009, 11:43 PM

I honestly don't feel qualified to say. I can't understand how accelerating hard can put more shock loading on the drive than a violent rear entry, but that's not to say it doesn't, just that I don't get it. Definately throttling well is a requirement. Make sure you have a rev limiter, especially while learning.
Unsure the age of the ign system you have, but IIRC the thunderbolt IV system doesn't have a limiter.

I did look into having a pressure switch attached to the bravo pitot sensor once, attached to a "hold" limiter - ie holds the revs steady. So that when exiting the water, the limiter holds the revs the same until re-entry. I guess an ign cut would also work OK, and RS components would seel all the bits you need.

larby · 04-09-2009, 06:53 AM

Thats a damn fine idea! Think i'll have a look into that one. I'm gonna be running MSD ignition with the blower, not keen on the old thunderbolt system, so I'll at least have a soft limiter on there set as low as posible.
You are definately right that jumping will put the most strain on her, i was just being thick earlier!

motorvator · 04-09-2009, 08:29 AM

Quote:

Originally Posted by Matt

Does that put more load on the drive than when you accidentally land after "wanging" it in the air?

Is "a heavy launch" defined as tipping the boat off the trailer before the tide is in

As for the supercharging, as I understand it James you haven't actually had the boat running with the full potential of what you have already got i.e. 415 hp as opposed to the 330 you bought it with. I would have thought you would be better to get the thing up and running sweet first to understand the rigs capabilities before going down this route.

Bolting on a supercharger is not the solution to a poorly prepared engine in the first place, they should only be fitted to something that is 110% to start with or you will be left with a box of bits in the engine bay.

Shock loading won't be a problem on the drive in the 415 configuration as long as you stay with rubber hubbed props and spend a bit of time learning to throttle, i.e. matching prop revs with re entry speed. Until you can confidently do this you are wasting your time as the art of racing is finishing not having the biggest fastest tool to start with. Once you have mastered that, that is the time to start looking at using solid hub props etc to gain outright speed.

If you look at successful racing drivers they tend to be ones who are sympathetic enough to get their kit to the end not the fast ones who end up in the dnf every round.

With 415 and the design / length of boat you have you should wipe the floor with any 2 litre boat and give the 4 litres a good run for their money regardless of the size of course or conditions. Learn to balance the boat with trim and tab settings and you'll be surprised just how tight this thing will turn while retaining speed.

Lastly "Cruisers" tend to be determined by the ability to stand up in at least a part of the cabin. Unless you are three foot tall I'm not sure I'd want the revenger referred to as a cruiser.

larby · 04-09-2009, 09:00 AM

Hi Kerry,

You're right that i haven't yet had the 502 running quite right. For that reason, I'm pulling it out in a week or so to take it back down and do it properly over the winter. At the same time, the revenger will be going into the vinery for a total rebuild/refit.
The reason for the engine not running right is simply that we rushed it together in an effort to make the races, having deemed the 330 underpowered.

Fitting with my dream to build a supercharged V8 powerboat, I'd rather build it for this in the first place, then build it n/a, drive it for part of the season and then wish it were supercharged for the rest.
I have no intention at all to bolt the 'charger to a poorly prepared engine, I plan to totally rebuild it, including forged pistons, to prepare it for the intended use. The guy who had the charger briefly before me found out what happens if you bolt it to a standard engine!
I'm rather hoping that with a bit of advice from Dean over here, along with all the great help i can get on this forum from people like you Kerry, I should be able to build a more than capable low boost engine which i'm sure the hull will be able to handle.

As i mentioned before, i don't intend to go out there next year and floor it from day one, I don't have to use full throttle, and i fully intend to take my time learning to drive the boat properly. It'll be nice knowing she's got the ability to go faster though, once the weather and my ability is up to it.
As for the racing, I should have a reasonable amount of test time under my belt by then, and as i did in the poker run and the part of the race i did enter, I'll drive according to my ability at the time.
If she only did 70 as Jon suggests with the 425hp, i can't honestly see 415hp cutting it for me, not to mention the fact that Richard will be more than capable of wiping the floor with me seeing as he's doing mid 70's.

As for the cruiser part, that sounds about right, will have to see what she fits into when we decide our class structure.

James

motorvator · 04-09-2009, 09:33 AM

James,

sorry if that came across as dismissing the idea, my thoughts are more that you have not discovered as yet the capabilities of what you already have.

It's all very nice looking at theoretical top speeds but what you have here is a very capable hull form that is able to sustain a high speed in conditions that others can't which can easily be worth 10mph top end. Driven right she will spend more time with the drive in the water where it counts than your average lightweight outboard powered boat.

I was going to say take a leaf out of Nick / JFs book, they have a boat that is highly capable but powered with relatively low power in preference for reliability. Unfortunately they done their best last time out to prove that wrong

but I still believe the philosphy is right.

I would be inclined to get the 415 right and use it a bit first before you go rebuilding as I just know your thoughts for set up are going to change once you understand the hull.

All the best whichever way you go,

Kerry

Jon Fuller · 04-09-2009, 11:49 AM

Quote:

Originally Posted by larby

If she only did 70 as Jon suggests with the 425hp,

James

Just for the record, I think the motor was probably closer to 400 horses.

I think Peter wanted to look after the boat, as a result, he never really got close, rough or flat. The boat always ran lovely and level, just a little off the pace.

larby · 04-09-2009, 06:39 PM

Jon - Thanks for the info, she does seem to run nice and level in all the photos I've got, he did manage a win against you and Tony one year though didn't he? '99?

Kerry - I think the issue i've got at the moment is that i didn't prime the oil pump enough before starting the engine, so the big ends are seeming a bit rattly, hence my decision to just rebuild rather than risk it. Don't really want to pull her apart twice though!
To be honest, i know it goes against a lot of advice, but i'm still planning to build with the charger over the winter, otherwise i just can't see it ever going on. I don't wanna be doing it mid season, the year after we'll be too busy moving out and then it's a slippery slope from there! If i'm gonna do it, now's my chance. I'll be keeping boost as low as possible at least to start with though to give me a chance to get used to her.

James

andy21 · 04-09-2009, 06:55 PM

Quote:

Originally Posted by larby

As i mentioned before, i don't intend to go out there next year and floor it from day one, I don't have to use full throttle, and i fully intend to take my time learning to drive the boat properly. It'll be nice knowing she's got the ability to go faster though, once the weather and my ability is up to it.

No you don't have to... but i'm pretty sure you will!!

Jon Fuller · 04-09-2009, 06:59 PM

James. We raced from '95-'97.

The very first race that Peter did was a basic at Bournmouth at the end of '95 in the experimental 'Sportsboat Class'. He ran the boat with the Stellings etc (not permitted in the National Production Class we normally raced in) I raced that day as a basic entry with Paul Gilley (Nicks Brother) in the Team Extreme boat to give Pete a race (TD & I had already won the National championship).

Early in the first lap we stopped, with what turned out to be a battery isolator clicking off (probably not switched on properly) by the time we got going again we were a mile or so adrift. (about a minute)

We caught Peter on the last lap and passed him just before the finish line. We assumed victory.

When we arrived for prize giving we found we'd been DQ'd.

It transpired that we'd done our large & small laps wrong, and had actually done longer small laps than we should have. As a result, the spotter on the beach thought we'd missed the mark on each small lap. The GPS track actually showed what we'd done, and we had passed the mark on the correct side (a little like Adrian and Ashleigh did a few races back) and done about 2.5 extra miles to boot.

We chatted to Ian Stuart-Ross, the then manager of UKOBA, and decided to let the sleeping dog lay, as it was a better sporting approach to let the newcomer have his win. and after all, there were no national points anyway with it being a basic, only our bruised pride.

So, we probably made up IRO 3.5 miles to win, but Pete collected the silverware.

When he entered the national class the following year, he had to run without the stellings etc. So the boat was a little slower.

Pete went on to compete for some years, so it was probably the right move.

Tony and I won every race in the '95 & '96 seasons and were beaten a couple of times in '97 by Roger Severy in the new P28, but were never beaten by Pete & John (or Pete & Shelly) they took it quite easy, and we were usually 6-8 miles ahead at close of business.

That sounds like a great record and probably a little big headed, but in reality the competition was a bit weak, either in performance, or reliability. (or both) especially in '95. I think there were 9 starters in our class at the start of '96, but still nothing 'strong', the numbers dropped throughout the season too.

Roger Severy's Phantom 28 'Wentworth Auto & Marine' (now 'Victory Inn Hamble') changed everything in Production / Touring class when it appeared in '97, it was virtually unbeatable in all conditions.

Quote:

Originally Posted by larby

Jon - Thanks for the info, she does seem to run nice and level in all the photos I've got, he did manage a win against you and Tony one year though didn't he? '99?

James

larby · 04-09-2009, 07:35 PM

Thanks for the insight Jon, I'd been painted a fairly different picture!
Given the lead you were managing on a regular basis, I'd say i'm definately going to have to add a fair wedge of horsepower to stand a chance against Richard in the Extreme! I won't be hammering her too much in the races, she's getting on a bit now and she'll be my leisure boat first and foremost. It'd be nice to have the power there to not be straining the tits off her all the time, whilst hopefully not overpowering her.

James

Big Dutch · 04-09-2009, 07:37 PM

51 MPH then

larby · 04-09-2009, 08:20 PM

So i'll be doing the same number of laps as the 1.3's then yeah??

andy21 · 05-09-2009, 08:57 AM

Quote:

Originally Posted by larby

So i'll be doing the same number of laps as the 1.3's then yeah??

Would be nice to know how the different groups are going to be worked out for next years racing...

I quite like the idea of an argocat with a 90 on the back, but if the number of laps are worked out on you're (estimated) top speed it could be a bit of a handicap?

larby · 05-09-2009, 12:45 PM

I believe the classes will be decided according to engine size, as is currently the case. The confusion is more with the bigger boats where large engine doesn't necessarily mean higher speed.

James

scooby_hugh · 05-09-2009, 12:50 PM

Would it not be easier to class by horsepower? That way the v8s would maybe be better classed, or maybe to still class by capacity but allow 4 strokes some leeway as they wont produce the same power per cc as the 2 smokes..

larby · 05-09-2009, 12:59 PM

Well yeah, there could be advantages to that, the classes are quite open though (up to 2 litre, 2 to 4 litre etc), so a 200hp 4 stroke would be in the same class as a 200hp 2 stroke. We can't end up with too many classes, it'd be a nightmare.
Whichever way you look at it though, 8.2 litre or 600hp, I won't be doing 3 times the speed of a 200!
To me the best way to class is capacity, mixed with a little common sense!

James