My thundercat - Page 16

Roflhat · 14 May 2018, 17:03

thanks, I reckon it's about the most fun you can have on the water!

Started putting together the steering damper, designed a bracket to mount the tiller to the cylinder. Also bought a bi-directional valve which will hopefully allow me to adjust the stiffness of the steering. Drilled out two of the brass connectors to allow fluid through

Roflhat · 19 May 2018, 21:47

Got the damper setup finished off today, seems to work well but couldn't get out to test it

Lee1 · 19 May 2018, 23:05

Quote:

Originally Posted by Roflhat

Got out for a blast yesterday, was still quite windy around 20 knots. Engine is running the best it ever has, everything is absolutely spot on. Need to get my steering damper setup though, plenty of speed wobbles now I've removed the bungees. Very very happy with how it ran, got 50 knots with the 15G yamaha, which given the conditions is excellent.

Nice, I get speed wobbles on my 2.7 v floor Waveline at 35 knots lol

Xk59D · 19 May 2018, 23:26

35 knots....25hp......on a sib.......need to see this, video please.

jwalker · 20 May 2018, 00:26

Quote:

Originally Posted by Roflhat

Got out for a blast yesterday, was still quite windy .....got 50 knots with the 15G yamaha...

You sound like a parents' nightmare!!

Lee1 · 20 May 2018, 00:32

See my post in this section today titled 4.5 and 20hp Sibbing not sure the video upload worked so I posted video stills

didn't have GPS today but I guessed it at atleast 28 or 3-5 more knots with the Thunderbolt 20hp 17" shaft, my Mercury 25 2 stroke 1995 long shaft gets me 38 knots on dead calm water or with 4 knots tide up my a**

I plane on just the rubbing streak protecting the join between the V floor, I forgot to wax the streak today lol

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Roflhat · 20 May 2018, 09:40

that's fairly shifting for a wee sib, it's a lot of fun using a 25/30hp on a sub 3 meter inflatable!

Roflhat · 20 May 2018, 09:44

Looks like you're running a 2 blade prop on that old Mercury, those give a fair bit of vibration by themselves, especially if they're ventilating. If you're getting to WOT in 1.5 seconds you could stick a higher pitch prop on it, even higher top speed

Lee1 · 20 May 2018, 23:43

I was thinking about putting a 3 blade on there and I have a 3 blade 7 inch, the Mercury parts do list that as an option as well as a 3 blade 9 inch pitch, How would a 7 inch be? I'm thinking I should really use a 9 inch?

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Roflhat · 21 May 2018, 08:04

What have you got on it just now? I'd be tempted to go for the highest pitch they offer given the weight and use of the boat

realdeal · 11 July 2018, 01:10

Hi guys. Seriously thought about purchasing a Ceasar Surfcat from Jacques at Ceasar but was informed that a 70hp Yamaha 4 stroke only comes in 20 inch shaft. I only want a 4 stroke and the Thunderbolt can take a 4 stroke 90hp Yamaha with a 20 inch shaft. My question to you guys is can Thunderbolt be made like a surfcat where it would be a drier boat with a round nose OR do any of you know of how it can be made to be as dry. Any and all replies would be greatly appreciated. Thank you. Louie

fel2 · 11 July 2018, 03:09

Hi louis.

I can only talk for the surfcat.

Its all about on what type of water you plan running the boat, when i go on the smaller river, there is less to almost no wind all the time, no wind, and any of these will be dry, even in some good waves, if the wind is not too bad i can still drive without my dry suit.

I think it happened 1 or 2 time that i had to wear glasses not because of the sun but because the constant rainfall i had on my head by the splash of the water.

I am already looking buying a bigger one since it's not so ideal 2up with all my gear -

One 5gallon main tank, 2 rotopax 4 gallon tank or one. My dry suit, my girlfriend drysuit. My dry bag and the beer, there still some place left, but it is not so pratical,

But when i go alone, its just the perfect size, i wish the boat was 1 feet longer !

fel2 · 11 July 2018, 03:15

https://youtu.be/E-EPmxbhKkU

Roflhat · 11 July 2018, 08:22

I'm sure Jacques could build a custom boat for you, or you could try the other manufacturers. I have no particular affiliation with Ceasar, and to be honest if I was buying a new thundercat now I would go for an Infanta, it's a better design and the quality is on par with the Ceasar. Gemini make quite a good variety of boats, I think they make a 4.7m round nose which would take your 70hp 4 stroke

When I drove the Thunderbolt up here I wasn't very impressed, there's far too much flex in it. It probably could have been pumped up harder but I think it's just too big a boat to have a floor like the thundercat. If you're only using it on flat water it would probably be fine. A thundercat shouldn't be too wet, although on my Ceasar some water does come over the front nose cone, on my old thundercat it never did

Aquarius make a 4.4m which would probably take a 50 or 70 long shaft, and would give you a decent amount more space. If you want a standard Surfcat a 50hp 4 stroke would work nicely and they do come in 15 in shaft

fel2 · 13 July 2018, 15:50

Any word on the gemini dive 530 ? Ive heard you can order it with hijacker

Roflhat · 15 July 2018, 16:57

Yes they have hijackers but it looks like it has a slight V hull too. Look like good boats, the gemini quality is good, I believe they're made from hypalon too
https://gemini-marine.com/shop/dive-470-530/

Roflhat · 23 July 2018, 08:13

Not had perfect weather for testing recently but got a couple things done, re-bled the steering damper which is much for effective now. Bought 1m length of ali angle which I'm going to fit across the transom to strengthen it, credit to fel2 for the idea. Had some really bad weather last week so decided to go out anyway, excellent fun. Managed to break the throttle roller, I've now had another waterjet out of aluminium, pretty sure this one won't break!

realdeal · 23 July 2018, 17:57

Guys. Great responses. After researching all your info, the infanta weighs 22 lbs. heavier than the Surfcat. Fel2, the new gemini is not made for speed. It seems the only alternative is the Thunderbolt and maybe Rolfcat when you drove it, it was not inflated enough. Fel2, if I order the thunderbolt, I would want the console AND the cushioned bucket seat AND I would want it to be telescopic for various wind/temperature conditions. Also be able to swivel so I can do a little fishing. Down here in southern New England, I don't know who could rig it? Thank you. Louie

Roflhat · 23 July 2018, 21:43

Pretty sure the Infanta will be lighter than the surfcat, probably by a good bit too, the numbers on the websites are rarely accurate!
It is possible the Thunderbolt was not inflated enough, but the owner tried it quite a few times and wasn't too happy with it. You could probably strengthen the floor somehow, maybe a couple of angle brackets like fel2 put on his transom.

I'm sure you could speak to Jacques about rigging it up like you're talking about. He offered ballast nose cones for a while too, where you could fill them up with water to add weight to the nose

realdeal · 24 July 2018, 02:06

Roflhat. What is the purpose of the water ballast at the nose cone? Louie