175 or 200 on an Osprey 6.5 vipermax??? - Page 2

TNDB · 26 November 2007, 14:07

Remember the 175 Suzuki is a 150 with more radical cams...

Effectively the 175 uses its variable valve timing mechanism to tame the cams at lower rpm to enhance the torque curve (which without the vario would be a typical "screamer" type high lift cam affair) then by 5500rpm the vario bit is fininshed and the cams can liberate your full 175hp.

I actually bought the DF150 for two reasons:
Firstly the 150 does not have the vario stuff so the cams are optimised for a broad torque curve with the peak hp (150) being their natural limit - IMO the lower end torque will always be better (higher) with a properly specced and matched set of camshafts than with a radical higher lift set which are then manipulated to enhace the lower end curve...

Secondly the extra 25 hp is only there after 5500rpm which in reality I don't breach that often since on my 6.5m I find the ~45mph @ 5500rpm tends to be a little uncomfortable for my passengers and the top end of 51mph @ 5900is plenty....

The boat tests on the Suzuki site do point towards their being little practical difference between the performance of the 150 and 175....

Personally I think the 3.6l 200 is overkill on a 6.5m rib, too heavy and probably too much torque - can't believe I just said that

Downhilldai · 26 November 2007, 18:43

TNDB: What boat is your DF150 fitted to?

TNDB · 27 November 2007, 10:36

Quote:

Originally Posted by Downhilldai

TNDB: What boat is your DF150 fitted to?

Rib X 640

Daniel · 27 November 2007, 16:20

Quote:

Originally Posted by Rogue Wave

I drove a 150 Vipermax and it seemed really well balanced, but hey, if the 200 gives you a bigger stiffy then go for it

Hi all, long time no comment from me.

Stu, was that my boat? She was only 6m, i reckon a 6.5 would be nice with a 200.

Rogue Wave · 27 November 2007, 16:31

Quote:

Originally Posted by Daniel

Hi all, long time no comment from me.

Stu, was that my boat? She was only 6m, i reckon a 6.5 would be nice with a 200.

Yes it was!

HI Ya buddy

K&S · 30 November 2007, 15:21

Hi,
I recently went through a similar scenario. I couldnt decide between a Suzuki 175 and 200 to put on the back of an xs 650.

I eventually decided on the 175 as i was recomended to add a second axle to the trailer. For the amount of time spent at wot, extra fuel cost, and extra cost in services etc. Idecided that the 175 would suit.

Dont get me wrong, i was very tempted by the 200 given the extra power if needed and the difference in purchase price was not much. Sadly comon sense and pressure from the boss (wife) got the better of me.

There was a report in Rib international on the Solent rib 6.5m with a suzuki 175 on the back the figures appeared as;

3k rpm - 18kn
4k - 29.12
5k - 36.97
6500 - 47.95

Zero to 30kn 8.5 seconds

Unfortunately there were no fuel consumption fig's

(I know its not the same boat before i get shot down )

I am still awaiting delivery of our boat and sorry i cant be any more help.

Erin · 30 November 2007, 19:16

Hi K&S, and thanks for your comments.

I have been out for a test drive on a Solent 6.5 with a suzy 175. I saw 42knots come up on the gps, but we weren't going for max speed, so there was probably more available in the right conditions. I also think the Solent is lighter than the Vipermax.

Last week I was convinced I was going for the 175. This week I'm back to the 200. The price difference is neither here nor there out of £20k+, but it's the weight and fuel consumption that I'm trying to balance, along with speed.

bedajim · 01 December 2007, 06:36

Quote:

Originally Posted by Erin

Hi K&S, and thanks for your comments.

I have been out for a test drive on a Solent 6.5 with a suzy 175. I saw 42knots come up on the gps, but we weren't going for max speed, so there was probably more available in the right conditions. I also think the Solent is lighter than the Vipermax.

Last week I was convinced I was going for the 175. This week I'm back to the 200. The price difference is neither here nor there out of £20k+, but it's the weight and fuel consumption that I'm trying to balance, along with speed.

Hi

My average fuel consumption is 1L = 1 mile with a 200 opti and I'm not soft on the throttle

I've also got a 15 2st aux on the back so I'd forget about the weight

Mollers · 01 December 2007, 08:25

The fuel consumption difference will also be 'neither here or there' or the weight. Your dilly dallying over the price of a bag of chips. All engines around that size do roughly 1ltr/Nm and if your too hung up about weight the mother in law will never get a trip out. Get the thing bought.

I'm about to hang a 263kg engine on a Vipermax only 500mm longer than yours.

Daniel · 02 December 2007, 12:00

to be fair, i agree with Mr Mollers. A few Kg, same a a bit of fuel or an extra person. Consumption? My 150 did 1li/mile, my mates 200 did the same when we travelled together (IE same sea state, same speed etc.)

Erin · 02 December 2007, 15:16

Thank you gentleman, I think I've reached a conclusion. Looks like a 200

Downhilldai · 03 December 2007, 08:37

Quote:

Originally Posted by Erin

….. I think it'll have to be a 200…..

Quote:

Originally Posted by Erin

I'm erring towards a 175…..

Quote:

Originally Posted by Erin

……Last week I was convinced I was going for the 175. This week I'm back to the 200. ….

Quote:

Originally Posted by Erin

Thank you gentleman, I think I've reached a conclusion. Looks like a 200

Are you sure now?

Ian M · 03 December 2007, 11:10

If it helps, I had the same dilemma. Drove the 150 6.5 metre Vipermax demonstrator with an etec, which it has to be said was lively enough, but went for the 200 as there was very little downside (except cost!). However, in my case, etecs were the only make under consideration.

Hugh Jardon · 07 December 2007, 13:23

Quote:

Originally Posted by Erin

Thank you gentleman, I think I've reached a conclusion. Looks like a 200

top man

you know it makes sense, i also think the vipermax's need the extra hp to push em along

do you have all the details sorted out now?

Erin · 12 December 2007, 21:27

Yep, all sorted. Thanks for the help along the way Chris

.

The new hull is now nicely nestled in my back garden awaiting some brighter weather to start the fit out. Needless to say, there'll be a few photos popping up on Ribnet in the near future along with sporadic write-ups of my progress and dilemmas.

Hightower · 12 December 2007, 21:39

What you want is one of these.

[YOUTUBE]DUDipAjTM8I[/YOUTUBE]

Petrov · 12 December 2007, 21:46

That 350 is sitting on a Osprey Viper Max 7,5 (acctually 7,8m) with tappered tubes.

Hightower · 12 December 2007, 22:22

I heard of a large Vipermax being built for a Yam 350. Is that the first Ospery Vipermax with tapered tubes?

Petrov · 13 December 2007, 06:10

Yes its the first one.

Mollers · 06 September 2008, 13:19

Quote:

Originally Posted by Petrov

You should be able to get +- 52knots with a 200hp 2-stroke (depending on brand)
Can you fitt the engine higher?
Do you have any pics of the boat.

I'm getting 49knts with my out fit running a 23p 4 blade BRP prop. I've jacked the engine one hole which has put the cav plate 40mm above the planning pad.

W'dya reckon Pretrov?