Search found 20 matches

by Bruce3477
Thu Jan 19, 2012 1:49 pm
Forum: Dufour Performance Discussion
Topic: IRC & the Dufour 34
Replies: 8
Views: 12750

Hi, have looked over the 2010 and 2011 UNCL certificates, and comment as follows: 2010 UNCL #0.997 No hull or rig changes 2010/2011 Hull factor remains 8.0 for iron bulb keel (std D34E) 2011 UNCL #0.983 Changes from 2010 Mass down by 118kg Mainsail increased “p” 0.120m Genoa decrease 1m2 Spinnaker i...
by Bruce3477
Mon Oct 17, 2011 11:44 am
Forum: Common Tecnical Issues - Dufour Grand Large & Dufour Performance Series
Topic: max prop 16 inch on a saildrive volvo penta 40 hp
Replies: 4
Views: 4724

At 7 ton mass, would rather stick with feathering props. An ideal prop option would be an Autostream in 18" diameter. With this style would have huge reverse control, and drag impact very close to a folder when sailing! Also with a stainless prop, there is no electrolysis between the SD prop shaft a...
by Bruce3477
Wed Oct 12, 2011 8:14 pm
Forum: Common Tecnical Issues - Dufour Grand Large & Dufour Performance Series
Topic: MS25s Saildrive Prop Advice
Replies: 1
Views: 3173

As far as aware the saildrive is the S130, and with approx 2.45:1 ratio. These were only in LH rotation, with the later S150 available in both rotations... Have done several prop changes on my D34P with the Volvo 2030,and ended up with good results with the Aussie Slipstream in 17dia x 9P LH item. W...
by Bruce3477
Thu Jul 28, 2011 7:12 am
Forum: Dufour Performance Discussion
Topic: IRC & the Dufour 34
Replies: 8
Views: 12750

I think the issue of the Dufour 34 is beyond "finger trouble", but more the attempt of RORC/IRC attempting to 'save face' with the new non-disclosure of o/h factor...they have not fixed the model, but are hiding behind 'smoke and mirrors'...to protect the "integrity of model" The model apparently ha...
by Bruce3477
Wed Jul 27, 2011 2:06 pm
Forum: Dufour Performance Discussion
Topic: IRC & the Dufour 34
Replies: 8
Views: 12750

From pic's on various regatta sites, Split Point appears to be a stock standard D34P with roller furler. If go back to the original D34P at 2004 in range 0.982-0.984, and if per your comment has a lower DLR, then would most likely be about 0.984 at that vintage. With the 0.001 age allowance of 0.006...
by Bruce3477
Mon Jul 25, 2011 2:39 pm
Forum: Dufour Performance Discussion
Topic: Dufour 34e – IRC Rating optimised?
Replies: 4
Views: 8371

Downwind, the 90-100m2 spinnaker would only be viable in light conditions, as with the high DLR, would be very overpowered...and into broach mode a lot of the time. I know on my D34P with 74m2 spin, that at 24kts TWS / approx 16kts AWS, it's on the limit! Perhaps the reason for a lot of X-34 running...
by Bruce3477
Fri Jul 22, 2011 11:33 pm
Forum: Dufour Performance Discussion
Topic: Dufour 34e – IRC Rating optimised?
Replies: 4
Views: 8371

Peter, I have spent 100's of hours on regression analysis, and built test computerised scenarios of the various combinations of the IRC formulae / methodology. Also have 100's of copies of IRC endorsed certificates. My data is good. Mass (empty) as a factor of rating works out at about 150kg per 0.0...
by Bruce3477
Fri Jul 22, 2011 7:41 pm
Forum: Common Tecnical Issues - Dufour Grand Large & Dufour Performance Series
Topic: Update of keel backing plates -2
Replies: 7
Views: 8081

The keel to hull join on my D-34 was tight ( < 0.5mm) alongside all the M20 studs, and about 1mm at front of keel (M16 stud). When I retorqued the M20 nuts, was very little movement of original sealant, but the M16 when torqued did squeeze a small ridge (white sealant) out of this join. Can only thi...
by Bruce3477
Fri Jul 22, 2011 7:01 pm
Forum: Dufour Performance Discussion
Topic: IRC & the Dufour 34
Replies: 8
Views: 12750

Peter, With IRC being unable to correct the original O/H factor of 1.04 for whatever reasons... Their best option was the current 2011 dropping of overhang factor, and basing immersed waterlines on actual individual boat measures, IRC is now 1/2 way there... When they correct the HF to that of a 5.5...
by Bruce3477
Mon Jul 11, 2011 9:03 am
Forum: Common Tecnical Issues - Dufour Grand Large & Dufour Performance Series
Topic: Dufour 34 Performance - backstay block failure
Replies: 1
Views: 3940

Dufour 34 Performance - backstay block failure

Last week fitted a new regatta cut mainsail to my D-34P and upon cranking up the back tensioner blocks, the top pulley/block failed. Backstay tension is 60mm wire block / 50mm wire block / 50mm wire block and 4:1 sparcraft rope purchase, a 32:1 compound leverage. Final tension by hand was about 30-4...
by Bruce3477
Fri May 27, 2011 12:14 pm
Forum: Dufour Performance Racing
Topic: Dufour 34 – Genoa/jib optimization
Replies: 1
Views: 5655

Dufour 34 – Genoa/jib optimization

As an owner of a Dufour 34 Performance, and having sailed and raced in many club events with wind range all the way to 32 kts TWS (true wind speed), herewith are some ideas as to the ideal foresail set-ups for the D-34 P. With the roller furler on D-34 P, and with an effective LL of about 12.2m, the...
by Bruce3477
Tue May 24, 2011 7:04 am
Forum: Dufour Performance Discussion
Topic: Dufour 34e – IRC Rating optimised?
Replies: 4
Views: 8371

Dufour 34e – IRC Rating optimised?

Following on from previous posts in this regard, the later Dufour 34e is being ‘punted’ as an IRC optimized yacht. Is this in fact so? With it’s non overlapping jib, it looks the part, but do the numbers make sense? With 2010 IRC ratings around the 0.997 range, it would seem very expensive against t...
by Bruce3477
Sun May 22, 2011 10:11 pm
Forum: Common Tecnical Issues - Dufour Grand Large & Dufour Performance Series
Topic: Update of keel backing plates -2
Replies: 7
Views: 8081

Interesting. Did you purchase the D34P new or used and do you think this was a build quality issue. Haven't heard many complaints about keel joint issues on the D34P on the newsgroups. My warranty on the hull is 10 years here so I wonder if this type of problem would get any assistance from Dufour ...
by Bruce3477
Sun May 22, 2011 7:32 am
Forum: Common Tecnical Issues - Dufour Grand Large & Dufour Performance Series
Topic: Update of keel backing plates -2
Replies: 7
Views: 8081

Had very little joy in past with warrantee issue(s), so did not bother this time. As yacht was 7 years old (#22x), would be pushing luck!
by Bruce3477
Mon May 16, 2011 8:52 am
Forum: Dufour Performance Racing
Topic: Dufour 34 – PHRF #
Replies: 0
Views: 3895

Dufour 34 – PHRF #

While is very difficult to determine relative PHRF #’s, yacht-on-yacht and in small local fleets, the USA PHRF ** database provides a lot of information. The basic PHRF rating and factors are: Standard Dufour 34 hull / std mast #117/sec/mile Performance mast/sails upgrade -6 sec/mile Or Oversize mai...