I can't seem to find a good guide of things to change on a basically stock boat to make it the best it can be.

Other things I have heard are about new centreboards being better and the new rudders being better also. How do the new style sails compare to the old ones in terms of performance, lifetime etc.

What else should I know?

I originally was sailing with non-regular crews so telling them to pull the blue rope was easier than telling them to pull this 5mm blue rope before pulling the 4mm blue rope etc. 

If you do go down the single line route the biggest advice i can give is use 5mm d12 for the tack line and 4mm anything as the kite halyard. this I've found is the perfect balance of friction to ensure both kite and pole go out equally.

Continuous kicker/downhaul is a must if you plan on any serious racing. The other unique upgrades I've got is;

Having the kite halyard run around the back of the boat, but to ensure I Don't stand on it/trip over it  the blocks are tied to around 150mm of string which are tied to the toe strap mounting points, This allows for the halyard to run tightly round the central mainsheet column and inside the drainage well without chafing or fouling anything

The wing wangs (the lines that control the sideways movement of the pole) have a 6mm bobble on them then  a bowline with a piece of flexible air hose round it. This is then pulled from forward (in front of the mast step) with the pole across to the side and tied tightly. This allows the bobble to hit the bowline knot and stand the handle in the air when the pole is set for the opposite side. Meaning when you gybe rather than trying to pick up the handle or get a grip of it you can just stick you're hand/arm into the hole of the hose and begin to pull without missing the handle.

The centerboards and rudders all got a new molding at around sail no. 1100 , these are much better but i wouldn't say crucial unless you want to compete at top level (I've still got my old ones)

Never sailed it with a good old style main so cant tell you the difference between them but its like everything, the newer the better.

If you haven't got righting lines i would put some on and if you get a chance on a windy day to just practice gybing it takes some getting used to at first with doing the pole as well as the main and you will do lots of swimming

Early boats had good foils from when the original tooling was new.  It was as the tools aged that the quality wasn't so good prior to re-tooling.

Generally there are few tweaks allowed and tbh few are necessary.  You might want to upgrade some blocks to a better brand of chandlery, but that's about it.  Other tweaks like a 2:1 main halyard are largely a matter of taste.  It's a great boat right out of the box, so enjoy it!

We have the spinny halliard led over in front of the crew so if there's a snag the crew see's it straight away. The helm can then concentrate on steering around the windward mark and setting the boat off in the right direction.

Single line hoist...anyone who is any good gave that up ages ago.

Foredeck lip (cockpit in front of crew) glue a car door protector here...when crews hoisting kite frantically, the thin halliard cuts grooves here. (My crew hoists standing up, not sitting down).

Spinny chute...lube every couple of weeks. Mast groove and all mast sheaves...lube every time the mast comes down.

Older foils not too much of a problem but make sure the rudder goes down at the right angle. If the pivot hole has worn it might end up going forward of vertical. It can be remedied by filling with epoxy and being redrilled correctly'

Slot gasket...big bummer if this is worn out. Days work to replace.

Make sure no cracks around the pintles.

Otherwise, pull up the sails and g oand enjoy one of the best 2-person hiking out boats ever designed!

The middle upgrades such as making the kicker 16:1 and either the rig tension or cunnigham 8:1 (can't remember which) although every single boat I've seen so far has already done this. Then making the kicker continuous, cunningham continuous and adding elastic take ups for them and the rig tension under the thwart.

Then there are the small upgrades or tweaks.

Tying the end of the outhaul to the kicker point on the boom at the max out setting makes it really easy to use, you just knock it out of the cleat when the crew comes into the boat at the windward mark.

On the new style booms its worth drilling an extra hole in the end to put your outhaul through so it can't hop out of the knook it is normally in in the end. Or tie a piece of elastic to the clew and the mainsheet attachment point to keep the outhaul always under tension. 

Making sure your tube loop wing wang handles sit tight to the cleat when the opposite handle is pulled means it is always in the same place and easier to grab. I've seen those with t handles use a piece of elastic between the thwart level jib block and the mainsheet turret area to make sure the t handle is always hanging in the same spot for the same reason.

A bit of neoprene or similar stuck to the back end of the boom to stop it scratching the boat when the main is dropped.

And finally a bit of pipe insulation wrapped around the king post zip tied on not too tight so it rotates so that when the pole comes back in it glances off the king post and doesn't dent it.

There is talk of a magical frictionless wing wang system but I have not seen it myself and it could be incredible, it could just be using the right blocks well lubed with the right rope or could just be psyche out material much like the towing tube I saw at rutland which directed air down inside the hull when the boat was being towed in order to make sure it was 100% dry inside. The guy had no idea if it worked but everyone wanted one after seeing it.

All are easy to do yourself and even the continuous take up system is sold as a pack with all the bits by RS and there are diagrams and info on how to rig it on the facebook page.

Settings for the old style sails are easily available and the settings used by the top 5 at nationals last year are also available if you use the new style sails.

Hope that helps.

I will keep you updated as the "project" moves forwards!

Piossibly if it went from something like polyester to vinylester or epoxy as polyester takes on ater over time and the other 2 do not (IIRC).

http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=7237&PN=1&title=rs400-proposed-changes

I dont think they have got that high in terms of sail number. 2011 was probably a number assigned just for testing.

I believe all the changes went through so hullds from some time in 2012 will be vinylester rather than polyester.

The hulls are almost bullet proof, there is very little or next to no difference in them. 

2016 nationals results places 3-4 boats from 2003-2004

Lots of discussion on the single line pole and spinnaker hoist proposal. What are peoples experience of doing this conversion since then? Worth it or not? It seems a lot of people still use the separate halyard and pole launch systems. Mine is set like that still.

I'm going to replace the jib sheets, kite sheets and those 3 control lines straight away. Also the kite sheet ratchet blocks. Am I also right in thinking some people put ratchets on the jib sheets? Is this really needed?

Having sailed other people's well-sorted 400s for so long I had actually forgotten how many tweaks there potentially are!  RS must have incorporated some of them as standard by now. 

My rule of thumb for ratchets is to always go a block size larger than i would if it wasn't a ratchet. this would be:

<6mm rope 30mm block or 40mm ratchet

7-8mm rope 40mm block or 57mm ratchet

im currently running 7mm with a 57mm harken auto, as i found even the 8mm was too much friction and 6 is too small on the hands in a blow

as for the kite, using 57mm harken autos with 6mm rope for the light stuff and 8mm for the heavy. I've also put a folded over bit of pro-grip on the deck around half way down inline with where the sheets would lay with the sole purpose of stopping them going over the side when not in use

someone earlier said about elastic going from shroud fixing point to the toestrap fixing point to tuck ur sheets in to do the same job, I've found putting some 2-3mm string round the toestrap fixing then hooking the elastic onto it means it can double up as a halyard holder to stop them flying away when not in use

The rig tension is not continuous but can be sucked under the thwart with elastic in a similar way. Mine is not but does get wrapped around the toe strap rope to prevent tripping up on it.

The elastic system can also be mounted entirely to the thwart so no blocks on the side tanks as per the guide on the website. I think this would be a neater solution.