As usual, just as the weather’s about to get cold, I’m planning what to do whilst frozen in the garage.
Needless to say I’ve got a list of things as long as my arm to look at, notwithstanding the engine issues discussed in the previous post.
So, as much as to help me get everything sorted, here’s the main things I’m looking at at the moment:
Suspension system
I’ve never really been completely convinced that the Fury suspension is exactly right for a race car. For one thing the IRS design is a cobbled together thing from the original live axle design and the race chassis has this really rather naff set of raised suspension mountings that have the effect of lowering the chassis whilst retaining the same geometry. To be honest I’ve wanted to re-design it all for years. However, I didn’t, and still don’t, have the time. All the same it seems to be time to find out what’s actually going on. Hence, I’ve spent the last day laboriously measuring up the suspension and putting the numbers into Susprog3D, from which that little picture above came. It’s the Fury front suspension, as you probably can’t tell.
I’ve not really formulated many conclusions as yet but it is kind of odd. The software reckons that there’s rather too much bump steer, although I’ve measured that for real and it seemed pretty good at the time. So, I probably need to look at it a bit harder over the aforesaid winter.
Another thing I’ve started looking at is the roll centres and the amount of camber recovery that the suspension achieves. However, the jury’s out on all that. The problem is that it’s all very well deciding that something needs to be different but knowing which of the zillion variable to change to effect that is something else. In an ideal world I’d complete remake the chassis and the suspension pickups. However, that’s not really a sensible option.
Whatever comes out of all that, I have an idea that it’d be a good idea to replace the bearings in the front rockers as I suspect they’re rather knackered. In fact, I wouldn’t be surprised if I decide, following the suspension calculations, that I’d like to change the dimensions of the rockers as well. That sounds perhaps like more work that I want really. Mind you, it’d mean that the complete suspension system was now made by me!
Engine
As discussed in the last post I’ve now decided to bite the bullet and go up to class B using a CBR1000RR engine. I phoned Andy yesterday and ordered an engine along with all the bits and bobs that make it work. These include a billet sump and some sort of gadget that moves the hydraulic clutch slave cylinder about a it so that the propshaft adapter can fit properly. The engine I’m getting is coming over from the US. That’s advantageous because the American bikes don’t have the security gubbins that plagues the use of these engines in the UK. If I had a British engine I’d apparently have to have a key!
As part of this, I’ve ordered some workshop manuals so that I have at least some sort of idea what to do with the thing should I take a spanner to it.
Needless to say there’s lots of engine related stuff that will need sorting as a consequence of this change including, but probably not limited to:
- New engine mountings.
- A tank with an injection pump mounted in it. I know Adrian had real trouble getting the CBR1000RR pump to seal last winter, but apparently Andy’s got a solution to this now. I seem to remember that Adrian had problems with low fuel pressure too, so that’s got to be worthwhile looking at carefully.
- A new exhaust system. As a consequence of new MSA regulations (don’t get me started) this will have to include a cat.
- Gearchange modifications. The CBR1000RR engine has a “cassette” gearbox that means the gearchange is in quite a different position so this will need reworking. I may bite the rather unpleasant bullet and end up using a push/pull cable again.
- Changes to the various engine sensors and their connection to the logger.
- I need to reinstate the oil cooler, I suspect. In fact, I need to do that before Mallory, I think.
- A massive bonnet hump will need making. There’s probably lots of airbox related stuff to go with this.
- Converting the pedal box to hydraulic actuation.
- Lots of stuff to do with enabling the ignition and fuelling to be remapped. I wonder if it’d be worth while including a wide-band lambda sensor in the exhaust so as to allow remapping at a circuit?
Tim, ref the push-pull cable concerns, I don’t pretend to know anything about your set-up, or the space limitations you’re working around but would it be possible to use a pull-pull arrangement instead?
I assume with the push-pull setup the same cable operates a single-sided lever fitted to the gearbox change shaft? Would there be room to have a double sided lever so you could have two cables, boith pulling?
If this makes as little sense as I suspect it does (blush) I can e-mail a fag packet drawing to you so it will (hopefully) become clearer?
That does make sense. However, I don’t think there’s enough space for the lever. (Athough, it would be possible to connect two cables to a bellcrank that then pushed and pulled a rod.
I’ll just wait until I’ve got the engine to see what’s possible.
My next suggestion was going to be a bellcrank if there wasn’t room for a more direct attachment. I know this seems like adding complication but it’s got to be better than a balky gearchange!