A Major Breakthrough!

After missing out on racing at Snett, I thought I'd attack the performance problems, and first on the list was getting the thing re mapped on a rolling road.  When I'd fitted the CBR engine fourteen months or so ago I just down loaded from the Internet a high performance fuel map for my Power Commander USB3.   I wondered if the problems with performance were due to this being slightly out.  In particular I wanted to Iron out the power delivery issues that had been so evident when Testing at Snetterton.

So I dispatched the car off to Power-Tec In Peterborough for a mapping session, they had some staffing issues due to people being absent at trade shows... so I left the car with them for a week or so.

On the Friday I got a call and the result of the conversation was that they couldn't map the car!

Why?.. Because it was running dangerously lean.  Their AFR sensor was showing a best ratio of around 17 but was mostly off the scale at 18+.... Bejesus! I've run it at Brands, Mallory and Snetterton like that  it's a wonder I haven't blown a piston. It is so lean in fact that they immediately stopped the rolling road session.  These CBR1000s are really bomb proof!

(Bing!... the big lightbulb goes on above my head) Running lean, also explains the lack of power, poor power deliver and the general overheating problems I've been experiencing since putting in the CBR1000RR. The root cause was low fuel pressure which I tested when I got the beast home.   The pump was delivering 2.5 BAR at idle, dropping to 2 bar under load.  The CBR specification is 50 PSI (3.5 BAR).  aargh!

I have a fuel pressure test guage and a wide band lambda sensor and If I'd had time to fit either of these diagnostic tools I would have seen the problem straight away.  But the focus on Diffs for the last 6 months or so meant that it had never entered my head.  Still hindsight is an exact science I suppose. At least we've found it now

The problem is that the in tank pump is for a zx12R, I had reasoned (erroneously) that this would output the same pressure as the dedicated CBR pump, plainly it does not.  Well I'm not about to change the tank and in tank pump... both are a right pain to get at and even bigger pain to seal correctly.  

The solution was to get a billet CBR pump mount CNC machined by Andy Bates at AB Performance (Series Sponsor for RGB). and then get this fabbed into a supplementary fuel tank along with a proper CBR1000rr pump.  That way the existing in tank pump acts as a low pressure lift pump to the tank and the CBR1000RR feeds the injectors at the right pressure.  I finished this in the final hours before going to Brands Testing.  I also fitted the Wide band Lambda sensor to see if it had any effect.

and so it was off to Brands Hatch for the first race of the season.

First Race of the Season - Not

After the carnage of the chain jumping in testing I didn't have much time to get the car ready for the first race of the season.... so some midnight oil was burned.

The other thing Dave Turner does is teach production engineering evening classes and I've been attending "Big Oily Toys Classes" for a while.  so when I examined the diff after the failure at Snett it was obvious that the problem is that the bearing carriers are just two thin in cross section.  this allowed them to twist out of alignment due to the poor shimming.. and carnage resulted.

So using new found skills learned in Evening class and my new Lathe, I made a couple of much more substantial bearing carriers out of some Ali billet... bolted the car together, shovelled out a couple of handfuls of  aluminium swarf, fitted a new sprocket and chain and off we went to Snett to race.

Except we didn't!  Horizontal wind blown rain meant that the meeting was cancelled, and will be rescheduled until June... "Oh Dear" we all said in our best anglo saxon.... in fact many of us were whispering "Thankyou" when Viv Ayres the Clark of the Course made the call to cancel it and saved us from ourselves.

So I've still never raced at Snetterton arguably my home track.