©2005 olilolo productions all rights reserved. or some crap, anyway

I started this project alone but along the way i have recieved the help and support of many people, mostly my friend Daniel [Fatty] who was there to bounce ideas off and who was also doing his own testing but along different designs.

Project Version: V1.0
Status: Failed

Ran hosing into the airbox and sealed it all up. Worked ok but as soon as I reached speeds of 150kph the mix leaned out and the bike stopped making power. Did some research and
I believe I have found the problem. As the pressure builds in the airbox the extra pressure throws the balance out between float bowls and the venturi causing a lack of adequate fuelling.

Project Version: V2.0
Status: Failed

I was originally going to attempt to create a new airbox lower completely encapsulating the carbs to equalise the pressure but after a friend of mine attempted to equalise the pressure by running all the carb vent pipes into the airbox. I realised that his idea only failed becuase he pressurised the sub air filter line as well as the float bowls. By pressurising that even worse performance came about because the slides could not lift at all.

Project Version: V2.1
Status: Failed

Well, i routed the float bowl vents into the airbox but was halted immediately because the pipes that come with the carbs sit right next to the intake stacks causing a vacuum effect inside the float bowls causing a no-fuel situation as soon as the carbs switched to needle circuit.

Project Version: V2.2
Status: Failed

Lengthened the vent tubing to place it into the top of the airbox to be away from the vacuum of the intake. worked a treat right up until the 150kph barrier returned. Defeated i once again returned to the drawing board and researched the problem.

Project Version: V3.0
Status: Upgraded

Some research showed to me that i would encounter fuel starvation again at speed due to the CBR having a gravity fed, vacuum actuated fuel supply. This is because that when the intake and float bowls are at the increased pressure, if the tank is at the normal pressure fuel will not be able to enter the float bowls.

#1 was to add a fuel pump to have a pressurised fuel supply line.

#2 was to plumb airbox pressure into the tank to equalise the whole setup.

I hate wiring so i chose to plumb the tank. Luckily a friend had a CBR tank that already had a VFR tank vent fitted. I ran some piping into the airbox and also revised the airflow into the airbox with some smooth bore clear hose and a straighter intake path to improve efficency. Got it all together and ran terribly due to what i believe is inadequately sized main jets.

Project Version: V3.1
Status: Partial Success

Have sourced some 122 main jets, changed the intake stacks to all long and completely removed the airfilter so the airbox is completely open. Took the bike for a test run and idle circuit works perfect but the transition to needles was less than promising. It was fluffy and created barely sufficent power delivery. Then the main jets kicked in and she tried to tear my arms out of my sockets. she accelerated amazingly and smoothly all the way to redline. Also passed thru the speed barrier, going past 150 for the first time in the project's history. I will be retuning with larger jets again and posting the change.

Project Version: V3.2
Status: Cancelled

Now that i have had a partial success and have been working on the tune i have found a slight problem with the refinement. When the tank is close to full or full the vacuum that occurs at idle or low speed/small throttle opening siphons fuel into the airbox. To solve this problem i was going to create a surge tank to compensate for this but have found another method.

Project Version: V4.0

I have now finished the whole project and have discovered that i did not need the tank pressurised at all because i was doing all my testing with less than a litre of fuel and if i had been using more fuel no starvation would occur because the weight of the fuel ensures the flow remains constant.

Stay tuned!