Over the summer break we realised that the clutch pressure sensors had been calibrated wrongly and set about putting them right. This meant abandoning the settings we had previously used to score our best 60′ time of 1.08 and starting again with the settings. We tried some tests remotely before the event and all looked good. However, the weather had other plans for us….
While we were waiting though this gentleman swung by and introduced himself as David Cooper from UWTSD (University of Wales Trinity St David). More on this later.
So after 48 hours of intermittent rain and heroic efforts by the Santa Pod crew in trying to dry the track we finally made it to the burnout box on the Saturday afternoon only for Eric Richard to fall off in front of us, followed within 5 minutes by another downpour. Thankfully Eric was fine and his bike sustained little damage. The crew were a little shaken but thankfully everyone was ok. Those sixes will have to wait til next year Eric! All the best from us, we hope we see you again soon.
When business resumed a couple of hours later we managed a decent burnout on the second attempt only for the bike to run weak and stall on the line. On investigation the drive belt off which drives the fuel pump and oil pump had given up under the strain. Graham noticed that one of the primary drive gears was cracked too, so that put us out of the event as we couldn’t risk using it and didn’t have a spare.
Congrats to Dale Leeks for his first event win, Stu Crane for an impressive 6.81 – unfortunately with a catastrophic looking fireball, great runs from Fast Fil and the SSB boys put on a great show as always.
We’re going to be out of action for the National Finals in 2 weeks but hope to make the bike event in October with new oil pumps and drive gears.
The Main Event started well with the van throwing a drive shaft the day before, necessitating a last minute repair by Barry before they even loaded the bike into the van!
At the event itself we continued to dial in the air clutch but the results were inconsistent. A PB 1.08 to sixty foot was followed by clutch slip, and applying more air to the clutch only seemed to make matters worse. There would be more to come with this issue. Q3 was shut off for drops of oil, but Q4 saw a near-PB 6.87 at 193mph to qualify us third in Top Fuel. Unfortunately the clutch slipped off the line in E1 against Otto Knebl which put us out of eliminations, and the event was then rained off.
Videos of the 6.87 run courtesy of Sarah White and Ian Blackett.
Pics from Santa Pod, Ian Blackett and Rose Hughes:
Race, Rock and Ride is a new “lifestyle event” for Santa Pod; bikes only and the first proper event for us with the air clutch. Problems in qualifying followed by heavy rain put us out of eliminations, but we did manage a 7.00 demonstration run with a 1.10 sixty foot so we were satisfied with that.
The first meeting of 2017 for us, and we have a new “air” clutch installed. Designed by Barry, it is entirely self-contained, with no external piston or ram. It has around 28 square inches of pressure area, so 1psi of air pressure means 28lbs of pressure on the clutch pack, 50psi means 1400lbs of clutch pressure.
Up til now we’ve been running the traditional 6″ Bentec-type Top Fuel type centrifugal clutch in various guises, the last of which had input from the late Brian Johnson and had 3 sets of 3 arms. All of these clutches had some kind of air/hydraulic hold-off, as unlike a Top Fuel bike we can’t launch from idle, and need at least 8000rpm on the dial to generate enough boost to haul our 400kg, 3 speed, turbo bike off the line. Unlike a Super Streetbike though, there is no “off the shelf” Gann/MTC slider that we can use either. We need the power handling capability of a Top Fuel clutch with the control of a Super Streetbike clutch.
The centrifugal/hold-off combination has always meant compromises for us, with our best 1.0 sixty foots to date being achieved by slipping the clutch to the rev limiter, using crank inertia to launch, then bogging the engine to 6-7000rpm, then letting the torque of the compound turbo system haul the engine back up for the change to second gear. This hold-off also created a delay of around 0.25 secs between releasing the anti-lag, and the hold-off piston moving far enough to engage the weights and move the bike. This could often be seen in our videos as the bike in the other lane gaining a big holeshot. Fine for qualifying, but not for racing where a much quicker acting system is needed to prevent us losing to a slower bike.
Here are some pics of the new clutch, without the cover.
And with the cover on.
The new clutch design needed a special air seal, capable of high rpm. Clive Munns of Sealmasters came up with the goods, and at a very reasonable price, thanks Clive!
The clutch is controlled by an AMS2000, supplied by Brad O’Connor and installed by Mark Harrison from Owen Developments, along with a Motec dash to expand our datalogging capability. We only finished the installation just before the Festival of Power though, so with no time to test the set up before the meeting, we turned up a day early. Things over the next 4 days didn’t go entirely smoothly…
Try 1: Bike stalls when anti-lag engaged – applying pressure when it shouldn’t.
Try 2: No drive in mode 3 (race mode) – not applying pressure when it should.
Try 3: Burns out, shut off for oil leak.
Try 4: Bike warmed up, oil pump seizes.
Try 5: Burns out, stages, leaves line, clutch slips to the moon. Wrong clutch mode selected by rider. 25 second pass.
Try 6: Burns out, stages, stalls. Too much clutch.
Try 7: Burns out, stages, clutch slips. Not enough clutch. 15 second pass.
Try 8: Burns out, stages, turbo overspeed limiter kicks in, 8 second pass. Eliminated by Phil Crossley, who went on to win the event (congrats Phil!).
After all this the good news is that the clutch now does what it should. It has a neutral. It drives to the line just off idle. It will hold-off at any rpm and then launch instantly without bogging. (In the datalog below the red line is the air clutch, black line is our typical run with the centrifugal.) Next time out we’ll be raising the launch rpm and aiming to beat our PB 60′ time.
Thanks as always to the hard working team: Mick, Barry, Dave, Graham, Paul and Sarah, to our sponsor Mark from Owen’s and to Brad for pointing us in the right direction.
After repairing the boost hose and the broken chain we’re good to go at the last meeting of the year, the Extreme Bike Weekend at Santa Pod. A bikes-only event with around 80 entered, but late in the year so no chance of a warm track.
Q3 6.89 rolled off at 1000′ as moving towards the centre line, with this run keeping us at #1 qualifier, 0.6 seconds ahead of second place with the rest of the field struggling for grip.
Julian Hunt pics:
In Q4 the bike clutch didn’t disengage after the burnout, stalling the engine. The team stripped the clutch and gearbox overnight, and re-seated a bearing in the gearbox that could have been the problem, but in the first elimination round Sunday morning the bike did the same thing, putting us out. Despite the cold weather though the bike took 6 men to unstick it from the track after the burnout!
The Storm team thrashed to get the engine and turbo repaired in time for the National Finals, including skulling the damaged head:
But it was not to be. On the first qualifying run the big turbo again popped its connector hose off. And on the second run the launch was very aggressive, snapping the drive chain.
Sarah White photo.
Fans of Barry’s “Tokyo Express” CBX funnybike might remember a similar incident where the chain broke and almost sawed the frame (and Barry’s leg) in half. Thanks to Barry’s experience Storm has the chainguard integrated with the frame which is very strong and minimises the chance of the chain hitting the rider’s leg.
We had another drive chain but unfortunately the broken one went through the alternator and we didn’t have another one of those, so once again we were out! The overboost was later traced to the fire which had melted the braided hose to the wastegate on the inside, blocking it and preventing the boost controller from working.
Set up, scrutineered, everything good to go, right? Nearly…
On the first run the large turbo came off its exhaust connector on the launch. The turbo dropped about an inch and touched a wire, which caught fire. 7.39 with a PB 60′ of 1.087 though qualified us 5th after the first round even though most of the run was on minimal boost. The small fire was extinguished in the waiting area at the finish after a brief “FIRE…FIRE” moment.
It was a tad busy on the banking…
Unfortunately on our second run just edging forward to the burnout box there were some unpleasant noises from the motor before it stalled and locked up. Three valve heads in cylinder number 2 had come off, one lodging itself in its port and the other two damaging the piston and head so we were out of the competition.
One theory is that a valve was slightly bent at the previous meeting when we popped the manifold. Valve spring pressure can mean that a slightly bent valve will straighten up and seal properly when it closes, only to return to being bent again when it opens, This repeated flexing ultimately causes the valve to fail some time later.
We’ll need to get the head skulled or welded and fit all new valves but hope to be out again either at the National Finals or the Extreme bike weekend. In the meantime good luck to our fellow competitors in Top Fuel Bike, see you next time!
PS congrats to Rene van den Berg on a storming 6.15 @ 229mph!
July and August 2016 were a bit difficult for us. We went to the Summernationals with the turbo repaired and some new EGT sensors in the hope of gathering some more accurate data but a loud pop on the burnout of the first run again killed the small turbo. The carbon seal hadn’t worked.
With the seal replaced with a stronger version we went to a RWYB at the Japshow but the same thing happened again, only this time on the first run and it blew the inlet manifold apart for good measure. The team decided to bit the bullet and move the throttle body from in between the large and small turbos to after the small turbo. Lots of time and fabrication, but it would mean the turbo wouldn’t need a carbon seal.