Monthly Archives: June 2011

More bits and bobs

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With the engine mapped the car’s now pretty much sorted mechanically. After the disappointment of lunching the original engine it seems the less pristine looking spare I got from Tim Cheney is in fact a good ‘un and after 3 race weekends, the Donington trackday and the rolling road session it’s time to have confidence in it and stop worrying about it.

After a disruptive few weeks of travelling all over the place I now have a quiet spell so I can progress with the minor developments I wanted to make. The first of these was a modification to the throttle pedal to allow me to start to try to heel and toe. My problem is that because legroom is so tight I physically can’t rotate my right leg to do a literal heel and toe and the pedals are too far apart to allow me to keep my right foot vertical and blip the throttle using the outside border of my foot. So the plan was to extend the pedal both along its left border and downwards. When I started to look at it I realised the throttle pedal is also too high to allow me to do this so I came up with a solution using a length of aluminium angle which then gives me a flange set about 15mm behind the pedal. I think it should work OK but will only really know when I get the car out on track and try it.

Next on the list was to glue some insulation matting on the corner of the airbox nearest the exhaust, I’m guessing it’s fine while circulating round the track but once you stop the engine bay temperature soars and the bottom corner was getting a bit warm and soft. I also ordered some new mirrors from Car Builder Solutions, these are the same as the mirrors on the racing Spires and Paul Rogers’ Contour, apart from the race visibility being poor in the Racetechs there’s no way they’ll meet the IVA requirements. I reckon a lot of the problem is the distance from the cockpit, the further away they are the narrower the field of view. I fitted the new ones (in the holes the Racetech ones were in) and although it was an improvement I was still pretty sure they wouldn’t cut the mustard for IVA and decided they needed moving.

With just over a week to go until Donington Brian contacted me to say the modified engine mounts were ready – these are some rather more triangulated parts to reduce the flex that is causing the nose of the reverse starter to impinge on the reverse gear. We had discussed me calling there on the Friday on my way up to Donington to fit them but Brian was concerned that apart from the job inevitably taking more time to complete than expected it was introducing an element of risk doing it the day before a race. So I’ll be picking the parts up from him at Donington and bringing them back with me.

With a day off on Friday I got on with the mirrors. I decided to fit them in the outermost corner of the upper front cover. This brings them much closer to me and gives them plenty of height. Once they were fitted I wheeled her out into the sunshine and measured up and strategically placed various jacks, petrol cans etc. to mark the IVA rear view requirements. I got into the cockpit and adjusted both mirrors and was pleased to find they gave a much more than adequate view. IVA requirements aside they’ll give me a much better view for racing too. I now need to find some 8mm grommets to fill the previous holes in, I’m not too worried about that and actually think the new mirrors look rather nice.

I got all four wheels off and gave the brakes an inspection and a clean. Nothing untoward going on so after giving them a clean the wheels went back on.

Another job that’s been lurking on the todo list was to fit the indicator side repeaters. They’ve been patiently sitting in a box waiting and I finally managed to get them fitted to the sidepods and wired in. Sadly because of the rear LEDs there isn’t enough current being drawn for the indicator relay so they’re still flashing too fast. I’ll have to either find an electronic relay that isn’t as fussy or get some resistors to wire inline.

I still have a few things to sort out before the final IVA prep including emissions and the handbrake. I’ve spoken to the guy in our local garage who’s happy for me to take the car round to use his exhaust gas analyser and I can try to get it mapped to pass emissions. I’m hoping I won’t need to reinstate the original PAIR system as that would be a real pain. The guy at the garage was telling me he’d had a Honda Civic Type R in with a decat pipe which had just managed to scrape through the test without the cat being refitted! The handbrake needs some form of compensator mechanism incorporating into the mechanism. All of this can wait until after Donington next weekend – the finals came out today and given there’s a good gap between the races I’ve entered the Allcomers race as well.

HLM Bromsgrove

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Before I went off to Le Mans I booked the car in with Hamish at HLM in Bromsgrove. They were first suggested to me by DynoJet and Austen subsequently went there to get his R1 engine mapped. I was going to go back to PDQ in Slough but Bromsgrove is over 50 miles nearer and I thought I may as well give HLM a try, Austen’s remap seems to be pretty good.

I decided it was about time the engine oil was changed, it hasn’t been changed since I installed it so it’s done 3 race weekends and the Donington trackday. So Thursday evening I removed the hatch in the undertray and drained he oil, changed the filter then spent a happy hour or so mopping up the oil that went everywhere. It’s the filter that’s the problem, it’s almost impossible to reach and there’s absolutely no way of changing it without leaking a load of oil into the engine bay. My long term goal is to mount a remote filter but I haven’t found one yet although I have discussed it with Andy Bates who reckons it should be doable. Once it was refilled I removed the plug caps and anxiously turned the engine hoping not to have a repeat of the air-locked oil filter again. After a minute or so of turning it I did indeed get a few psi on the gauge so I refitted the plug caps and got the engine warmed up and checked for leaks.

I got there a bit early and Hamish was busy with a Volvo on the rollers and there seemed to be some sort of problem with it so in the end he got that off and we got the BDN on. Once the rear bodywork was off the BDN was chocked and strapped down and the lambda sensor and Power Commander connected up. Hamish wanted to get at the rads to direct a fan through them but I explained that they’re fully ducted in and that cooling wasn’t normally a problem so we just directed his huge fan at the front of the car. Once everything was ready Hamish did a power run to see what he had already. Max power was 145bhp with a big dip in the torque curve between 7k and 8k, the AFR was clearly very rich. This was no surprise, I’d deliberately loaded a map with lots of positive numbers to make sure there was no risk of running lean.

Hamish then switched to the DynoJet software to modify the map, it seems the software he uses autoadjusts a column at a time. He did a couple of runs of 100% throttle then hopped out as there was a problem with the water temperature – it was running too cool :) So one of the BDN’s nostrils got taped up as you can see in this pic. This seemed to do the trick and once the 100% throttle map was done he worked his way down the table through 80%, 60% etc. It was then time to do another power run to see what the gain was.

 

So, there we have it, an improvement of 10bhp to 155bhp with a smaller increase in torque to 79ft-lbs but a significant improvement in the flat spot and a nice solid air-fuel ratio. Looking back at the graph of the Fury at PDQ the Busa only produced 145bhp although with 90 ft-lbs. So the ZX10′s making pretty good power, at least comparable with the other litre engines – TimH’s 07 Fireblade and Austen’s R1 both made 148 although of course Austen has slightly higher losses cos of the front engine with prop and diff. It’ll be interesting to see how much difference it makes on track, I suspect quite a bit as the improved drivability should count for almost as much as the additional power.

A passenger …

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So, with the airbox sorted I was committed to going up to Donington for a Bookatrack trackday. My younger son Chris has been keen to have a go in the car so he and I had a very early start and got there before 8am to sign on followed by the briefing. I hadn’t been on a Bookatrack event for several years but apart from looking a bit older and having gained a few pounds Jonny hadn’t changed a lot. It was all very well organised and although it was fairly expensive there were only 33 cars booked on and we had 7 hours of open pit lane track time available. It was also a lovely warm sunny day with a good forecast.

Chris had never driven on track before and in fact had never driven a rear wheel drive car before. We got the intercom working and got in the line of cars for the slow paced sighting laps, during which Chris got to familiarise himself with the clutch, throttle and gear change as well as the general handling of the car. As readers will be aware the gear change is pretty stiff so he struggled a bit at first.

My main worry was noise. Donington’s really strict with a noise limit of 98dB on drive by, I’d been in touch with Jonny beforehand who reckoned generally cars were 2-3dB quieter on drive by than on static reading so we thought we should be OK but bike engined cars are notoriously a problem. Austen had confirmed that he’d been booted off at Donington for noise in his previous car, mainly through induction noise. It was a bit of an expensive gamble since if you trigger the noise meters you’re off unless you can demonstrate that you’ve made a modification to reduce the noise, but I’d decided that if I didn’t try it I’d always be wondering. So I reset my shift lights from 12,000 to 9,000 for the first proper session.

I hadn’t driven Donington since I had my Evo which must be about 10 years ago. I did come to the Ron Haslam Race School on a bike about 3 years ago but I couldn’t really remember my way round. It’s a fantastic circuit with some great corners and huge elevation changes, the whole section from Redgate round to the Dunlop Straight really flows beautifully. It’s tricky though with some quite technical corners and a couple of combinations that tend to have you coming out of one corner out of position for the next unless you’re careful – particularly from Craner into the Old Hairpin and then from Schwantz into Macleans. Unsurprisingly having Chris sitting in the passenger made a huge difference to the feel of the car, mainly on turn in rather than accelerating or braking and I found I was running wide a lot.

Once the car had had a rest it was Chris’s turn again. He’d been pretty tentative round the sighting laps and had struggled with the gear change but on his first proper session I was quite impressed, he was quite smooth and got up to a good pace quickly. He generally tends to be a bit on the reckless side but he caused me no concern at all and I felt more comfortable in the passenger seat than I’d expected to. He was pretty animated when we came in, he’d found the car easier to drive than he expected and as well as enjoying the power he was really impressed with the handling and brakes, and particularly with the amount of feedback the car was giving him. I couldn’t really see the shift lights properly from my seat and he thought he’d probably gone well over the 9,000 rpm on a few occasions. We hadn’t been black flagged but I thought I might as well go and ask Jonny if he could give me any information. He checked with noise control who said only one Porsche had spiked over 98dB but that no-one else had been close.

So I upped the shift lights to 10,000 and we headed out again with Chris at the helm. We alternated sessions and after checking there were still no noise issues I set the shift lights back to 12,000 and we were giving it the full beans by the time the morning session finished at 12.30. I did get one session on my own in the car but the other sessions were all 2-up.

Early afternoon there was a short but heavy shower so we waited for a while. Chris certainly didn’t want to take the car out in the wet so once I could see it was getting a bit drier I headed out, having driven the car in the wet at Mallory I wasn’t too worried about it. It was a bit strange, it was wet round Redgate, very wet round Craner and the Old Hairpin the quite dry round Coppice and the Dunlop Straight. For a little while I think I was the only one out on track until it was really getting quite dry when a few of the others came out to play.

By 4.30 we’d had enough, we’d been up since 4am so we were both absolutely knackered and we still had the 190 mile drive back. We were both struggling with our necks I think mainly due to the lack of aeroscreen on the passenger side, the padding on the roll cage was just a bit too far back to comfortably rest your head on it. I’d checked the chain tension during the day and hadn’t needed to adjust it, I’d given it a spray with some lube but apart from that and fuel I didn’t need to touch the car at all. I think we used about 55 litres of fuel altogether, so we’d had plenty of track time. Chris had really enjoyed himself and it was fantastic to have had a full day at this fabulous circuit with the car performing flawlessly.

Difficult to say if the airbox had made a difference, certainly the engine needs mapping – it’s pretty snatchy at part throttle sometimes, noticeable several times when on a balanced throttle round the last part of Schwantz just before the braking for Macleans. So the next job on the to do list is to get it on a rolling road.

Onwards and upwards

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The hiccup in qualifying aside Snetterton had been a good weekend, the car had performed flawlessly and I’d got a bit more seat time and a bit more confidence in the car. With six weeks to go before the next race at Donington I had time to get on with a little development of the car. There were two main issues – the gearchange and the power deficit. Although the gearchange was much better I was still having to work much harder than everyone else changing gear and I had missed a few gears. I had helpful discussions with my technical gurus – my brother Andy and Brian. Andy suggested that the problem was due to using a long cable essentially turning through 360° and suggested considering a mechanical linkage with rods/bellcranks, perhaps even using a straight run of cable running fore/aft. Brian agreed that the cable run was the problem but pointed out that everyone else is using the same configuration without issues, we decided that there isn’t a problem at the paddle end, the ZX10 gearbox isn’t inherently a problem and I’d had the same issue with both engines, so the problem must lie with the cable. Brian isn’t a fan of paddle shifts and indeed on their car now running in Bikesports has converted it to have a stubby gear lever mounted on the central chassis rail with a short push/pull cable running directly back into the engine bay. Tim Grey requested the change and reckoned it gave a vastly better shift. Brian pointed out that even with the paddle you can’t really change gear while turning the wheel without taking a hand off the wheel anyway and their gear lever is right next to the wheel. I ended the discussion with a couple of plans – I’m going to take my spare cable up to Speedy Cables in Abercrave (about half an hour away) and see if they think they can make a better cable. If I don’t get any joy there I’m going to go with Brian’s gear lever.

On the performance front it was suggested to me that my over-gearing was responsible but I wasn’t convinced – it’s a pretty close ratio box and although I didn’t really need 6th gear at Snett the engine was well within the power band. Here’s the run through the gears on Sunday at Snetterton – engine rpm in red, speed in pink. This is the longest, fastest straight we do even with the circuit changes and we had a strong following wind on the day so I suspected I was over-geared – you can see that although I did pull 6th gear I didn’t really need it. The biggest drop in revs was between 1st and 2nd gears where they dropped from 12,500 to about 10,300, in the higher gears (where the ratios are closer together) it’s only dropping to just over 11,000. Peak power on the stock bike is about 11,600rpm. For some reason I thought I had a 48 tooth rear sprocket on and planned to change this to a 50 but on checking I already have the 50 on there. Comparing my spreadsheet with the logs it seems my gearing calculations are well out, presumably as a result of being misinformed about the wheel circumference. The conclusion is that the engine’s down on power and I’m pretty confident it’s down to the mapping but lack of a cold air supply is probably also partly responsible. So priority number one is to get a new airbox fabricated and get the car on the rollers. From the logs it looks like my top speed in 6th is about 130mph which should be about right if I get a bit more power out of the engine so I’ll leave the gearing alone for now.

Here’s the log from the whole of Sunday’s race showing water temp (light blue), oil temp (green) and oil pressure (dark blue). The water gets up to about 80° and stays there, oil gets up to between 100° and 105° (interesting how it varies around the circuit – it rises around the slower sections after the fast straight) and oil pressure declines a little as the oil heats up and becomes less viscous but plateaus out nicely around 60psi.

And here’s the log of my fastest lap, lap 12. Oil pressure is again dark blue and the lowest trace in purple is lateral G, speed is pink and engine rpm red, you can see that the only dips in oil pressure are when the engine speed drops going into the slower corners, it’s nice and solid around Coram (from 55 to 70 seconds on the graph) showing that the baffled sump is working nicely.

At Snett I had a good look at Paul Rogers’ airbox and had a chat with both Paul and Tim Pell. They’ve both taken different approaches – Paul has modified the bike airbox and added an extension with a sort of snorkel on top while Tim has fabricated one from scratch. Tim used the blue builder’s foam which sounds like it’s easier to work with than the 2 part polyurethane foam and sands to a better finish. So the first step was to decide whether to fabricate a box from scratch or to modify the existing box. Looking at the ZX10 airbox the shape isn’t as amenable to modification as Paul’s GSXR1000 and modifying it introduces compromise in terms of how I incorporate a filter and the volume of the box so I decided to fabricate a new one. Helpfully the section of the box which the throttle body rubbers connect to is separate and screws onto the airbox so I could remove it and build my new box around that.

I got some foam from Wickes for a fiver a sheet, only 2″ thick unfortunately but easily laminated. Not blue but it’s very small celled and cuts and sands nicely. It’s much easier to work with than the 2 part foam which often ends up quite an uneven consistency and is quite hard/brittle. I made an aluminium baseplate for the box and got to work hacking the foam into a shape that would fit under the bodywork and maximise the airbox volume. This was actually quite tricky because in his mission to keep the bodywork as slippery as possible Ian hasn’t left a lot of room under the engine cover. I’d been hoping to construct the box without actually cutting any of the original plastic to allow me a route to revert back to the OEM box if the project went wrong, but this was somewhat scuppered by the way the various bits fit together and the only way to make it work while maintaining a smooth tract into each throttle body was to cut a section out of the base of the Kawasaki box.

So I did that and trimmed back the aluminium plate to accommodate the circular frames that hold the rubber trumpets in place. Once I had it all assembled I was ready to prep it for fibreglassing. Having discussed this at length with Andy I decided to use brown paper and PVA. THis was initially pretty difficult getting the paper to follow the compound curves but I soon got the hang of it and it dodn’t actually take too long.

 

I got it fibreglassed in several stages then it was time to try to extract the plug from inside its GRP cocoon. I cut a hatch that included the air inlet on top, the idea was to somehow fit the filter element underneath this. Getting the foam out turned out to be a complete PITA and I ended up basically picking it out bit by bit. I discovered that the resin sticks pretty well to the PVA’d paper. I then left the whole lot to soak in water overnight to try to dissolve the PVA.

 

Here’s the airbox after pulling out the foam. I then used a combination of hot soapy water followed by some acetone to shift the gooey film of PVA that was left coating the inside of the box. This took much longer than expected – I’d been hoping to get up to Donington on Saturday for a Bookatrack open pit lane trackday and early on Friday morning while struggling getting the airbox cleaned up I could see it not happening.

 

I did eventually get there though and I could then focus my attention on my next problem – that of getting the air filter in there somehow. I needed a good seal and I really wanted to be able to remove the filter relatively easily. I came up with a cunning plan involving an aluminium sheet with another piece of aluminium fabricated and riveted to it to provide a slot for the filter to slide into. Here’s a photo of the finished filter panel assembly. I was pretty pleased with this and once it was done I took the filter out and gave it a good clean and some fresh oil. I then sorted out some rivnuts to hold the little cover incorporating the air inlet onto the aluminium panel then bonded and riveted the panel in place. By now it was Friday lunchtime and I was confident it would be finished in time so I finalised the trackday booking.

After a bit of paint, voila! Here we have the finished article, it just fits under the engine cover and gives me just about as much volume as I could reasonably get. I plan to stick a bit of the insulating mat on it but it’s not as close to the exhaust as the old one was so I don’t expect it to be a problem.

 

Here’s how the filter element sits – For now the gaps round the edges at the front are sealed with some gaffer tape but that’s temporary. The top cover is held on with six 6mm screws and with it removed the filter just slides out of the aluminium housing. So now the engine should be getting a nice supply of fresh air rather than sucking it in from around the engine.

My younger son Chris wants to come and have a drive of the car so I had a few other jobs to do – fitting a passenger harness and adapting (i.e. hacking!) the original seat I made to fit in the passenger side. I also dug out the intercom I used to use on the bike and wired that in so we should be able to hear each other. After a check over and some fuel it was time to start loading up.