After an offer we couldn't refuse from Rohith de Silva, Vetech decided to break with tradition and effectively develop and test the new VetechBusa engine in public at the 2016 Fastest Mini in the World race at Brands Hatch. This is the story of the days before the race.
With just 5 days to go until the race, the engine is tested for the first time with the blow through supercharger fitted, just under a year after it ran for the first time normally aspirated.
The engine has been fitted with a DTA ECU, Rotrex supercharger, and other associated induction components but was otherwise 100% standard: the shortage of time means that the compression has not been lowered nor have uprated head bolts or uprated head gasket been fitted. This is normal practice to avoid the risk of cylinder head gasket failure when using higher boost levels. Given that risk for this temporary build spec, we're going for a moderate power increase only. A 42 mm restrictor is fitted into the supercharger inlet to limit the boost to limit the power increase.
Consequently, the power of the engine is only around 250 BHP instead of the 300 which would be normal for this state of tune. The emphasis is on reliability rather than extracting every last bit of power: there is no time for a full map or for various optimisation options (including part throttle), and ignition advance is kept fairly retarded for safety.
An oil spill on the track and other factors mean that only a single, very slow lap is possible. The engine gets very hot at one point during prolonged noise tests - the first time heat problems have been encountered with the engine. We don't realise it yet, but this is an indicator for issues to come...
What we should have learnt on Tuesday's ill-fated test session is found somewhat belatedly at the event itself, with cooling problems surfacing after the first 2 laps. The car goes out several times with Shayne Deegan driving. Shayne is a last-minute stand in for Rohith, who, after a week with virtually no sleep preparing the car for the race is in no condition to compete.
Despite overheating, the car in Shayne's hands is shown to be exceptionally fast. Maybe only 10 laps are completed. The car is geared for 130mph at 11,000 RPM but we were on the rev limiter almost at the start of the straight. Nothing we can do about that now. Also, there was far too much bump steer - we'll have to live with that too. Fuel is being expelled out of the tank breather and we have a fuel surge issue causing the engine to cut. Both of these can be sorted. However, at the end of these few laps, the diff is found to have locked solid.
A pot joint is found to have seized in the diff and cannot be removed with the engine in situ. At this point, somewhat jaded and certainly very sleep deprived, we very nearly give up but the enthusiasm and offers of help from so many people is a massive tonic and we decide to give it a go. We start to strip off the ancillaries to enable the engine to be lifted out. Many thanks to all the well-wishers and in particular the Fire Fighters Race Team for all their help at this point.
The diff problem is now understood. The trailer on which the mini has done so many miles recently is not ideal for a low race mini - too many things to catch on. The exhaust has caught at some point and pulled the downpipe back so it has been rubbing on the pot joint - nearly having rubbed all the way through. Heat transfer from the literally red hot exhaust combined with frictional heat has cooked the pot joint causing it to seize in the diff. The pot joint still cannot be removed and we dare not risk damaging the engine housings by attempting to remove it by excessive force. The engine starts to be stripped to remove the diff.
Meanwhile, Andy and Josh set off early and zig-zag down to Brands from Derbyshire, via Silverstone, Wallingford and then High Wycombe, picking up a swirl pot, plumbing, and Davies Craig pump on the way, as well as bringing down all the extra tools and components needed to fully strip the engine.
Fellow competitor Bill Richards contacts his friend Michael the owner of Quaife and arranges for a diff to be brought over by a member of the Quaife staff who was coming to the event that afternoon. Many thanks to everyone involved here - this gets us going again. True sportsmanship.
The engine is lifted off the transmission, a new pot joint and diff are fitted and the engine reassembled and refitted. A very, very long day and we miss the barbeque! Very high temps inside the tent make for an unpleasant working environment. Bed at 2am, then up again at 5:45 on Sunday.
There is never going to be a chance to make qualifying so we miss this.
We suspect that the small Bosch water pump, which is commonly used for Hayabusa engines in cars and has performed fine up until now, is inadequate for the supercharged engine. Unfortunately, we cannot fit the new Davies Craig pump bought this morning as do not have any water pipe of the right diameter. It's now about midnight and so there is no chance of obtaining any pipe from anyone. We cannot upgrade the water pump before the race. The original pump will have to be refitted as there is no other option. We just have to hope that the other cooling improvements are enough.
Shayne lines up on the start line with a new diff, a smaller intercooler (just in case this is shielding the rad too much) and various improvements to help air get to the rads. The swirl pot and tall tank breather have now been fitted.
The flag drops and Shayne puts in a blistering first lap, going from 12th to 5th in no time: 5 places claimed before the second bend. He's fourth by the end of the second lap and now showing in Jim Lyons' mirrors. Bad news though: oil temp has begun to spiral and so Shayne backs off for a couple of laps but the oil temp does not come down. Shayne shows great maturity and retires rather than risk the engine.
There is a lot of speculation as to what power we are putting out, with a figure of 400BHP mentioned by the commentator. We know the power is 250BHP, but we keep it secret until the end of the race.
In an attempt to resolve the oil temp issue, we cut a letter box slot in the bonnet, rather than relying on the 5 holes there up until this point. Baffles are fitted above and on each side of the oil cooler to ensure all air passing through the oil cooler also passes through the rad. Improvements are also made to plug the last hole alongside the rad - now all air has to pass through the rad.
Shayne lines up at the back of the grid for the second time in the Vetech/A2Z mini. Another blistering start and up to second within the first few laps. Shayne was going strongly and very soon began to hassle Bill Richards for first place. The cooling problems have not gone away though, now it just takes longer for things to get hot - at about half distance Shayne is forced to back off again, giving up his 2nd place to Jim and then cruising to secure third with a very hot engine. There were vibration and handling problems as well over the last few laps - just for good measure we had a puncture on the nearside front tyre. The tyre is almost flat at the end of the race and we're not at all sure about how the head gasket is feeling. 17 laps completed - we have now doubled our lap count.
A podium finish at least, but not the fairy tale win we had hoped for! Congratulations to Bill Richards, who won both races, and Jim Lyons.
The primary issue was cooling. In the few hours since the race, the more we have analysed this, the current belief is that we have simply gone beyond the capability of the small electric water pump currently fitted, which had been fine until the supercharger was added. The engine conversion itself performed faultlessly.
This event showed several things. Pubs and sleep, strangers recently, are great things in life. But once we have resumed normality, what is next? The engine project did not achieve the fairly tale debut victory we had all worked for - but it was so, so close. Just a short length of 25mm silicone hose might have changed everything! One thing is very clear though: the conversion has massive potential - just a little bit more development required.
Better cooling is clearly paramount. A higher capacity pump will be fitted - very easily sorted.
Even with 250 BHP, wheelspin was less than expected and so the compression will be lowered and the engine remapped to deliver 300 BHP. This will still be reliable.
Taller gearing is desperately required, but it might require a bit of work to do this.
We'll need to think about wheels and tyres too: one race destroyed a set of tyres.
Launch Control, traction control etc. All the gizmos are there on the ECU, but were not enabled due to time constraints. It would be good to use these. Consolidation of the various boxes of electronics into a single box would also be good.
The supercharger is now driven off the end of the crank. There is a redundant supercharger drive at the back of the engine. This will be removed which will give much more space for a proper 4 into 2, or 4 into 2 into 1 exhaust in place of the 4 into one currently squeezed alongside the supercharger drive bulge. This will liberate a bit of power, but more importantly the extra clearance which can be made around the exhaust will reduce the risk of cooking another diff.
It's at this point Vetech would like to thank everyone one who helped in this whole project.
Most important and notably Rohith de Silva for his initial insight, and the partnership of his car and Vetech's engine. Rohith and his son Leon put in superhuman amount of effort to help this happen. The A2Z Minis team somehow coped with sleep deprivation on a simply unbelievable scale. Rohith put in all the effort but was unable to drive the event himself.
From the Vetech side all the staff weighed in to make this happen and so thanks to Andy, Josh, Neil, Lucy. Jennifer and Rob. Andy and Josh in particular gave it their all over the weekend in question.
A truly inspired drive by Shayne, coping instantly and brilliantly with an unfamiliar car with a few niggles right at the start of its development curve.
Total strangers at the event gave great encouragement and assistance - several have already been mentioned but thank you also everyone else. This was the only thing that kept us going.
Prior to the event, Phill Lanes @ G&G Motorsport mapped the ECU on Richard Albans' TTS roller - thank you to both.
Most of all, Vetech owner Andrew would in particular like to show appreciation here to some very important people in his life: his wife Jennifer and children Gwilym and Rowan for the fantastic support and encouragement they gave during his reclusive phase over the last few months.
We are now considering what the next event will be - suggestions welcome...
Vetech Product Design & Development Ltd
Staden Lane Business Park
Telephone: 01298 213810 Fax: 01298 213816 Email: firstname.lastname@example.org www.vetech.co.uk