The car is now sold.

0-60 Time

In the absence of a rolling road it is nice to see if the performance of the car is dwindling in horses in any way.

There is an excellent on line 0-60 mph calculator http://www.060calculator.com/

For the Megabusa this gave 3.9s for 621.5kg and 176.4bhp. The weight was taken from the recent corner weight measurement and the bhp was taken at Sitech racing last year http://westfieldbusa.blogspot.co.uk/2014/06/dynamometer-test.html

I set up a track on Race Chrono, using a safe bit of road where the terminal speed was less important and 60mph was obtainable in relative safety. You can see that the example gave a result of 3.7s which is about 0.2s optimistic (or the Sitech results are pessimistic). However if you take into account that the test track was up a gradient and the starting speed is not 0 then the level of correlation is not bad.

I have measured my wife's Mondaeo, Sylva J15 and a Westfield Zetec and all gave results that were within about 0.5s of prediction.

Corner weights

I have been pondering for some time the issue of corner weights and how far the setup on the Westfield was from optimal. There is a very good on line spread sheet and explanation of how to set up your car at: https://robrobinette.com/corner_weight_calc.htm

There is also a very good Excel spread sheet by Nick Warinner of ntw@360racing.com that I copied and modified to add the cross weight calculation information recommended in the above advisory site.

Cross weight = (Right Front + Left Rear)/Total weight.

I also purchased a set of Proform Bluetooth corner weight measuring pads from ebay tegiwaimports these are a budget product but works well and is easy to use.

Here are the results, you will have to open the image by double clicking it.

In summary I did the following.
1) Ensure the tyres are all the same pressure
2) The suspension height front and back are correct. In my case the lower front wishbones are horizontal and the front to back was 20mm
3) Adjust all the spring lengths FL = FR and RL = RR as a good starting point.

Starting point no driver

Adjusted no driver

Adjusted + driver

In summary I cannot see the advantage in my car of biasing it to handle with the driver only as it only makes a 0.3% difference. It means the handling is optimal with a passenger also depending on weight.

Progress spring 2015

I had a whale of a time during summer 2014 visiting as many track days as my budget would allow. The car has mostly behaved itself but you can always improve these cars. The major issues mechanically was 1) The slave cylinder giving me poor clutch control 2) The drive shaft coupling bolts come loose fro time to time. With the addition of the SBD slave cylinder that should help the clutch issue and the wiring the drive shaft bolt heads should help the loosening issue. There is so much vibration at this junction I guess this problem never really goes away.

I have concentrated recently on the weight of the car which I think was unnecessarily high for a Megabusa. The outstanding issues were mainly due to the economies  of the original build, no criticism implied.

I have just upgraded the front suspension with new light weight RD uprights and hub carriers (8Kg saved) and the battery to Lithium ion (8Kg saved) and the carbon bonnet with (2.6Kg saved) that makes a total of 18.6Kg saved. If we add in the metalwork thrown away on the paddle shift upgrade that makes a round 20Kg total. It is not just the weight saving, but the overall value and look of the car has been improved yet again.

The other changes  are to improve the oil cooling so I added a duct at the rear of the nose cone and heat shield to stop the new bonnet overheating.

In summary another years improvements to try out on the track.

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Carbon weight saving bonnet

The bonnet on my car has always been an irritant. The 2009 builder had reused an old V8 bonnet and filled in holes in the side for a previous air intake. Also I think there have been various repairs over the years that have resulted in the bonnet being very heavy.

I commissioned Scottish Kit Car Centre (Andy) to make me a lighter one. With his amazing contacts in the industry he came up with the goods. The pattern was taken off the original bonnet and a set of moulds made. The carbon was then layered into the mould with resin.

Here are the results, as a first fit. The vents have still to have the mesh bonded in however the result is fantastic. The weight difference is 7.3Kg vs 4.7Kg a total saving of 2.6Kg.  The GRP bodywork is from an early sierra wide bodied kit and has fixed arches and different swage lines to the latest production panels. We decided to paint the panel in two pack to match the rest of the car. Over the last few changes 

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Front uprights and hub carriers

The next on the list for upgrade this winter are the front uprights and hub carriers. The existing uprights are still serviceable but I am on a mission to save more weight. The Cortina geometry uprights currently fitted are made of steel so is the hub carriers. A potential weight saving of 4kg per side is achievable. To improve the looks and reduce the weight of the steel Cortina uprights a lot of filing and grinding was obviously necessary in the past.

Rally Design (RD) make an alloy upright that is rather pleasing to the eye compared to the Westfield part. I also wanted to retain my Dynalite calipers that I had just paid for at the recent  vented disk upgrade.

 I also made the acquaintance of Callan from http://www.t89.co.uk/ who is a registered trader on the Locostbuilders forum and offered me his help with the upgrade because he had some useful parts and advice.

The key part that Callan provided were some adapters to take the RD upright and adapt it to the M16 type calliper in the form of a Willwood Dynalite. Apparently RD supplied that part at one time and Callan had a spare s/h set. He titivated them and shipped them (although I am sure he can make some for you) with the rest of the RD kit along with some adapters for the upper rose joints (which I have still to install, perhaps!).

The fitting of all this lot was not easy and was made more difficult by the vented disk which is thicker than normal. My setup is unique I guess, most people would probably be upgrading the callipers at the same time which would already fit the RD kit. Here is a list of all my modifications in case you  wish to follow my path.

* Missing M16  x 1.5 castle nuts and Ford keyed washer. The only washer supplied has to be opened out to 18mm. The stub axle has to have 5mm removed to allow the alloy cap to fit. After adding the castle nuts the alloy cap had to be opened out (internally) to stop it fouling the alloy cap with the slit pin.
* The lower Maxi ball joints comes with a 3/8" hole and the wishbones have a 10mm hole. This can and did lead to wearing of the bolts (on previous build) if not changed to 10mm.
* Alloy hub needs turned in lathe to provide the extra room for the vented disk. This amounted to 2mm.
* Brake calliper fits but needs 3mm spacers when the above is done.
* Cycle wing supports are a total misfit to upright, lots of thought went into this as I did not want the expense/effort of adding new wing stays. Minor fabrication welds to the original cycle wing stays. A bit tricky you need two people to get the fit right.
* The Dynalyte calliper mounting bracket fouls the RD upright casting. A chunk of the alloy bracket needs removed but not enough to weaken it.
* The existing ball joints don't fit the RD upright. A search on the Locostbuilders forum revealed the following.
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FYI found this thread on  Locostbuilders

”TRE (Track Rod Ends)

There are two different tapers and two different threads

1) Escort MkII Escort are M14 with the metric (large) taper. (this also include granadas to 1987, Cortinas MkIII and Mk V to 1982). FT722 , QR1834
2) Capri MkI, MkII, MkIII all up to September 1987, also some Escort Mk I and other fords (Fiesta up to 1993, Orion and Escort MkIII and MkIV, to 1990). are imperial thread and imperial (small) taper. Part number; Ford 6128814 & 5021410. Direct Part Number DR2377, AMR1205
MkII RS2000 uses MkII Escort rack and Capri uprights and so uses a hybrid TRE (M14 thread, but small taper). These are also known as “green” TRE, as they are (you guessed it) Green (at least the For original one, this doesn’t apply to the equivalent pattern parts!). AMR4118. 1564468. AM260

Most TRE labelled RS2000 on e-bay are wrong. I had to send 2 pairs back before spending more money on proper ones. “
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New RD upright and wing stays fit issue

Old Cortina uprights

Mod to Dynalite bracket

Washer needs to be 18mm

Missing Ford washer





Reduced stub axel

 

Castle nut in place stub axel too long

Drilling out cap to fit

 

View from front ball joint still to tighten



Modified wing stay arrangement

Not a lot of disk to adapter plate clearance but enough!

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Lithium Ion Battery

I invested a new LIP012C Lithium Ion motorcycle battery. The weight difference between the battery it had in and it's hi tech replacement is 9Kgs. I have no idea of the down side, it appears to start the engine immediately from stone cold. I have not had an attempt at using the electric reverse yet.

I look forward to the weight saving in my new bonnet when it eventually comes.

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Heat shield

One of winters outstanding jobs on the car is reducing the heat induced into the GRP bodywork with the Hayabusa exhaust. I am hoping to get a new bonnet some time and I don't want to stress it with heat. The Hayabusa exhaust gets mega hot and I don't think this is unique to my car.



Shield attached to the EGR blanking plates

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Oil cooler air duct

The oil temperature on my Hayabusa is a bit high on prolonged sessions on track days especially at Knockhill. I was either going to shift the oil cooler from behind the radiator to the front or duct some cooler air directly to the oil cooler. I decided to do the latter. It will still get some air from the front via the electric fan and water radiator.


New air duct

New air duct in place

From above

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Concentric clutch slave cylinder

When I described my lack of clutch control precision with Andy from AB Racing he directed me immediately to a SBD part CLT-HCA-BUSA-01K. It is a custom billeted concentric slave cylinder for the Megabusa engine. The fitting of the part is fairly straight forward only having only to change the bleed pipe outlet from the water pump (as the rubber pipe was in the way). The pump housing bleed uniion was easily modified by cutting it off and tapping out the remaining steel tube stub to  a 7mm metric thread and making a brass union and installing a remote external 8mm brass elbow. The standard SBD fitting kit for the cylinder was perfect despite warnings from them that this part was designed to mount on top of their billeted oil pump.

Water pump modification



SBD part from top




Hewland part in same location

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Fuel overflow management

I have been hauled up on several occasions about fuel discharge during track days and sprint/hill climb events. This only happens when the tank is above half full. I fitted a Mocal valve which I thought would cure the problem as it has a dual function a) When the vacuum in the tank exceeds 0.5bar it will ingest air from outside. b) If however the tank pressure increases due to temperature effects (or sloshing) then the valve release in the other direction if that pressure exceeds 0.75bar. By this method the valve can act as a roll over valve and hopefully keep the fuel in the tank.

The problem occurs on track days when the fuel is warming up (so positive pressure) and the corners pull some g, if now the pressure release happens on a right hander then fuel is emitted momentarily till threshold of the valve closing is reached.

I have tried fitting a catch tank (jam jar) but this only delays the problem till the catch tank is overflowed. This results in dumping fuel from the catch tank between sessions.

The answer may be quite simple, let the main tank overflow when positive pressure exists, collect the fuel and suck it back in when the fuel is used up and the pressure becomes negative.

principle

catch tank mounted under chassis

I will let you know if it works.

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New brakes and oil pres warning lamp

  The brakes have been a problem from day one in that they were causing lost time at the hairpin and fading two up. They looked the part being single x drilled discs and early billeted 4 pot Dynalite's  from Wilwood.

I changed the discs to vented x drilled and grooved parts and as a consequence had to upgrade the callipers as well to the latest Dynalite forged part from Wilwood supplied by RD.

Dynalites with vented discs

The results were a dramatic improvement in both hill climbs and circuits.

Oil pressure warning

I have been advised by several hill climb veterans that a very bright visible oil pressure lost lamp is essential equipment for racing. This lamp BL0102-14-34 is the bees knees. Thanks to Matt as he had a spare in his garage.

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Seats crotch and Hans

I have been considering a safety upgrade to the Megabusa. I decided to invest in a set of seats that were more substantial than the GRP shells fitted and fit an additional crotch strap to the seat belts and Hans device for my neck.

If you want to know what a Hans device is then there is a very good explanation on Wiki (*).

The crotch strap is a simple addition to the existing Willans seat belts. It stops you sliding under the harness in extreme conditions.

The seats were ordered while at Stonleigh and are made by a company called Intatrim (*) and the product is called Endeavour. Although still a GRP seat it is a much more substantial product than the basic shell seats and they have thought about the crotch strap void in the design.

Hans adapter

A Hans device was purchased from JJC earlier in the year at significant cost. However I was never able to use it in the Westfield as the seat belt straps need to be precisely aligned with the seat apertures and the Hans device. This requires the attachment points in the Westfield to be radically altered. After some discussions with various scrutinisers at the track and after even more thought I designed and fabricated  a Hans adapter using the existing Westfield seat belt attachment points. You can see not only have the attachments been aligned horizontally with the Hans device but a 50mm elevation to the attachment has been applied because of the Hans thickness resting on your shoulders.

The adapter was fabricated out of 4mm sheet steel and bright steel studs taped and welded in place on both sides of the plate.

I propose to submit this for scrutinising soon at Kames.




Hans adapter

Hans device

Drivers seat with new belt attachments

Comparing drivers and passenger seat belts

Passenger seat belt points

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References (*)
Hans explanation: http://en.wikipedia.org/wiki/HANS_device

Seat manufacturer: http://www.intatrimtelford.co.uk/index.php

Engine prop shaft adapter

The Hayabusa engine normally has a toothed gear to transmit the power from the gearbox to the rear wheel of a motorbike. Wesfield in their cars mount a special adapter on the gearbox output shaft that adapts it to a split Sierra drive shaft. The adapter is normally made of mild steel and is rigidly attached to the gearbox shaft via a large M20 lock nut and a large washer. If you trawl the forums this nut comes undone with amazing regularity. Mine unwound at Croft on 7th June 2014. It was trailered back home as I had no chance of repairing it at the trackside. The mild steel adapter was badly damaged and I did not want the gearbox shaft to go the same way.

I took the advice of Andy at AB Racing. He has a special adapter made to his exacting requirements which is reported to solve the problem. It is designed to be loose fit on the gearbox shaft unlike the Westfield part and is made of hardened steel.

It is unfortunately about 10mm shorter than the original Westfield part so I had to make an alloy spacer in the lathe to make it all fit back together.

The M20 nut was also modified to make the adapter a loose fit on the shaft and I tightened it up such that it will not come off again. I used the permanent nut thread fluid to bond it up tight.

I have no idea if this will permanently solve the problem but is seams like a good approach. Time will tell.




Westfield adapter after failure

Gearbox splines

10mm custom spacer



Nut modified on right to remove some of the step



Reassembled

Update 11th Sept 2014

Kept a regular eye on this part of the car and it regularly gives an 1/8-1/2 turn between race events on the cap head screws no evidence of the 32mm nut loosening again. I decided to wire the bolts to ensure they don't come loose again. I drilled the cap heads in place using some carbide burrs (long job).

Wide carbon wings

I was having difficulty changing the tyres at the trackside with the standard Westfield wings. I was also having difficulty sourcing wider wings. Carbon Copies (Warren Sheridan) made me new ones in carbon. Unfortunately due to ill health he has had to give up his business. It took a long time to get these parts but he came good in the end with the help of his son. Top marks for commitment right to the end. The wings now match the headlights, see bottom image.



From front

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Dynamometer Test

The last open pit lane session at Knockhill with the Westfield club revealed some performance issues on the straight from Taylors up to Duffus. Every time I changed up the power was taking too long to build up again. I took the car to Sitech to find out what was going on. Simon revealed that in the lower (throttle openings) and high engine revs it was being over fuelled. The theory is that this was throttling the engine when lifting off to change gear. Simon completely remapped the Power Commander such that at all throttle openings and rev ranges the correct fuelling was being delivered. All I need now is a track day coming up soon to try it out. Simon did say tht the power sensor on his Dyno is playing up and could be 10-20% down in absolute numbers. I have pencilled in another session after Croft.

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Carbon effect headlights

After a moment of weakness I purchased these new headlight units at Stoneleigh this year, what more can I say!

 

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Shift advisory lights

Decided to fit another box of electronics made by a company called DRE (Digital Race Electronics). It is a computer that works out when to change up gears called an SDL5 Sequential Shift Light. The box measures 58mm x 16mm x 35mm and the idea is you are to mount it in your direct line of sight. This should avoid the potentially detrimental dependence of the rev limiter. It also wastes track seconds going into the rev limiter. I spotted this shift light box on a car at Doune this year.

The box worked well when directly connected to the Hayabusa ECU rev counter drive cct but refused to work with ETB rev counter connected to the same wire. I scratched my head and went back to basics with my electronics knowledge and made a cct that allows both to co-reside. The ETB rev counter appears to put a 5V offset in the ECU circuit when connected. I basically removed that offset with a capacitor resistor and diode to protect the DRE unit. The values of the capacitor and resistor are not that critical being 33uF and 2.2Kohm. If you require more details mail me, I doubt this is a common problem.

10/06/14: The signal to the unit was correct as designed above, however the setting for "Cylinders" should have been 2 to match the ECU signal of one pulse per rev. Now working fine.

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Tonneau

There are no dependable people around central Scotland to get a Tonneau made. I pondered the issue for some time and came across some favourable references to a company called Soft Bits for Sevens. As they reside in West Sussex then a template was the obvious answer. I made an accurate template from Toolstation tarpaulin. After several months the finished product arrived from Softbits. I made some time ago a special tool for riveting the buttons in place while the tonneau is in process of being fitted. This is a much more accurate way of fitting a tonneau as you can drill each stud position one at a time and fit both half's of the stud fastener without removing the Tonneau from the car. The tool is made in part by a Rolson crimping tool with alternative stakes and anvil on each side.

I used the spare seat belt attachments to locate the Tonneau with brass eyelets.

I also took the opportunity of fitting a Longacre racing (rear view) mirror saved me thinking too much about the mounting brackets. It gives a 14" panoramic view a good safety feature for the track.

 

Soft bits logo and attachment eyes

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