General, Race cars Digging up some old pictures

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Some years ago I worked on a race team running a BMW 320i Super Tourer in a race series.

These cars used to run in the main touring car category in the 90’s, and competed against the Holden and Ford V8s at Bathurst.

The Super Tourers were similar to the British and European touring car categories, running 2L n/a engines limited to 8500rpm, with limited aerodynamic aids, and limited tyre width (225 from memory).

Apart from that the rules were fairly open, so the big budget cars had some very impressive engineering.

Engines were generally swapped out for each race - with the new one installed for qualifying. Engine life spans were around 300 - 500km, and a “rebuild” cost around $100k.

This particular car was a fairly late model, with many improvements over the earlier ones - including a very controversial active lateral brake bias controller, which was a completely mechanical system using a pendulum to control the left-right brake pressure to allow harder braking into corners without locking wheels.

It was very well hidden behind some carbon fibre panels under the dash!

In their time, the Super Tourer engines were pretty advanced - making 300+ hp from a naturally aspirated 2L production based engine. They were heavily modified from standard, for power as well as lighter weight. These ones ran titanium conrods, very short skirt pistons, dry sump, and featured a lot of carbon fibre parts.

The carbon fibre cam cover is especially nice

Note the oil pump is driven from a normal multi-rib belt (not a toothed belt)

The pipe running along the head under the intake ports is the coolant outlet manifold. Instead of the coolant having to flow through the head and exit in one place as in a production engine, this manifold keeps the coolant flow even across each combustion chamber to avoid uneven temperatures.

The porting job on this engine was pretty amazing. It was obviously all CNC, and the valve guides had been machined in place to avoid any excess disturbance to the intake air flow.

The exhaust ports are similarly nice, but a bit less clean!

The valve train was fairly interesting. There was obviously not enough space in the head to achieve the intended valve lift with the traditional production round tappet design, so the head had been machined to fit a rectangular tappet and allow clearance for the much larger cam lobes.

The intake is fed by a set of flat slide throttles, so when the throttle is open there is no restriction to the air flow.

The airbox is possibly the most impressive part on this engine. It’s all carbon fibre, and huge! The intake bellmouth is about 150mm in diameter. The offset intake trumpets allow much larger bellmouths and a larger airbox volume.

Note the secondary set of injectors inside the airbox. Under full throttle conditions fuel is injected via these as well as the usual ones close to the intake ports. It allows more time for the air and fuel to mix properly. This injector rail failed at a race and filled the airbox with fuel. Fortunately we caught it before hydro-locking the engine or starting a fire!

The exhaust headers were super light weight, made of very thin wall stainless steel, or possibly inconel.

They get pretty warm in operation :)

The ignition coils appear to be pretty standard, but are mounted in a very intricate carbon fibre frame! Interestingly, the engine runs “wasted spark” ignition, using two coils with twin ouputs, so the spark plugs fire every revolution and a spark is “wasted” every exhaust stroke.

The engine drives the car through a very fancy multi plate carbon fibre AP Racing clutch. Even though it is tiny and very light, the flywheel section has holes drilled around the edge to lighten it further!

The clutch is actuated by a concentric slave cylinder and thrust bearing mounted in the bellhousing, which also happens to be the oil tank for the dry sump lubrication system! This part is all cast magnesium alloy. The plastic tube on the front with a cable tie in the middle is the oil level gauge, and the two blue fittings at the top are for the oil return from the engine and the breather / vent.

The aluminium pipe pointing forward from the bottom of the oil tank mates up to the inlet of the oil pump. It runs through the middle of the engine mount, as seen in this picture.

Behind the bellhousing / oil tank sits a magnesium cased Holinger 6 speed sequential gearbox. These reportedly cost about $60k! It was fairly quick to remove from the car, open the case, and stack a new set of gears with different ratios in it for each track. Not pictured is the $20k carbon fibre tailshaft which used kevlar flex plates instead of universal joints like a normal car. The gear lever had a strain gauge on it, which was used to cut the ignition during gearshifts so clutch was not required.

The cooling setup in this car was pretty impressive. Two radiators are mounted in a V configuration inside a very complex carbon fibre duct which feeds the outlet air into the wheel arch area in front of the tyres - reducing the amount of air going under the car. Underbody aero / flat floors were not allowed in the rules, but this car had a suspiciously large and flat “fuel tank protector” and some oddly shaped mufflers which happened to fill in a few of the underbody gaps :)

The whole engine bay was designed so that the engine and gearbox could be removed very quickly - and the engines came with a trolley that wheeled into place for the pre-qualifying engine swap. Note the roll cage tubes completely containing the suspension strut tops.

Brakes were an important part of the performance of these cars, and there were two common options - 8 piston Brembo calipers, or dual 4 piston AP Racing calipers as this car had. Wheels were 18″ in diameter, with center lock hubs. We had a massive torque wrench (about 2m long) for tightening the wheel nuts - which had opposite threads on each side of the car to add to the confusion! In this picture there is a “transport nut” installed - which provided a convenient tie down point. Not pictured but of some interest are the wheel bearings. This car ran huge diameter wheel bearings lubricated by a light oil instead of the usual grease - for less rolling resistance but also less bearing play, which could cause brake pad “knock off” and slower braking response. In their heyday, teams would replace the brake rotors with super light ones for qualifying. They could only handle one lap at full pace, but reduced unsprung mass!

Suspension was also a “no expense spared” part of this car. It was apparently built by McLaren, and was vastly different to the earlier versions of these cars. Almost all parts were CNC machined from billet aluminium. In this picture of the strut top you can see the fine adjustment wheel for the camber.

From underneath you can see how the strut is attached to the cast magnesium front hub / knuckle assembly, as well as the carbon / kevlar brake cooling duct and the pushrod and bellcrank setup for the swaybar linkage.

The swaybar is a proper blade adjustable type. You can see the adjustment cable which rotates the “blade” at the end of the bar. Front and rear swaybars have in-cabin adjustment. Linear potentiometers attached to the swaybar bellcranks provided suspension travel readings to the onboard data logging system.

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Auto electrics, Metalwork, Race cars Minetti race car

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The Minetti is a race car very similar to a Radical.

It’s a tubular steel frame chassis running a motorcycle engine (Hayabusa), with fibreglass / carbon fibre bodywork.

This one had a few electrical and mechanical issues, and needed a few upgrades to be competitive with the newer cars it’ll be racing with.

First step was to fix some of the wiring problems, with some parts connected up wrong, and a few damaged and melted connectors:

The next step was adding a mounting frame for a rear wing. This also supports the rear half of the body, replacing the original frame which wasn’t strong enough to support a wing.

A proper front undertray / splitter can really help generate downforce at the front of the car, and smooth out the air flow under the floor. This one is a foam core composite and I attached it with some aluminium angles underneath to spread the load and provide some rub strips.

The rear wing mount also provides a mounting point for a rear diffuser, which is the final ingredient in the aero setup. It keeps the air flow clean from the floor to the rear of the car and allows the air to gradually increase in pressure to keep the low pressure zone under the floor for downforce.

The bolt in the middle is a jacking point, as well as a handy place to attach a safety chain for towing.

After changing the springs to handle the extra downforce, moving the data logger / dash unit to be more visible, messing with a few sensors, and tidying up most of the loose ends it was time to take the car to the track for a shakedown:

We found a few more issues to fix up before racing (some more lingering wiring issues, and failing oil pressure sensors) but the car went well while it ran, and is looking good for the racing season!

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General, Metalwork Moving a giant ship’s propeller

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This propeller had been used as the stand for a large office meeting table, and had to be moved out as the company was closing down.

I built a trolley using an old pallet jack with an engine hoist was able to lift the prop into a vertical position, roll the trolley under it, and bolt the “axle” through to keep it in place.

The prop is 1.75m in diameter and weighs 420kg, so it’s not the easiest thing to move around!

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Auto electrics S14 engine into an S13 Silvia

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With the original S13 Silvia engines hitting 20+ years old, people are starting to break them (usually due to a lack of maintenance).

Rather than finding another S13 engine in good condition, which is getting harder, it’s becoming more common to install an S14 or S15 engine.

This car had an SR20DE (non turbo), and was replaced with another SR20DE, just the later version.

The mechanical part of the conversion is fairly straight forward, but where people get stuck is the wiring.

Unfortunately there are no proper diagrams available for the SR20DEs, but by comparing to the various versions of DET (turbo) diagrams it’s possible to work it out.

The main difference is that the S14 and 15 run the power supplies for the ECU and sensors through the dash wiring loom rather than the chassis loom at the front of the car like the S13, so a large section needs to be added, and the dash loom connection changed to work with the S13.

The coolant temp sensor is also different, but swapping in the S13 one from the old engine means the temp gauge on the dash will still work properly.

It’s a bit of a slow process, but once it’s done you can have a later model engine working in the earlier car.

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Cars V6 MR2 exhaust

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Changing to a different engine means that a lot of the original ancillary parts don’t fit any more.

The Camry V6’s Y-pipe actually sits in a similar position to the MR2’s exhaust section that passes under the engine.

I cut the pipe just after the flexible section (which allows for engine movement) and then made a new pipe from there to the cat using 2.5″ mandrel bends.

The Camry Y-pipe is a bit restrictive so eventually it will be upgraded to a nice set of extractors.

The factory cat was replaced with a high flow stainless steel one, and I welded some extra pipe and flanges onto it in the same positions as the original so they can easily be swapped if necessary.

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Race cars Racing surge tank

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To prevent fuel pickup problems under hard cornering loads in race cars a surge tank is often used.

Generally there’s a pump in the fuel tank feeding the surge tank, then a second pump picks up from the surge tank to supply the engine.

If the fuel moves away from the pickup in the fuel tank during cornering there’s a backup supply in the surge tank, which can run the engine until the main fuel feed comes back.

Usually surge tanks are mounted in the boot, which means bringing a bunch of fuel lines inside the car, which is not ideal for safety reasons, and always results in fuel smell in the cabin.

For this one the idea was to mount it under the car, which meant it had to sit close to horizontal. It’s best if a surge tank can be vertical, to reduce the fuel sloshing around away from the pickup at the bottom.

I mounted the tank with as much angle as possible in the available space, and added a baffle inside it to minimise sloshing.

The fuel pump mounts beside the tank, and has its own power supply directly from the battery - via a relay triggered by the original fuel pump power.

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Boats Installing a GPS chart plotter on a boat

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This was a bit of a change from all the long projects that have been on lately!

Just an upgrade from an older depth sounder / fish finder to a new one with GPS mapping and more advanced features.

It’s just a matter of mounting brackets and connecting up wiring, but because I was replacing an older system I had to use a larger than necessary hole that was already in the transom.

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Cars, Race cars V6 MR2 progress

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I’ve been pretty busy since the last update!

After getting most of the wiring done for the V6 it was time to remove the original 3S-GE engine.

Even removing the engine is a bit of work on the MR2, with cramped access and a ridiculous amount of hoses and wiring! The gearbox also has to come out, along with the crossmember and rear hub assemblies.

While the engine bay was empty I mounted the oil cooler between the engine bay cooling fan and its mounting plate. This will eventually be controlled by the ECU depending on oil temperature.

The next step was to get the gearbox lined up with the engine and modify some of the mounting holes to allow it to bolt up properly.

Once it’s in the engine bay it looks like it’s meant to be there! (and really Toyota should have done this!)

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Entertainment, Metalwork, Projects Yellow Box Spring Carnival

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After being invited to this: I decided I’d have to build something pretty decent to compete :)

Looking at the available materials I figured a trike was the best idea - starting with the front forks from a Kawasaki GPX250. First step was removing the headstock from the frame:

Then welding it to some 4″ tube which I can only assume was scrap truck exhaust:

A borrowed boat trailer axle provided the rear wheel setup:

after being welded to the frame tube with a nice thick steel plate in between:

With the addition of an old race seat and a foot peg, the trike was complete:

I was going to keep it “rust core”, but decided that it didn’t match the sections of blue painted steel, so it really needed a proper coat of paint:

The event itself was awesome, and the 700m long track with 100m fall was suitably fast and scary!

We had round robin heats for the first half of the day, and a full grid race for the final at the end.

I was lined up on P2, and got a bit of a slow start due to the trike’s weight. The wide rear axle makes overtaking difficult so I was a bit stuck until the leading kart snapped a wheel off and spun out and I managed to take the win!

Here’s my wrap-up video of the event:

Full helmet cam video from the final race:

Next year I’m going to have to build something lighter and narrower :)

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Projects, Race cars Datsun 260Z race car project

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This project has been on the back burner for years now, but it’s time to resurrect it and get to the race track again :)

I originally bought it as a rolling shell:

I ended up stripping it down to repair rust, mainly in the floorpan.

I since found that the wheels had broken spokes and various other parts needed replacement, so I ended up doing completely new suspension. I couldn’t find wheels wide enough for the wide body rear guards on the car though, so after much deliberation (6 years or so!) decided to remove them:

Underneath there are various areas with rust, but it’s not too bad. The panels have been “massaged” a bit for the widebody install, but I think it will tidy up ok:

At least it’ll save some weight :)

The next step was to cut out the old spare wheel well, which will be replaced by a piece of aluminium sheet with a racing fuel cell mounted underneath.

Holes for the tank filler and vent lines:

A pair of steel straps will hold the fuel cell in place:

Currently the fuel pump is mounted in the engine bay, but it might end up moving to the back for better fuel pickup:

Once the fuel setup is working the next step is the exhaust, then some body work and fitting out the interior - including a roll cage, harness, etc.

The aim is to have the car set up as a very minimalist race car, keeping the weight down, and not needing massive power to be reasonably fast - and most importantly, fun!

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