Aero

Other than the standard bodywork, the only aero development has been the addition of a rear GT style alloy spoiler.
Both Jeff and I have found it beneficial in high speed bends/kinks like turn 1 at Wakefield Park when the car feels more stable with the wing than without.
When we have horsepower that justifies it in the future, we have plans to look at a front splitter, side skirts and rear diffuser, but for now the aero is working for us as is.

Trackday outings

A quick run down of some recent trackday results with the trackcar.

Wakefield Park 26th May 2004 - UAS - 1.19.1840 Jeff Stock auto UZZ3x Baseline

Oran Park 31st Jan 2009 - JCCC - best lap - 0:55.5 Jeff

Wakefield Park 20th March 2009 - Toymods - best lap 1:14.71 Jeff

Oran Park GP 13th June 2009 - Circuit Club - best lap 1:27.336 Jeff

Wakefield Park 25th July 2009 - Circuit Club - best lap 1.11.99 Jeff

Wakefield Park 5th September 2009 - Circuit Club - best lap 1.11.18 Jeff

Looking at the times above, we can see that we have dropped about 8 seconds a lap at Wakefield Park by notable weight reduction, improving the braking performance, improving the handling, improving the grip/traction, removing the autobox, helping the engine breathe more and by driver training/refinement.

Wheels & tyres

We run three current wheels/tyres setups on this track car.

Our normal track slick setup comprises a lightweight set of Oz Racing 18x9+40ET front and AVS 18x9+40ET rear running used sets of Michelin ex Porsche Cup control slicks in 24/64-18

Our back up semi slick setup is based on a set of OEM JZA80 Supra 17x8+50ET front and 18x9.5+50ET rear running Dunlop D01J sems measuring 235/45/17 and 255/40/17

Our street setup is a set of OEM JZA80 Supra 17x8+50ET front and 18x9.5+50ET rear with Kumho Supra ECSTA 235/45/17 and Falken Ziex 275/40/17s

Safety & monitoring

A few safety items have been added to the car including a remote battery cutoff, a pair of easy reach fire extinguishers, a secondary bonnet restraint and 5 point racing harnesses.

Alloy tread plates with grip tape have been added where front floor mats would normally be to minimise footing slippages getting in to or out of the car.

Gauges have been added to monitor water and oil temperatures, oil pressure and vacuum to try and pick up any issues with engine vitals as early as possible.

A fixed three point camera mount has been fabricated to capture race footage and a RaceChrono GPS setup comprising a Nokia 6120 classic mobile and QSTARZ BT-Q890 5Hz Bluetooth GPS receiver is utilised for reliable yet affordable lap timing.

EFI upgrade

The factory fuel injection system is a very effective device for a standard, daily driven car with excellent fuel economy, considerable power, smooth driveability, effective cold start and idle control, reliability etc but does not allow adjustments as the engine is modified or as needs arise to modify the performance and running parameters.
An Adaptronic E420C aftermarket EFI ECU was chosen to take over our requirement for programmable EFI capability.
The Adaptronic ECU allowed us to simplify the fuel delivery by deleting the factory cold start injector as it could now electronically adjust injector duty cycle to compensate for cold starts.
Additionally the air flow meter could now be eliminated by utilising a MAP and IAT sensor for load metering - this is understood to remove a measurable airflow restriction to the throttle body and inlet tract.
The 19 year old dual duty factory fuel pump was ditched for a new high performance drop in Walbro 255lph intank fuel pump for reliability and to future proof our future fuelling needs.
The variable duty fuel pump ECU circuit was removed so the pump could run at a constant duty at 12 volts and the power feed to the pump was upgraded to minimise any voltage drops.
The Adaptronic ECU was custom wired to a gutted factory ECU case/plugs and plugged into the factory wiring loom with a sub loom for the added MAP and IAT sensors.
A wideband O2 sensor was fitted and fed into the Adaptronic, a laptop attached and after loading a preset map for this engine and adjusting inputs and outputs to suit our installation, the ECU allowed the engine to be fired up and was set to self learn based on the wideband O2 sensor feedback.
A few short trips adjusting the numerous load cells and the car was driveable.
The car was booked for dyno tuning with Mark at MRC dyno, was driven there and after it was tuned, was received back with significant driveability and power gains throughout the rev range.
The car picked up between 30 an 40 rear wheel kilowatts after being tuned with the Adaptronic and will now allow us to retune as and when we modify it in the future.

Help the engine breathe

The first real modification to the engine has been to add a dual throttle body manifold I picked up from Andrew who never got to finish fitting it to his engine and to see what the difference was to response or performance.
A second throttle body was acquired and modified by removing the TPS and welding all auxiliary ports shut.
A hybrid link cable was commisioned through Maltech.com.au using an UZZ31 auto kickdown cable and cruise control cable and a mounting bracket modified to suit the second throttle body.
A pair of steel mesh pod filters have been fitted to finish the modification off.
After tuning and back to back comparisons, the second throttle body made more power and trque across the rev range and particularly higher in the rev range between 4500-6000rpm where it peaked up to 8kw higher!

Diff swap

An open diff was never going to cut it on a race track, so a complete Torsen LSD diff assembly from a JZZ30 Soarer was swapped in.
The ratio was consequently changed from a 3.9:1 to 4.1:1 for quicker acceleration
Applicable Toyota axle codes are, from A01A to A02B.
The Soarer now has excellent traction out of tight corners and the inside wheel no longer spins up on acceleration.

Bye bye auto, hello 5 speed

Driving an automatic track car on a racetrack was never going to satisfy us or achieve ideal lap times, so a manual transmission swap was first and foremost on our plans driveline.

We settled on using a late model remote shifter W58 gearbox mating it to an auto bellhousing with a Phil Bradshaw adapter plate.
A custom lightweight 5.1kg billet chromoly flywheel, heavy duty 10" Hilux clutch / pressure plate and Howe 82870 concentric throwout bearing / Earls braided line were chosen and utilised.
A JZZ30 clutch master cylinder resleeved to 3/4", JZZ30 5 speed clutch pedal assembly and a JZZ30 rear tailshaft was used whilst and custom length JZZ30 front tailshaft section was professionally fabricated and balanced.
Finally, an MX83 mechanical to electronic speedo adapter was used to convert to the signals expected by the Soarer speedometer.

The auto to 5 speed conversion transformed the Soarer and it finally started feeling like a track car.

Cooling

The rigours of lap after lap of track days have a significant effect on the car's fluids and the last thing we wanted was overheating so in went a new higher capacity alloy radiator.
An alloy fill panel was fitted to direct incoming air through the radiator and foam fill strips were used extensively to seal the radiator chamber for the same purpose.
Next a cooler was fitted to the power steering fluid which will boil rapidly after a few laps of a race track.
Lastly, an oil cooler and remote mount oil filter were plumbed in to keep the engine's oil supply nice and cool.