R154 5 Speed "Upgrade"

The W58 5 speed previously fitted has been serving us very well with an excellent shift quality, no fuss reliability with a very nicely weighted and acting clutch.... however our greed for more power which will possibly result in power output almost doubling, has lead us to make the decision to replace the W58 before we break it with an almost indestructable R154.
Conversion kits are now available from Neil at Rush Imports for both the R154 and Tremec T56 gearboxes behind the 1UZ V8 engine for which both boxes have their pros and cons.
Having test driven Neil's silky smooth Tremec T56 backed 1UZ blown Soarer I was seriously tempted to sell all the accumulated R154 parts and switch to it but we ultimately decided to stick to our initial plan of using the Toyota sourced R154 based on previous personal experience using one in a high power JZZ30 Soarer and JZA70 Supra and knowing it will handle the expected power and then some as long as we are reasonable with it in selecting gears which can unfortunately be agricultural at times.
Cost was also a significant factor in our decision as the T56 based kit would have cost a few thousand more based on the custom adapter kit, custom flywheel and clutch combo required for fitment and not to mention the higher cost in sourcing a suitable box.

Components used in this conversion are:

OEM R154 sourced from an xA70 Supra
OEM R154 to JZ bellhousing
OEM JZZ30 R154 mount
OEM JZZ30 R154 crossmember
OEM JZZ30 auto tailshaft lenthened by 65mm
OEM JZA70 R154 shifter - modified
Rush Imports JZ to UZ adapter plate & mounting hardware
Howe 82870 concentric slave cylinder & 5 shims
Round faced throwout bearing
Earls braided slave cylinder supply/bleed lines and fittings
Custom 30mm mild steel spacer for Howe unit
Alloy Race Components billet alloy flywheel with armour plate insert - 5 kgs
Roadrunner high clamp pressure plate and cerametallic cushioned 5 puck clutch plate
Otomoto/OS Giken HT reusable flywheel bolts

Engine Mounts

I recently noticed excessive movement of the engine relative to the engine bay when lightly revved in neutral.
Forceful rocking of the egine resulted in even more movement and some worrying clunks, so the engine mounts were diagnosed as being split.
There was no fear of the actual engine dropping out of place as the mounts are held captive by some safety plates even when completely split.

I had previously used heavy duty aftermarket Japanese made Kazama engine mounts on my high powered JZZ30, so I set about and replicated the Kazama style mounts with some Nolathane bushes, some round tube, flat bar, angle bar, hight tensile bolts and Nyloc nuts.

After a bit of effort with access to the top bolts we removed the old mounts and fitted the new ones without too much fuss for a solidly mounted engine that should not have the same degradation as the silicon filled OEM mounts which are designed for NVH not for longevity.

Old split mounts

New mount vs old mount

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.