Hilborn Injected Chev Powered 1976 Holden LX Torana

 

         

  

 

 

The A9X Torana is one of the best Aussie Muscle Cars ever built. It was General Motors race track weapon, to which Ford had no answer at the time. The combination of a compact body, agile handling, 5 litre V8 motor and tough stance has made it a motor sport favourite, with many records still to its credit today.

 

Background

In 2007, me and my partner Trish starting looking for the right Torana. We wanted a car that was fully rebuilt and improved in all areas (especially the engine/trans/diff), whilst in keeping with the A9X theme. Importantly, the car had to be engineered and street registered. Early in 2008, we finally found the ideal car - 2TOUGH.

Build History

A Torana that was manufactured before June 1976 was used as the base for the 2TOUGH project so there could be the maximum amount of latitude for motor modifications, whilst keeping the vehicles emissions within legal limits.

Race teams were allowed to use L34 parts in the A9X in the late 70's, and that then made them extremely competitive on the track, with race teams achieving approx 400 hp with a twin crossflow Weber carburettor setup. For 2TOUGH, by using the latest engine management electronics (such as a sequential motorsport computer, 8 port electronic fuel injection and full electronic ignition) a motor producing over 500 reliable horsepower and which complied to the pre-June 1976 emissions regulations was achievable.

A March 1976 build Torana was found in Qld, and in early 2002 it was bought by Ian Williams of Sydney. It was already a tough street performer with a 350 Chev, 750 Holley , Victor Junior manifold, 4 speed Toploader gearbox and a Ford 9 inch diff.

The rebuild was completed in August 2004, and was further refined over the next few years, the replacement of the Tremec manual gearbox with a 4 speed automatic in 2007 being the latest major change.

The motor was designed to be a reliable and strong street driveable unit with a good torque curve. Even though horsepower was not being chased, 2 TOUGH was dynoed with 396 hp (295 kW) at the rear wheels on 98 octane pump fuel. This equates to around 536 hp (400 kW) at the flywheel.

Despite being built to be driven rather than shown, 2 TOUGH has won 21 trophies in the 13 shows that it has been displayed in. Awards included Best Sedan, Best Engine Bay, Car of the Day and Peoples Choice.

On display with the Sydney Torana Club. To find out more about the club check out STC

 

 

 

Motor

A normally aspirated V8 motor was planned in keeping with the Torana's racing tradition. It also had to be different to the normal "four barrel" V8, put out over 500 reliable horsepower, and it had to be suitable to be driven legally on the street.

The motor that was chosen for power and reliability was a 350 cu in Chev V8 with Trickflow alloy heads and a Crane roller cam. This combination had been successfully used on speed boats and was capable of maintaining high power output over a lengthy duration. Induction was originally via a 750 Holley and Victor Junior manifold, but this was changed to a 8 stack Hilborn Electronic Fuel Injection unit, but more about that later.

Motor before Hilborn Injection was added:

 

 

The Trickflow alloy heads have 64cc CNC profiled chambers, dual valve springs with titanium retainers, ARP rocker studs and Yella Terra roller rockers. Valves are 2.01" inlet and 1.60" exhaust.

The Crane hydraulic roller cam has 234 degrees (inlet) and 242 degrees (exhaust) duration @ .050 lift, and valve lift of .558 (exhaust) and .539 (inlet). RPM range is 2800 to 6800. This was matched with Crane hyraulic roller lifters, Crow 5/16" chrome moly push rods and a Crow heavy duty timing set.

The motor is a balanced and blueprinted small block Chev V8 built by Autotech Engineering of Granville NSW. The 4 bolt main bearing 010 block was decked to 10.5:1 compression allowing the use of 98 octane fuel for the street.

 

 

 

The block was bored to 4.040" and fitted with a 3.750" Eagle stroker crank which brought the total capacity up to 384.6 cubic inches or 6.302 litres.

Motor componentry includes Scat rods, Speed Pro dished pistons, Chrome Moly rings, Clevite bearings, Miloden studs and freeze plugs, ARP bolts, High Energy oil pan, Fel-Pro gaskets, Romac 7" Steel/alloy balancer, Edelbrock two section timing chain cover, CSI high torque starter, MSD Pro Billet Distributor and Magnecor competition ignition cables.

 

 

Lubrication is Penrite SIN 5 SAE 5W-60 full synthetic motor oil circulated by a Clevite oil pump with welded pickup through a remotely mounted oil filter.

 

 

Temperatures are kept under control by a custom built Aussie Desert Cooler aluminium radiator, an Ice 2800cfm electric fan and a CSI electric water pump circulating Tectaloy Vplus coolant.

 

 

Engine Management

2 Engine management programs are employed, one for the street on 98 octane fuel and the other for performance work on 110 octane Martini racing fuel. Engine management computer program change is simply achieved by the flick of a "missile" switch. The "performance" program is designed to provide even more grunt through the midrange, whilst maintaining the top end power.

An EMS 8860 sequential motorsport computer controls the electric water pump, thermo fan, fuel pumps, ignition and injection. With such a demand on the electrics, and the necessity to provide a constant level of power to the computer, a Bosch 120W alternator with an integral voltage regulator was installed, and additional high quality earth and battery cables were fitted.

The engine bay has had all wiring, lines and hoses removed, the MSD "Blaster coil" and MSD 6AL ignition controller are positioned under the dash The radiator overflow bottle and horns are hidden under the front mudguards, and the alloy windscreen wiper fluid reservoir was placed in the boot.

The MSD Ignition Controller is a Capacitive Discharge unit capable of delivering multiple sparks to a spark plug, instead of the usual single spark. It also has a "smooth" rev limiter to protect the engine in case of missed gear shifts.

 

 

The EMS computer operates with 3D software and has data logging. Being lap top programmable, it can be tuned whilst being driven - this has been very useful for converting dyno horsepower into something that is street and track drivable. Accurate engine timing is relayed to the ECU by a Hall effect sensor taking its signals from the Romac crankshaft pulley.

 

 

Fuel System

The motor is fed by a specially imported Hilborn electronic fuel injection system that breathes through eight 55mm diameter intakes. The manual Hilborn system is used on sprint cars and results in over 800 horsepower from a small block Chev. The electronics that controll the Hilborn unit are able to "tame" such a high flowing system so that it is able to be driven on the street, and produce emmissions that comply with legal requirements.

 

 

In the past, 2TOUGH has been displayed at Car Shows fitted with tall 55mm intake "stacks" that do not contain any air filtering, as shown in the pic below:

 

 

For street and strip use the Hilborn manifold is fitted with a Custom Cold Air Box and Turbo Porsche K&N Filter. Built by Leon Sokalski of Performance Metalcraft, the cold air box sits up in the bonnet scoop and takes full advantage of the cold air that flows in from the high pressure area at the base of the windscreen. This set up provides a noticable improvement in power, particularly on cool days.

 

 

Service pic's - Chromed 55mm Hilborn ram tubes are visible inside the cold air box in the below pic (left). Hilborn manifold minus ram tubes is shown in the below pic (right):

 

 

A custom Performance Metalcraft 100 litre, street legal alloy drop tank feeds the fuel injection system through a Carter low pressure fuel pump into a surge tank mounted in the boot. A Bosch high pressure fuel pump is mounted behind the diff.(pictured below) and draws fuel from the surge tank which feeds the Bosch injectors in the Hilborn manifold via a Malpassi regulator.

 

 

Exhaust

A mandrel bent exhaust system was custom fabricated by Stuart Vale of Racers Choice. HPC coated 1 3/4" primary pipes feed into twin 3" merge collectors. The internal merge design can be seen in the below pic. This design reduces turbulence and improves the scavenging effect (hence power) by increasing exhaust gas velocity.

 

 

To achieve the required tuned length within the tight confines of the Torana's engine bay, the system was fabricated in multiple sections as shown below:

 

 

When assembled, the extractor system is bolted together by means of small metal tabs like those in the below pic:

 

 

This design enabled a complex extractor system to be routed through the engine bay and front end components, achieving good clearances as well as providing the ability to remove the extractors with a minimum of difficulty:

 

 

The remainder of the system maintains the 3" pipe diameter, and is of a "cross over" design. Twin free flow mufflers have been custom built to keep noise volumes within legal limits whilst maintaining very low gas restriction. This system resulted in an increase of more than 60 rwhp over the "off the shelf" system that was originally installed.

 

 

The exhaust system is 3 inch all the way through...

 

 

Drivetrain

Power is transmitted via a GM TH700R4 4 speed transmission.  A fully manualised valve body is currently being fitted, to maximise performance and reliability.   A new 3700rpm stall, TCE torque converter is also being fitted to replace the previous 2800rpm unit.  Changes are via a B&M Quicksilver ratchet shifter which enables clutchless sequential shifts to be made.  It also prevents missed shifts.  The transmission also has a dash mounted torque convertor lockup switch, and an extra large alloy cross-flow transmission fluid cooler mounted in front of the radiator.

 

 

A 3.5" custom thickwall tailshaft passes though a safety hoop onto a Jeff Holland custom built extra heavy duty diff. housing with Superior axles. Competition Warehouse boxed trailing arms fitted with nolathene bushes keep things tightly under control.

A Detroit TrueTrac 9" clutchless torque proportioning differential was chosen instead of a "locker" as smooth power-to-wheel transition is necessary for powering out of corners on the track. Even though fitted with 4.3:1 gears, the 17" wheels and 0.70 overdrive 4th gear means that 2 TOUGH can reach 260 kph (>160mph) at a safe 6,300rpm.

.

Body & Interior

The body retains the A9X theme and has been sprayed in two pack GMH "Sting Red", with "Brilliant Black" bonnet and engine bay. Clear coats over both colours enhance the shine.

 

 

 

 

The flares, spoilers and reverse bonnet scoop are all of original factory design.

Interior is A9X Torana with plush pile carpet. The B&M ratchet shifter and the UC Torana centre mounted handbrake and console can be seen in these pics.

 

 

The front Recaro seats have a pneumatic lumbar support system, and the rear seats were custom trimmed by Roman Autotek to match.

 

 

Autometer guages (including a calibrated electronic speedometer), Momo steering wheel and dual fire extinguishers complete the interior. Autometer tacho has a very handy shift light, manual overide "missile" switches for fuel pumps, water pump and cooling fan enables a good cool down protocol. Safety is enhanced with a dash mounted fused battery cut-out switch, and the sound system is by Chevrolet and Hilborn and is located under the bonnet. No other audio is necessary ;-)

 

 

An Optima "Spiracell" 800 CCA non spillable battery was mounted in the boot. The rear number plate hides the fuel filler, and is operated by a remote electronic (Ford) locking mechanism. The fuel surge tank, mounted behind the spare wheel together with it's associated plumbing, can just be seen in the below pic too.

 

 

Chassis

The body has been made rigid with a Hadfield chassis kit. The Torana's standard good handling has been enhanced with Koni gas shocks, K-Mac custom lowered heavy duty springs, custom made adjustable 24mm front and 20mm rear stabiliser bars and nolathene bushes all round.

 

 

Brakes

The braking system has been completely replaced by a custom system with stainless steel lines and braided hoses. The brake lines and proportioning valve have been hidden. The foot controlled parking brake has been replaced with a centre floor mounted handbrake which connects to 293 mm DBA slotted rear disks and colour coded WB Statesman calipers. These rear disks are the same diameter as the original A9X Torana's front disks. This setup enables handbrake application to get around tight corners :-) Try doing that with the foot operated unit!

 

 

At the front, 330mm DBA slotted and curved vane vented disks with 4 piston Brembo Calipers and custom alloy hats are mounted on WB Statesman stub axles.

Wheels & Tyres

17" wheels were required to clear the large diameter disks. Cragar Supersport were selected, 8" wide on the front and 9" wide on the rear.  These are fitted with 235/40/R17 Federal SS595's on the front and 265/40/ZR17 Falken 451's on the rear.  A second identical set of rear wheels wearing 275/40/R17 Mickey Thompson ET Street Radials is fitted when 2TOUGH goes to the drags.

 

 

2TOUGH at the drags  - Best ET 11.67 secs @ 115 mph: 

 

 

 

 

2 TOUGH at home.....

 

 

2 TOUGH at the gym .....

 

____________________________________________________________________________________

2 TOUGH Show History for 2008:

 

South Coast Holden Owners' Club Annual Charity Car Show Kembla Grange, NSW June 2008 Trophies: Best Holden Sedan

 

 

Sydney Torana Club's Annual Show Rouse Hill, NSW November 2008 Trophies: Best Overall LX, Runner Up: Best Sedan, Best Paint and Torana of the Day.

________________________________________________________________________________________________________________________________________________________________________________________________________________

2 TOUGH was featured in Street Machine Magazine July 2005 edition ...

 

 

 

 ________________________________________________________________________________________________

2 TOUGH was also pictured in Street Machine Magazine Jan 2009 edition ...

...............................................................................................................................................................................................................

2 TOUGH was featured in Sydney's Daily Telegraph 11 Jan 2008, with previous owner Ian Williams. Click on the following link to check out Ian's awesome HSV Clubsport: HSVLS3

 

 ................................................................................................................................................................................................................

Below are pics of 2TOUGH parked with Howard Bells legendary LITRE8.  For more on this awesome Torana, click on the following link: LITRE8 Virtual Garage

         

...............................................................................................................................................................................................................

Previously engineered and registered in Queensland, 2 TOUGH has been engineered to the much tougher NSW requirements, and was NSW Street registered in 2005.

 

 

...............................................................................................................................................................................................................

2 TOUGH in Bed .....

 

 

...............................................................................................................................................................................................................

CREDITS

Ian Williams: For having the vision and persistence to make 2TOUGH what it is today - thanks Ian!

Engine building and management systems, Fuel injection and dyno tuning: Autotech Engineering, 18-20 George Street, Granville NSW Australia 2142 Phone (02) 9897 1378
www.autotechengineering.com.au

Body, Paint & Interior: RSV Repair Special Vehicles, 12 Berry Street Granville NSW Australia Phone (02) 9637 8349

Email Me
If you wish, you can email me direct at 2tough.torana@gmail.com and I will get back to you as soon as I can.

Thanks for visiting this page, hope you liked our project, and we wish you well with yours.

Page 2 shows a few "before and after" the rebuild comparison pics ...