TRE Motorsport 911S/T - Agent Orange

This early 911 has a real sting in its tail.

Date Published: 11 Sep 2018
TRE Motorsport 911S/T - Agent Orange

Long before the Cayenne and Panamera era, it was widely acknowledged that Porsche aficionados fell into either the air-cooled or water-cooled camps. Today however, we are also seeing early and late model camps forming within the ranks of 911 enthusiasts.

A few years back, the soaring values of the 1973 Carrera RS 2.7, prompted an explosion in replicas of this iconic lightweight homologation model, with 911SC and Carrera 3.2 models being used as the donor cars because of their relatively low values and galvanised bodyshells.


Although original 911RS and RSR values have further skyrocketed as people flee the banks as a place to park their cash, the RS replica mania has now slowed down somewhat. Part of the reason for this is that many enthusiasts keen on the smaller and lighter early ‘70s cars, have now fixed their sights on even earlier ‘long hood’ competition models like the 911R, S/R and T/R as their inspiration.

These late ‘60s, early 70s models are iconic in their own right because they too are covered in competition glory. Making their mark in European race and rally events in the hands of champion drivers like Bjorn Waldegaard, long before the eventually more famous 911RS was even conceived, is certainly something to be proud of.

One man inspired by the image of these pre-RS competition 911s is early Porsche enthusiast, Robert Abbott. He decided that this orange 911S/T replica was to be built out of the fourth car he acquired in his seven model early Porsche collection, which includes a 356 speedster and a ‘68 911S.


Originally a 1971 911T that left the factory in the same signal orange colour it wears now, this car already had four Cibie Pallas lamps mounted on its bonnet and front wings when he acquired it.

I was after a mix of 911R feel and performance combined with street oriented comfort,” Rob explained, and with this in mind, he went to see early 911 specialist Dave Bouzaglou of TRE Motorsports in Van Nuys, a suburb of Los Angeles.



Dave, who is one of the old Mulholland racers, stripped the car to bare metal to assess its condition, which turned out to be not bad. Once they had agreed that the goal was to construct a car that could have been an interim competition model between the 1971 and 1972 S/T models, the work began.

To the expert, the clear visual difference between this car and a factory S/T is the lack of the distinctive front lip spoiler fitted to the seven factory built cars. Other than that, the external oil cap on the right rear wing and fuel cap in the middle of the bonnet are a homage to the 911R and the ultra light 70/71 factory backed S/T cars that competed in the Tour de France.



The bodyshell was taken to Kundensport, in Camarillo, California for installation of the TRE supplied S/T steel wheel arch flares. Kundensport also reworked the original steel bumpers into the S/T look before carrying out the bodywork preparation, painting and exterior re-assembly. They fitted the client supplied ‘72 oil tank, and modified the fuel tank to take the race-style through-the-bonnet filler.

TRE also supplied the aluminum engine lid, balsa reinforced clear framed front lid, bladed gas cap and filler neck, ST/RSR front welded-in strut brace, oil tank cap and neck, full weather seal kit, lenses and lights, and the lightweight, cross-drilled chrome door handles.

The completion-style front and rear lid hold-downs for front and rear are also TRE parts, along with the drilled, lightweight engine lid hinges. The unusual Talbot 300 door mirrors had been saved by Rob for just such a project, and suit the car well.

Being forged, the factory Fuchs alloy wheels are really light and strong, but original early 15-inch wheels are now like gold dust, and probably just as expensive if you can find them.

So a set of 8.0J x 15-inch Fuchs wheels were given to Harvey Weidman of Weidman’s Wheels in Oroville, CA, to turn into 9.0J and 10.0J x 15-inch replicas. These perfectly reworked wheels were then shod with sticky 18/60/R15 and 26/61/R15 Michelin TB Course intermediate compound tyres.


While the shell was away being transformed for its new life, the motor was undergoing its own rejuvenation. The original 911S/T was powered by a highly- strung 2.5 litre flat six. Rob chose to go the bigger displacement route with a 1980s Carrera 3.2 motor, which is not only pretty bulletproof, but also a much better partner for life in today’s traffic.

With a swept capacity of 3,164cc from a 95.0 x 74.4 bore x stroke, the stock Carrera motor has a lot more inherent grunt, and feels especially potent when asked to move a car nearly 250kg lighter than its original partner in crime.


The 3.2 litre motor was left stock internally, but its ability to breathe and rev were helped by a list of bolt-on goodies that include a lighter aluminum flywheel, aluminum pressure plate, 2.7RS distributor, suitably-jetted triple throat Weber 40 downdraft carburettors, SSI aluminium exhaust manifold/heat exchangers, and a Dansk silencer modified by TRE to replicate the period three-outlet rally exhaust. Once installed, the motor is visually complemented by TRE’s clear shroud that replaces the surrounding factory tinwork in the engine bay.

The transmission is a period 1971 five-speed 911 box with dogleg first gear, reworked to handle the extra output of the 3.2 litre motor. While the 240bhp and 338Nm of torque on tap in this configuration may not sound like a lot by today’s standards, you have to remember that this car weighs less than 900kg.

The suspension was uprated with period correct Koni struts and hydraulic dampers. Then 930 Turbo 26mm diameter torsion bars at the rear were paired with the stock 18.8mm ones in front.


This is the set-up used by the much heavier 930 Turbo, which also has a greater rear weight bias, so the fine-tuning of the handling is done with a 22mm diameter Weltmeister adjustable anti-roll bar on each axle to rebalance the relative front-to-rear roll stiffness. Finally, the brakes were uprated using 911S alloy calipers.

When you do a backdating project like this you have to make up your mind if the car is only going to look like an S/T from the outside, be a near perfect replica inside too, or have a totally custom interior.

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