Plans to upgrade the engine began prior to the accident. Don’t get me wrong, I loved the crossflow. It sounded fantastic, had great throttle response, a strong low-end, and really began to scream – both aurally and from a seat-of the-pants perspective – as the tachometer swung past 4000 rpm. However, the gas mileage was pretty poor for the power output (~22 mpg and 120hp), it was a bit rough, and it lacked ultimate oomph.
After investigating many options,
ranging from modifying the crossflow with an alloy head, steel bottom end, and fuel injection, to installing a tuned Zetec, I finally settled on the (then) new Duratec option. Raceline was just putting the conversion parts into production and I as able to source a new engine for a ridiculously low price. The Duratec was much lighter than a Zetec, yet it promised the potential for far more horsepower. I was sold.
The accident, however, had changed things. I had anticipated performing just an engine swap, but suddenly I was faced with the task of also doing a rebody. Although Peter Egan praised my car’s build quality when he wrote about it for Road & Track in March 1996, I was less impressed. Magic marker lines were still visible on parts of the body where fiberglass had been removed, the carpeting was fit poorly and was of cheap quality, and the whole car had an air that is was assembled to a price point. After 2 years of ownership, I had also decided that I wanted to take the car in a slightly different direction: from vintage feeling sports car to a modern interpretation of the Chapman’s original Seven
concept. I wanted cutting edge components, less weight, and for lack of a better term, a purer driving experience.
The changes made during the build were profound. Virtually every component was replaced with a nod towards improving some aspect of performance, be it acceleration, handling, or braking. The only items that carried over unchanged were the frame, fuel tank, drive shaft, rear suspension arms and calipers, front & rear rotors, front & rear
uprights, and windscreen & pillars. Virtually everything else was either replaced or modified.
The end result is a completely different car. When it was tested in Road & Track, it had about 115-120hp (the claim was 145hp, but it put out just 96hp at the wheels on a Dynojet.) and according to their scales weighed 1405lb. Today it has closer to 210hp (174hp at the wheels on a more conservative Mustang dyno) with more torque at 1500rpm than the crossflow put out at peak, and the weight with over ½ tank of fuel is down to only 1223lb. That last change is worthy of more detail.
As I have discussed elsewhere in this website, I am a big fan of Colin Chapman’s famous mantra “add lightness.”
Carving weight out of a car improves everything about it: acceleration, braking, handling, fuel consumption, total load of Murphy’s Irish Cream Stout it can carry without bottoming out, etc. When the decision was made to rebuild the
entire car and replace the engine with the Duratec, I decided to get the car’s weight down a bit further to really shake things up.
First off, the Duratec with aluminum bell housing and Direct-to-Head Throttle Bodies would cut about 20-30lbs from
the front end. Second, going with CAT Motorsport’s alloy front hubs, and 4-pot calipers, would shave off another 15lbs. and third there were the ultra light MOG carbon fiber seats… Okay, so now you see where this is going.
In the interest of research, I bought an accurate scale that records up to 30lbs. and began the process of weighing
old parts as I remove them and new parts as they arrive from vendors. Unfortunately in the chaos that accompanies
moving into a new house I misplaced a piece of paper where I had logged many of the weights, so the list in this spreadsheet is not complete, but it does give a sense of where weight was saved. How much weight? Well when the car was in Road & Track, they listed the weight as 1405lb. I am not sure how much fuel was on board (and they never returned any of my e-mails on this subject, despite many years as a subscriber - the bastards!) but suffice it to say, the car is now much lighter.
After the rebuild I had the car corner balanced with ~4 gallons of fuel and it tipped the scales at 1239 lb. I later made some additional changes that increased the weight by 6 lb. (rear wheel spacers at 2 lb/ea and a heavier duty fan that was 2 lb heavier), and others that shaved over 22 lb (3-1/4 lb savings from the plastic valve cover, 5lb. savings from the Protech alloy shocks, 11 lb moving from a PC680 battery to an EVO2 LiFePO4 battery, and 3-1/4 lb from the
removal of the upper shock mount truss). So the weight should be down to about 1223 lb.