4engines

TR7 Frenzy

v8_vs_16v

Extract from a article of the magazine ‘Practical Classics’, November 1995.

Article featured in WWWedge Ezine no. 8 (July 1998).

Writer: David Lillywhite

0.2 Moderator: I'm not going to quote the entire article just the interesting (IMHO ;-D) parts.

"Who says it's only early Triumph TRs that give you a hairy chest? It doesn't take much to beef up a TR7, as these four very different examples prove. David Lillywhite reveals his chest wig.

After years of abuse and mockery from owners of 'real' Triumph TRs, enthusiasts of the TR7 are fighting back. 'Fine', they say to the claims that their cars aren't powerful enough, and don't count as classics, 'if they're not classics then no-one's going to moan when
we tune and modify them, are they?'

Probably not, especially when you consider the cheap prices asked for TR7s. Even a near immaculate fixed-head model won't fetch much over 2000 GBP, and you can buy decent convertibles for 3000 GBP or so. Thankfully the bargain basement values haven't resulted in the Kev and Tracey brigade taking the TR7 as their own. Most have been subtly tweaked by sympathetic owners simply to overcome the model's inherent shortcomings, discussed later in this feature. If you don't believe that, take a look a the four we have here.

We start at midly modified, go on to a 16-valve Dolomite Sprint engine conversion, then a Rover V8, and end up with an interpretation of how the TR7 could have been developed to sell in the 1990's. Not one of these machines would be turned away from a classic car show.

The difference between the four cars on the road are staggering, but before getting too excited about them it's important to understand the strengths and weaknesses of the standard TR7. To do that, forget everything you've heard about them -- the loudest voices have always belonged to TR6 owners, and that's one car the TR7 is absolutely nothing like -- hence the TR enthusiasts' disgust when it was launched in 1975.

No, where other TRs are cast in the true mould of classic British sports car -- buckets of raw power, lots of noise, rock-hard suspension and wet-weather handling as hairy as their owners' chests -- the TR7 is more civilised. It's also stronger, much quieter and arguably less exciting, but significantly more comfortable and safer than its prececessors. It healthily outsold the TR6 by over 20,000 units.

What the TR7 did have in common with its earlier brethren was a fair share of shortcomings -- suspension was soft, brakes faded with hard use and the 2-litre overhead camshaft engine ran out of breath a little early in its rev range. Coupled with an appaling build quality
in its early days, the TR7 was scorned for years.

THE MIDLY ONE
The modifications to this car are basic. A sports exhaust system and manifold, plus K&N air filters, allow the engine to breathe more easily, particularly at the top end of its rev range, releasing an extra 10bhp on top of the standard engine's 105bhp (home-market version). On the suspension side, the car is equipped with lowered uprated springs, Spax adjustable dampers and harder suspension bushes. Harder front discs pads (Mintex M171s) reduce fade, but the rear drums are standard.

midlyone

The changes are immediately apparent on the road. While a standard engine feels like it's being trashed when you push it, this modifiedunit is more willing, without losing any of the low-down torque that makes the standard TR7 so good to drive.

Unmodified brakes don't worry Steve Gales, owner of the Sprint-engined TR7, though, and for reasons other than a monomanical refusal to slow down: 'Mine are standard,' he explains, 'I just replaced all the parts, and they're prefectly adequate.' The same
goes for the suspension.

Steve has owned his silver convertible for 12 years, but didn't fit the Sprint engine until five years ago. 'I fancied more performance, but didn't want the hassle of fitting a V8', he syas. Those 16V extra valves improve the flow of gases into and out of the engine, increasing power output to 127bhp (against standard 105bhp). In a TR7, that 127bhp is usually improved upon by around 10bhp because the Dolomite's restrictive cast iron exhaust manifold won't fit, and a more efficient purpose made tubular manifold (sold by specialists)
has to be used.

The Sprint engine is so more responsive, more so even than the modified TR7 engine, with enough power to make extremely rapid progress. It's still relatively economical despite the high power output, as Steve proved by winning the TR Register's economy run
(29mpg round a variety of town and country roads).

v8

But that's enough of four-cylinder engines. Now we're onto the
man-size V8 car. This V8 converted TR7 convertible is a little
special in other ways, having been built to celebrate the TR
Register's 25th anniversary. S&S Preparations (UK) provided their labour - 700 hours - for nothing, and most mechanical parts at cost price. Rimmer Brothers (UK) supplied panels free of charge.

Throughout the summer, the car has been on the show circuit as a raffle prize (presented at the National Classic Motor Show). The car has new sills, wings, floors and doors and been converted to virtually standard TR8 specifications.

Driving the V8 after frenetically revvy four-cylinder cars was almost a disappointment for the first few minutes. There's little gearchanging needed, the engine will pull from tickover even in fifth, and very little effort is needed to drive the car smoothly. It seems so relaxed, even around the twisty lanes that in previous cars had caused extra-ordinary rushes of adrenaline.

It takes a while to sink in that you're travelling just as swiftly. Sure, the excitement levels are lower, but you could keep up rapid progress on any kind of road for long periods without feeling tired or stressed.

Of all the cars, this is the one that felt the most solid, but then it's the one that has covered the least number of miles since being rebuilt.

Now close your eyes and imagine that British Leyland (now Rover Group) had continued producing and developing the TR7. Simon Carr and Steve Wilcox of S&S Preparations did just that, and the yellow convertible is their interpretation of a TR7 for the 1990s.

It looks very different, to the extent that it needs a least a second glance from many to work out what it is, yet the body modifications certainly don't look out of place. This TR7

20v16

would give a Toyota MR2 or Mazda MX5 a run for its money in a beauty contest, and in performance terms it might even outrun them - under the TR's retina-burning yellow bonnet there's a modern 2-litre, 16-valve fuel-injected Rover 820 engine. Inside, luxurious leather trim and Jaguar quality carpet abound. Wow, what made you do it Simon?.

'We just wanted to show what could be done to a TR7 - it would cost a customer around 5000 GBP to have one of these built by us, and what new car can you get for 5000 GBP? A Skoda!'

It wasn't an easy conversion, despite Simon and Steve's years of experience with TR7's. Engine mounts were specially fabricated and the unit was matched to the TR7's five-speed gearbox via a Sherpa van clutch and bell-housing, but it was the fuel-injection system's plenum chamber that caused the most trouble, having to be extensively modified to fit under the bonnet.

As a everyday sports car, this conversion would be hard to beat. Performance betters the Sprint's, with 150bhp on tap and around 10 percent more torque. A modified injection system and K&N air filter are responsible for the increase of Rover's original 136bhp.

Keep the revcounter needle swinging towards its red line and you'll fly. Okay, the V8 is far more relaxing, but this is serious fun. Heading back to S&S through the twisty Lancashire A-roads the other three cars got left behind; not so much due to the yellow car's performance, but more because of Simon's demonic shouts from the passenger seat. 'Don't brake, this is an 80mph corner,' or 'rev it harder, it pulls well at the top end', are the ones that stick to my mind.

TR7's were fitted with racks of 3, 3.8 or 4.5 turns lock-to-lock. If you can put up with heavier steering, the 3 turn item is the one for fast cornering. With Compomotive split-rim alloy wheels - 15in x 7in, compared to a standard TR7's 13in diameter - and low profile Bridgestone tyres, there's no shortage of grip. The suspension has been fitted with harder bushes, 200lb springs (standard are 90lb) and Spax dampers, and the brakes have vented discs, plus TR8 rear brake cylinders. Next in line is a rear disc conversion, the latest development of S&S.

Some will hate this car, others will love it, but you can't ignore the attention it attracts wherever it goes - and that includes several classic car shows. Like any TR7, it's perfectly suitable for all-year-round, everyday use, but it stands out from the dreariness of modern day saloons and hatchbacks.

Watch out for the TR7, it's teetering on the edge of becoming the definitive modern classic.

David Lillywhite.