If a standard MG RV8 isn’t quick enough for you, then here’s how to give yours more sting in its tail

In theory this MGB with the most shouldn’t need a lot of improving. After all, it already comes with a 195bhp V8 engine, five-speed transmission and a fully re-engineered and modernised suspension – stuff the original MGBGTV8 fully deserved more than 40 years ago.

Sadly, the RV8 also suffered from typical Austin-Rover (nee BL) under development when it left the factory, and that’s why some suitable tweaking can make this inherently good car even better.

BEFORE YOU START

Many of the cars now on the market have been brought back over from Japan and as you’d expect from a car a little over 20 years old, rust isn’t, and shouldn’t, be a major problem.

Rather lack of use is the RV8’s biggest enemy, with the most likely victim being the Austin Ambassador- derived brakes. The unique callipers have a wider spacer in the middle and expensive to replace with OE parts, so why not uprate at the same time while you have the chance?

That trusty Rover V8 is so well known and tunable. Again, a lack of use together with infrequent oil changes (use a top 10W/40 semi synthetic or mineral lube such as Mobil 1 or Castrol Magnatec) gums up the hydraulic tappets leading to camshaft wear while the exhaust manifolds are prone to blowing their gaskets.

The Land Rover gearbox and axle are generally sturdy but the limited slip differential can wear and costs around £1000 for a thorough overhaul.

HOTTING ONE UP

If in a decent state of tune and health, a standard MG RV8 churns out a pretty genuine and, for many, perfectly ample 195bhp, plus a diesel-like 234lbft of torque. A sprint to 60 in 5.9 seconds and 140mph is adequate for road use and if set up right (a session on a rolling road achieves this brilliantly) is hard to improve upon without spending a lot of money and effort.

Unlike the earlier BGT V8, the RV8 engine, is a modern installation boasting engine mapping and electronic fuel injection. As a result, you can have its ECU re-chipped for a tad more grunt but, more importantly, a sharper response for around £350, from the likes of Superchips. Some owners report good experiences of the RPI Optimax alternative which increases torque and yet can also improve fuel consumption at the same time.

RV8 specialist Clive Wheatley reckons attending to the exhaust set up instead is the best first step. As MoT regulations state that limited production cars do not need catalytic converters, you can legally remove the cats (which may well be coming up for replacement anyway), gaining an extra 3bhp and saving the ultimate cost of their future replacement. However, MoT testers are not all in total agreement over this so check with yours first…

Wheatley recommends fitting a stainless single box exhaust in its place, complete with larger tail pipes, which, if supplemented by a new ignition amplifier to give better sparks along with a set of sports HT leads (£50.55p), will yield no less than extra 20bhp as well as giving a nicer exhaust note into the bargain; budget on £297 or £333 for a double system. Simpler separate pipes to take into account the cat removal cost £100 per bank.

Assuming the engine is in good shape you’re now looking at around 210bhp which is ample for road use and for motorsport use like sprinting and hillclimbing. If you demand more then look to the camshaft, which can be replaced with a racier type for around £300 (plus fitting). Be careful here as while a wilder cam will give more top end power, it will be at the expense of the excellent low and mid-range torque. In the real world, if you never use more than 4000rpm on the road then you’ll be worse off all round and be poorer financially!

After this, any tuning becomes rather more expensive and beyond most folks’ budgets. Wheatley believes that because the RV8’s engine originally derived from the Range Rover, it was never meant for ultra high revs and so never properly balanced by the factory. If you intend an engine rebuild, he suggests a full balancing act, including crank, flywheel, pistons, rods, clutch pressure plate, as well as polishing and crack-testing the conrods. Done with care, and perhaps taking off around 5-6lb of weight off the flywheel by skimming, a smoother, more responsive unit will ensue. However, while it will rev better between 5-6000rpm and yield perhaps up to 270bhp with a camshaft change, costs could be as high as £3000 so you need to think hard about this modification.

This stalwart of an engine also figures in later Range Rovers, and certain TVRs of course, in larger capacities, such as 4.2, 4.6 and a full 5-litres where here, TVR wrung out a healthy 325bhp. TVR units can be fitted into the RV8 with some mods – it’s not difficult as the engines are inherently the same. Wheatley adds that RV8 heads can be skimmed in line with TVR practice but doesn’t really recommend it just for road use cars. Cooling is not generally a problem but as original radiators are 20 years old now can do with replacing for peace of mind. Clive can offer a high efficiency exchange unit for just over £200.

HANDLING THE POWER

In comparison to the original MGB and BGT V8, the revamped RV8 doesn’t handle at all badly, but would have been better straight out of the box if Austin-Rover hadn’t skimped on the job by using cheap low spec-Koni shock absorbers. These are the first upgrade replacements. Wheatley initially offered upgraded Konis but then, in conjunction with SPAX, he developed dedicated Krypton gas-filled types, specifically tuned for the car. As you can appreciate, at more than £520, plus fitting, they are not the cheapest shox around, but as we said, they are tailored for the RV8 plus come with 28 adjustments for fine tuning for road and track work, and best of all, this can be done in situ.

After this another must-do is to fit polyurethane bushes to the bottom wishbones, rear anti roll bar, spring shackles, anti-tramp bar and front cross member. Total cost for this little lot is some £350, but it’s money well spent as it not only tightens up the chassis no end but also improves the ride, making it smoother and more supple enthuses Clive.

While MG did a good job improving such an ancient chassis design, they could only go so far within its inherent limitations, especially that leaf sprung rear. Parabolic springs are already fitted and are hard to improve upon if in good order.

The ultimate fix has to be the Hoyle independent rear suspension. Wheatley has fitted this Ford Sierra-derived set-up to several cars and while the cost is around £4500, the transformation is amazing and justifies the expense. “If I was keeping a car, I’d have it fitted”, stresses Wheatley.

A cheaper upgrade are poly bushing the rear springs, anti roll bar and anti tramp bars to the axle at well under £150. At the other end you may decide upon power steering as it was never offered when new. The EZ Holland electric conversion for around £2050 (including fitting by Wheatley), is the answer as Wheatley is particularly impressed with its quiet, precise operation on the cars he has converted.

The standard disc drum set up suffices so long as the brake fluid is regularly changed; it improves pedal feel no end as do braided pipes. Wilwood rear disc kits, are available but we also understand that Sherpa van rear brakes are bigger so may be a good cost-effective upgrade.

Wheatley reckons low profile tyres markedly improve the general handling and make the RV8 a proper sports car. He has 17inch alloy wheel designs which include a Minilite-style and an original-style starting from £173 each. Currently, the Continental Sport Contact 2s seem to suit the RV8 well (Khomos are a good cheaper alternative) and are a popular choice among MG RV8 enthusiasts adds the V8 registrar, part of the MG Car Club.