Jonty's MR2 Turbo

Brakes & Suspension

Brake fluid

The standard brake fluid in an MR2 Turbo is of DOT3 specification. DOT3 and DOT4 are glycol-based fluids and absorb water. DOT5 fluid is silicon-based and doesn't. As DOT3/4 brake fluid absorbs moisture, its boiling point decreases. As DOT5 doesn't absorb moisture, its boiling point will remain relatively stable. On the flip side, DOT3 is cheap and easy to find whereas DOT5 is expensive and harder to get hold of.

During periods of prolonged braking, or simply driving the car hard and using the brakes to match, a driver can inadvertently boil his brake fluid as the temperatures rise and the fluid bubbles into gas thus impairing braking ability. Gas (air) compresses too easily which is why we use fluid.

Thankfully, there is a good compromise between DOT3 and DOT5 -- DOT5.1, which ironically is glycol-based. The main advantage of DOT5.1 fluid is that it has a higher boiling point (dry and wet) than DOT3 or 4 -- its dry boiling point (approx. 275 degrees C) is almost as high as racing fluid, and its wet boiling point (approx. 175 to 200 degrees C) is much higher than racing fluid. It's also compatible with rubber components (so doesn't encourage premature wear), reasonably priced within a performance motorist market, and found with just a little looking.

Delphi Lockheed's Ultra DOT5.1 fluid, for me, is a sensible upgrade path given that my MR2 is sometimes subjected to hard driving. Comma also produce a similar fluid which is of a similar price and which I've used previously.

NOTE: When changing brake fluid to a different DOT specification, ensure the reservoir cap is labelled accordingly.

Discs and pads

Modified car or not, brakes are a fundamental part of a vehicle -- there's no point in moving forwards if you can't stop! The MR2 is well known for having excellent stopping power, even in standard form where the set-up is fine for fast road use. Given the opportunity to uprate the stopping power (due to warped discs) I've invested in some Black Diamond and Pagid products.

Having replaced both the front calipers during my MR2's ownership the front discs are currently of the Black Diamond 12-groove variety with Pagid fast-road pads. Previously the discs were of Black Diamond's Combi flavour (grooved and drilled) but with suspicions arising regarding reliability and heat, having only been used for 6,000 miles I've left the drilled element behind.

In whichever guise, Black Diamond discs offer ferocious stopping power encompassed with extra cooling and instant response when used with a set of Pagid fast-road pads. The jury's still out on the reliability of the combination discs but my car's always stopped superbly even with a set of Blue Print plain discs still on the rear (with Pagid pads).

NOTE: Due to a NSF hub problem (fixed) the front discs are now standard units. All previous discs were subject to adverse wear because of this problem.

Shock absorbers

Even in standard form Toyota was on the ball when it came to its choice of shock absorber, selecting Bilstein as its official supplier. Although the standard ride is quite firm and positive there's always room for improvement so when a front strut began to degrade I decided to replace all the shocks with a set of aftermarket Bilstein Sport struts from Fensport -- a worthy upgrade over the standard units.

At the time of fitment it was evident the faulty shock absorber had failed completely, with most of the oil having escaped and there was no remaining pressure. The new ride quality certainly appreciates the use of 4 struts compared to 3 and working with a new set of springs (see below) the ride is far more positive.

Springs

Like the shock absorbers, standard springs work very well to give the MR2 a very good suspension setup in stock form. When work was to be carried out on the suspension the decision was made to upgrade the springs at the same time. Made and supplied by Fensport, a set of 20% uprated and -20mm lowering springs were fitted.

As per the Rev2 the ride height was reduced for the MR2 however another 20mm off and the car sits even better, especially at the front which in my opinion had always looked a little high. Twinned with a new set of Bilstein shock absorbers (see above) not only does the car's stance look good but it handles perfectly.

Braided brake hoses

In standard form the last 12in of brake line is made from rubber as opposed to metal which occurs throughout the rest of the system. Braided brake hoses are a popular upgrade as high quality hoses reinforced with stainless steel over braid are less likely to expand or burst under braking, even in extreme conditions.