Upgrades for SP250s

Daimler Dart
The cars we love were developed in the fifties when motoring in the UK was rather different to today. Traffic was less dense and slower making the demands on brake and cooling systems far less. We drove on spindly cross ply tyres requiring less steering efforts and electronics were often a weak link. Whilst some purists require their classics to remain the way they rolled off the production line, more and more the requirement to add reliability and reduce driving efforts is coming to the fore. However the majority of upgrades we fit can be easily reversed to production standard - especially useful when the time comes to sell.

Rack and pinion steering

SP 250 rack and pinion steering
By general consensus, the steering is one of the least impressive features of a Dart. It is extremely heavy, especially on wider radial tyres. It tends to be rather vague and it requires rather too much attention to keep it serviceable. It also has a rigid steering column and an underslung steering box which was vulnerable to low kerbs, potholes and the like. Over the period of several years, I have seen numerous rack conversions ranging from competent to downright dangerous. I therefore set about developing a system based on Triumph Spitfire components. I like to think Edward Turner would have approved of this as he frequently raided the Triumph car and motorcycle parts bins for bits! The SP250 side lights for example come from a Triumph motor bike! I have paid a lot attention to reducing bump steer, which is an issue with many conversions, and I also use the column mounted switch gear to control headlamp dip, direction indicators and overdrive when fitted. I use a period Derrington wood rim steering wheel with a centre horn push which I had commissioned by Moto Lita as this wheel was used by the Daimler factory as an option. Recently Spitfire racks have been hard to come by and many are beyond renovation. So I have taken the plunge and commissioned the development of a bespoke column. Still based on the Spitfire design, the RGR column uses thicker metal for rigidity and incorporates needle rollers to reduce "stiction." I shall be fitting the column to my SP250 and, if satisfied, we will build the first batch shortly. The new column will accept all Triumph switchgear and shrouds. Fitting rack and pinion steering necessitates discarding the metal, engine driven fan (there is insufficient clearance between the fan and the rack} and moving to an electric fan mounted on the radiator. This is electronically controlled providing reassurance when you're caught in those summer traffic jams. See price list.


SP250 rolling chassis at NEC
For me, this is one of the must-haves particularly if you use the car for touring and use motorways. The Laycock de Normanville overdrive operates on 3rd and 4th gear and gives you around 25mph per 1,000rpm in overdrive top. The reduced engine rpm improves fuel (and oil) consumption, reduces noise and places less demand on the cooling system. What's not to like! We need to put a small bulge in the gap transmission cover to accommodate the slightly altered gearbox profile but this is not sufficient to require new carpeting. You also need to consider the o/d switch location. If you have the Triumph steering column, there is provision on the right hand side of the column to install a Triumph switch (see rack & pinion upgrade page.) Otherwise you can install a dash mounted switch such as that used on an MGB.

Daimler aficionados may be interested to know that whilst the availability of overdrive as an option was mentioned in the 1959 SP250 launch material, it was never listed as an option after launch and records show that only two cars were built with this feature. Curiously, one of them was exported to the West Indies; an area I would never have thought of as "overdrive territory!" See prices.

4 pot calipers

SP250 billet aluminium front brake caliper
The standard brakes on a Dart are so good many drivers will wonder why they need upgrading. But the high speeds available to Dart owners on today's motorways are far in excess of roads in the fifties when this car was conceived. The front brakes can comfortably provide greater retardation without unbalancing the brake feel. We started our upgrade journey with 3 pot calipers borrowed from the E-Type parts bin but now have gone one stage (or do I mean pot) better with dedicated 4 pot calipers made for us in the UK. These calipers, made from billet aluminium, provide significantly increased pad area and seem less susceptible to squeal than the standard set up. They are supplied complete with pads. They are a straight replacement for the standard calipers however sometimes when fitting replacements it is necessary to shim them in order to centralise the caliper with the brake disc. I have had some shims manufactured and can supply these if required. See price list.

Telescopic rear dampers

RGR telescopic rear suspension for Darts
RGR rear suspension upgrade for SP 250
I have now sold approaching two hundred rear suspension conversion kits literally all over the world and have been very pleased with the favourable comments I have received. Some people keep the dampers on a soft setting for improved ride quality whilst others crank them up hard and enjoy the handling benefits. The choice is yours! I designed the system to ensure the dampers are vertical, that they can be adjusted without removing wheels and that the upgrade is reversible should the car be sold to someone who wants originality. There is no welding or hole drilling required so it is a project that can be installed at home although you need to be confident that your rear springs are in good condition otherwise you will not obtain the full benefit. It is also prudent to ensure that the front suspension is working effectively if you are seeking handling improvements. I supply this upgrade as a kit with a full set of hardware and fitting instructions can be accessed here. Recently Spax have provided bespoke dampers especially for RGR. They function identically but are now finished in black as opposed to the green/yellow pictured which is more in keeping with Daimler values. See price list.

Stainless steel exhaust manifolds

Stainless exhaust manifolds for SP 250
I didn't get these manifolds made simply to improve performance (though they do) or to improve the exhaust note (they do that too) but chiefly because the cast manifolds are in short supply. The saloon exhaust, which are plentifuI, exit to the rear of the engine rendering them unsuitable for the Dart whose exhausts exit in the middle of the block on both sides. I have them on my own SP250 and can confirm that they look great and perform very well indeed. I can also supply this as a complete, large bore stainless steel exhaust. See price list.

Diaphragm clutch

V8 diaphragm clutch upgrade
This is borrowed from an Austin Healey 3000 but works so well that you would think it had been purpose-built for an SP250. I use the SP250 clutch fork which accepts the AH3000 release bearing. We also have to skim the flywheel and move the locating pegs. The hydraulics are unchanged. It may not be the most exciting upgrade but the diaphragm pressure plate addresses a weak link and the much reduced pedal pressure adds considerably to comfort when crawling in stop-start traffic.I have been fitting this conversion for around 10 years and some of my customers have now completed many thousands of miles without issue. I'd say that if you need to take the engine out for any reason, this is a must-have upgrade.

Sun visors

SP250 sun visors
It's inconceivable nowadays that you would develop a car without sun visors but that is exactly what Daimler did. However a quick raid of the AC parts bin provides an attractive and functional alternative to driving with your hand in front of your eyes! These fit the windscreen frame and can be fitted without having to drill any holes or alter the frame in any way. They can be used with both soft and hard tops and are available in blue, red, green and grey. See price list.


Dart seat belt upgrade
Driving a car without seatbelts is an uncomfortable experience for many drivers. Wearing them been a legal requirement for front seat occupants since 1983, so to most people, buckling up is second nature. Because of the age of the car, there is no requirement by law to install seat belts in an SP250, but if they are fitted, you must wear them or face prosecution. The system we install is provided by third parties and has never been crash tested under controlled conditions, so its efficacy cannot be assumed. The system relies on steel hoops which are bolted around the rear wheel arches and the transmission tunnel to provide two mounting points while the third point bolts into the chassis. The belts can be provided with a variety of webbing colours either as static or inertia reel.

Aluminium fuel tanks

Aluminium Dart fuel tank
UK made especially for us, the only difference between this tank and factory one is that it is made from aluminium which won't corrode and is ethanol proof. I commissioned this tank because I found that many replacements were of very poor quality and in some cases, simply didn't fit! Your existing sender unit, fuel filler cap and petrol reserve fittings drop straight in making this tank straightforward to install. See prices

Brake servo

Dart brake servo upgrade
When the SP250 was launched you could say that the steering, clutch and brake efforts all harmonised. Heavy perhaps, but harmonised. Whilst many owners consider the braking effort to be satisfactory without servo assistance, I have found there is a considerable demand for servo assistance. I mount the servo between the radiator and the grille, so that it is out of sight and does not obstruct what is a pretty full engine bay. It is bolted to the right hand side of the radiator mounting bulkhead where it does not impede air flow through the radiator. The vacuum feed is taken off the rear of the inlet manifold using Daimler V8 Saloon components.
This upgrade combines well with rack & pinion steering and the diaphragm clutch in order to harmonise control efforts at a lower level. It is also well suited for use with either 3 or 4 pot front calipers.

Aluminium radiators

Aluminium SP250 radiator and fan
I was so pleased with the quality of the petrol tank, that I've decided to have replacement radiators and header tanks manufactured as well. Aluminium radiators make a lot of sense. They are lighter, corrosion free and more thermally efficient than the standard radiator. Starting with a clean sheet of paper also enables me to address two issues. Firstly the bottom hose outlet is now sited at the bottom of the radiator instead of being some inches higher on the standard rad. This means that you can use the full area of the radiator to reduce coolant temperatures. Secondly, it enables you to mount the cooling fan on specially constructed arms that guarantee rigidity. As so many SP250s are fitted with fans in order to cope better with today's traffic conditions and to accommodate rack and pinion conversions, I am supplying the radiator with a new premium quality fan fitted as standard. The new radiator is dimensionally the same as the standard part. See prices.

I do not yet have a photograph of the header tank but will post one as soon as it becomes available. It is a straight replacement for the standard tank but once again manufactured from aluminium instead of sheet steel. See prices.

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