Triumph TR8 Introduction



TR8-TR7 Compatibility
There are many components that are common to TR7's and TR8's, and clearly others which are not. Sometimes the difference is obvious. TR8 Engine for instance clearly has no common parts usage with TR7, so the parts data in the TR8 engine section is extremely comprehensive. In other areas however, the differences are not so prominent or numerous- because only minor changes or modifications are required from the standard TR7 specification.

For example, rear axle ratio and battery location. Here we only show the parts that relate solely to the TR8. The rest will be TR7 !

Please remember, if you have any difficulty whatsoever you only have to phone, our staff are here to help you.

An Introduction To The TR8 Conversion
The conversion of a standard TR7 to TR8 specification (TR7-V8) is relatively straightforward and can be carried out by any competent DIY car enthusiast.

The basic components to substitute are: Engine, Subframe, Propshaft, Brakes and Exhaust, with the option of fitting Uprated Suspension to improve handling, and changing the 5-speed rear axle Ratio to improve gearing.

At Rimmer Bros, we believe original is best (i.e. what the factory actually designed), so we strive to supply as many original parts as possible. One area where we do believe it is important to use the original component is the subframe. Our TR8 conversion kits include a Brand New original subframe with the original type brackets, - designed to cope with the stress and torque of the V8 engine, unlike some types that are on the market. Another bonus with the original subframe is that when used as a datum, everything else in the drive train, i.e. Gearbox, Propshaft, Rear Axle, all line-up. This is not the case when non-standard parts are purchased separately in an attempt to save money. The end result could well be clearance, vibration, and fitting problems, resulting in false economy.

Ultimately, the value of your car will be enhanced by using original specification components when converting your TR7 to a TR8, and if you ever decide to sell, prospective purchasers will soon identify (and value higher), a car that has been converted correctly opposed to one that has just had a V8 engine 'thrown in'.

Generally, it is best to start with a 5-speed car (the 4 speed gearbox and rear axle are not sufficiently robust). If you have a 4-speed or an automatic TR7, we will be pleased to quote for a package to supply the necessary parts to give you a 5-speed TR8. The 5 speed TR7 gearbox can be re-used but it must be fitted with the V8 bellhousing and clutch release arm pivot pin (and bearing carrier). We also supply a TR8 propshaft (for use with the original TR8 subframe & engine/gearbox mountings), it is shorter and stronger than the TR7 propshaft. The 5-speed rear axle can also be re-used, though you may find the ratio (usually 3.9:1) too high, resulting in a low top-end. We supply exchange axles with either standard or Limited Slip Diff's, fitted with the 3.08:1 ratio if required. (NB - larger wheels/tyres can also affect final gearing).

It goes without saying that the entire exhaust system will need to be replaced, and it is essential you uprate the braking system. We also recommend the fitting of uprated springs and shock absorbers - to improve handling, and that you check the condition of bushes, ball joints, steering etc, for wear.

Last but not least is the engine. The Rover (3.5 Litre) SD1-V8 unit is a reliable and robust unit which can be easily adapted to fit the TR7. It provides increased power and torque, with an almost unlimited capacity for modification and tuning. Probably the best starting point for the conversion is for you to obtain a used SD1 3.5 litre engine unit - complete with all the ancillaries. You can then consider rebuilding the used engine yourself - which can be relatively inexpensive if the crankshaft & bearings are in good order, so, for the price of gasket sets, and a camshaft & follower kit, you could have a reliable engine ready to go!

Finally, depending upon the type of carburettors used in the conversion, it may be necessary to use the later type 'double bulge' bonnet (if not already fitted).

It is impossible to list here all the different combinations of parts to carry out a TR7-V8 conversion. We have selected the most popular for our conversion kits, offering the best value for money coupled with simplicity.

How far you wish to take the project is entirely your choice!

Our TR8 Conversion Kits Make it Easy

3 Kits To Choose From
We have tried to make it as easy as possible for you to select and order the kit that best suits your budget and requirements, so we have created 3 starter kits for you to choose from to convert your TR7 to a TR8.

How To Choose Your Starter Kit
Starting with the basic kit, we have listed the major components required to do the job. Kits A, B & C are based on the basic kit, but offer different combinations of exhaust systems.

For example, you can have a 'quieter' twin centre box system (in lieu of the 'H' pipe) or the 'loud drainpipe' large bore single exhaust.

All systems are supplied with a pair of stainless steel tubular manifolds for improved performance.

The uprated brake kit supplied with all three kits uses calipers derived from the Rover Vitesse, adapted for use with special vented discs that can be bolted direct to the TR7 4-stud hub.

A minimum of 14" diameter road wheel is required to clear the calipers (see Minilite Replicas in roadwheel section.)

Why Stop Here?
Our Starter Kits give you the basic parts needed to initiate the TR8 conversion, but there are many other parts (listed throughout this web site) you may wish to consider fitting to further enhance your TR8 such as; uprated anti-roll bars, front anti-dive kit, uprated/lowered road springs, uprated shock absorbers such as Spax, Koni or Gaz, uprated suspension bushes (hard and polyurethane), power steering, rear axle/ratio, body styling kit, and if the standard 3.5 V8 is not powerful enough for you we have performance parts too!

See Road Wheels (in the main TR7 section) for details on 14" Minilite Replica wheels, and Accessories for body kits/wheel arches/spoilers.

Full details of our Uprated Brake Kit can be found in V8 Brake System, and Uprated front/rear Suspension Kits under V8 Suspension Packages.

Note; your old TR7 rev' counter and radiator is required in exchange for the units that we supply in our conversion kits. Although we don't apply a surcharge, we would ask for your cooperation by returning these items so we can continue the service for other customers.
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