BMW E30 Tuning

"Thank you for reading this BMW E30 tuning article."

E30 Series buyers guide and introduction.

Rolling back the years, these classics also had an excellent range of low, mid, and high-powered engines. Most notably the inline 6-cylinder M20 engine that ran from 1977 to 1993, ranging from a 2.0L unit to a 2.7L unit in the E30.

This is where more mechanical options are the best upgrades. With a performance racing cam, more air flow through the engine as the valves are lifted higher.

Few cars enjoyed a production run of 16 years, so we're branching this article into engine specific guides, and covering a general approach to adding mods to your E30 here.

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The early E30's are commanding very high prices, if they are in good condition and by buying an E30 you are entering an exclusive realm of collectable and appreciating cars.

This upgrade paves the way to ECU re-mapping alongside fuel pump and injector upgrades that fine-tune the torque and power gains.

We get asked for some tips on improving the E30 and which tuning modifications we rate as the best, so this guide has been assembled which covers our go to modifications and methods of modifying and tuning on the E30 engine.

The E30 is an awesome tuning project to execute. If you do your homework then you can create an awesome E30 but don't be fooled there are lots of high performance upgrades out there that will simply not suit it read our unbiased guides first.

Early models are commanding premium prices now, and the E30 was a definitive 3 series model, that won a place in the hearts of many BMW fans and enthusiasts.

E30 Handling/Suspension upgrades

Many E30 owners uprate the handling of their cars with Coilover suspension parts as a priority, this will certainly increase your enjoyment of the car.

Poly bushes are a good option if your current rubber bushes have started to degrade and wear, and can really pep up the handling. We would recommend a softer compound, especially on higher mileage cars where the suspension is not as effective at damping the vibrations and shocks.

If you set the toe out to 1-1.7 degrees on the front, and add some negative camber then cornering will substantially be enhanced.

Front strut braces can also optimise the suspension with many E30 owners reporting that the car is a little prone to flex, especially as it ages and the miles clock up.

Drop the car optimally somewhere in the region of 26mm - 40 mm. and fit motorsport grade stiffer dampers, bigger drops will need other modifications in most instances.

Coilovers are a good option as they allow a little fine tuning to suit your driving style, and you really do get what you pay for, there is a reason so many cheap coilover kits end up for sale on online auction sites.

E30 brake upgrades

For radically enhanced braking you should get better high-performance brake pads and combine this with meatier brake discs.

Vented, grooved and slotted discs are all available and will improve your stopping distance and will reduce brake fade.

As a word of warning please note that race brake pads can grind and will have to be hot before they bite.

On a road car the brakes are only used rarely, therefore won't be as effective at slowing you up so specify friction pads which have a low working temperature.

E30 engine tuning mods.

In this article we shall give a little insight into the world to the best upgrades for your car, but we'd encourage you to spend some time on the site looking into the details of each type of performance part.

Fast road cams offer one of the biggest torque gains for your money as far as a bolt on tuning modifications goes on a NA (naturally aspirated) engine. They are hard to find for most E30 but a few companies are offering a regrind on the stock cams, which can lift your peak performance.

Our aim in engine tuning should be to increase peak power at the top end. The E30 came with some impressive engines (for their time), and new developments over the years can be retroffited to provide power gains, such as fuel injection.

Because the engines vary so much we are aiming to cover each of the engines in more specific detail, and would be grateful if you could pass on your tips, suggestions and comments below to make sure we provide the most up to date information.

• M20B25 325i
• M42B18 318i
• M20B27 325e
• S14B23 M3
• S14B25 M3

Enjoy your E30 to the max with our modding guides - do the right mods in the right order and plan carefully, mapping and timing adjustments are best carried out at the end so you can maximise the mods you have done.

Most notably the inline 6-cylinder M20 engine that ran from 1977 to 1993, ranging from a 2.0L unit to a 2.7L unit in the E30. This is where more mechanical options are the best upgrades unless you are prepared to install a fuel injection system and modernize the engine.

E30 performance camshafts

The concept with camshaft upgrades is that it maximises the intake and exhaust flow and increases the power if done right. A vernier pulley will allow you to fine tune the opening and closing of the valves, effectively moving your power band and allows a way to try out different positions without having to remove the camshaft.

With a performance racing cam, more air can escape as the valves are lifted higher and for
Sourcing  an E30 performance cam can be a challenge in some regions so getting a custom grind done on a stock cam would be the way forward.

This upgrade paves the way to ECU re-mapping alongside fuel pump and injector upgrades that fine tune the torque and power gains allowing you to put the higher power band exactly where you want it to be.

The following performance parts are usually carried out by our members, decide how far you want to go before you get started.

Getting the correct grade of modified modifications for your planned usage of the car is vital. Stage 3 competition upgrades just won't work well on the road and will make the car undrivable.

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Best mods for your E30

1. Internal engine mods - crank, pistons, conrods & compression ratio including balancing and blueprinting
2. Flywheel lightening - a lighter flywheel will improve the engines ability to rev freely. But not always suitable for all E30 engines.
3. Air Induction and Sports Exhausts - Note that on their own these mods won't ADD POWER on most cars, but they can help lift power after other mods by removing the restriction.
4. E30 Handling Mods (suspension) - Replacing worn bushings and shocks dramatically improves E30 handling Coilovers and Bushings are the usual go to mods
5. Brake Mods - Stopping your E30 should be near the top of your Mods list.
6. Fast road cams are generally the biggest mechanical mod upgrade, but they must be fitted by someone who knows what they are doing and you might struggle to find one but there might be a local firm to regrind a stock camshaft for you.

E30 Tuning Stages

Typical stage 1 mods often include: Panel air filter, Alloy wheels, Sports exhaust, Engine Tunes/Remapping, Lighter flywheel, Suspension upgrade (drop 23mm - 43 mm.).

Typical stage 2 mods often include: high flow fuel injector, Ported and polished head, Power/Sport clutch, Fast road cam, fuel pump upgrades.

Typical stage 3 mods often include: Engine balancing, Sports gearbox, Competition cam, Adding or upgrading forced induction (turbo/supercharger), Internal engine upgrades (pistons/head/valves).

Your aims when tuning the engine should be a flat and wide torque band. You don't want all the power to be at the top end of the rev range unless you are creating a motor sport car.

E30 ECU Tuning maps

Remaps, depending on the engine you have you should see peak power gains of around 13-25hp, and generally speaking you get more from a tune/remap when it is combined with other mods and upgrades.

We see tunes or remaps as the biggest power gains for your money, there are few mods out there so easy to apply that give a noticeable power hike.

Early carb engines were a pleasure to drive, but setting up the jets and getting the timing set proved to be a challenge, so thankfully the modern world has provided ECU's and timing/fuel maps which makes things somewhat easier.

Retrofitting fuel injection to the early models has been done a few times, and to good effect.

Ideally you'd add other mods and then finish up with a reflashed ECU. We'd also caution you not to go with an aggressive (motor sports, or competition) profile cam as this upsets the engines idling and general town driving characteristics.

E30 fuel upgrades

A higher capacity fuel pressure regulator on the early engines gives a snappier throttle response and provides an easy way to deliver more fuel. There is not much clearance in the engine bay so adjustable fuel pressure regulators are often mounted remotely via a fuel rail adapter.

Unless you are adding significantly more power or have an older engine, then the fuel system should prove to be more than adequate.

Don't forget to pay attention to the fuelling when you are increasing the power - it makes the car more thirsty.

If you find you experience flat spots and power surges after your mods have been applied, you should check the fuelling and try a higher octane fuel as well, this has solved a few rough and flat spot issues for some of our members.

Uprated injectors will enable you to supply sufficient fuel to the engine.

If you've uprated your fuelling with bigger injectors you will also need to get a bigger fuel pump to supply it.

E30 Intake and Exhaust Headers & Performance exhausts.

The next area for modification is the intake and exhaust.   Flow of air into and out of the engine is always a priority, but if you are only planning to change the exhaust and intake you are unlikely to be making much more power.

These mods are best done to remove a restriction caused by a large power increase, and in some cases they have been known to rob you of power.

Contrary to popular belief there is generally a small if any power gain obtained by fitting an induction kit, they only work well and are recommended after you increase the engines power to the point where the standard air intake box cannot cope!

Always source a cold air feed and shield the filter from the engine bay.

Induction kits can work well on turbo engines and larger engines (if supplied with a suitable cold air feed or air box), generally though we'd just recommend for E30 engines you should just fit a performance panel air filter preferably made from cotton.

Sports exhausts equal out the flow of gases through the engine. But if the exhaust pipe is too large, ie: over 2.5 inches bore, you will lose a lot of your flow rate and end up sapping power and torque.

The only gains you'll get from an exhaust upgrade are generally around the headers, where the catalysts rob you of power. The loss is generally around 3% but adding a higher flowing catalyst can improve the power, keeping the car road legal if you are permitted to replace a catalyst in your area.

Head work including a head port and polished and 3 or 5 angle valve job will really help to release the potential of the engine. In nearly all cases of E30 tuning your clutch will start to fail and this should be improved - read our guide on clutches for more information. The best mods in our opinion for your E30 are a tune/remap especially on a turbo, a fast road camshaft and sports exhaust, with a good air intake.

Despite the large cost involved adding forced induction to a NA (naturally aspirated) engine will give large power gains. It is generally simpler to bolt on a supercharger than it is to install a turbo. Turbos provide boost in exponential proportion to rising engine speed and this can make mapping difficult.

The nice directly proportional boost and rpm characteristics of the supercharger make them more straightforward to map. Alternatively, you could add water injection to cut down knock.

Best alloy wheel sizes for the E30.

It seems that many people are not wowed by the choice of alloys provided by BMW, so there is a thriving aftermarket with options to suit every taste.

As we are performance fans, we would stress the following. Choose lighter wheels and avoid large alloys. Let's break this advice down and discuss our reasoning.

Alloy wheels can help the brakes cool down and are usually lighter than the steel ones. Pay attention to your choice of tyres (tires) for your car, a good directional tread pattern tire can really enhance your cars handling.

The drawback to large rims on your E30 is that you're changing your effective final drive ratio so this will have a detrimental effect on acceleration.

It also adds weight which is detrimental to the E30's handling. We would also recommend you avoid the run flats, these are typically removed at the first opportunity by our members.

Although some people have fitted larger wheels we would restrict ourselves to a 16 inch rim size as the maximum on the early models. The 17's especially and sometimes the 18's are nicely suited to the more recent models, and although 19's may look cool you'll end up with a really crashy ride and will end up with tires rubbing.

For more information on Tuning your car please join us in our friendly forum where you can discuss E30 options in more detail with our E30 owners. It would also be worth reading our unbiased BMW tuning articles to get a full grasp of the benefits and drawbacks of each modification.

Please help us improve these tips by sending us your feedback in the comments box below.

We love to hear what our visitors have got up to and which mods work best for them on each model of car. We use your comments and feedback to improve the accuracy of these tuning guides which get regular updates and revisions.

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This article is flagged for an update, so please pass on specific tips below that I can include. All articles, and content was written by me, Waynne Smith TorqueCars founder. Some outlines are just too general so I appreciate your feedback and suggestions. This entry was filed under BMW. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

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