Tuning the M30 engine from BMW

Find out about "Tuning the BMW M30"

"Comprehensive guide to tuning the BMW M30 engine!"

The BMW M30 make a good tuning project and with the best tuning tuning mods like ECU maps, turbo upgrades and camshafts you will certainly maximize your driving fun.

In this article we examine M30 tuning and report on the optimum mods that work.

Just because particular tuning mods are are common on M30 it doesn't mean its worth having, instead we'll concentrate) on the top tuning mods that will give your M30 the best value for money to power increase.

Altering your M30 cam will make a dramatic difference to the engine engines power. Choosing a higher performance cam profile raises the engines power accordingly.

NB: Fast road camshafts commonly increase the performance over the rpm band, you may lose a little low down torque but the high end rpm power will improve.

Competition camshafts, increase the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

On a car driven daily must carefully try to match your engines power to your cars usage.

I'd be amazed if you have ever thought a M30 Race cam is a pleasure to live with when driving around busy urban areas.

Some M30 engines respond better to extreme camshaft durations check your engine on a rolling road.

The ECU mapping and injectors and fuel pump also will say much on the bhp gains you'll make.

Altering valve durations can alter the bhp band and on most engines the exhaust and intake durations do not need to match, although most cams and tuners use matched pairs there are some advantages to extending the intake or exhaust durations.

Our top 7 top upgrades for your motor, and we will break these into stages and discuss them in detail for you.

  1. Map Tunes - remapping, via either OBD port, or piggyback ECU's and aftermarket ECU's can all make decent gains
  2. Fuelling Pump Injectors - You'll need to match the greater air flow with more fuel to unlock the power
  3. Turbo upgrades - Improving the intake charge with a large turbo and better flowing intercooler will be the biggest power gain you'll see (but one of the most complex especially where conversions are required).
  4. Suspension Upgrades - always improve your cars handling, tuning is not just about engine mods
  5. Brake Upgrades - Even before adding power improve your cars brakes to effectively stop the car
  6. Intake - make sure the intake is not restricted, use filters and intake upgrades to improve this
  7. Exhaust - as with intakes it helps to remove a restriction in the exhaust, cats are the usual bottleneck

This video guide to tuning cars is a great starting point to work from in your project.

Stage 1 mods: Panel air filters, Remaps/piggy back ECU, Sports exhaust manifold, Intake headers, Fast road camshaft, Drilled & smoothed airbox.

Stage 2 mods: Ported and polished head, fuel pump upgrades, Sports catalyst & performance exhaust, induction kit, Fast road cam, high flow fuel injectors.

Stage 3 mods: Competition cam, Engine balancing & blueprinting, Twin charging conversions, Crank and Piston upgrades to alter compression, Internal engine upgrades (head flowing porting/bigger valves), Adding or Upgrading forced induction (turbo/supercharger).Plan your options and then buy your tuning parts and set yourself a power target to avoid costly mistakes.

ECU mapping allows a tuner to to establish the full potential of all the modifications you've done to your M30.

You will typically expect to see gains of approximately 20-30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but the outcome will differs on the modifications you've done and the condition of your engine.

  • M30B25V
    110 kW (148 bhp) at 6,000rpm 211Nm (156 lbft) @3,700 rpm
  • M30B25
    110 kW (148 bhp) @6,000rpm 215Nm (159 lbft) @3,700 rpm
  • M30B28V
    125 kW (168 bhp) @6,000rpm 235Nm (173 lbft) @3,700
  • M30B28
    135 kW (181 bhp) @5,800rpm 240Nm (177 lbft) @4,200 rpm
  • M30B30V
    132 kW (177 bhp) at 6,000rpm 255Nm (188 lbft) @3,700 rpm
  • M30B30
    149 kW (200 bhp) @5,500rpm 272Nm (201 lbft) @4,300 rpm
  • M30B32
    147 kW (197 bhp) @5,500rpm 285Nm (210 lbft) @4,300 rpm
  • M30B33V
    139 kW (186 bhp) @5,500rpm 289Nm (213 lbft) @3,500 rpm
  • M30B34
    160 kW (215 bhp) @5,800rpm 310Nm (229 lbft) @4,200 rpm
  • M30B35
    155 kW (208 bhp) @5,700rpm 305Nm (225 lbft) @4,000rpm
Tuning tips and articles Engine tuning Transmission tuning Care care Intake & exhaust mods Improve handling Forums

Forcing more air and fuel into the M30 engine is vital to any performance tuning job.

Headers flow the air from the air cleaner and allow it to be fed into the engine cylinders.

Shape and flow characteristics of the Air Intake manifolds can make a large effect on to fuel atomisation on the M30.

Commonly we find the intake headers are in dire need of an upgrade, although a few manufacturers provide well optimised intake headers.

Big valve conversions on the M30, doing a bit of 3 or 5 angle valve jobs and porting and head flowing will also improve torque, and importantly will make space for increasing the torque increase on other parts.

Turbo upgrades

To get a turbo working on a NASP engine there is a lot involved, from lowering compression ratio to improved fuel supply and mapping, so we have a separate guide to helpavoid the common pitfalls or end up with an unfinished project because you were not told what you were getting into by doing this on the M30

The more air you can get into an engine, the more fuel it can burn and uprating the induction with a turbocharger upgrade makes massive power gains.

When the engine has a turbocharger parts are more reliable and you will discover turbo charged engines use stronger components.There are weak spots for every engine, with some being incredibly solid and some only just able to handle stock power

We recommend you find these limits and fit higher quality crank and pistons to cope with the power.

We see many people spending a loads on turbo upgrades on the M30 only to suffer the indignity of watching the whole thing catastrophically fail when it's completed.

Big upgraded turbo units tend to suffer a bottom end lag, and small turbo units spool up quickly but won't have the peak rpm engines power gains.

We are pleased that the world of turbo units is always evolving and we commonly find variable vane turbo units, allowing the vane angle is altered according to speed to lower lag and increase top end bhp.

Twin scroll turbo units divert the exhaust flow into two channels and flow these at differently angled vanes in the turbo. They also help the scavenging effect of the engine.

You'll commonly see there's a limitation in the air flow sensor AFM/MAF on the M30 when a lot more air is being sucked into the engine.

We see 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting bhp and torque at a much lower level.Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large bhp gains, although more challenging to configure. We have this in depth look at twinchargers if you want to read more.

Fuelling upgrades and mods on M30

You will need to ensure that the engine is not starved of fuel so should ramp up the fuelling when you start extending past 20% of a bhp increase.

Don't forget to over specify your injector capacity.

The rule of thumb is to add 20% capacity when buying an injector, which takes into account injector deterioration and affords you some spare capacity should the engine require more fuel.

Don't forget that different fuel grades will usually require different settings, a high octane fuel will burn more efficiently than lower octane fuel for example. A car will trim fuel supply to keep within the ideal air fuel mix but at the extreme ends you may need to adjust your injector capacity, or the mapping or you'll get flat spots and potential lean or rich fuel issues..

M30 Exhaust upgrades and mods

You may need to uprate your exhaust if the existing exhaust is actually creating a restriction.

On most factory exhausts you'll find the flow rate is fine even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust. Do not go with the biggest exhaust you can buy you'll slow the exhaust rate - the best exhausts for power gains are usually between one and a half to two and half inches. Your exhaust design, the bend angles and construction are what have more effect on flow rates than your pipe width to a certain extent. So the exhaust design is a big factor.

The usual suspects causing problems in your exhaust flow rate are in the filters installed, so adding a better flowing high performance alternative will help avoid this restriction.

Issues & common problem areas on the M30

The M30 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the M30, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your M30 engine please join us in our friendly forum where you can discuss tuning options in more detail with our M30 owners. It would also be worth reading our unbiased 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 really like hearing from our readers, and hearing about which upgrades were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our M30 guides and tips are kept up to date.

Best M30 mods

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.

Check out TorqueCars new YouTube channel, and see their awesome new content...


Please use our forums if you wish to ask a tuning question, and please note we do not sell parts or services, we are just an online magazine.

Help us improve, leave a suggestion or tip

Your Constructive comments on this article