Tuning the Volvo B42

"Comprehensive guide to tuning the Volvo B42 engine!"

We are frequently getting messages about the premier B42 mods that work. So let us look into Volvo B42 upgrades and outline the best modifications on this great engine and point out some problems along the way.

The Volvo B42 great bases for a tuning project and with the right uprated parts like a remap, turbo upgrades and camshafts you will definitely improve your driving fun.

Our aim here is to look at B42 tuning and provide tips on the premier mods that work.

The optimum B42 tuning mods on an engine are as we have found the ones that give the biggest return for your cash.

We won't be swayed by popular B42 tuning mods, they need to be cost effective.

The cam profile plays a big part in the engines power output so cam upgrades make quite a large difference. The intake and exhaust durations will alter depending on the chosen cam profile, so large engines power gains are on offer for cam upgrades.

NB: Fast road camshafts normally boost the bhp through the rpm range, you might lose a little low down torque but the top end will be higher.

Race camshafts, boost the top end band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Motorsport camshaft will just annoy you whilst in heavy traffic.

You should ideally match your power band to your typical driving style so for a typical daily driver stick with a shorter duration B42 camshaft

Each engine responds better to less aggressive cam durations so view each engine as unique.

The engine timing and injectors and fuel pump also will make differences on the power gains you'll make.

Longer valve durations can alter the power 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.

B42 Tuning Stages

Stage 1 B42 modifications: Remaps/piggy back ECU, Fast road camshaft, Sports exhaust manifold, Panel air filters, Intake headers, Drilled & smoothed airbox.

Stage 2 B42 modifications: high flow fuel injectors, induction kit, Fast road cam, Ported and polished head, fuel pump upgrades, Sports catalyst & performance exhaust.

Stage 3 B42 modifications: Competition cam, Adding or Upgrading forced induction (turbo/supercharger), Engine balancing & blueprinting, Twin charging conversions, Crank and Piston upgrades to alter compression, Internal engine upgrades (head flowing porting/bigger valves).

Mapping helps fully realize the full potential of all the upgrades you've done to your B42.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but your results will rely on the upgrades you've applied and the condition of your engine.

Feeding more air into each cylinder is the main goal to any car tuning project.

Intake manifold take the air from the filter and allow it to be sucked into the engine cylinders with fuel for the squish phase.

The size of bore and shape and flow characteristics of the Plenum can make a substantial effect on to fuel mixing and power on the B42.

It's not uncommon that intake are in desperate need of a performance upgrade, although a few OEM provide reasonably good intake.

Fitting big valve kits, doing some port matching and head flowing will also increase bhp and torque, and more importantly will give you raising the bhp and torque increase on other modifications.

Turbo upgrades for the B42

NASP engines need quite a lot of work when you add a turbo, so we have a separate guide to help you take into account the pros and cons of going this route on your B42

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 a car has a turbo already fitted parts are giving better power gains and turbocharged engines will have uprated components.

However most engines will have power limits

Research these limits and upgrade to better pistons and crank to utilize the power.

There are many people spending a loads of money on turbo charger upgrades on the B42 only to watch the car catastrophically fail when it's been completed.

Larger upgraded turbochargers will usually suffer a bottom end lag, and smaller turbochargers spool up really quickly but won't have the top end bhp gains.

We are pleased that the selection of turbo units is always increasing and we are seeing variable vane turbo units, permitting the vane profile is altered according to speed to lower lag and increase top end bhp.

Twin scroll turbo units divert the exhaust flow into 2 channels and feed these at differently angled vanes in the turbo charger. They also improve the scavenging effect of the engine.

It is common that there is a limit in the air flow sensor AFM/MAP on the B42 when loads more air is being fed into the engine.

We note 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor limited power at a much lower level.

Adding a supercharger or additional turbo will make large bhp and torque gains, although more difficult to configure. We have this article covering twinchargers if you want to read more.

Uprating B42 fuel injectors

You will need to ensure that the engine is not starved of fuel so will need to look at the fuelling when you start going beyond 20% of a performance increase.We strongly recommend you to over specify your flow rate on the injectors.

The accepted safe increase is to add 20% when fitting an injector, this takes into account injector deterioration and allows a bit of spare capacity should the engine need more fuel.

We think this one is common sense, but you'll need to match your fuel injector to the type of fuel your car uses as well.

Best B42 performance exhausts

You only need to to boost your exhaust if your exhaust is actually creating a restriction in flow.

On most factory exhausts you'll see your flow rate is still good even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Sports exhausts can usually air flow out of the engine but do not go too big or you may end up will reduce the flow rate. Stick to 1.5 to 2.5 inches for best results.

Usual exhaust restrictions are traced to the catalyst installed, so adding a faster flowing race alternative will help avoid this restriction.

Problems and issues to look out for on the B42

The B42 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the B42, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your B42 engine please join us in our friendly forum where you can discuss tuning options in more detail with our B42 owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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We really like hearing from our readers, and hearing about which tuning parts were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our B42 guides and tips are kept up to date.

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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 Volvo. 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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