Tuning the Volvo B234

"Comprehensive guide to performance tuning the Volvo B234 engine!"

We often are seeing threads about the best B234 mods that work. So let us look into Volvo B234 parts and outline the best modifications on this great engine and point out some frequent tuning mistakes along the way.

Now we shall outline options for your B234 tuning and report on the greatest modifications for your car. Volvo B234 are popular tuning projects and with carefully picked tuning upgrades like a remap, turbo upgrades and camshafts you will noticeably maximize your driving enjoyment.

The best B234 modifications on an engine are in our opinion the ones that give the best power gain for you spend.

We won't be swayed by popular B234 modifications, 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 & exhaust durations will alter depending on the chosen cam profile, so large power band gains are on offer for cam upgrades.

NB: Fast road cams commonly increase the bhp and torque across the rev band, you might lose a little low down bhp but the high end rpm power will be better.

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

For a car driven daily you need to optimize your torque band to your driving style.

You'll never find a B234 Race camshaft is a pleasure to live with when on the daily commute.

Each engine responds better to mild cam durations than others.

The map and fuel pump and injectors also have a large bearing on the bhp gains you'll achieve.

A longer valve duration 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.

B234 Tuning Stages

Stage 1 B234 modifications: Drilled & smoothed airbox, Panel air filters, Fast road camshaft, Sports exhaust manifold, Intake headers, Remaps/piggy back ECU.

Stage 2 B234 modifications: high flow fuel injectors, Sports catalyst & performance exhaust, Fast road cam, Ported and polished head, fuel pump upgrades, induction kit.

Stage 3 B234 modifications: Engine balancing & blueprinting, Twin charging conversions, Competition cam, Adding or Upgrading forced induction (turbo/supercharger), Internal engine upgrades (head flowing porting/bigger valves), Crank and Piston upgrades to alter compression.

ECU mapping allows a tuner to unlock the full potential of all the upgrades you've done to your B234.

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

It is the whole point to any engine tuning task to feed fuel and air into the B234 engine

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

Design and flow characteristics of the Headers can make a big improvement to fuel atomisation and engine efficiency on the B234.

Most intake are in dire need of performance upgrades, although a few OEM provide fairly well optimized intake.

Big valve conversions on the B234, doing some port work and head flowing will also lift bhp, & importantly will give you a greater bhp increase on other parts.

Turbo upgrades for the B234

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 B234

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 an engine has forced induction modifications are relatively easy and you will discover turbo engines are built using more solid components.

There are common areas of failure for every engine, with some being extremely strong and some only just able to handle stock power

It is important to find these limitations and fit better pistons and crank to handle the power.

We see many people spending a lot of money on turbocharger upgrades on the B234 only to watch the motor literally blow up soon after it's completed.

Larger upgraded turbochargers commonly experience a bottom end lag, and little turbochargers spool up much more quickly but do not have the peak end power band gains.

In the last 10 years the choice of turbochargers is always evolving and we commonly find variable vane turbochargers, allowing the vane angle is altered according to speed to lower lag and increase top end performance.

Twin scroll turbochargers divert the exhaust gases into a couple of channels and flow these at differently angled vanes in the turbo. They also improve the scavenging effect of the engine.

It is common that there is a limit in the air flow sensor (AFM/MAF/MAP) on the B234 when considerably more air is being sucked into the engine.

You'll see that 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting torque at a much lower level.

Adding a supercharger or additional turbo will make large bhp gains, although harder to get working. We have this guide to twinchargers if you want to read more.

Uprating B234 fuel injectors

You will need to ensure that the engine is not starved of fuel so will need to ramp up the fuelling when you start going beyond 20% of a bhp increase.Don't forget to over specify your flow rate on the injectors.

As a rule of thumb add 20% capacity when buying an injector, which takes into account injector deterioration and provides some 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 B234 performance exhausts

You should look to improve your exhaust if the current exhaust is actually causing a restriction in flow.

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

Don't go with the biggest exhaust you can get you'll reduce the exhaust flow rate - the best exhausts for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Usual exhaust restrictions come around the filters installed, so adding a faster flowing sports alternative will help avoid this restriction.

Problems and issues to look out for on the B234

The B234 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the B234, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your B234 engine please join us in our friendly forum where you can discuss tuning options in more detail with our B234 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 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 B234 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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