Tuning the Volvo B6254

"Comprehensive guide to performance parts and tuning the Volvo B6254 engine!"

We are regularly getting messages requesting information on the greatest B6254 mods that work. So let us look into Volvo B6254 parts and outline the best upgrades on this great engine and point out some problems along the way.

The Volvo B6254 really good project engines and with a few sensible tuning mods like ECU maps, turbo improvements and camshafts you will positively increase your driving enjoyment.

Our aim here is to look at B6254 tuning and highlight the greatest mods that work.

The ultimate B6254 upgrades on an engine are sensibly the ones that give the best value for money.

We won't be swayed by popular B6254 upgrades, they need to be cost effective.

Altering your B6254 camshaft will make a dramatic difference to the engine engines power. Choosing a higher performance camshaft profile raises the engines power accordingly.

NB: Fast road cams usually bump the bhp and torque throughout the rpm band, you could sacrifice a little bottom end torque but the high end rpm power will be higher.

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

A Race cam is not great on the daily commute.

You should ideally match your bhp range to your typical driving style so for a road car stick with a shorter duration B6254 cam

Each engine responds better to extreme cam durations than others.

The map and fuel pump and injectors also have an effect on the bhp gains you'll hit.

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.

B6254 Tuning Stages

Stage 1 B6254 modifications: Fast road camshaft, Remaps/piggy back ECU, Intake headers, Drilled & smoothed airbox, Panel air filters, Sports exhaust manifold.

Stage 2 B6254 modifications: high flow fuel injectors, Ported and polished head, fuel pump upgrades, Sports catalyst & performance exhaust, Fast road cam, induction kit.

Stage 3 B6254 modifications: Twin charging conversions, Engine balancing & blueprinting, Internal engine upgrades (head flowing porting/bigger valves), Crank and Piston upgrades to alter compression, Adding or Upgrading forced induction (turbo/supercharger), Competition cam.

ECU flashing will help to establish the full potential of all the upgrades you've done to your B6254.

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

It is the aim to any engine tuning project to feed more fuel and air into the B6254 engine

Intake flow the air during the suck phase from the filter and allow it to be fed into the engine cylinders.

Design and rate of flow of the Air Intake manifolds can make a big improvement to fuel engine efficiency on the B6254.

Most intake headers are improved through a performance upgrade, although a few makers provide well optimised intake headers.

Increasing the B6254 valve size, getting B6254 port enlargement and head flowing will also boost bhp and torque, and more importantly will allow you to get an improved bhp and torque increase on other modifications.

Turbo upgrades for the B6254

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 B6254

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

If the engine is fitted with a turbo upgrades are relatively easy and we find turbo engines are built with better components.

There are reliable limits for every engine, with some being incredibly solid and some only just able to handle stock power

Discover these limits and install more solid crank and pistons to cope with the power.

We see many people spending a loads on turbocharger upgrades on the B6254 only to suffer the humiliation of seeing the engine throw a rod just after it's completed.

Large capacity turbo units tend to suffer low end lag, and low capacity turbo units spool up more quickly but won't have the top end engines power gains.

We are pleased that the selection of turbochargers is always evolving and we are seeing variable vane turbochargers, where the vane angle is altered according to speed to lower lag and increase top end performance.

Twin scroll turbochargers divert the exhaust flow into two channels and feed these at differently profiled vanes in the turbocharger. They also increase the scavenging effect of the engine.

It is common that there's a limit in the air flow sensor AFM/MAP on the B6254 when a lot more air is being pulled into the engine.

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

Adding a supercharger or additional turbo will make large torque gains, although more difficult to setup. We have this article on twincharging if you want to read more.

Uprating B6254 fuel injectors

Don't dismiss the need pay attention to the fuel delivery when you are increasing the performance - it makes the car more thirsty. Most tuners we speak with say to be generous with your injector capacity.

The rule of thumb is to add another 20% when buying an injector, this allows for injector deterioration and allows some spare capacity should the engine require 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 B6254 performance exhausts

Only look to uprate your exhaust if the existing exhaust is actually creating a flow problem.

On most factory exhausts you'll find the 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.

Sports exhausts generally help improve air flow out of the engine but do not go too large or you may end up will reduce the flow rate. Stick to 1.5 to 2.5 inches as a rule of thumb.

Usual exhaust restrictions can be located the filters installed, so adding a higher flowing sports alternative will help avoid this restriction.

Problems and issues to look out for on the B6254

The B6254 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the B6254, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your B6254 engine please join us in our friendly forum where you can discuss tuning options in more detail with our B6254 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 B6254 guides and tips are kept up to date.

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