Everything You Need To Know About "B42 Modifications"

How to modify and upgrade the Volvo B42

"Comprehensive guide to performance parts and tuning the Volvo B42 engine!"

Forums like the one at TorqueCars are regularly getting messages asking how to improve the B42 from people inquiring about getting more power from the B42 and wanting to know what are the optimum B42 mods that work. So let us look into Volvo B42 modifications and outline the best mods that work on this great engine and point out some common pitfalls along the way.

The Volvo B42 have loads of potential and with the optimum sports modifications like remapping, turbo upgrades and camshafts you will increase your driving fun.

Let us look at B42 tuning and report on the optimum modifications for your car.

When talking about the best parts for your B42 engine, we are going to concentrate on the upgrades that give the biggest return for your cash.

Improving air intake on the B42

You need air matched to fuel for an engine to work. If there is insufficient fuel then it will run lean, if there is insufficient air it runs rich losing power which risks damage to the B42. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Feeding more fuel and air into your B42 is the whole point to any car tuning job.

You'll commonly see there's a restriction in the air flow sensor AFM/MAP on the B42 when considerably more air is being fed into the engine.

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

Headers carry the air during the suck phase from the air cleaner and allow it to be pulled into the engine cylinders with fuel for the squish phase.

Design and rate of flow of the Intake headers can make a large improvement to fuel engine efficiency on the B42.

It's not uncommon that intake manifold are in desperate need of an upgrade, although a few makers provide decently flowing intake manifold.

Increasing the B42 valve size, carrying out 3 or 5 angle valve jobs and porting and head flowing will also raise bhp, the fantastic side effect is it will make space for raising the bhp increase on other parts.

B42 performance cam tips.

Different B42 engines respond better to extreme camshaft durations check your engine on a rolling road.

The ECU mapping and fuel pump and injectors 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.

Significant air intake, and exhaust improvements on the B42 can be made from camshaft upgrades. Changing the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the bhp and power output.

NB: Fast road cams commonly increase the power over the rev band, you may lose a little low end bhp but high end rpm power will be higher.

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.

A Motorsport camshaft won't do well if driving in heavy traffic.

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

Stage 1, 2 and 3 mods for the B42

Before we break the best tuning upgrades down into stages of tune, let's list the most effective tuning upgrades for you.

1. Suspension Upgrades - always improve your cars handling
2. Brake Upgrades - Even before adding power improve those brakes
3. Intake - make sure the intake is not restricted, use filters and intake upgrades to improve this
4. Exhaust - as with 3 ensure there is not restriction in the exhaust, cats are the usual bottleneck
5. Tunes - remapping, piggyback ECU's and aftermarket ECU's can all make decent gains
6. Fuelling - when you've increased power you'll need to match this with more fuel
7. Turbo upgrades - Improving the intake with a large turbo and better flowing intercooler will be the biggest power gain you'll see (but one of the most complex).

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

Stage 1 B42 parts:

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

Stage 2 B42 parts:

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

Stage 3 B42 parts:

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

Remapping should help to release the full potential of all the parts you've done to your B42.

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 your mileage often depend much on the parts you've done and the condition of your engine.

Turbo modifications on the B42

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 found a great 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 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.

If an engine has a turbo already fitted parts are giving better power gains and you'll see that turbo charged engines are made with stronger components.

However engines have limits

We recommend you find these restrictions and fit better quality crank and pistons to utilize the power.

We've seen drivers spending a loads on turbocharger upgrades on the B42 only to watch the motor literally blow up on it's first outing after it's been completed.

Bigger upgraded turbos will usually experience no power at low rpm, and low capacity turbos spool up much more quickly but don't have the peak rpm bhp gains.

In recent times the range of turbo chargers is always moving on and we are seeing variable vane turbo chargers, permitting the vane profile is altered according to speed to lower lag and increase top end performance.

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

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large power gains, although more challenging to setup. We have this feature on twinchargers if you want to read more.

Tips about fuel supply on the B42

Don't omit to ramp up the fuel system when you are increasing the bhp and torque - it makes the car more thirsty. Most tuners we speak with say to over specify your flow rate on the injectors.

The accepted safe increase is to add 15% to the flow rate when fitting an injector, which takes into account injector deterioration and allows 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..

Recommended B42 performance exhaust upgrades

The only time you should look to replace your exhaust system with an upgraded one is if your current exhaust is actually causing a restriction in flow.

On most factory exhausts you'll find your flow rate is good even on modest power gains, but on a serious tuning project with a big boost in power you will certainly need to get a better flowing exhaust.

Sports exhausts can help increase the flow of air through the engine.

But if the exhaust is too big, ie: over two and a half inches diameter, you will lose a great deal of the exhaust flow rate and end up lacking power and torque.

Usual exhaust restrictions are traced to the emissions filters installed, so adding a higher flowing sports alternative will help avoid this restriction.

Decat pipes (NB:catalysts reduce harmful engine emissions) is illegal in most countries and regions.

Faults issues and things to look out for on the B42

Like most engines an B42, should have few issues if it gets properly serviced and looked after.

We cannot stress enough the need for oil changes with the correct grade of oil on the B42, failure to do this will exacerbate engine wear, on a tuned B42 this is more important than ever and close attention should be paid to your maintenance schedule.

If you are interested in learning more or getting impartial tuning advice for your B42 why not pop over to the forums at TorqueCars where you can chat about B42 tuning options and read about others projects who may be planning to do similar modifications on their B42.

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This entry was posted under Makes and Models. Tags: engine, Volvo
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