Modifying and improving: "F Series Modifications"

How to modify and upgrade the Honda F Series

"Comprehensive guide to performance tuning the Honda F Series engine!"

Our friends at TorqueCars often are getting messages asking about how to improve the F Series from people inquiring about getting more power from the F Series and wanting to know what are the things tuners are recommending when it comes to F Series mods that work. So let us look into Honda F Series parts and outline the best upgrades on this great engine and point out some common pitfalls along the way.

The Honda F Series are popular tuning projects and with a few sensible motorsport parts like remapping, turbo improvements and camshafts you will dramatically improve your driving enjoyment.

Our aim here is to consider F Series tuning and provide tips on the optimum upgrades.

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

Improving air intake on the F Series

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

So Getting air and fuel into the F Series engine is vital to any car tuning project.

It is common that there's a limitation in the air flow sensor MAF/MAP on the F Series when considerably more air is being drawn 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.

Air Intake manifolds transmit the air during the suck phase from the filter and allow it to be sucked into the engine cylinders.

The shape and flow characteristics of the Air Intake manifolds can make a substantial effect on to fuel atomisation on the F Series.

Many mass produced engine air intake manifolds are begging for performance upgrades, although a few makers provide reasonably well designed air intake manifolds.

Fitting big valve kits, doing some port matching and head flowing will also boost power, and more importantly will make space for a greater power increase on other parts.

F Series performance cam tips.

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

The map and fuelling also will say much on the torque gains you'll achieve.

Altering valve durations can alter the torque 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.

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

NB: Fast road camshafts normally bump the bhp across the rpm band, you may lose a little bottom end torque but higher rpm power will improve.

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

A Race cam makes it harder when driving around busy urban areas.

You should ideally match your torque band to your driving style so for a car driven daily stick with a mild fast road F Series cam

Stage 1, 2 and 3 mods for the F Series

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 F Series parts:

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

Stage 2 F Series parts:

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

Stage 3 F Series parts:

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

ECU mapping allows a tuner to unlock the full potential of all the parts you've done to your F Series.

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 often differs on the parts you've fitted and the condition of your engine.

Turbo modifications on the F Series

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 F Series.

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 your motor is fitted with a turbocharger tuning parts are relatively easy and we find turbo engines will have strengthened components.

However you'll find engines will need better parts at higher power limits

It is important to find these restrictions and upgrade to more solid crank and pistons to utilize the power.

We've seen guys spending a lot of money on turbo upgrades on the F Series only to have the motor go up in smoke when it's completed.

Bigger upgraded turbos often suffer a bottom end lag, and low capacity turbos spool up really quickly but won't have the peak rpm power band gains.

Thanks to progress the world of turbo chargers is always increasing and we are seeing variable vane turbo chargers, where the vane angle is altered according to speed to lower lag and increase top end power.

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

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large bhp gains, although more difficult to get working. We have this guide to twinchargers if you want to read more.

Tips about fuel supply on the F Series

You will need to ensure that the engine is not starved of fuel so should pay attention to the fuelling when you start extending past 20% of a bhp and torque hike. It makes sense to over specify your flow rate on the injectors.

The rule of thumb is to add 20% capacity when buying an injector, which takes into account injector deterioration and provides you some spare capacity should the engine need 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 F Series performance exhaust upgrades

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

On most factory exhausts you'll see the flow rate is fine 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 will certainly help air flow through the engine but avoid an exhaust that is too big or you could will reduce the flow rate. Stick to one and a half to two and half inches for best results.

Typically exhaust restrictions are in the emissions filters installed, so adding a higher flowing performance alternative will help avoid this restriction.

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

Faults issues and things to look out for on the F Series

Like most engines an F Series, 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 F Series, failure to do this will exacerbate engine wear, on a tuned F Series 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 F Series why not pop over to the forums at TorqueCars where you can chat about F Series tuning options and read about others projects who may be planning to do similar modifications on their F Series.

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