Tuning the Honda B20

"Comprehensive guide to performance parts and tuning the Honda B20 engine!"

Now we will look into B20 tuning and summarise the optimum modifications. Honda B20 make a good tuning project and with carefully picked modified modifications like remapping, turbo upgrades and camshafts you will dramatically improve your driving fun.

When talking about the best greatest for your B20 engine, we are going to concentrate on the tuning parts that give the best power gain for you spend.

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 bhp gains are on offer for cam upgrades.

NB: Fast road cams normally increase the bhp throughout the rpm band, you might lose a little low end power but top end will be better.

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

On a car used daily one should, ideally, try to match your engines power to your usage of the car.

I'd be gobsmaked if you have ever thought a B20 Motorsport and race cam is a pleasure to live with when driving around busy urban areas.

Different B20 engines respond better to more aggressive cam durations check your engine on a rolling road.

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

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.

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

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

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

Remaps allows a tuner to unlock the full potential of all the parts you've fitted to your B20.

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

It is the whole point to any engine modification project to pull air into the B20 engine

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

Shape and flow rate of the Intake can make a large change to fuel mixing and power on the B20.

Commonly we find the air intake manifolds are in desperate need of aftermarket tuning parts, although a few OEM provide reasonably good air intake manifolds.

Fitting big valve kits, carrying out port matching and head flowing will also increase bhp and torque, the fantastic side effect is it will raise potential for raising the bhp and torque increase on other mods.

Turbo upgrades

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 B20

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

When an engine is turbocharged, parts are simpler to install and you will discover turbocharged engines use harder and stronger components.

There are practical limits for every engine, with some being over specified and some only just able to handle stock power

Discover these restrictions and upgrade to higher quality components to utilize the power.

It's not unheard of people spending a lots of money on turbo upgrades on the B20 only to have the engine block go up in smoke on it's first outing after it's completed.

Bigger upgraded turbos commonly experience no power at low rpm, and smaller turbos spool up really quickly but won't have the top end torque gains.

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

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

It is not unusual that there is a restriction in the air flow sensor (AFM/MAF/MAP) on the B20 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 torque at a much lower level.

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

Fuelling upgrades and mods

When you lift the performance you will need to increase to the fuelling.

More performance needs more fuel. It makes sense to over specify your flow rate on the injectors.

As a rule of thumb add 20% to the flow rate when specifying an injector, which takes into account 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.

Exhaust upgrades and mods

You may need to replace your exhaust if your current exhaust is actually creating a restriction in flow.

On most factory exhausts you'll see the 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 avoid an exhaust that is too wide or you could will reduce the flow rate. Stick to 1.5 to 2.5 inches as a rule of thumb.

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

Weak spots, Issues & common problem areas on the B20

The B20 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the B20, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

Check the water pump and head gaskets for leaks, overheating can be costly to fix, so is best avoided.

History of the B20 Engine

Vtec was not fitted to the B20 series engine, the focus was on reliability and performance.

• B20B-B20B4  1996–1998  126–142–140 hp 
• B20B-B20B8  1999 - 2001 148–150 hp
• B20Z2 1999 - 2001 148 - 150 hp
• B20B JDM 1995–1997  146 hp

NB: B20A/B20B (The B series components were extensively revised from the A series and cannot be interchanged or swapped)

For more information on Tuning your Honda engine please join us in our friendly forum where you can discuss B20 tuning options in more detail with our B20 owners. It would also be worth reading our unbiased Honda tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help improving this article, so please send us your feedback in the comments box below and pass on any tips, points or facts we have wrong or have not covered.

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 guides and tips are kept up to date.

Please Check out my YouTube channel, we're regularly adding new content...

Click to accept YouTube Cookies & Play.

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 Acura, Honda. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.