Guide to tuning the B18 engine from Honda

"Thanks for reading our B18 engine tuning guide"

We examine the options for your B18 tuning and point out the greatest mods that work.

Honda B18s great bases for a tuning project and with a few sensible motorsport parts you can improve your driving pleasure.

Some of the JDM spec versions of these B18 engines had increase compression and higher power outputs than in other markets.

Check out our video introduction to Honda Tuning, all you need to know about mods and upgrades on your Honda.

History, Power & Specs of the B18 Engine

The B18 was the most popular B series engine produced by Honda, and was deployed in family cars and performance cars alike with various states of tune.

VTEC and compression ratio played a large part in the power figures on offer.

We cover the B17 and B17, B20 in another more focussed article, although they share the B series design and block with a few differences.


  • 1990–1991 Acura Integra USDM "RS/LS/LS Special Edition/GS" (DA9 Liftback/Hatchback, DB1 Sedan)
    Power: 130 bhp (97 kW; 132 PS) at 6000 rpm & 121 lbft (164 Nm) at 5000 rpm

 B18A shares much with the B20A engine.

  • 1986–1989 Accord Aerodeck LXR-S/LX-S (Japan)
  • 1986–1989 Accord EXL-S/EX-S (Japan)
  • 1986–1989 Vigor MXL-S (Japan)
    Power: 100 hp (75 kW; 101 PS) at 6100 rpm & 128 lbft (174 Nm) at 4700 rpm


  • 1992-1993 Acura Integra USDM "GS/LS/LS Special Edition/RS" (DA9 Liftback/Hatchback, DB1 Sedan)
    Power: 140 bhp (104 kW; 142 PS) at 6300 rpm & 126 lbft (171 Nm) at 5000 rpm


  • 1990-1993 Honda Integra LS DB1 Sedan (Made in India)
  • Power: 140 hp (104 kW; 142 PS) at 6300 rpm & 126 lbft (171 Nm) at 5000 rpm


  • 94-01 Integra RS/LS/SE/GS - DB7/DC4/DC3
  • 1994–2000 Honda Integra "RS/LS/GS/SE/(GSI Australia)" (DC4/DB7)
  • 1992–1996 JDM Honda Domani (MA5)
  • 1993–1994 JDM Honda Integra (DB7)
  • 1996–1999 JDM Honda Orthia (EL1)
    Power: 140 bhp (104 kW; 142 PS) at 6300 rpm & 127 lbft (172 Nm) at 5200 rpm


  • 94-01 Integra RS/LS/SE/GS - DB7/DC4/DC3
  • 1994–2001Honda Integra "RS/LS/GS/SE/(GSI Australia)" (DC4/DB7)
    Power: 143 bhp (107 kW; 145 PS) at 6300 rpm & 127 lbft (172 Nm) at 5200 rpm


  • 1992–1995 Honda Civic – Middle East & South Africa Ballade (SR4)
    Power: 143 hp (107 kW; 145 PS) at 6000 rpm & 123 lbft (167 Nm) at 5000 rpm


  • 1996–2000 Honda Civic – Middle East & South Africa Ballade (SO4)
    Power: 103 kW (140 PS; 138 hp) at 6200 rpm & 126 lbft (171 Nm) at 4900 rpm

JDM B18C Type R  Honda Integra (JDM) DOHC VTEC

  • 96-01 Honda Integra JDM Type R (DC2 & DB8)
    Power: 197 hp (147 kW; 200 PS) at 8000 rpm & 180 Nm (133 lbft) at 7200 rpm (96 spec) ; 200 hp (149 kW; 203 PS) at 8000 rpm & 186 Nm (137 lbft) at 6200 rpm (98 spec)


  • 95-98 Honda Integra JDM SiR/SiR II (DB8, DC2)
  • 98-99 Honda Integra JDM SiR-G (DB8, DC2)
    Power: 132.5 kW (180 PS; 178 bhp) at 7200 rpm & 126 lbft (171 Nm) at 6200 rpm


  • 1994–2001 Acura Integra USDM GS-R (DC2 & DB8)
    Power: 170 hp (127 kW; 172 PS) at 7600 rpm


  • 1994-2001 Honda Integra AUDM/NZDM VTi-R
    Power: 170 hp (127 kW; 172 PS) at 7300 rpm


  • Honda Integra Asian market
    Power: 187 hp (139 kW; 190 PS) at 7600 rpm & 174 Nm (128 lbft) at 7500 rpm


  • 1996–2000 UK Civic VTi 5-door Hatch (MB6)
  • 1996–2000 UK Civic 1.8i VTi-S (Limited Edition) 5-door Hatch (MB6)
  • 1996–2001 UK Civic Aerodeck 1.8i VTi 5-door Wagon (MC2)
  • 1998–1999 EU Civic Aerodeck 1.8i VTi 5-door Wagon (MC2)
  • 1998–1999 EU Civic 1.8i VTi 5-door Hatch (MB6)
    Power: 169 hp (126 kW; 171 PS) at 7600 rpm & 128 lbft (174 Nm) at 6200 rpm

B18C5 (Type R) DOHC VTEC

  • 1997-1998,1999 CDM, 2000-2001 Acura Integra USDM/CDM Type R
    Power: 195 hp (145 kW; 198 PS) at 7800 rpm & 130 lbft (176 Nm) at 7500 rpm

B18C6 (Type R) DOHC VTEC

  • 1998–2001 Honda Integra UKDM/EUDM Type R
    Power: 190 PS (140 kW; 187 hp) at 7900 rpm & 131 lbft (178 Nm) at 7300 rpm

B18C7 (Type R) DOHC VTEC

  • 1999-2001 Honda Integra AUDM/NZDM Type R
    Power: 189 hp (141 kW; 192 PS) at 8200 rpm & 172 Nm (127 lbft) at 7500 rpm

Best B18 mods

The optimum parts on an engine are in our opinion the ones that give the biggest return for your cash. We won't be swayed by popular B18 parts, they need to be cost effective.

Altering your B18 cam will make a dramatic difference to the engine torque. Choosing a higher performance cam profile raises the torque accordingly.

Fast road cams normally increase the torque over the rev range, you could sacrifice a little low end power but the top end will be higher.

Motorsport 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 road car should ideally to match your engines power to your usage of the car.

I would be surprised if you have found a Competition camshaft is a pleasure to live with when on the daily commute, because the lumpy idle will make the car prone to stall and smooth driving at low rpm becomes impossible. If you are developing a track car this doesn't matter as you are in the high end of your RPM range anyway and that is where you want the power to be.

Different B18 engines respond better to extreme camshaft durations check your engine on a rolling road.

The ECU mapping and fuelling also will say much on the bhp gains you'll hit.

Extending exhaust or intake 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.

Please watch our video which covers the principles of tuning your B series engine. Be sure to keep up with our latest YouTube content and subscribe.

Best Engine Mods for your car

  1. Engine Tunes - engine tuning/remapping provides the most advantage in terms of cost savings,  aftermarket ECUs, and piggyback ECUs are all alternatives.
  2. Fast road cams are one of the most significant mechanical changes, but they must be installed by someone who knows what they're doing and they are not always easy to source but you might find a local firm to regrind a stock camshaft.
  3. Intake and Exhaust - Note that on their own these mods will NOT ADD POWER in most cases, but they can help enhance power after other mods by removing the restriction.
  4. Upgrades to turbochargers and superchargers - forced induction is the most efficient approach to increase air supply, allowing you to burn more fuel and make more power. It is one of the most costly upgrades but provides the best gains.
  5. Head work - The goals of porting and flowing the head are to get air flowing into the engine while removing flow restrictions and turbulence.

Typical stage 1 mods often include: Intake manifolds, Sports exhaust header/manifold, Fast road camshaft, Panel air filters, Remaps, .

Typical stage 2 mods often include: Sports catalyst & performance exhaust, Ported and polished head, fuel pump upgrades, Fast road cam, high flow fuel injectors, .

Typical stage 3 mods often include: Engine balancing & blueprinting, Adding or Upgrading forced induction (turbo/supercharger), Competition cam, Internal engine upgrades (pistons/head/valves), Twin charging conversions, .

The B18 engines are great to work on and we see that there is a lot of mods and tuning parts out there.

ECU mapping helps unlock the full potential of all the upgrades you've fitted to your B18.

(In some cases, as the factory ECU is locked flashing is not an option, so an aftermarket ECU is the route to take, and many of these will outperform factory ECU's but make sure it has knock protection and that you get it setup properly.)

It will usually give you around 30% more power on turbocharged vehicles and 15% on NA (naturally aspirated) engines, but you mileage will vary depending on the upgrades you've done and the condition of your engine.

It is vital to any car tuning project to pull more air into the B18 engine

Plenum take the air from the air filter and allow it to be sucked into the engine cylinders.

Design and flow rate of the Plenum can make a large effect on to fuel delivery on the B18.

Commonly we find the intake manifolds are in desperate need of aftermarket tuning parts, although some OEM provide well optimised intake manifolds.

Larger B18 valves, getting port matching and head flowing will also improve bhp, and significantly will afford you raising the bhp increase on other parts.

B18 Turbo upgrades

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

NA (naturally aspirated) 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 B18

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

See where you'll find these restrictions and upgrade to higher quality components to survive the power. We've seen drivers spending a lot of money on turbocharger upgrades on the B18 only to have the engine explode just after it's used in anger.

It is not unusual that there is a limitation in the air flow sensor MAF/MAP on these engines when loads more air is being fed into the engine. Going up you'll find 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor limited bhp at a much lower level.

Adding a supercharger or additional turbo will make large power gains, although harder to setup. We have a twincharger power adding guide if you want to read more.


When you raise the bhp you will need to pay attention to the fuelling.

More bhp needs more fuel. We strongly recommend you 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 affords you some spare capacity should the engine need more fuel.


B18 Exhaust

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

The Type R versions show the way for the other versions, with improved exhaust design.

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

Do not go with the largest exhaust you can source this will slow up the exhaust flow rate - the best for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Common exhaust restrictions are traced to the filters installed, so adding a better flowing high performance aftermarket one will improve air flow, and rather than doing an illegal decat, will keep the car road legal.

Weakspots and problem areas on the B18

The B18 engines are generally reliable and solid units, as long as you follow the manufacturers service schedules, and use a good quality oil to ensure longevity. Few problems should happen as long as they are regularly serviced and maintained.

Carbon build up in the head, particularly around the valves which will sap power or create flat spots, this is a larger issue on direct injection engines but should be looked out for on all engines. We have tips on removing carbon build up.

Some of our members have had issues with flat spots or glitches after applying mods and upgrades or tuning, this is not usually related to this engines design, so instead see our article on diagnosing flat spots and problems after tuning which should help you get the bottom of this issue.

Regular oil changes are vital on the B18, especially when tuned and will help extend the life and reliability of the engine.

If you would like to know more, or just get some friendly advice on Tuning your Honda engine please join us in our friendly forum where you can discuss B18 tuning options in more detail with our B18 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.

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