Modding uprating the Nissan SD33 engine!

All you need to know about "SD33 Modifications"

SD33 Modifications Guide

How to modify and upgrade the Nissan SD33

"Comprehensive guide to tuning and performance parts on the Nissan SD33 engine!"

Forums like the one at TorqueCars are regularly getting posts asking how to improve the SD33 from people inquiring about getting more power from the SD33 and wanting to know what are the things tuners recommend when it comes to SD33 upgrades. So let us look into Nissan SD33 parts and outline the best mods that work on this great engine and point out some potential pitfalls along the way.

The Nissan SD33 are good project engines and with the best performance parts like remaps, turbo kits and camshafts you will positively enhance your driving experience.

This pages aim is review SD33 tuning and summarise the greatest mods that work.

When talking about the top parts for your SD33 engine, we are going to concentrate on the ones that give the best power gain for you money.

SD33 induction kits

Improving air intake on the SD33

You need fuel and air for an engine to work. If there is too little fuel then it will run lean, if there is not enough air it runs rich sapping power . We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Feeding air into each cylinder is vital to any engine upgrade task.

It is not unusual that there is a restriction in the air flow sensor (AFM/MAF/MAP) on the SD33 when loads 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 limited performance at a much lower level.

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

The shape and rate of flow of the Headers can make a noticeable difference to to fuel atomisation on the SD33.

Commonly we find the air intake manifolds are in dire need of an upgrade, although a few manufacturers provide reasonably well designed air intake manifolds.

Larger SD33 valves, getting port work and head flowing will also lift performance, & importantly will give you raising the performance increase on other tuning mods.

SD33 performance cam tips.

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

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

A longer valve duration 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.

Significant air intake, and exhaust improvements on the SD33 can be made from cam upgrades. Changing the cam profile alters the intake and exhaust durations on the engine and can dramatically change the torque and power output.

NB: Fast road camshafts usually push up the power across the rpm band, you could sacrifice a little low down torque but the high end rpm power will be higher.

Motorsport and race camshafts, push up the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

For a car used daily you must carefully try to optimize your engines power to your typical driving style.

I'd be amazed if you find a SD33 Motorsport and race cam is a pleasure to live with when in heavy traffic.

Stage 1, 2 and 3 mods for the SD33

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 SD33 parts:

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

Stage 2 SD33 parts:

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

Tuning tips and articles Engine tuning Transmission tuning Care care Intake & exhaust mods Improve handling Forums

Stage 3 SD33 parts:

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

Plan your options and then acquire your upgrades and set yourself a power target to avoid costly mistakes.

Remaps helps fully realize the full potential of all the mods you've done to your SD33.

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 may depend much on the mods you've done and the condition of your engine.

Turbo modifications on the SD33

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 SD33.

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

If the engine is fitted with a turbo parts are giving better power gains and we find turbo engines are made with harder and stronger components.

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

Discover these limits and fit better quality components to handle the power.

We've seen drivers spending a loads of money on turbo charger upgrades on the SD33 only to watch the engine block literally blow up just after it's completed.

Larger capacity turbo chargers often suffer a bottom end lag, and little turbo chargers spool up really quickly but do not have the peak rpm engines power gains.

Thanks to progress the market of turbochargers is always developing and we commonly find variable vane turbochargers, where the vane profile is altered according to speed to lower lag and increase top end performance.

Twin scroll turbochargers divert the exhaust gases into two channels and feed 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 torque gains, although more complex to install. We have this in depth look at twinchargers if you want to read more.

Tips about fuel supply on the SD33

You will need to ensure that the engine is not starved of fuel so need to increase the fuelling when you start exceeding 20% of a power hike. At this point we flag up the need to over specify your injector capacity.

The rule of thumb is to add 20% capacity when specifying an injector, this 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 SD33 performance exhaust upgrades

You only need to to upgrade your exhaust system with an upgraded one is if your current exhaust is creating a restriction in flow.

On most factory exhausts you'll find the exhaust flow rate is still 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 can help balance the flow of gases through the engine.

But if your exhaust pipe is too big, ie: it's over two and a half inches diameter, you will lose much of the exhaust flow rate and end up lacking power and torque.

Usual exhaust restrictions are in the catalyst and filters installed, so adding a better flowing performance alternative will help avoid this restriction.

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

Faults issues and things to look out for on the SD33

Like most engines an SD33, 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 SD33, failure to do this will exacerbate engine wear, on a tuned SD33 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 SD33 why not pop over to the forums at TorqueCars where you can chat about SD33 tuning options and read about others projects who may be planning to do similar modifications on their SD33.

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