Modding upgrading and tuning the Nissan SD33T engine!

Tuners tips on "SD33T Modifications"

SD33T Modifications Guide

How to modify and upgrade the Nissan SD33T

"Comprehensive guide to tuning the Nissan SD33T engine!"

Our friends at TorqueCars are always seeing threads about how to improve the SD33T from people inquiring about getting more power from the SD33T and wanting to know what are the best tips for SD33T power upgrades. So let us look into Nissan SD33T parts and outline the best upgrades on this great engine and point out some common pitfalls along the way.

The Nissan SD33T offer good returns when tuned and with the optimum modified modifications like remaps, turbo improvements and camshafts you will really maximise your driving enjoyment.

Here we consider SD33T tuning and point out the greatest modifications.

Just because particular modifications are appear in lots of SD33T projects it doesn't mean its worth having, so we'll focus on the top modifications that will give your SD33T the best power gain for you spend.

Without us subscribing to the common myth of 'if it's shiny and makes more noise it must be good' you seem to get in many tuning magazines and on car forums'.

SD33T induction kits

Improving air intake on the SD33T

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

So Forcing fuel and air into each cylinder is the whole point to any engine modification task.

You'll commonly see there is a limit in the air flow sensor AFM/MAP on the SD33T when considerably more air is being sucked into the engine.

When tuning you may well find you need to get an air sensor or flow meter capable of upto 4 bars to cope with quite large power gains, whereas the OEM air sensor sapped power at a much lower level.

Intake manifolds flow the air from the air filter and allow it to be drawn into the engine cylinders with fuel for the squish phase.

The shape and flow characteristics of the Plenum can make a big difference to to fuel mixing and power on the SD33T.

Most plenum chambers are improved through motorsport parts, although a few car makers provide decently flowing plenum chambers.

Larger SD33T valves, getting 3 or 5 angle valve jobs and porting and head flowing will also improve performance, and significantly will raise potential for a greater performance increase on other tuning mods.

SD33T performance cam tips.

Each engine responds better to mild cam durations check your engine on a rolling road.

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

Altering valve durations can alter the power 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.

Altering your SD33T camshaft will make a dramatic difference to the engine bhp. Choosing a higher performance camshaft profile raises the bhp accordingly.

NB: Fast road cams tend to push up the bhp and torque throughout the rev range, you may sacrifice a little low down power but the high end rpm power will improve.

Motorsport and race cams, 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.

In a road car you should ideally to optimize your torque band to your typical driving style.

I'd be surprised if you have ever thought a SD33T Motorsport and race camshaft is a pleasure to live with when on the daily commute.

Stage 1, 2 and 3 mods for the SD33T

Stage 1 SD33T parts:

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

Stage 2 SD33T parts:

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

Stage 3 SD33T parts:

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

The SD33T power trains respond well to upgrades and we note that there is a lot of modifications and tuning parts about.

Remapping should help to unlock the full potential of all the parts you've done to your SD33T.

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 vary depending on the parts you've applied and the condition of your engine.

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

Turbo modifications on the SD33T

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 SD33T.

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

When your motor is fitted with a turbocharger tuning mods are giving better power gains and most turbo engines are made with many forged and stronger components.

There are weak spots for every engine, with some being very over engineered and some only just able to handle stock power

See where you'll find these restrictions and fit higher quality crank and pistons to survive the power.

It's not unheard of tuners spending a fortune on turbocharger upgrades on the SD33T only to have the engine block explode on it's first outing after it's been finished.

Large capacity turbo chargers will usually experience a bottom end lag, and small turbo chargers spool up more quickly but won't have the top end power band gains.

Over the last 20 years the range of turbos is always improving and we now see variable vane turbos, permitting the vane angle is altered according to speed to lower lag and increase top end torque.

Twin scroll turbos divert the exhaust flow into a couple of channels and direct these at differently profiled vanes in the turbocharger. 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 power gains, although more difficult to install. We have this feature on twinchargers if you want to read more.

Tips about fuel supply on the SD33T

Don't omit to look at the fuelling when you are increasing the torque - it makes the car more thirsty. Experienced mechanics will tell you to be generous with your flow rate on the injectors.

The rule of thumb is to add 15% to the flow rate when buying an injector, which takes into account injector deterioration and allows a bit of 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 SD33T performance exhaust upgrades

You may need to improve your exhaust system with an upgraded one is if your exhaust is actually creating a restriction.

On most factory exhausts you'll find the flow rate is still ok 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 your exhaust is too large, ie: it's over two and a half inches diameter, you will lose a great deal of your flow rate and end up sapping power and torque.

Typically exhaust restrictions can be located the catalysts installed, so adding a freer flowing race 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 SD33T

Like most engines an SD33T, 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 SD33T, failure to do this will exacerbate engine wear, on a tuned SD33T 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 SD33T why not pop over to the forums at TorqueCars where you can chat about SD33T tuning options and read about others projects who may be planning to do similar modifications on their SD33T.

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