Modding uprating the Vauxhall Z16SE engine!

Tuners tips on "Z16SE Modifications"

Z16SE Modifications Guide

How to modify and upgrade the Vauxhall Z16SE

"Comprehensive guide to performance tuning the Vauxhall Z16SE engine!"

Sites like TorqueCars often are getting messages requesting information on how to improve the Z16SE from people wanting to know what are the best Z16SE upgrades. So let us look into Vauxhall Z16SE mods and outline the best upgrades on this great engine and point out some common pitfalls along the way.

The Vauxhall Z16SE offer good returns when tuned and with a few sensible sports mods like a remap, turbo upgrades and camshafts you will noticeably enhance your driving fun.

Our aim here is to examine Z16SE tuning and highlight the optimum modifications.

When talking about the best parts for your Z16SE engine, we are going to focus on the tuning parts that give the best value for money.

Z16SE induction kits

Improving air intake on the Z16SE

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

So Feeding more air into your Z16SE is vital to any engine performance tuning project.

It is common that there's a limitation in the air flow sensor AFM/MAP on the Z16SE when considerably more air is being pulled 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 bhp and torque at a much lower level.

Air Intake manifolds carry the during the engines suck phase from the air filter and allow it to be drawn into the engine cylinders with fuel for the squish phase.

The bore size, shape and flow characteristics of the Intake headers can make a big effect on to fuel delivery on the Z16SE.

Many mass produced engine intake are begging for performance upgrades, although a few makers provide well optimised intake.

Increasing the Z16SE valve size, doing some port work and head flowing will also improve power, and significantly will give you raising the power increase on other parts.

Z16SE performance cam tips.

Some Z16SE engines respond better to more or less aggressive camshaft durations so set your engine up on a rolling road.

The engine timing and fuelling also have an effect on the power gains you'll hit.

A longer valve duration 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 Z16SE camshaft will make a dramatic difference to the engine bhp. Choosing a higher performance camshaft profile raises the bhp accordingly.

NB: Fast road camshafts usually increase the performance through the rpm band, you might lose a little bottom end torque but your higher rpm power will be better.

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

A Motorsport and race cam won't do well if driving around busy urban areas.

You should ideally match your bhp range to your driving style so for a car driven daily stick with a mild fast road Z16SE cam

Stage 1, 2 and 3 mods for the Z16SE

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 Z16SE parts:

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

Stage 2 Z16SE parts:

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

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

Stage 3 Z16SE parts:

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

The Z16SE power trains respond well to upgrades and thanks to their popularity there are increasing numbers of mods and tuning parts about.

Remaps allows a tuner to release the full potential of all the parts you've done to your Z16SE.

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 end result usually differs on the parts you've applied and the condition of your engine.

Turbo modifications on the Z16SE

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 Z16SE.

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 car has a turbocharger upgrades are simpler to install and most turbo engines use stronger components.

However engines will need better parts at higher power limits

We recommend you find these limits and upgrade to better quality crank and pistons to utilize the power.

We've seen people spending a fortune on turbocharger upgrades on the Z16SE only to watch the whole thing catastrophically fail just after it's been completed.

Big upgraded turbo units tend to suffer low end lag, and small turbo units spool up much more quickly but don't have the peak rpm bhp gains.

We are pleased that the choice of turbos is always evolving and we commonly find 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 two channels and push these at differently profiled vanes in the turbocharger. They also increase the scavenging effect of the engine.

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large performance gains, although more difficult to install. We have this article on twincharging if you want to read more.

Tips about fuel supply on the Z16SE

When you increase the bhp and torque you will need to ramp up to the fuelling.

More bhp and torque needs more fuel. Experienced tuners recommend to over specify your injectors flow rate.

The rule of thumb is to add another 20% when specifying an injector, this takes into account injector deterioration and provides a bit of 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 Z16SE performance exhaust upgrades

You should look to upgrade your exhaust system with an upgraded one is if your exhaust is actually creating a flow problem.

On most factory exhausts you'll see the flow rate is still good 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 generally help improve air flow from the engine but avoid an exhaust that is too big or you may end up will reduce the flow rate. Stick to one and a half to two and half inches for best results.

The usual suspects causing problems in your exhaust flow rate come around the catalyst installed, so adding a higher flowing performance alternative will help avoid this restriction.

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

Faults issues and things to look out for on the Z16SE

Like most engines an Z16SE, 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 Z16SE, failure to do this will exacerbate engine wear, on a tuned Z16SE 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 Z16SE why not pop over to the forums at TorqueCars where you can chat about Z16SE tuning options and read about others projects who may be planning to do similar modifications on their Z16SE.

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