Modding and performance tuning parts for the Vauxhall C16SEI engine!

All you need to know about "C16SEI Modifications"

C16SEI Modifications Guide

How to modify and upgrade the Vauxhall C16SEI

"Comprehensive guide to performance tuning the Vauxhall C16SEI engine!"

TorqueCars are always getting messages asking how to improve the C16SEI from people wanting to know what are the best tips for C16SEI upgrades. So let us look into Vauxhall C16SEI parts and outline the best modifications on this great engine and point out some problems along the way.

Now we shall examine the options for your C16SEI tuning and provide tips on the optimum upgrades. Vauxhall C16SEI are popular engines and with the right performance upgrades like remaps, turbo kits and camshafts you will certainly improve your driving enjoyment.

Just because particular upgrades are are common on C16SEI it doesn't mean its worth having, we will focus on the optimum upgrades that will give your C16SEI 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'.

C16SEI induction kits

Improving air intake on the C16SEI

You need air matched to fuel for an engine to work. If there is too little fuel then it will run lean, if there is a lack of air it runs rich losing power which risks damage to the C16SEI. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So the goal to any performance tuning task to pull air into your C16SEI but this has a knock on effect with the air flow sensor.

It is not unusual that there is a limit in the air flow sensor AFM/MAF on the C16SEI when considerably more air is being drawn into the engine.

We note 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting torque at a much lower level.

Engines intake headers take the on the suck phase from the intake filter and allow it to be drawn into the engine cylinders with fuel for the squish phase.

The bore size, shape and rate of flow of the Plenum can make a big improvement to fuel atomisation on the C16SEI.

Commonly we find the intake manifold are in desperate need of performance upgrades, although a few car makers provide fairly well optimized intake manifold.

Big valve conversions on the C16SEI, doing a bit of port matching and head flowing will also boost torque, & importantly will make space for a greater torque increase on other tuning mods.

C16SEI performance cam tips.

Each engine responds better to less aggressive camshaft durations so set your engine up on a rolling road.

The engine timing and injectors and fuel pump also have a large bearing 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.

Significant air intake, and exhaust improvements on the C16SEI can be made from cam upgrades. Changing the cam profile alters the intake and exhaust durations on the engine and can dramatically change the power band and power output.

NB: Fast road camshafts usually increase the performance over the rev range, you may sacrifice a little low end power but the high end rpm power will be better.

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

On a typical daily driver you should ideally to match your bhp range to your preferences.

I would be surprised if you find a C16SEI Competition camshaft is a pleasure to live with when in heavy traffic.

Stage 1, 2 and 3 mods for the C16SEI

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 C16SEI parts:

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

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

Stage 2 C16SEI parts:

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

Stage 3 C16SEI parts:

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

The C16SEI engines respond well to mods and we see that there is a lot of modifications and tuning parts around.

Mapping should help to unlock the full potential of all the parts you've done to your C16SEI.

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

Turbo modifications on the C16SEI

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 C16SEI.

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.

When your motor is turbo charged upgrades are more reliable and we find turbo engines will have strengthened components.

However every engines will need better parts at higher power limits

It is important to find these limitations and fit higher quality crank and pistons to survive the power.

There are many tuners spending a a stack of money on turbo upgrades on the C16SEI only to suffer the humiliation of seeing the engine go up in smoke just after it's used on the roads.

Larger upgraded turbos commonly experience low end lag, and smaller turbos spool up more quickly but do not have the peak end torque gains.

Thankfully the choice of turbos is always increasing and we commonly find variable vane turbos, permitting the vane profile is altered according to speed to lower lag and increase top end bhp and torque.

Twin scroll turbos divert the exhaust gases into a couple of channels and direct these at differently designed vanes in the turbocharger. They also boost 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 setup. We have this guide to twinchargers if you want to read more.

Tips about fuel supply on the C16SEI

You will need to ensure that the engine is not starved of fuel so will have to increase the fuelling when you start extending past 20% of a power hike. Don't forget to be generous with your injector capacity.

As a rule of thumb add another 15% when specifying an injector, this accounts for injector deterioration and affords 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 C16SEI performance exhaust upgrades

You may need to increase your exhaust system with an upgraded one is if your exhaust is creating a restriction in flow.

On most factory exhausts you'll see your flow rate is 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.

Do not go with the biggest exhaust you can buy this will reduce the exhaust flow rate - the best exhausts for power gains are usually between one and a half to two and half inches. Your exhaust design, the bend angles and construction are what have more effect on flow rates than your pipe width to a certain extent. So the exhaust design is a big factor.

The usual suspects causing problems in your exhaust flow rate are traced to the filters installed, so adding a faster flowing high performance alternative will help avoid this restriction.

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

Faults issues and things to look out for on the C16SEI

Like most engines an C16SEI, 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 C16SEI, failure to do this will exacerbate engine wear, on a tuned C16SEI 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 C16SEI why not pop over to the forums at TorqueCars where you can chat about C16SEI tuning options and read about others projects who may be planning to do similar modifications on their C16SEI.

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