Tuning the Vauxhall C16SEI

"Comprehensive guide to tuning the Vauxhall C16SEI engine!"

We are frequently getting posts requesting information on the things we are recommending when it comes to C16SEI mods that work. So let us look into Vauxhall C16SEI modifications and outline the best upgrades on this great engine and point out some problems along the way.

Therefore we review C16SEI tuning and summarise the optimum modifications. Vauxhall C16SEI make a good tuning project and with a few sensible performance parts like ECU maps, turbo kits and camshafts you will substantially increase your driving enjoyment.

When talking about the optimum parts for your C16SEI engine, we are going to concentrate on the ones that give the biggest return for your cash.

The camshaft profile plays a big part in the engines power output so camshaft upgrades make quite a large difference. The intake and exhaust durations will alter depending on the chosen camshaft profile, so large engines power gains are on offer for camshaft upgrades.

NB: Fast road cams normally push up the torque across the rpm range, you may lose a little low end bhp but the top end will be lifted.

Competition cams, push up the top end band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Motorsport and race camshaft won't do well if on the daily commute.

You should ideally match your bhp range to your driving style so for a car driven daily stick with a fast road C16SEI camshaft

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

The ECU mapping and injectors and fuel pump also will say much on the torque gains you'll achieve.

Longer valve durations 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.

C16SEI Tuning Stages

Stage 1 C16SEI modifications: Intake headers, Sports exhaust manifold, Remaps/piggy back ECU, Panel air filters, Fast road camshaft, Drilled & smoothed airbox.

Stage 2 C16SEI modifications: induction kit, Ported and polished head, high flow fuel injectors, Fast road cam, Sports catalyst & performance exhaust, fuel pump upgrades.

Stage 3 C16SEI modifications: Internal engine upgrades (head flowing porting/bigger valves), Crank and Piston upgrades to alter compression, Competition cam, Engine balancing & blueprinting, Adding or Upgrading forced induction (turbo/supercharger), Twin charging conversions.

ECU flashing should help to fully realize the full potential of all the tuning parts you've done to your C16SEI.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but the outcome will rely on the tuning parts you've carried out and the condition of your engine.

It is the whole point to any engine modification task to get fuel and air into the C16SEI engine

Intake headers take the air from the filter and allow it to be fed into the engine cylinders.

The size of bore and shape and rate of flow of the Air Intake manifolds can make a noticeable effect on to fuel engine efficiency on the C16SEI.

We often see intake manifold are ripe for an upgrade, although some car makers provide reasonably well designed intake manifold.

Increasing the C16SEI valve size, doing a bit of port matching and head flowing will also lift bhp, and importantly will permit a better bhp increase on other mods.

Turbo upgrades for the C16SEI

NASP 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 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 significant power gains.

When the engine is fitted with a turbo parts are more reliable and you'll see that turbo engines will have uprated components.

However you will find an engines will have power limits

See where you'll find these restrictions and upgrade to better quality components to utilize the power.

We've seen people spending a loads of money on turbo charger upgrades on the C16SEI only to experience the engine literally blow up when it's finished.

Large turbo units commonly experience no power at low rpm, and smaller turbo units spool up much more quickly but don't have the top end torque gains.

In recent times the market of turbo chargers is always evolving and we now see variable vane turbo chargers, permitting the vane angle is altered according to speed to lower lag and increase top end performance.

Twin scroll turbo chargers divert the exhaust gases into two channels and direct these at differently profiled vanes in the turbo. They also improve the scavenging effect of the engine.

It is common that there is a restriction in the air flow sensor AFM/MAF on the C16SEI when considerably more air is being drawn into the engine.

Going up you'll find 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting performance at a much lower level.

Adding a supercharger or additional turbo will make large bhp gains, although more difficult to install. We have this feature on twinchargers if you want to read more.

Uprating C16SEI fuel injectors

Don't miss you'll need to look at the fuel system when you are increasing the torque - it makes the car more thirsty. It makes sense to over specify your injectors flow rate.

The accepted safe increase is to add another 20% when specifying an injector, this takes into account injector deterioration and provides some spare capacity should the engine require more fuel.

We think this one is common sense, but you'll need to match your fuel injector to the type of fuel your car uses as well.

Best C16SEI performance exhausts

You may need to improve your exhaust if your exhaust is actually causing a restriction.

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

Sports exhausts will certainly help air flow out of the engine but avoid an exhaust that is too wide or you could will reduce the flow rate. Stick to 1.5 to 2.5 inches for best results.

Typically exhaust restrictions come around the catalysts installed, so adding a faster flowing sports alternative will help avoid this restriction.

Problems and issues to look out for on the C16SEI

The C16SEI engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the C16SEI, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your C16SEI engine please join us in our friendly forum where you can discuss tuning options in more detail with our C16SEI owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help to complete and improve this page, so do give us your feedback in the comments box below.

We really like hearing from our readers, and hearing about which upgrades were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our C16SEI guides and tips are kept up to date.

Please Check out my YouTube channel, we're regularly adding new content...

Click to accept YouTube Cookies & Play.

This article is flagged for an update, so please pass on specific tips below that I can include. All articles, and content was written by me, Waynne Smith TorqueCars founder. Some outlines are just too general so I appreciate your feedback and suggestions. This entry was filed under Vauxhall. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.