Modding upgrading and tuning the VAG 2.7TDi engine!

Tuning guide "2.7TDi Modifications"

2.7TDi Modifications Guide

How to modify and upgrade the VAG 2.7TDi

"Comprehensive guide to tuning and performance parts on the VAG 2.7TDi engine!"

Sites like TorqueCars are frequently getting emails requesting info on how to improve the 2.7TDi from people wanting to know what are the premier 2.7TDi mods that work. So let us look into VAG 2.7TDi upgrades and outline the best modifications on this great engine and point out some problems along the way.

We shall outline options for your 2.7TDi tuning and report on the best upgrades. VAG 2.7TDi are fantastic to work on and with the best performance parts like remapping, turbo improvements and camshafts you will really improve your driving opportunities.

When talking about the ultimate parts for your 2.7TDi engine, we are going to concentrate on the modifications that give the biggest return for your cash.

2.7TDi induction kits

Improving air intake on the 2.7TDi

You need air and fuel for an engine to work. If there is a lack of fuel then it will run lean, if there is little flow of 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 Getting air and fuel into the 2.7TDi engine is the main goal to any engine modification job.

It is common that there is a restriction in the air flow sensor (AFM/MAF/MAP) on the 2.7TDi when considerably more air is being drawn into the engine.

You'll see that 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped bhp and torque at a much lower level.

Headers take the during the engines suck phase from the air filter and allow it to be sucked into the engine cylinders with fuel for the squish phase.

Structure and flow characteristics of the Air Intake manifolds can make a noticeable difference to to fuel mixing and power on the 2.7TDi.

It's not uncommon that intake manifold are in desperate need of aftermarket tuning parts, although a few manufacturers provide decently flowing intake manifold.

Adding a 2.7TDi larger valve kit, doing a bit of 2.7TDi port enlargement and head flowing will also raise torque, and significantly will give you a better torque increase on other modifications.

2.7TDi performance cam tips.

Some 2.7TDi engines respond better to more aggressive cam durations than others.

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

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.

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 bhp gains are on offer for camshaft upgrades.

NB: Fast road cams commonly bump the power over the rev range, you could drop a little low down torque but the higher rpm power will be lifted.

Competition cams, bump the higher rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

For a daily driver you should ideally to match your power band to your preferences.

I'd be shocked if you have found a 2.7TDi Race camshaft is a pleasure to live with when in heavy traffic.

Stage 1, 2 and 3 mods for the 2.7TDi

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 2.7TDi parts:

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

Stage 2 2.7TDi parts:

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

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

Stage 3 2.7TDi parts:

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

The 2.7TDi engines make great tuning projects and thankfully there is an increase of modifications and performance parts out there.

Mapping will help fully realize the full potential of all the parts you've done to your 2.7TDi.

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

Turbo modifications on the 2.7TDi

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 2.7TDi.

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.

If your motor has forced induction parts are giving better power gains and most turbocharged engines are made using many forged and stronger components.

However most engines will have power limits

Discover these limitations and fit more solid crank and pistons to survive the power.

We see many people spending a loads on turbo charger upgrades on the 2.7TDi only to have the 2.7TDi throw a rod when it's used in anger.

Bigger upgraded turbo units often experience a bottom end lag, and little turbo units spool up more quickly but do not have the high rpm power band gains.

Thankfully the market of turbochargers is always moving on and we are seeing variable vane turbochargers, allowing the vane profile is altered according to speed to lower lag and increase top end performance.

Twin scroll turbochargers divert the exhaust gases into 2 channels and feed these at differently angled vanes in the turbo. 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 power gains, although harder to get working. We have this in depth look at twinchargers if you want to read more.

Tips about fuel supply on the 2.7TDi

You will need to ensure that the engine is not starved of fuel so will have to look at the fuelling when you start exceeding 20% of a bhp hike. We strongly recommend you to over specify your flow rate on the injectors.

As a rule of thumb add another 15% when specifying an injector, this accounts for injector deterioration and gives 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 2.7TDi performance exhaust upgrades

The only time you should look to improve your exhaust system with an upgraded one is if your exhaust is actually causing a restriction in flow.

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

Please dont run with the widest 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 catalyst and filters installed, so adding a better flowing 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 2.7TDi

Like most engines an 2.7TDi, 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 2.7TDi, failure to do this will exacerbate engine wear, on a tuned 2.7TDi 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 2.7TDi why not pop over to the forums at TorqueCars where you can chat about 2.7TDi tuning options and read about others projects who may be planning to do similar modifications on their 2.7TDi.

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