DIESEL TUNING METHODS IN DETAIL

TUNING BOXES/TUNING MODULES

Tuning boxes have been on the market in various guises for many years, every since the first 'fly by wire' diesels hit the market (Toyota EFI in 1992 followed by VWTDI. BMW 318/325TDS in the mid-nineties - YES, the Japanese where the first!).
The principle of all tuning boxes is to increase fuel delivery to the engine increasing power & torque.
The way the fuel delivery is increased is by manipulating the signals between the vehicles ECU (Electronic Control Unit) & the engines injection system.
Some of the early tuning boxes where designed, built & on the market before proper long term tests where carried out resulting in a multitude of problems & expensive repair bills. Some of these earlier developed units are still available, a poorly designed unit can damage or wreck the injection system so it's critical that a properly designed unit is fitted.

Pro's

• Delivers a modest power/torque increase.
  
• For the vast majority of vehicles, easy to fit/remove so ideal for warranty purposes.
  
• No need to uprate any other parts of the vehicle.
  
• Increases engine efficiency giving the potential for increased mpg.
  
• The vehicles ECU remains untouched.
  
• Once the unit is removed the engine reverts to standard.

Con's

• Poor units cause excessive smoke from the exhaust.
  
• The overall power increase is very limited (compared to ECU alterations).
  
• The power/torque is only increased in certain areas of the engines RPM band.
  
• Pretty much all vehicles from 2006 CANNOT be successfully 'tuned' via any tuning box.
  
• With the 'Diesel Tuning' market now at saturation level many companies are having to offer very cheap poor quality devices to be competitive, BEWARE!

Who should choose a Tuning Box?

Anyone wanting to increase the power & torque of there diesel by a safe percentage.
Anyone wanting an easy but very limited performance enhancement.

Does Diesel Bob (UK) Ltd offer fuel remapping units?

NO.

ECU ALTERATIONS

A method commonly used to tune modern diesel engines is by altering the factory set parameters within the ECU. This is achieved by either:

Removing the standard chip & soldering a 'performance chip' in it's place.

Removing the factory set data from the ECU & uploading revised data with modified parameters.

Plugging a device into the diagnostic port which will interfere with the standard data within the ECU.

These are also many variants of the above methods but the results are invariably the same.

Pro's

• Generally quite a clean method of tuning, no extra cables or getting your hands dirty.
• Some very high power gains can be achieved.
• Ideal alternative when the fitting of a tuning box is very difficult.
• A well balanced 'MAP' gives a smooth power/torque increase over a far greater RPM range than a tuning box could hope to provide.
• High quality 'MAPS' completely transform an engines power/torque characteristics, rather than just 'enhance' certain parts of it.
• A good 'MAP' will provide vastly better mpg improvements than a tuning box.

Con's

• Usually expensive (though the quality of the result is price dependant)
• Not transferable between vehicles
• Poor quality 'ECU flashing' can give ridiculous increases in power causing an all manner of problems.
• Not mail order (though we can remap certain ECU's this way).

WHO SHOULD CHOOSE ECU ALTERATIONS?

• Anyone wanting more power than what a tuning box can provide.
• An ideal solution when fitting a tuning box is difficult due to poor access.
• Anyone looking for maximum MPG gains.

DOES Diesel Bob (UK) Ltd OFFER THIS METHOD OF TUNING?

YES!

UPGRADE INJECTORS

The use of upgraded injectors is a safe way of increasing power & torque from a diesel engine. Power gains vary depending upon the engine type but anywhere from 2 -15% is possible. The method of upgrading an injector does vary but here is SOME of the methods WE employ, exact procedure depends on application.
Injector break pressure/s are modified.
Pressure springs are replaced with uprated items.
Needle lift is altered.
Nozzle spray pattern is modified.
Nozzle hole positions are altered.
Nozzle hole diameter is enlarged.
Upgraded injectors can be combined with other methods of tuning though please note, our upgraded injectors where developed to use our fuel remapping units or to be used in a standard engine.

Pro's

• A safe method of increasing efficiency, power & torque.

Con's

• Power gains are not always high (application dependant).
  
• Very heavily upgraded injectors can cause idle speed instability, smoke & poor economy.

WHO SHOULD USE UPGRADED INJECTORS?

Anyone looking to add that bit more power &/or wanting a 'crisper' running engine. Ideal time to fit upgrade injectors is when the current injectors are ready for overhauling.

DOES Diesel Bob (UK) Ltd OFFER UPGRADED INJECTORS?

YES.

TURBO BOOST ALTERATIONS

The turbo boost maximum operating pressure is pre-set at the factory, it is set to achieve optimum power/torque gains, turbo charger life, engine longevity.
A very easy way to increase the power of any turbo charged engine is to increase the turbo boost pressure either by fitting a hybrid turbo (a turbo designed to spin faster &/or to generate a higher boost) or altering the wastegate setting thus increasing the boost pressure.

Increasing the boost pressure TOO MUCH will reduce turbo charger operating life. increases the temperatures within the engine & places extra stresses on the engine components, clutch, transmission & final drive components. Basically increasing boost pressure is highly effective but a very savage way of increasing the power output of an engine.

When boost pressure is increased & it's done properly, the engine requires uprating (e.g. heavier duty pistons, crankshaft), the clutch needs to be replaced with a stronger more robust item & uprating of the final drive components is carried out. Water injection is fitted when engines run very high turbo boost pressures to reduce the extremely high temperatures that occur.

Pro's

• Increases power output by a large percentage

Con's

• When carried out professionally, expensive.
• When carried out without uprating the rest of the engine (cheaply), wrecks the engine.

WHO SHOULD CHOOSE TURBO BOOST ALTERATIONS?

Those that demand a high power increase & are prepared to pay to have the job done properly or are prepared for the expensive repair bills. Rally car drivers when the engine will be rebuild after every race.

DOES Diesel Bob (UK) Ltd OFFER TURBO BOOST ALTERATIONS?

ONLY MODEST INCREASES, CARRIED OUT DURING OUR ECU REMAPS.

DUMP VALVES

Although not a true tuning option these devices are now available for all engines fitted with a turbo charge including diesels. These devices release excess turbo boost pressure when it's not required i.e. When changing gear, which is often claimed to reduce turbo lag.

Pro’s

• Everyone will know your coming.
  
• Something to polish at the weekend

Con's

• Makes the vehicle sounds like it has asthma or some serious bronchial problem.

WHO SHOULD BUY A DUMP VALVE?

The perfect companion to a performance filter (something else to polish)
Anyone wanting there vehicle to sound like it has asthma.

DOES Diesel Bob (UK) Ltd OFFER DUMP VALVES?

NO!

PERFORMANCE AIR FILTERS

An age old method of increasing an engines power output from the days when air intake systems where poorly designed.
Modern diesels have long used free flowing air intake systems & filters so the trend to use performance alternatives has very limited effects, if any. Many companies who supply such 'performance filters' show a before & after graph & the power gains achieved but the only possible way such increases can occur is when the 'performance' filter is tested against an old partial clogged filter. The standard intake system & filter is more than capable of handling the extra power created by most commonly employed tuning methods (ECU alterations, fuel remapping units) so provided the standard air filter is changed at the correct service intervals there's no need to use performance filters.

Pro's

• The filter element is generally reusable so in the very long run a performance filter may prove cost effective.
  
• The 'cone' or 'trumpet' versions can look attractive, if that's what your into!
  
• Useful when modifying the intake system (i.e. Fitting an intercooler) or if a different engine is being fitted & the original intake system/filter will not fit.
  
• Makes the engine sound more responsive & 'lively'.

Con's

• Noise levels can become unacceptable (the original system was developed to be quiet).
  
• Requires washing & drying at the correct intervals (messy).
  
• Over rated, power increases are very negligible.

WHO SHOULD BUY PERFORMANCE AIR FILTERS?

Anyone wanting the 'boy racer' sound or if fitting a standard air intake system is not possible. A viable option to save money in the very long run rather than using standard filters.

DOES Diesel Bob (UK) Ltd OFFER PERFORMANCE AIR FILTERS?

No.

INTERCOOLERS

The intercoolers purpose is to cool the air after it leaves the turbo charger (where it becomes very hot due to compression & it's close proximity to the exhaust gases) before it enters the engine.
Cool air is more dense containing the much needed oxygen essential to any combustion process, the more air (or to be precise - oxygen) one can force into an engine the better & cleaner the combustion process which also equals more power.
The turbo & the diesel engine are the ideal partner, the turbo, intercooler & diesel engine are the perfect combination. When looking to purchase a diesel turbo vehicle we strongly advise opting for one with an intercooler, non intercooled diesels are common but never as efficient as the intercooled variants.
Fitting an enlarged intercooler is an effective method of increasing power especially when combined with fuel remapping units.

Pro’s

• A safe & effective method of increasing power.
  
• Fitting an intercooler to a non intercooled engine increases efficiency.

Con’s

• Good quality intercoolers are made from high grade aluminium alloy = expensive.
  
• Depending on vehicle, fitting an intercooler or fitting an enlarged unit can be very difficult & require rather serious modifications.

WHO SHOULD FIT AN INTERCOOLER OR ENLARGED INTERCOOLER?

Anyone running a turbo diesel without an intercooler (ie Toyota Surf owners with the 2.4 2L-TE engine) Anyone who has had fueling alterations carried out & the exhaust emits thick black smoke, you need more air (OXYGEN)!

DOES Diesel Bob (UK) Ltd RETRO FIT INTERCOOLERS OR OFFER ENLARGED INTERCOOLERS?

Not at the moment.

PERFORMANCE EXHAUSTS

Performance or 'free lowing exhausts' are another product that came into being when the original exhaust systems where poorly designed & had too much 'back pressure'. Modem vehicle designers have addressed this issue by fitting an optimum efficiency exhaust at the factory. Modern standard exhaust systems are more than capable of handling commonly employed tuning methods (tuning boxes, ecu alterations) so as with performance air fillers' there really is no need to spend your hard earned on a ‘free flowing exhaust'. The before/after graphs shown when a performance exhaust is fitted really should be taken with a pinch of salt.

Pro’s

• 100% stainless steel exhausts will last forever, so in the long term a financial saving may be seen.
• A performance exhaust will make the engine sound more powerful.
  
• Big bore tail pipes are supposedly 'bling'.
  
• Useful if the engine is undergoing very heavy modifications.

Con's

• Can make the vehicle sound more like a tractor.
• Over rated, power gains negligible if any.
• If the 'CAT' pipe is bypassed may cause MOT failure when the law is reviewed.

WHO SHOULD FIT A PERFORMANCE EXHAUST?

Anyone wanting a noisier exhaust sound.
Anyone wanting an exhaust to last the lifetime of the vehicle (only applies to 100% stainless steel systems).

DOES Diesel Bob (UK) Ltd OFFER PERFORMANCE EXHAUSTS?

No.

PROPANE (or L.PG.) INJECTION

Duel fuel diesels have been around for many years, mainly found in truck engines, to help eliminate smog problems in many large cities. The truck runs on 100% diesel outside the cities but once within the smoke restriction areas the driver activates a switch to allow propane to be introduced to the combustion process. Diesel fuel use is reduced & the propane also produces a much cleaner 'burn' so reducing emissions. Whilst propane injection was developed as a clean running system the potential for massive power gains was realised, probably by accident!!

The power increases obtained from propane injection are quite amazing, the damage created by a poorly set up system is equally impressive! Having to chisel out the pistons from a MAN truck engine due to the propane set up being 'a tad out' is hard work.

Whilst propane injection is an effective method of increasing the power of a diesel engine the same uprating of the engine components should be carried out as when increasing turbo boost pressure.

Pro's

• Very high power gains are achievable.
• When set up for efficiency benefits rather than just power this system gives a very clean running engine with good economy returns.

Con's

• Can wreck an engine very quickly if not set up 100% correctly.
• A reliable, effective & safe system will be expensive.
• Locating the propane tank needs to be carefully planned & must conform to the relevant regulations.

WHO SHOULD USE PROPANE INJECTION?

• The ideal option for anyone wanting their diesel to run cleaner & more efficiently.
• Anyone looking to use their diesel on the drag strip.

DOES Diesel Bob (UK) Ltd OFFER PROPANE INJECTION?

Not at the moment but we are investigating further into this method of tuning.

OTHER METHODS

There are a few other 'tuning' devices on the market which claim to provide quite amazing power & economy gains.

FUEL MAGNETS

These things have been on offer for petrol & diesel vehicles for over a decade now & keep reappearing in different, guises.

Two main types exist.

One type comes in the form of a 2 piece magnet that you place around a fuel supply pipe & cable tie it in place. The other type is an electro-magnet powered by the vehicles battery with a coil of wire wrapped around a fuel pipe.

How do they work ? Gullible springs to mind.

WHIRLY/ SPINNYTHINGS

One of the latest 'amazing products' now available for diesels.

A metal fan is fitted in the air intake pipe between the air filter & turbo (or inlet manifold) which spins due to the air being drawn over it. This then makes the air swirl which supposedly increases engine efficiency.

Surely the turbo charger spinning at thousands of rpm will 'swirl' the air better than any added fan? And the turbo charger came as standard.

DOES Diesel Bob (UK) Ltd OFFER ANY OF THE ABOVE?

NO.