320cdw Posted April 30, 2014 Report Share Posted April 30, 2014 (edited) Hi all, To begin I will say that this is my own write up I have not copied from anywhere, it is coming straight out of my little noodle so if you see it elsewhere it is a copy of this! I noticed there is no real definitive guide anywhere on this site, and any other I know of to that end, that gives a basic set of guidelines for diesel engine tuning. I think that many people get a bit overwhelmed when it comes to diving into the world of tuning their car because there is such a lack of information of the basic rules to follow to get the most from their engine. I’ll start this by saying that I am writing this as a guide for you to read, after you’ve read it you’re on your own, I will take and feel no responsibility for anything that goes wrong with your car. It is up to you to have the basic brain ability to know when something is or will go wrong. I’ve just written this for advice, I’m not pretending to be a pro so don’t get high and mighty if I’ve got something wrong because I couldn’t give a…………… Now I am no ECU programmer, never have been and probably won’t get the chance to be but I know how to prepare my car in readiness for the ECU tuning process, which is what this guide will hopefully teach you – it will give you the chance to do everything you can before the car is put on the rollers and made perfect! A diesel engine works under a compression-ignition basis, which means no spark is used to ignite the fuel, the process uses heat and compression to ignite the fuel, as the name suggests. This makes the tuning process a lot different from that of a petrol engine. Before tuning begins please take into consideration the state of the vehicle and its engine, you don’t want to pour time, effort and money into something that will die due to being poorly maintained or kill you due to being too quick for its safety features! Brakes and drivetrain could potentially take a lot of stain from a tuned engine you don’t want them to let you down! I have used the following basics to tune every diesel engine I have had, I like to break the process down into the elements that the engine needs to run; Air Fuel Compression As DIY tuners we can make changes to all 3 listed, but some much more than others. Here’s how I look at it: Air Needs to be; Clean Cool High pressure High quantity Fuel Needs to be: Clean High pressure Well atomised Rationed well with air Compression Needs to be; Correct for the engine in question Not leaking We’ll start with air; A diesel engine needs as much clean, cool, high pressure air as possible to really fulfil its potential. But how to achieve it? Clean Buy a quality high flowing air filter, there are lots of brands and different types, ranging from stock fitting filters to full induction replacement kits. Ensure there are no splits in any hoses, pipes or breathers between your air filter and the inlet on the turbo, sucking in any moisture or crap here won’t do anything any favours. Remove any contaminating parts – EGR valve being the culprit here, it pumps pre-burnt gases back into your engine, these gases will only dampen performance by taking up room for the clean air needed. Cool Ensure the intercooler is man enough for the job – if its small install a larger one Ensure the intercooler is front mounted - allowing the full flow of air from movement Ensure there are no un-needed heat sources in the engine bay – anything that can be “heat-wrapped” should be to prevent the boost pipes from soaking up any unwanted heat upgrade the boost pipes to aluminium – it will deflect heat better than plastic ones and be more stable in general If space allows route the boost pipes as direct and “smooth flowing” as possible – the lower the number of bends and the smoother they are the better the air will flow causing less friction, air friction causes heat Consider porting and polishing – again in the aim of reducing friction Have a look at a water-methanol injection system – this system drastically lowers air intake pressure by spraying a fine mist of water/methanol mix into the inlet manifold, tried and tested it really works and practically steam cleans your engines internals High Pressure/High Quantity Ensure there are no leaks – leaks in the inlet system will cause a drop in pressure and air quantity, from your turbo to your head every part needs to be checked Install aluminium boost hoses – these will not swell under high boost pressures unlike the plastic ones, keep the amount of rubber/silicone hoses to a minimum Ensure the intercooler being used is a good free-flowing one – a restriction here will cause a boost drop and a heat rise Install a larger turbo – larger turbo size means a larger air output, the more air your cramming into the boost pipes the higher pressure it will be Next is fuel; Clean Don’t use cheap fuels – cheap fuels have less good stuff and a lot of crap in them to make them cheap, meaning they don’t burn as well Properly maintain your fuel filter – this will ensure your engine is being fed dirt free fuel, meaning it will flow better and keep your components clean, don’t forget the diesel pump relies on the fuel to keep it lubricated! High Pressure Ensure your injectors are clean and sealing properly – a leaky injector will give off a crap spray pattern and cause an imbalance between cylinders Ensure there are no leaks anywhere along the fuel system – a leak will cause a pressure drop, low pressure means a bad spray Well atomised Ensure injectors are sealing properly – a worn/leaky injector will not atomize the fuel properly causing drops of fuel to be injected, this doesn’t burn very well so will dampen performance Consider a pump refurb – after a lot of hard work a diesel pump will wear and not be as efficient as it once was might be worth getting it refurbed Rationed with air Install larger injectors/nozzles – after upgrading the air system you may find the fuel system cannot keep up with demand installing larger injectors will allow more fuel to be injected to meet demand Lastly compression; Correct/Not leaking Check the engines compression – a lot of hard work will cause wear, wear will cause loose fits between internal sealing components, loose fits means a drop in compression Ensure the head gasket is in good nick – if its leaking and you tune on it, not only will it dampen performance it could cause a lot of damage Consider an engine rebuild – if an engine is worn and low on compression it could benefit from a rebuild, new sealing parts will ensure the compression is up at a level where combustion is efficient Well that’s about it, I use these basic rules before I have my car mapped to give it its best chance of coming out smelling of roses with a decent bit of poke…. Thanks for reading – please feel free to let me know if there’s anything I can add D Edited April 30, 2014 by 320cdw Link to comment Share on other sites More sharing options...
Pauly123 Posted April 30, 2014 Report Share Posted April 30, 2014 You're a clever cookie I'll give you that :-) Link to comment Share on other sites More sharing options...
Rich_D Posted April 30, 2014 Report Share Posted April 30, 2014 Diesel tuning... just add boost & fuel, simples Pauly123 1 Link to comment Share on other sites More sharing options...
320cdw Posted April 30, 2014 Author Report Share Posted April 30, 2014 Diesel tuning... just add boost & fuel, simples I knew I could have saved myself some time, I should have just written that..... Rich_D, TriggerFish and Pauly123 3 Link to comment Share on other sites More sharing options...
