Diesel tuning thoughts please....

[knightly]

I'm interested to hear anyones thoughts on Diesel Tuning. With an aim to being around or above 200Bhp from a 2.0L engine, particularly with regard to:-

1) Re-entrant piston bowl shape (aspect ratio)
2) Compression ratio
3) Injector spray angle
4) amount of spray holes
5) size of each injector spray hole
6) fuel pressure
7) Intake charge temperature
8) typical RPM
9) amount of fuel squirts during the combustion stroke
10) boost levels
11) Cylinder pressure
12) Fuel Cetane level
13 Swirl ratio

I have my thoughts on many of the above, but am keen to hear the diesel experts thoughts, as from what I can see, many diesel boffins seem to be regular visitors to thi site

>> Edited by knightly on Thursday 25th May 08:52

[busa_rush]

Speak to Superships, they have got 250+bhp from the VAG 1.9 TDi engine.

[chuntington101]

i remember readng about VWuk tuning a car for the VW championship and they where sing a diesel. the major things that came out form that was you cant just increas the boost you have to increase fueling to! the way hey did it was by drilling out the stick injectors so they would flow more! this is quiet intence but is worth looking at as only increasing boost willl only go so far!

also i hear traktor pullers use EGT's to tune the engines! worth looking at.

as for normal tunning i would say get a chip, a better intercoler and look at water/meth injection. after that and it starts getting serious!

thanks Chris

[Mikey G]

I think the original posters question asks more about the design aspects of a diesel engine required to get the power not just chipping a current engine.

I think with the modern advancements in common rail technology a lot of the gains can be had in controlling the fuel into the chamber more precicely rather than just squrting more in.

[knightly]

Mikey G is quite right - I'm interested in the intricate comustion aspects of high level diesel tuning......250Bhp from a 1.9 TDI sounds very interesting - I wonder how much black smoke it produces?

yes - adding more fuel is the basics of diesel tuning - not necessarily more air via increased boost - as to state the obvious - a diesel is throttled by fuel - not air!.....the clever bit when tuning is ensuring all the fuel gets burnt in the re-entrant combustion chamber, and doesnt leave the engine unburnt and produce bags of black smoke.......the above 13 points all contribute in one way or another......so come on you lot - spill your beans

>> Edited by knightly on Thursday 25th May 09:12

>> Edited by knightly on Thursday 25th May 09:13

[Pigeon]

On my supercharged two-stroke diesel project my plan is to sidestep the tricky and expensive process of optimising direct injection by using air-cell injection. A single-jet pintle injector sprays a jet of fuel across the combustion chamber (which is in the head) into the air cell, which is a hollow lump shaped like a CO2 cartridge making poor thermal contact with the head. Combustion begins in the air cell and a jet of hot gas blasts back out of the air cell head-on into the fuel jet still issuing from the injector. The heat and turbulence provides good vaporisation and mixing of the fuel.

There are fewer variables to fiddle with, especially where the injector is concerned, and the fiddling can be done without taking the head off. Also the setup is generally much less critical than direct injection. Other advantages are reduced maintenance due to the essentially self-cleaning pintle injector, a much less savage combustion pressure spike and a lighter piston.