Deisel tuning.

Was thinking about porting and polishing recently and wondered what could be used with turbo deisels?

Could you have mirror polished inlet ports as you don't need the turbulence to mix the air/fuel mixture in the port, or do you still need turbulence in the cylinder to encourage mixing? Is that function performed by the shape of the piston?

What's the best way to drag more performance out of a turbo deisel apart from winding the wastegate open and opening the fuel pump up a bit?

groan...

well someone had to do it sooner or later..
Its the rattly can brigade.

It's engineeering! Lol.

yeah,I know..

*walks of sulking*

i recently did a head for one of the lads on E38 (project mince meat in readers rides).

The development on the head proved a lot of grief as the intake ports are what are known as swirl ports. The idea is to introduce a controlled direction to the airflow which turns into turbulance as it enters the cylinder to aid mixing with the stratisfied charge. Much like the tumbe flap does on the intake mani's of the fsi engines.

So the aim was to retain the original flow pattern or even better accentuate it whilst attempting to retain correct port velocity and increase volume of flow.

This is where the fun came into it didn't matter what you did to the port workup flow could not be improves on a swirl port. All that one could achieve is an improved flow pattern to aid mixing in the cylinders. In the end I got 10% gains on the intake through a lot of r&d work.

As for polishing the intakes yes you could mirror finish them with no detriment to performance. There is however no physical flow gain to be had from doing this. What is to be gained however is the reduction in the possible build up of that sticky goey mess tha all the turbo diesels suffer from on the intake through time as there is less surface texture for it to adhere to. Although the same is achieved and in a more succesful way by using a water injection setup.

The exhaust is another story where some extroardinary end flow figures where achieved for the small 31mm valves. Hopefully early next year the head will be bolted on with a gt25 coupled with a remap. At which point the theory can be put into practice. All being well it will end up being the most powerful 8v PD in the UK, but only time will tell.

Looking forward to seeing the result of that!

The only thing that puts me off Diesels is the lack of revs due to the long throw crank and the slow speed at which diesel burns compared to petrol.

We all know long gearing helps the torque stay usable for longer, but it would be really nice to get the benefits of diesel torque + petrol revving A diesel engine like the BMW 335d that could rev to 7K would be ballistic on the road!