Thread: How to get 400Nm from RRC

Originally Posted by uninformed

I certainly would not call it very much either. Even when not comparing it to the stock diesel cars/4x4 we see on our roads and then taking into account the HP those race engines are making from their respective capacities

For the use and performance figures its not much, for me!...was just a point of view, since someone claimed there was never a "wisp" emitted!

Regards

Originally Posted by rovercare

“In theory, theory and practice are the same. In practice, they are not.”

...

If theory and practice is not the same then either:

a. The practicians do not understand the theory.

or

b. The theory has been (over) simplified so is no longer a sufficiently accurate representation of the system.

Some things are so complex that they should be tested, such as comparing CFD and confirming flow or in the wind tunnel. A blanket hp rating on a motor based on A/F ratios and boost is an oversimplification that does not account for the associated technology and environments.

Originally Posted by Slunnie

Some things are so complex that they should be tested, such as comparing CFD and confirming flow or in the wind tunnel. A blanket hp rating on a motor based on A/F ratios and boost is an oversimplification that does not account for the associated technology and environments.

Of course theory should be validated! That is a completely different issue.

(most) CFD is not theory. Most CFD methods are numerical approximations of the theory, for situations where the theoretical equations cannot be solved analytically (completely) - often with many simplifications included. CFD also needs to be validated.

HOWEVER, a correctly implemented DNS (direct numerical simulation) is more accurate than any experiment.

Originally Posted by Slunnie

Some things are so complex that they should be tested, such as comparing CFD and confirming flow or in the wind tunnel. A blanket hp rating on a motor based on A/F ratios and boost is an oversimplification that does not account for the associated technology and environments.

There is no blanket HP rating, no such thing was even hinted at.
You need to read that entire post again and then get back to us.

This isn't some wild arse untested theory on how engines work. This is how a/f ratios, torque, egt and smoke interact.

Increasing power and torque substantially comes next. But only once you get the first relationships as it requires understanding of those to build upon.

Originally Posted by isuzurover

Of course theory should be validated! That is a completely different issue.

(most) CFD is not theory. Most CFD methods are numerical approximations of the theory, for situations where the theoretical equations cannot be solved analytically (completely) - often with many simplifications included. CFD also needs to be validated.

HOWEVER, a correctly implemented DNS (direct numerical simulation) is more accurate than any experiment.

Indeed, CFD and FEA are approximations requiring thousands or even millions of calculations for situations where analytical calculations aren't practical or can't deal with the detail. But for every critical FEA plot I run, I back it up with hand calcs for verification before complicating the model. Simply because the chance of a typo in any input is very real.

I'll get that intake model sorted for you today Ben. I've been sick.

For the record Jose has done it he has sent me a map that does all I want.
Very little smoke can drive the TD5 like a 4BD1 not like a 2 stroke motor bike.
This guys skills are exceptional.

Thank you Jose

So, with no more questions about A/F ratios and smoke. Lets look at what the TD5 can and can't do in relatively stock form.

Turbo diesel performance hangs entirely on boost and what boost can and cannot be produced by the turbo attached to it.

The stock turbo on a TD5 disco is a garrett GT2052S Model - 452239-0008.
The GT2052S model designation means it has a 52mm compressor wheel, a GT20 turbine and is wastegated.
Turbomaster have the whole parts listing here: Garrett Model GT2052S Repair List - 452239-0008 reference - Turbos - TurboMaster

The 52mm compressor wheels are available in many different trims to bias them towards either more airflow or more boost. Dig through the turbomaster build list above and the compressor wheel used is the 451584-0007.
Turbomaster are kind enough to also list all common garrett compressor wheels here with their measurements: Compressor Wheels - Garrett Racing - Applications - TurboMaster

Scroll down and we find the wheel in the TD5 has a 38.3mm inducer, which with the 52mm exducer works out to 55 trim.
Trim is the area ratio of inducer (intake) to overall diameter. Smaller trim wheels are suitable for higher boost, larger trim wheels are suitable for higher flow.

Garrett don't publish a compressor map for this exact compressor wheel, their 52 trim 52mm wheel is the closest. It is here:


I'll plot out some operating points on it soon to show where the stock engine runs and what scope their is for more boost and airflow without exploding anything.