t2 turbo

[n0v0s]

Yes and no really, our engine have a relatively low VE about 76% I calculated at, and since we aren't making monster amounts of power then we don't need mega amounts of air, and because we aren't making peak power at 6 or 7 k rpms so we need more torque to make up for the lack of revs and engines that make power at lower RPMS need more boost pressure because were are making peak power at 4 or 5k rpms.

this is the compressor map for the TD04L-13g that's commonly found on Impreza WRX's (what year I don't know..) that we tend to use....

From looking at that compressor map, the maximum amount of boost that compressor is designed to run is about 25 psi, which is plenty for most people and maximum flow is about 280 hp worth of air which way more than we would need on a standard engine, and obviously you can run less than that....

Now lets have a look at the GT2056's....

Again just looking at the compressor map, the maximum boost that this turbo is designed is around 37 psi, which is an extra 12 psi! granted it is at the very top of the compressor map and our plot might not end up there but it just give you and idea of what we potencially have to play with.... as for maximum flow, it's around 240 hp worth of air which again is less than we would probably require.

The point being, on the GT2056 there's more room for when we do want mega amounts of power and on the TD04 there isn't due to the fact that it won't make the same boost levels as the GT2056.

Jarrus, thanks for taking the time to explain that. When you say 280bhp/240bhp - is that a calc for the XUD? Or is it modelled on a petrol example? As i was under the impression that a diesel requires ~50/60% more airflow in general for similiar power.

So if i understand you correctly, you are saying that the boost pressure (in the case of a lev reving diesel) is more important for helping to generate the low down characteristic torque we have? Thus emphasis should be placed upon a turbo that i capable of supporting greater boost levels rather than outright flow/cfm - which in turn will give best torque rather than outright peak psi?

Surely a gt2056 is going to chuck rods awol then? Is the XUD capable of generating the low down torque though with the relatively low injection pressures of an IDI? In terms of spool, would you say the td04/gt2056 would display similiar characterstics?

So to sum up, if a gt2056 was strapped to an XUD and cranked up to the limits of around 37psi, it would make for quite a :dance: ? haha