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The Garrett is well sized for the 2.3 5 pot.
In terms of manifold adapter, you can either mill the Volvo manifold flat, or you can use an adapter- problem with the adapter is that they tend to leak.
The US guys call bullshit on this, but they tend to use full power for ~10 seconds, then mooch around at partial throttle for ages, feedback from UK 850 owners who visit the Nurburgring is that the heat makes the seals life a hard one.
The TD04HL that you have is a 20T - which is pretty unbalanced as the exhaust side is shared with the 16T, but the compressor side is significantly larger. It's the Volvo pattern on the hot-side though, so it all bolts on and there's no seal issue.
These engines respond very well to a larger hot side, if you can deal with the manifold issues.
Dammit-
The Garrett is well sized for the 2.3 5 pot.
Surely for a fast Volvo a big fuckoff Holset is the appropriate choice of fan?
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If I were to do this in the future, I know some guys who make some very sexy manifolds so I don’t think that would be an issue. Some reading suggests that the standard manifold is good for 500bhp which is probably sufficient, so probably more economic to machine the standard manifold to accept different turbos but probably more exciting to get a tubular manifold built for a GTX
Brommers
NurseHolliday
Does anyone know a book or a website where I can learn more about how to size turbos for the engine and the intended use?
I'm not planning on doing something unique, or arguing with well tried techniques, I'm just interested in how it all works. I could probably dig out some old fluid dynamics books and start working things out, but I'd prefer a more simple explanation if it's possible.
Essentially, the TD04 is an old turbo, turbo design and technology has moved on since it was first introduced.
My basic understanding is that a turbo too small will spool up very quickly, but run out of steam quickly, and a turbo too large will spool up very slowly so although you get more power, it will take an age to become available. A larger turbo will allow you to run higher boost, whereas a smaller turbo can't cope with big boost. New turbos such as the GTX supposedly allow you to run a bigger turbo than you would have been able to in the past and not suffer from major lag.
Above is the sort of statements banded about at meets, in the pub, and on forums, to me it would appear that the main KPI of a turbo system is how much boost it can produce, so sizing is a turbo is about how long it takes to get to your target PSI and how much of the rev range it can maintain it. How do you calculate that for a given engine and turbo?
I think we did this before but I can't find it.