Twin TD04l-12t

[Grid]

These are the TD04 turbos from a 2.0l petrol S60. They can be had very cheap over here, question is does anybody have any experience with these? Reading through the forums here I can see that the TD04L housing is just the right size, the -12t part I've no idea about is it no differet from a -13t or massively different.

I am looking for a 50kW boost in power without losing much bottom end.

Thoughts? Flange-wise, the TD03s will be sacrificed for flanges, they will be chopped off and welded to the TD04L bodys for minimal fab work.

 

[pretzil]

2 questions:
How do you plan to achieve not much loss in bottom end?
Why are there 2 wastegates on each turbo?
Edit: Ohhh, internal blow off valve?

 

[Kaldek]

The twin TD04 is going to sacrifice bottom end power. I have dual customised high-flowed TD03s and they gave me a peak of 230awkw (225awkw when smoothed) where we stopped because the motor in the car is really tired and has this super weird inconsistent knock. That was at 17.5psi and there was much more scope left in those turbochargers. However, even they sacrificed some bottom end. Full boost moved up by about 350rpm.

An unmodified TD04 won't spool up as nicely as a set of hi-flowed TD03s (whether that is a full custom rebuild like mine or just a different compressor wheel). Also, while the turbo is cheap your pipework won't be. You'll need new manifolds, dumps, and turbo outlets/Y-pipe.


Here are my power figures on my eventual detuned "drive safely back home" tune (214awkw, result from taking a couple degrees of timing out of the motor. The power curve shows how these hi-flow TD03 turbos behave.

@TME_Steve tried twiddling with the wastegate duty cycle. Even at 100% duty cycle these turbos do not spool up any faster. The curve you see is the curve you get on stock cams and 98RON fuel. Cams and E85 will alter that curve.

 

[Grid]

2 questions:
How do you plan to achieve not much loss in bottom end?
Why are there 2 wastegates on each turbo?
Edit: Ohhh, internal blow off valve?

Yeah it's an internal blow off on these. The "bottom end" is more my assumption rather than knowledge. Never seen a compressor map of a TD04l-12t.

The twin TD04 is going to sacrifice bottom end power. I have dual customised high-flowed TD03s and they gave me a peak of 230awkw (225awkw when smoothed) where we stopped because the motor in the car is really tired and has this super weird inconsistent knock. That was at 17.5psi and there was much more scope left in those turbochargers. However, even they sacrificed some bottom end. Full boost moved up by about 350rpm.
An unmodified TD04 won't spool up as nicely as a set of hi-flowed TD03s (whether that is a full custom rebuild like mine or just a different compressor wheel). Also, while the turbo is cheap your pipework won't be. You'll need new manifolds, dumps, and turbo outlets/Y-pipe.

I have a mechanic who will do the manifold/dumps etc. for not much money, so that is not a real concern. Thanks for the remarks about spool. Not really a fan of hi-flowing the TD03's as they seem weak/wimpy to start with. Cost-wise it seems to be a similar cost to hi-flow a set of turbos as it is to make the manifolds/dumps for TD04. Hence the decision to go larger.

Who knows - perhaps the later spool will mean the slushbox and diff will live longer

 

[Kaldek]

If you have a mate that can do cheap fab work, go single turbo. Best of both worlds as you'll be able to find one that will spool quicker and provide the big power.

I went for a factory look and a very specific peak power target, hence the hi flow work.