Turbo Stage 3 Upgrade & Supporting Mods

[Belly1987]

Hi Guys

Currently running a DMS Stage 2 Remap 412bhp z4 e89 35i 2009

Supporting Stage 2 Map:
Masata Hard Pipe
VRSF Down Pipes
Still Have Secondary Cats
ITG Intake filter
Wagner Intercooler
Walnut blasted recently
New NGK spark plugs
Oil catch can



Looking to go stage 3.


What Turbos have people in the UK gone for and supporting mods needed to run it?

What power are you achieving on high octane pump fuel?

Not really interested in Meth/ port injection of 100% needed (Hassle)



Do I definitely need:

Hpfp?
LPFP? Do I need both?


Oil cooler
Specialised intakes
New injectors
New Coil Pack
New Spark Plugs
Oil Change

Any other supporting mods needed



I’m not draggying or tracking the car.

Pure stage 2?
Litco?
Turbo Engineers?

Any experiences of these? Pros and cons etc


Thanks

[The.Analyst]

I will be interested in your journey…

That 412 bhp is that a dyno figure?

[Belly1987]

Yes DMS Dyno figure reputable company and dyno

[sunnydays]

How much power do you want to make? Single turbo or retain the twins setup?

On 93 octane fuel, you can comfortably make 600bhp on some RB Turbos with no meth. The Z4 Fuel system is solid (better than the 335i fuelling) and good for that level of power, IIRC it shouldn't be an issue till around 700bhp.

You already have:
Downpipes
Intake
Intercooler
Charge Pipe Upgrade

Outlets / Inlets could be useful for this, @R.E92 is the best person to talk to if he is still around on these forums.
Alternatively reach out to RB Turbos and Ken at Wedge Performance, they will guide you.

If you go down this route, please use a good tuner who knows what they are doing.

[R.E92]

The big headache is the turbo outlets. On our RHD cars the steering column is in the way.

The stock turbo outlets are too restrictive for upgraded turbos. Most larger turbos come with larger diameter outlet ports so you can't re-use the standard ones and I'm not aware of any upgraded ones that fit past the steering column on RHD cars. I think some people use silicon outlets but I've seen plenty of horror stories about these falling apart under the heat.

The intake pipework to the turbos also needs upgrading but that's not a problem as there's no differential fitment between the RHD and LHD models. The Z4 is different though so make sure any components you buy are listed as fitting the Z4.

[The.Analyst]

The big headache is the turbo outlets. On our RHD cars the steering column is in the way.

The stock turbo outlets are too restrictive for upgraded turbos. Most larger turbos come with larger diameter outlet ports so you can't re-use the standard ones and I'm not aware of any upgraded ones that fit past the steering column on RHD cars. I think some people use silicon outlets but I've seen plenty of horror stories about these falling apart under the heat.

The intake pipework to the turbos also needs upgrading but that's not a problem as there's no differential fitment between the RHD and LHD models. The Z4 is different though so make sure any components you buy are listed as fitting the Z4.

That’s very informative….I wondered why often you saw items listed as not suitable for RHD..thank you .