What limits power on N54 with stock turbos?

[suspect]

The N54 is capable of 500-600 bhp but not really on stock turbos. Is this due to stock turbos just can't flow that much air? Is the workaround to increase the timing advance once limits of turbos is reached which then demands more octane or ethanol?

Is the N54 also limited by the compression ratio? Doesn't this affect how much timing advance you can get before getting a knock/pre-detonation? Do bigger turbos allow less timing advance and more air? When people talk about "aggressive" tunes are they talking about timing or boost or both?

 

[ShocknAwe]

Spin up the stock turbos too fast and they just get hot. Head doesn't flow well. There isn't a big enough intercooler made to cool it back off without meth.

Two solutions to the same problem. Low timing high boost or high timing low boost. Not both.

 

[suspect]

Spin up the stock turbos too fast and they just get hot. Head doesn't flow well. There isn't a big enough intercooler made to cool it back off without meth.

Two solutions to the same problem. Low timing high boost or high timing low boost. Not both.

Would the bigger turbos like 14T or 17T run cooler?

So what do high octane (95oct/102ron) or ethanol maps do? High boost or higher timing?

 

[RTA]

N54 is pretty octane sensitive after some tuning, 102 does make a difference.
My engine is tuned for 98ron and I give it 102 when on the racetrack.

I personally would prefer a timing based tune instead of a boost driven tune. Less energie (heat) for the same power.
The turbo's produce a lot of stress on your oil system.

Bigger turbo's might run cooler, also depending on the overall solution. (Water/Oil cooling,housing, internals etc)

Additional solutions:

- Run good oil ( Motul 300v etc)
- I run a second radiator
- I run a second oil cooler
- I did a foglight remove and installed the 335is ducts
- Coat or wrap the turbo's
- Watterwetter
- Boostane (Pretty fun stuff)

 

[suspect]

N54 is pretty octane sensitive after some tuning, 102 does make a difference.
My engine is tuned for 98ron and I give it 102 when on the racetrack.

I personally would prefer a timing based tune instead of a boost driven tune. Less energie (heat) for the same power.
The turbo's produce a lot of stress on your oil system.

Bigger turbo's might run cooler, also depending on the overall solution. (Water/Oil cooling,housing, internals etc)

Additional solutions:

- Run good oil ( Motul 300v etc)
- I run a second radiator
- I run a second oil cooler
- I did a foglight remove and installed the 335is ducts
- Coat or wrap the turbo's
- Watterwetter
- Boostane (Pretty fun stuff)

What makes it octane sensitive? Is just mostly the heat?

 

[SlowE93]

The N54 is capable of 500-600 bhp but not really on stock turbos. Is this due to stock turbos just can't flow that much air? Is the workaround to increase the timing advance once limits of turbos is reached which then demands more octane or ethanol?

Is the N54 also limited by the compression ratio? Doesn't this affect how much timing advance you can get before getting a knock/pre-detonation? Do bigger turbos allow less timing advance and more air? When people talk about "aggressive" tunes are they talking about timing or boost or both?

Stock turbos run out of breath. They were designed for low end torque, not top end power. There is no simple workaround as you stated. Swap turbos (upgrade) is the best way to go about getting more power. The limiting factor as I said is the turbos themselves along with supporting mods.
Even if you do all supporting mods, and keep stock turbos you are still limited at the amount of power you can make.
Aggressive tunes can be aggressive in different ways. Timing, vanos, AFR, etc.

 

[SlowE93]

Would the bigger turbos like 14T or 17T run cooler?

So what do high octane (95oct/102ron) or ethanol maps do? High boost or higher timing?

Bigger turbo(s) flow more air. You can achieve the same CFM at a lower PSI vs stock turbos.
Ethanol maps will mainly have different fuel scalars as keeping stocking scalars will run lean.
There is added safety using ethanol or race fuel so you can run a more aggressive tune to extract more power.

 

[SlowE93]

N54 is pretty octane sensitive after some tuning, 102 does make a difference.
My engine is tuned for 98ron and I give it 102 when on the racetrack.

I personally would prefer a timing based tune instead of a boost driven tune. Less energie (heat) for the same power.
The turbo's produce a lot of stress on your oil system.

Bigger turbo's might run cooler, also depending on the overall solution. (Water/Oil cooling,housing, internals etc)

Additional solutions:

- Run good oil ( Motul 300v etc)
- I run a second radiator
- I run a second oil cooler
- I did a foglight remove and installed the 335is ducts
- Coat or wrap the turbo's
- Watterwetter
- Boostane (Pretty fun stuff)

All this is good for a track car. Overkill for a street car. Far off from OPs question though which the simple answer is turbos.
Watter wetter is amazing stuff BUT does very little in our cars.....actually does NOTHING. I tried it before understanding why it does nothing.
I used to run it on my small block N/A cars though with good results.
As far as timing vs boost goes, it depends on the fuel IMO.
How fast / slow of a burn do you need ?
Stock N54 I will pick boost over timing especially on E85.

 

[oVeRdOsE]

I'm still impressed how much power you can do with stock turbos

 

[wheela]

I'm still impressed how much power you can do with stock turbos

View attachment 101548

View attachment 101549

True, those things are tiny. That picture with your thumb really puts it into perspective!

 

[SlowE93]

True, those things are tiny. That picture with your thumb really puts it into perspective!

Maybe he just has big thumbs

 

[wheela]

Maybe he just has big thumbs

Good point...

 

[SlowE93]

@oVeRdOsE
Please change your name to "THUMBS"

Thx !

 

[oVeRdOsE]

hahaah.

I should have put a banana for scale

 

[suspect]

Stock turbos run out of breath. They were designed for low end torque, not top end power. There is no simple workaround as you stated. Swap turbos (upgrade) is the best way to go about getting more power. The limiting factor as I said is the turbos themselves along with supporting mods.
Even if you do all supporting mods, and keep stock turbos you are still limited at the amount of power you can make.
Aggressive tunes can be aggressive in different ways. Timing, vanos, AFR, etc.

Thanks

 

[ShocknAwe]

hahaah.

I should have put a banana for scale

Is that an optimistic or humble comparison?

 

[SlowE93]

Is that an optimistic or humble comparison?

Get a room !

 

[TheFixer]

Is that an optimistic or

Spin up the stock turbos too fast and they just get hot. Head doesn't flow well. There isn't a big enough intercooler made to cool it back off without meth.

Two solutions to the same problem. Low timing high boost or high timing low boost. Not both.

I've been muling over whether I need a meth kit on my little build. I've got a full vrsf intercooler that seems like it's doing the job well. So....idk.