Why aren't some concerned about putting a turbo on a high compression motor?

[lexusb3]

Originally Posted by ecko04

I am. Eneos Sustina 0w-20. Using it since my first oil change, nothing else has gone in it.

I've just heard bad stories with that weight!! So I went higher 10-40w lol. What boost level?

[ecko04]

Originally Posted by lexusb3

I've just heard bad stories with that weight!! So I went higher 10-40w lol. What boost level?

Here you go again taking a thread off topic. There are already countless threads on what oil for boost.

In all seriousness though, the tuner and shop I frequent, @ptuning, have stated time and time again that there's no need to change the oil weight when boosting for most people.

The motor was built with specific tolerances in mind. The choice of changing weight should be independent of boost and based on weather conditions and driving style. And of course use a good quality oil and filter. Hence the reason why I stuck with what I've been using.

UOA show that my decision has not caused any additional wear on the motor and the tune is working effectively. If anything changes I'll be sure to tell you.

[lexusb3]

Originally Posted by ecko04

Here you go again taking a thread off topic. There are already countless threads on what oil for boost.

In all seriousness though, the tuner and shop I frequent, @ptuning, have stated time and time again that there's no need to change the oil weight when boosting for most people.

The motor was built with specific tolerances in mind. The choice of changing weight should be independent of boost and based on weather conditions and driving style. And of course use a good quality oil and filter. Hence the reason why I stuck with what I've been using.

UOA show that my decision has not caused any additional wear on the motor and the tune is working effectively. If anything changes I'll be sure to tell you.

I was just asking.

[mrk1]

Am I concerned about putting boost on my high comp motor, yes. Is it going to stop me, no. It's just another factor to be considered when building the setup.

[lexusb3]

Originally Posted by mrk1

Am I concerned about putting boost on my high comp motor, yes. Is it going to stop me, no. It's just another factor to be considered when building the setup.

Very nice way to put it lol

[CSG Mike]

Originally Posted by ecko04

Don't listen to your mechanic ever again if he told you 6psi max. All FI isn't the same.

6psi with an Innovate is not 6psi with a Vortech is not 6psi with Kraftwerks. 6psi with a T3/T4 60 trim is not with a 57 trim is not with a 50 trim is not with a GT3076R.

The guys pushing your stated 14-20psi are not doing so on pump gas.

This.

A Greddy T518Z 5 psi isn't the same as a Garrett GT42R 5 psi.

PSI is a pressure measurement, not a flow/volume/mass measurement.

Blow as hard as you can through a coffee stir. Difficult right? That's high PSI with little flow. Now blow through a normal straw. Much easier? That's medium psi with medium flow. Now blow as hard as you can with your mouth wide open. No resistance at all? That's low psi with big flow.

Which example moved the most air mass? Which one had the most pressure?

[CSG Mike]

Originally Posted by ecko04

In all seriousness though, the tuner and shop I frequent, @ptuning, have stated time and time again that there's no need to change the oil weight when boosting for most people.

The motor was built with specific tolerances in mind. The choice of changing weight should be independent of boost and based on weather conditions and driving style. And of course use a good quality oil and filter. Hence the reason why I stuck with what I've been using.

[dave77]

ok thanks for the replies. just was wondering if people were actually aware of this potential issue and what they thought about.

still, what do people think about Subaru lowering the compression on their oem fa20 turbo motor? Why not just do it high compression if it is so safe?

[mrk1]

Originally Posted by dave77

ok thanks for the replies. just was wondering if people were actually aware of this potential issue and what they thought about.

still, what do people think about Subaru lowering the compression on their oem fa20 turbo motor? Why not just do it high compression if it is so safe?

OE setups are always engineered for a larger margin of safety compared to what the aftermarket will push.

Subaru also gets to just say, "make the new motor X compression ratio". The aftermarket has to spend thousands to build the motor to there desired ratio.

[s2d4]

Originally Posted by dave77

ok thanks for the replies. just was wondering if people were actually aware of this potential issue and what they thought about.

still, what do people think about Subaru lowering the compression on their oem fa20 turbo motor? Why not just do it high compression if it is so safe?

because people in the US will put in gallons of piss?

[WHITE]

Simple answer,

The people who arent concerned are one of two types of people.

1. Wealthy or dont care.

2. Understand how an engine works and know how far it can be theoretically pushed.


High compresssion + turbo isnt some new thing that started with the frs/brz....people have been doing it for years.

[StormTrooper]

From what i understand there is a lower limit for the amount of boost based on several things including compression ratio. VVT DI head flow ect.


not sure about the upcoming wrx but the forester dit has been tuned to allow for 87oct aka piss water.

[RAN94A]

Originally Posted by dave77

I'm not an expert at all on engines

This is why you are worried and we are not

[RAN94A]

Originally Posted by OjiGeorge

Don't forget WMI. It seems to be underused on this platform with FI.

This is my next planned power mod