Stock Max Boost Pressure?

[Hites]

Hello!
What is the common observed max boost pressure on a completely stock 8V A3?
What about stock except for stage 1 tune on 91 octane?
What about stock except for stage 1 tune on 93 octane?

Full disclosure, I'm trying to determine safe max boost pressures depending upon octane for a United Motorsport loaded tune 8V A3.
Thanks!

[MikTip]

I VCDS logged mine with stock and UM Stage 1 91 tune...2.6 bar...that day.

[ralphie_43]

I VCDS logged mine with stock and UM Stage 1 91 tune...26.6 bar...that day.

26.6 bar or psi?

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[MikTip]

26.6 bar or psi?

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oops!

2.66

[ralphie_43]

oops!

2.66

It's all good lol I was like i'm pretty sure it's not 26.6 bar but you never know

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[MichiganRS3]

I VCDS logged mine with stock and UM Stage 1 91 tune...2.6 bar...that day.

Really? 2.6 bar is like 38psi. Seems kinda high for an A3.

[larbel]

1.8-1.9 bar is usually the upper limit for S3's stock IS38, but for IS20, I think it's 1.6 bar or 24 psi...

[MikTip]

Really? 2.6 bar is like 38psi. Seems kinda high for an A3.

A week after I got my S3 United Motorsports tune... I VCDS data logged it as the tune changed the way the OE boost gauge displayed boost...so I was curious of what the boost actually was...



Thats what VCDS showed...

[larbel]

A week after I got my S3 United Motorsports tune... I VCDS data logged it as the tune changed the way the OE boost gauge displayed boost...so I was curious of what the boost actually was...



Thats what VCDS showed...

That can't be right, anything close to 2.4 bar is pretty much an instant boom for IS38... 1.9 bar IMO is already pushing it...

[tdietro]

That can't be right, anything close to 2.4 bar is pretty much an instant boom for IS38... 1.9 bar IMO is already pushing it...

Perhaps the first bar is standard atmosphere? Then the 1.7ish bar over that is boost and equates to 24-25 PSI.

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[larbel]

Perhaps the first bar is standard atmosphere? Then the 1.7ish bar over that is boost and equates to 24-25 PSI.

Sent from my SM-G965U using Tapatalk

Oh yeah, that's right! Totally forgot VCDS does that LOL

[MichiganRS3]

Perhaps the first bar is standard atmosphere? Then the 1.7ish bar over that is boost and equates to 24-25 PSI.

Sent from my SM-G965U using Tapatalk

This makes mores sense. I’ve never used VCDS, this is kind of wonky way of reporting.

[MikTip]

substract about 1000 mbar from the total to get actual boost pressure

1 bar = 14.7PSI = 1000mbar

[Hites]

Thanks for all the good discussion!
So would I be accurate in saying stock is around 18 psi, stage 1 91 octane is around 23 psi, and stage 1 93 octane is around 25 psi?
These would all be maxes of course.

[MikTip]

Thanks for all the good discussion!
So would I be accurate in saying stock is around 18 psi, stage 1 91 octane is around 23 psi, and stage 1 93 octane is around 25 psi?
These would all be maxes of course.

I'm stage 1, 91 octane...United MotorSports tune...

I would say the specific numbers depend on the tune...your location, and engine mods...

[Hites]

I'm stage 1, 91 octane...United MotorSports tune...

I would say the specific numbers depend on the tune...your location, and engine mods...

With UM offering the loaded tune for the 8V, I'm trying to determine what max boost pressure can be run with what octane.
Like if I were in a pinch and a gas station only had nothing higher than 87 available, which when mixed with a tank of 93 would likely equal 88 or 89, what max boost pressure could I drop it to? 19 or 20? IDK. Might need to experiment, it sounds like...

[MikTip]

With UM offering the loaded tune for the 8V, I'm trying to determine what max boost pressure can be run with what octane.
Like if I were in a pinch and a gas station only had nothing higher than 87 available, which when mixed with a tank of 93 would likely equal 88 or 89, what max boost pressure could I drop it to? 19 or 20? IDK. Might need to experiment, it sounds like...

I think your splitting hairs here...and penny pinching on gas while trying to drive a turbo car thats suppose to be run on premium....

[Hites]

I think your splitting hairs here...and penny pinching on gas while trying to drive a turbo car thats suppose to be run on premium....

Correct me if I'm wrong, but starting in 2016, the A3 can run 87 octane. Obviously it'll pull timing like crazy if you drive it hard, but Audi says it can run 87. Sounds like this is uncharted territory.

[MikTip]

Correct me if I'm wrong, but starting in 2016, the A3 can run 87 octane. Obviously it'll pull timing like crazy if you drive it hard, but Audi says it can run 87. Sounds like this is uncharted territory.

The ECU adapts to the various octane/conditions...nothing new...just less performance, but only 4 octane worth.

IMO if this is your main concern...dont buy a upgrade in power performance tune. Because you will burn more gas!