40PSI on Audi A4

[danstyx]

Hi all,

I recently went through all the trouble of repairing my wastegate & now my A4 is running great. It spools quickly and achieves around 18.5psi untuned.
Today I went Stage 1 with IE & now I see at times, I'm spooling to 40psi!

To clarify PSI in certain situations:
When I was stock tune spooling while in like 3rd or 4th at 2k rpm, I spool to about 23.5psi & when I'm doing a pull in high rpms, I only go to about 18.5psi.
I haven't done a good pull yet with the tune; however, when I'm in low rpms in 3rd or 4th and spool my turbo, I see myself go to like the high 30s-40psi.
Maybe it's normal to spool higher when you are low rpm applying the throttle? I don't know.

I don't wanna blow up my engine. I will be reverting to stock tomorrow morning until I can figure this out.

EDIT: Stock A4 B8.5 turbo, CTS HFC & downpipe, no resonators or muffler, repaired wastegate, K&M intake, pierson upgraded DV, forge bov kit & IE Stage 1 tune. When I say I've never heard my blowoff valve be that high-pitch, I mean it!

Thanks for any responses!
Dan :)

[Mars2]

I bet you get throttle closure. Those 40PSI are pre throttle body not what you engine actually get.Boost sensor is upstream from Throttle body
often coming from too high WG cracking pressure setup compare to tune request cracking pressure.

[danstyx]

I bet you get throttle closure. Those 40PSI are pre throttle body not what you engine actually get.Boost sensor is upstream from Throttle body
often coming from too high WG cracking pressure setup compare to tune request cracking pressure.

Ahh. So it sounds like I need to loosen the WG and I should be golden. Didn't even think of where the boost tap was. Thank you!

[cybernet99]

That's an awful lot of boost pressure, what turbo is this with? Do you have adequate fueling to be able to match that type of boost level? Even though it is just spiking, be careful ... would hate to see you start melting things because the fueling is not matching the boost spikes, and it leans out for those moments ...

[Perry01]

How are you measuring boost pressure?

[apeck240]

Hi all,

I recently went through all the trouble of repairing my wastegate & now my A4 is running great. It spools quickly and achieves around 18.5psi untuned.
Today I went Stage 1 with IE & now I see at times, I'm spooling to 40psi!

To clarify PSI in certain situations:
When I was stock tune spooling while in like 3rd or 4th at 2k rpm, I spool to about 23.5psi & when I'm doing a pull in high rpms, I only go to about 18.5psi.
I haven't done a good pull yet with the tune; however, when I'm in low rpms in 3rd or 4th and spool my turbo, I see myself go to like the high 30s-40psi.
Maybe it's normal to spool higher when you are low rpm applying the throttle? I don't know.

I don't wanna blow up my engine. I will be reverting to stock tomorrow morning until I can figure this out.

Thanks for any responses!
Dan :)

Sounds like absolute, so 25 boost plus 15 atmospheric

[danstyx]

How are you measuring boost pressure?

P3Gauge attached to OBDII

- - - Updated - - -

That's an awful lot of boost pressure, what turbo is this with? Do you have adequate fueling to be able to match that type of boost level? Even though it is just spiking, be careful ... would hate to see you start melting things because the fueling is not matching the boost spikes, and it leans out for those moments ...

The stock B8.5 turbo. My AFr pre-tune was 14.7 w/ 91. I will check when I'm out again today and see if the AFr is still around the same.

[danstyx]

Sounds like absolute, so 25 boat plus 15 atmospheric

Sorry, but what do you mean by absolute & boat?

[apeck240]

Sorry, but what do you mean by absolute & boat?

Sorry, edited, meant boost

[danstyx]

Sorry, edited, meant boost

By 15 atmospheric, you mean it's exiting the wastegate?

[apeck240]

P3Gauge attached to OBDII

- - - Updated - - -



The stock B8.5 turbo. My AFr pre-tune was 14.7 w/ 91. I will check when I'm out again today and see if the AFr is still around the same.

Lol yeah you're reading map sensor, aka manifold absolute pressure, which includes 1 atmosphere which is around 15 psi, so anything over that is "boost". Stock sensor can't even read 40 over atmo, trust me lol

[danstyx]

Lol yeah you're reading map sensor, aka manifold absolute pressure, which includes 1 atmosphere which is around 15 psi, so anything over that is "boost". Stock sensor can't even read 40 over atmo, trust me lol

Ok, phew. So I'm only at 25psi? I assume I just need to loosen the wastegate.

After I repaired it, I made the actuator adjustable. I just reaaallly don't want to take it back out. I have three times now.

[danstyx]

Lol yeah you're reading map sensor, aka manifold absolute pressure, which includes 1 atmosphere which is around 15 psi, so anything over that is "boost". Stock sensor can't even read 40 over atmo, trust me lol

Just noticed this & remember on a short drive this morning, but my boost gauge at no throttle starts at -18.0psi.

[thatauditech34]

Just noticed this & remember on a short drive this morning, but my boost gauge at no throttle starts at -18.0psi.

Negative number on your gauge means your engine is in vacuum. -18inHg

[danstyx]

Negative number on your gauge means your engine is in vacuum. -18inHg

Ah so it isn't an adjustment for 1 atmosphere. Thank you. :)

[bb-tt]

Ok, phew. So I'm only at 25psi? I assume I just need to loosen the wastegate.

After I repaired it, I made the actuator adjustable. I just reaaallly don't want to take it back out. I have three times now.

you dont need to take it out. You are not hitting 40 PSI as Apeck said the map reads boost plus atmosphere and even if you are hitting 25 psi as long as you are not getting throttle cut it is fine. You need to do some wot 3rd gear pulls and log and see what it is doing.

[danstyx]

you dont need to take it out. You are not hitting 40 PSI as Apeck said the map reads boost plus atmosphere and even if you are hitting 25 psi as long as you are not getting throttle cut it is fine. You need to do some wot 3rd gear pulls and log and see what it is doing.

Phew. Glad I don't have to do that. I hate draining my coolant.

What do you mean by wot? I noticed this morning when I'm doing hard pulls it only pushes to low 20s.

[jjvwg]

If your running the P3 gauge do yourself a favor and get the boost sensor for it so you can pull an actual boost reference from the motor and not just from the ECU readings.


Sent from my iPhone using Audizine Forum

[danstyx]

If your running the P3 gauge do yourself a favor and get the boost sensor for it so you can pull an actual boost reference from the motor and not just from the ECU readings.


Sent from my iPhone using Audizine Forum

I was looking into it. Will do that soon! :)

[Theiceman]

wot = wide open throttle.

Earth's atmosphere is 14.7 psi so that has to be subtracted from your readings as stated..


start logging when you put it into third at low rpms... it will chug at first but you want to see how it builds when the turbo kicks in.
post the results. better be on a good road cuz this car flies at 3rd at red line

Sent from my SM-G973W using Audizine Forum mobile app

[Jason11213]

Hi all,

I recently went through all the trouble of repairing my wastegate & now my A4 is running great. It spools quickly and achieves around 18.5psi untuned.
Today I went Stage 1 with IE & now I see at times, I'm spooling to 40psi!

To clarify PSI in certain situations:
When I was stock tune spooling while in like 3rd or 4th at 2k rpm, I spool to about 23.5psi & when I'm doing a pull in high rpms, I only go to about 18.5psi.
I haven't done a good pull yet with the tune; however, when I'm in low rpms in 3rd or 4th and spool my turbo, I see myself go to like the high 30s-40psi.
Maybe it's normal to spool higher when you are low rpm applying the throttle? I don't know.

I don't wanna blow up my engine. I will be reverting to stock tomorrow morning until I can figure this out.

EDIT: Stock A4 B8.5 turbo, CTS HFC & downpipe, no resonators or muffler, repaired wastegate, K&M intake, pierson upgraded DV, forge bov kit & IE Stage 1 tune. When I say I've never heard my blowoff valve be that high-pitch, I mean it!

Thanks for any responses!
Dan :)

There’s a way to calibrate the P3 gauge to adjust for atmospheric pressure if you haven’t already done that. I think you have to hold the two buttons until it takes you to the config menu. Then scroll through until you get to the Calb option. P3 has the steps on their website.

[bb-tt]

Phew. Glad I don't have to do that. I hate draining my coolant.

What do you mean by wot? I noticed this morning when I'm doing hard pulls it only pushes to low 20s.

Wide Open Throttle form 2k -~7k in third or fourth gear

[bb-tt]

There’s a way to calibrate the P3 gauge to adjust for atmospheric pressure if you haven’t already done that. I think you have to hold the two buttons until it takes you to the config menu. Then scroll through until you get to the Calb option. P3 has the steps on their website.

what???? instructions are for wuses, we dont need no stinking instructions