Boost - 20PSI with JB4 Map 1?

[JacobAllison]

Hello everyone, just installed my New South Performance boost gauge today and noted that during WOT I'm seeing a max of about 20PSI at WOT. Does this sound right?

Running a JB4 with Map 1.

I shot a video of it but I lifted right after hitting 20 so I'd like to shoot another one tomorrow when I can hold it a bit.

I'm more concerned that I messed up the gauge install than that the JB4 isn't working. I haven't logged it with VCDS yet but the MB4 was showing 33-35 psiG while the guage was showing 20... So with a 14psi drop for atmo I suppose that's about right?

Video I shot today w/ liftoff after hitting 20psi: https://www.youtube.com/watch?v=lLkkqI1FQCY

 

[Dr. Kenneth Noisewater]

Hello everyone, just installed my New South Performance boost gauge today and noted that during WOT I'm seeing a max of about 20PSI at WOT. Does this sound right?

Running a JB4 with Map 1.

I shot a video of it but I lifted right after hitting 20 so I'd like to shoot another one tomorrow when I can hold it a bit.

I'm more concerned that I messed up the gauge install than that the JB4 isn't working. I haven't logged it with VCDS yet but the MB4 was showing 33-35 psiG while the guage was showing 20... So with a 14psi drop for atmo I suppose that's about right?

Video I shot today w/ liftoff after hitting 20psi: https://www.youtube.com/watch?v=lLkkqI1FQCY

That's surprisingly low, I don't have a JB4, but I once hit 20.6 on a hot day bone stock.

Analog boost gauge similar to yours.

Sent from my ONEPLUS A3000 using Tapatalk

 

[JacobAllison]

That's surprisingly low, I don't have a JB4, but I once hit 20.6 on a hot day bone stock.

Analog boost gauge similar to yours.

Sent from my ONEPLUS A3000 using Tapatalk

Hm. And that's why I'm wondering if I messed up somewhere.

 

[Dr. Kenneth Noisewater]

Hm. And that's why I'm wondering if I messed up somewhere.

Where did you install your tap?

Sent from my ONEPLUS A3000 using Tapatalk

 

[Diggs24]

Sounds like you aren't running map1 anymore. Probably hit boost safety at some point and it went to map4.

 

[JacobAllison]

Sounds like you aren't running map1 anymore. Probably hit boost safety at some point and it went to map4.

I'll check that in the morning.

Tap is installed on the spare manifold port.

 

[ashiun]

Would ambient temps make a difference here?

 

[Diggs24]

Would ambient temps make a difference here?

Not unless there is a San Diego in Northern Canada.

 

[ashiun]

Not unless there is a San Diego in Northern Canada.

Oh. Didn't even think to check his location there

 

[rr1santos]

was the gauge pod easy to install?? i'm looking at the tanabe boost gauge and that specific gauge pod so i don't block the driver side vent...any chance you have POV pic from driver seat?

 

[Dr. Kenneth Noisewater]

Would ambient temps make a difference here?

Unless the JB4 does something drastic, yes.

The Bosch ECUs aim for power targets and adjust fuel/air/boost to hit them. I don't know exactly how it works, but hotter air requires more pressure from the turbo to get the same power.

On cold days I could be +18PSI at the manifold and on hot days I'd be around +20.

When people talk about the advantage of turbos at higher altitudes, this is (also) why.

But again, I don't have a JB4 and I did not engineer it, so it could bypass all this entirely. Other tunes don't though.

Edit: I just looked it up on StackExchange and the increase boost is due to higher humidity in warmer air. Air density wouldn't effect manifold pressure, just colder air would require less work from the turbo. More humidity means more water vapor in the air, so more boost is needed to get the same amount of oxygen so it's not running rich.

Sorry if I confused anyone.

Sent from my ONEPLUS A3000 using Tapatalk

 

[JacobAllison]

was the gauge pod easy to install?? i'm looking at the tanabe boost gauge and that specific gauge pod so i don't block the driver side vent...any chance you have POV pic from driver seat?

It's a great pod. Fits perfectly and doesn't block a view at all or the vent there. Finish could be slightly better, the color doesn't perfectly match the other black plastic trim. I'll be posting a review of it tomorrow!

 

[rr1santos]

It's a great pod. Fits perfectly and doesn't block a view at all or the vent there. Finish could be slightly better, the color doesn't perfectly match the other black plastic trim. I'll be posting a review of it tomorrow!

awesome. i think this is the one i'm going to get..i wonder if their is a way to touch up the finish to match..

 

[JacobAllison]

awesome. i think this is the one i'm going to get..i wonder if their is a way to touch up the finish to match..

Should be easy enough to get a paint-match. It's a subtle difference.

 

[JacobAllison]

Update: Tried it all again today, got up to 25psi with a ful range 3rd grear WOT run. That's more like it.