What's the easiest/most common place to tap boost?

[WhyNotZoidberg?]

Hi all! This is my first post here

I'd like to install a boost gauge in my '15 TDI and would like some advice from people who have already figured this out and done it: what is the easiest place to tap boost on the EA288 engine?

On my Mk7 GTI there's a blind hole on the plastic intake manifold and installing an APR boost tap is a 5min job. While it might not be as easy on the TDI, I hope I won't have to spend an afternoon draining coolant and removing/reinstalling boost pipes..

I've searched around the forum, but I couldn't find a good answer.

Any help is appreciated, TIA.

 

[Lightflyer1]

Why not just use an Android phone and Torque app to do this and not mess with anything? There is also another electronic dohickey that lets you add this display to the MFD IIRC.

 

[WhyNotZoidberg?]

Why not just use an Android phone and Torque app to do this and not mess with anything? There is also another electronic dohickey that lets you add this display to the MFD IIRC.

The ECU will only display up to 26psi (everything higher will just show 26).

I want to be able to do some tuning and knowing actual boost level is paramount for not blowing up the turbo.

 

[DivineChaos]

The ECU will only display up to 26psi (everything higher will just show 26).

I want to be able to do some tuning and knowing actual boost level is paramount for not blowing up the turbo.

the plastic pressure line after the turbo, either before or after the intercooler. and that is strange because my mk6 will read well over 50psi. its displayed that much anyway.

 

[WhyNotZoidberg?]

the plastic pressure line after the turbo, either before or after the intercooler. and that is strange because my mk6 will read well over 50psi. its displayed that much anyway.

Those 50psi have to be absolute pressure (subtract 15psi for atmospheric), but even so it seems high..

Our cars' MAP is 2.5 bar sensor, is why it cannot output over that (absolute pressure).

 

[DivineChaos]

not sure. all i know is i see it sometimes. i know its a boost spike. i see it less now that im tuned.

 

[WhyNotZoidberg?]

the plastic pressure line after the turbo, either before or after the intercooler.

There's no plastic after the intercooler that I know of, the intake manifold with the integrated IC is aluminum.

I'd really like to be able to get boost readings AFTER the IC, rather than the higher pressure of the hot air coming out of the turbo.

Has anyone with a Mk7/EA288 done this?

 

[WhyNotZoidberg?]

There's no plastic after the intercooler that I know of, the intake manifold with the integrated IC is aluminum.
I'd really like to be able to get boost readings AFTER the IC, rather than the higher pressure of the hot air coming out of the turbo.
Has anyone with a Mk7/EA288 done this?

Anyone?.. Bueller?..

 

[DivineChaos]

Anyone?.. Bueller?..

i thought there was a length of plastic after the ic.

 

[WhyNotZoidberg?]

i thought there was a length of plastic after the ic.

Water-air IC is integrated in (part of) the intake manifold. All aluminum.

It's why I specifically keep saying "EA288 engine" and posted in the MK7 part of this forum, not in the 'MK6' or other versions.

 

[Victor Huge]

Any news? I found a video showing the map sensor connected by a hose (to the intake I suppose?) and figured this would be the best way to go about it, a T would be great if we could find one that fit between the map and the intake as well as the hose to the boost gauge...

 

[DivineChaos]

Pull the hose off the turbo and drill and tap a hole. Just make sure to block the impeller and clean all shavings out.

 

[Victor Huge]

Not worth the risk at all, there's a map sensor that connects before the water air intercooler and it would be quite simple to connect to that if i can find a tee that fits.

 

[LanceMalm]

Dark side developments offers a boost tap T-fitting for our cars. It’s meant to be installed right before the MAP sensor near the intake manifold. It’s like 18 British pounds so like 25 USD

 

[740GLE]

If you're tuning for higher PSI than your MAP sensor can read sounds like a recipe for disaster. There have been a few big turbo swaps on the EA288 and i don't believe any of them needed upgraded MAP sensors to keep boost spikes in check.

I've seen 38-40 PSI via torque with malone turning on stock hardware.

I'd say if you want the boost tap bad enough, pull the intake manifold off and tap the aluminum housing of the W2A intake for your mechanical boost tap needs.

 

[LanceMalm]

If you're tuning for higher PSI than your MAP sensor can read sounds like a recipe for disaster. There have been a few big turbo swaps on the EA288 and i don't believe any of them needed upgraded MAP sensors to keep boost spikes in check.

I've seen 38-40 PSI via torque with malone turning on stock hardware.

I'd say if you want the boost tap bad enough, pull the intake manifold off and tap the aluminum housing of the W2A intake for your mechanical boost tap needs.

The only issue is that the computer only outputs “requested” boost pressure, not actual pressure, or so I have heard. That’s why I was looking into this but I could be wrong. Gotta look into it deeper

 

[Cuzoe]

I have the "performance monitor/sport" screen on my MIB unit... 39.1 PSI is what it shows when pegged. It shows atmospheric otherwise, right around 14 at idle, I'm ~900ft above sea level. Don't know if that's requested, or actual but I guess that's what would be seen on Torque too... Kerma tuned.

 

[LanceMalm]

Yeah. That’s what I’ve been hearing. When you account for the atmospheric it’s only 25-26 pounds. Normally your actual pressure isn’t exactly at a precise decimal when your under load. It fluctuates which is what makes me believe the stories of it only showing requested. Again, I could be wrong

 

[Cuzoe]

True, but 39ish is just above 2.5 BAR... could we be seeing the MAP sensor max, as opposed to the requested max? The max reading of a given sensor would also not fluctuate.

And I say 39.1 pegged because that's what I've seen the few times I take a quick peak down while also at full throttle. But I try to keep my eyes up when flat out, haha. So it may have shown a tic higher at some point, but I would have noticed 40 if it ever got there.

 

[LanceMalm]

That’s also a possibility. I’m really not sure. Been trying to gather info from other pages. But there aren’t many, so I’ve been reading GTI forums and their cars could be set up differently

 

[Diesl]

The previous version (not the EA288 that the OP is specifically asking for) puts out both requested and actual manifold pressure on the OBD.
The maximum I'm seeing for my 2012 JSW TDI for either is 2.4 bar, which is 34.8 psi absolute pressure.

My pet peeve is why anybody would want to subtract the local atmospheric pressure, and then convert to pounds force per square inch.
The power that the engine produces is related to the mass of air, which is proportional to the absolute pressure, not the relative overpressure over atmospheric. The pressure in bar is very close to the pressure in standard atmospheres, which is a good estimate of the power multiplier provided by the turbo. Subtract the baseline pressure and convert to PSI, and all you have is just some arbitrary number; you lost the direct relation to the turbo power gain. So, why would you want to do that?

 

[Cuzoe]

I think it's simple, atmospheric pressure and/or bar is not a unit that many people use on a regular basis. So for most people pressure in bar is as arbitrary a measure as PSI. I'm not saying I disagree with you on the merits of bar, but for most people PSI is a measure that they believe they understand, even without knowing what it means in application/practice. I have to think the overwhelming majority of people aren't concerned with an accurate power estimate for their car. They don't have to do all of that math you mentioned because their gauges show psi, or the manufacturer says "for the 2022 model year" or "for the limited edition sport version" we have bumped the boost by 3 PSI.

 

[Diesl]

Cuzoe, you are so close! The whole point is that bar is not arbitrary. We live on a planet where the pressure on the surface is darn close to 1 bar. Why not take advantage of it? Apologies if you're posting from Mars.

 

[Nevada_TDI]

My charge manifold boost gauge says 24PSI, and my Vag-Com says whatever 24PSI plus 1000 millibars is. I live at 4600' elevation, so I have to calculate the pressure differential from Sea Level to where I live.

 

[Diesl]

Nevada, at 4600 feet you start with 15% less air pressure, so the turbo is working 15% harder to compensate. I assume your manifold pressure at idle reads 1013 mbar or 1 atmosphere or 14.7 psi (absolute), not 856 mbar or 0.85 atmosphere or 12.4 psi (absolute)?
Charge air cooling will also be less efficient. I don't know what the OBD on your car spits out; mine (2012 TDI) gives the charge air temperature and both requested and actual manifold pressure, and the exhaust temperature right before the turbo. I think that should be all one would want to keep an eye on.
Of course the car will do that (keep an eye on these parameters) all by itself, without you watching. I assume it will throw an error code should the turbo no longer keep up with requested manifold pressure. I would also assume that this would still be true for an ECU-tuned TDI.

But we are drifting away from the OPs question, for where to drill a hole into his motor...

 

[Nevada_TDI]

Nevada, at 4600 feet you start with 15% less air pressure, so the turbo is working 15% harder to compensate. I assume your manifold pressure at idle reads 1013 mbar or 1 atmosphere or 14.7 psi (absolute), not 856 mbar or 0.85 atmosphere or 12.4 psi (absolute)?
Charge air cooling will also be less efficient. I don't know what the OBD on your car spits out; mine (2012 TDI) gives the charge air temperature and both requested and actual manifold pressure, and the exhaust temperature right before the turbo. I think that should be all one would want to keep an eye on.
Of course the car will do that (keep an eye on these parameters) all by itself, without you watching. I assume it will throw an error code should the turbo no longer keep up with requested manifold pressure. I would also assume that this would still be true for an ECU-tuned TDI.

But we are drifting away from the OPs question, for where to drill a hole into his motor...

Thanks for the info. But you are right, OP still needs to find a location to drill.

 

[Cuzoe]

No worries, I'm not saying bar is arbitrary. I'm suggesting that lots of people would have no idea what you were talking about if you told them "the pressure on the surface is darn to close to 1 bar." I imagine you would be met with questions like... "the pressure of what?" So to them bar meets the common, though in this case completely wrong, interpretation of arbitrary.

And to be fair, people seem to like comparing whole numbers more than decimals. Even where PSI doesn't provide a useful/comparable measure (because of all the factors you mention), increased by 5 PSI sounds more significant than increased by 0.3-ish bar.

 

[Nevada_TDI]

The previous version (not the EA288 that the OP is specifically asking for) puts out both requested and actual manifold pressure on the OBD.
The maximum I'm seeing for my 2012 JSW TDI for either is 2.4 bar, which is 34.8 psi absolute pressure.

My pet peeve is why anybody would want to subtract the local atmospheric pressure, and then convert to pounds force per square inch.
The power that the engine produces is related to the mass of air, which is proportional to the absolute pressure, not the relative over pressure over atmospheric. The pressure in bar is very close to the pressure in standard atmospheres, which is a good estimate of the power multiplier provided by the turbo. Subtract the baseline pressure and convert to PSI, and all you have is just some arbitrary number; you lost the direct relation to the turbo power gain. So, why would you want to do that?

What confuses me is this engine has a 4 bar MAP sensor which will read 58 PSI maximum, so subtracting the 20% or so safety margin still leaves 46.4 PSI of readable boost, minus 1 Bar equals 31.4 PSI...

 

[Diesl]

I think that (2.4 bar) is just what VW chose to program in the ECU. There might be tunes that program higher boosts.
Total sidetrack:
From what I read about tunes, the problem is not getting more power, but getting it through the clutch to the road. And if you want to preserve the emissions control features (DPF, NOx converter etc.), you might be exceeding their limits. VW has some training documents out there that show graphs for the DPF and NOx converter cycling, and if I remember correctly, taken at face value those sample graphs indicated that at full load the NOx converter would already cycle once per minute. Which doesn't sound all that healthy for longevity of the exhaust components. Maybe that was the thinking behind the whole dieselgate scandal.

Even more sidetrack:
Similar for the fuel pressure: I seem to remember it going beyond 2000 bar (now that's some real pressure; almost 30.000 psi!), and now (after the fix) both requested and actual fuel pressure max out at 1800 bar. But I could be wrong.

Still not back on topic:
I switched phones and had to reload my extended PID file for the torque app. And then I had to recreate my screen layout. What a hassle!
But now it's all back, and one could argue it's even more important now to keep an eye on DPF soot load and turbo and fuel pump health while the car is sitting most of the time.

Cuzoe, you might be right, but that is still wrong!

 

[Declan023]

I drilled into the plastic piping after the intercooler, just threaded a brass fitting in with some thread sealant and used quarter-inch airline to go to the gauge.