My r56 seems to be holding 17 -18psi.. spiking to about 20 - 21psi.. I am running stage 2 AP tune with catless downpipe, alta catback, alta intake, and I have upgraded OEM DV internals to attempt to help boost loss i was exprincing.

 

Unless you plan on upgrading your engine's bottom end I would not go any higher than this.

 

it will cut out at 22 anyway

 

Sounds good. What tubing do you guys recommend when upgrading from stock? I also want to delete the noise generator.

 

This is something I've been looking to find out for a little while now.
I've felt like mine has been running low

Car is a 2008 MCSa with ~44700 miles

For engine mods I've got the ALTA FMIC and a M7 cold side Boost tube installed on my car with a stock tune (aFe filter and JCW tube too) and I've been using the Android app "Torque" to watch some of my vitals on the car.

With those mods I am only seeing a max of 11psi with over boost with a rare spike of 12psi
The range I see with mine is usually between 11 psi to 9 psi under full throttle depending on what gear and RPM's

Now I know that there are some factors like outside temp (which being the winter in New England are much lower and denser which could cause the ECU to lower boost) but I still feel like it's lower than what it should be.

Any ideas what I should actually be seeing or if anyone has experienced a similar situation as me?

 

Seems normal for cold weather with a stock tune, you need to get a tune.

 

like sabes said, your PSI levels seems to be normal. You will need a tune to increase boost levels. just installed my boost gauge and it seems to be reading 20psi dropping to 18-19psi when almost at redline.. the funny thing is the AP is reading lower than the boost gauge. Its a prosport electronic gauge, might be off a little i guess. Destroyed a 2004 mustang GT today. So i guess im happy for now but im craving more like everyone lol

 

Good to know, I just wasn't sure if maybe I was running a bit low. I mean it makes sense with the increased core size that I would lose boost I just didn't think it would be 2 psi. Kinda makes me want to get a Helix or Forge, I could have sworn that they only lose .5 psi


wow 18-19 psi on a regular basis I was thinking of having mine tuned to run a consistent 15 psi for a safe increase in power over stock and maybe 18 psi with over boost since it's so rarely seen.
now that I mention it does that sound reasonable or too much too little?

also
wait wut?
Hope everything's ok

 

Peter, you are running normal. The stock R56 has 12psi boost and about 14psi with overboost. Because you have an upgraded intercooler with the stock boost preasure it is taking longer to fill the larger volume of the intercooler, that is why it may seem like your running lower boost. In order to take advantage of the larger intercooler you need a tune to increase your boost.

By the way I'm running 19psi and 21.5 with overboost and Meth injection, I have lots of fun every time I step on the gas. It is almost impossible to hold on to the steering wheel in sport mode.

 

This may sound dumb...but those of you getting some of these numbers by reading it from you Alta AP, what menu listing gives you actual boost under the "Live Data" menu...

 

I knew the stock numbers where around there, with overboost i'll spike to 12 but hold about 11 and it will gradually drop as I head towards redline. I've been waiting for a decent night (weather wise) to head out late and do some pulls on the highway in various gears while logging to get some concrete data on where my boost is at what RPM and what not. maybe this week since the weather is looking good.

I have noticed that there is a fair amount of lag that has been introduced into the system after installing the intercooler which is unfortunate. I am hoping that with a tune it will bring it back to stock levels or better of response.

I would ask if your levels of boost are safe but I am assuming that with the water/meth injection system reducing the chance of detonation that you are ok. I can only imagine what it would be like with that much boost. I need to keep it relatively conservative because it's my only car and I do not have the money to fix it if I blow something up

 

Killer, are you seeing 19psi even in this cold weather? I'm in CT and am seeing max 17 when it's under 40F here.

 

Erik, I do see 19psi easily even in this cold weather. I do have the VAG diverter valve internals installed that does help a bit.

 

18psi, stg II tune

 

how do you get lag and drop PSI after the alta FMIC??? i thought it made 15hp????
I noticed after installing mine that it wasn't as responsive and i didn't feel any power gain at all and that is with a tune.

 

It induces lag because the Intercooler core is larger than the original IC which in turn takes longer to fill and pressurize before the air can get back to to the turbo; this is the lag (time). Additionally since you have a larger volume to fill in a closed system the pressure drops as a result having a larger surface area for the air to spread across (Volume; PSI, Pounds per Square inch)

Think of how showmen can sit or lay across boards of nails, because the pressure of their body is being spread out over a larger area.

The loss of response you feel is the lag that has been introduced into the system.

The HP claims come from the intake charge being much lower in temperature than before. Colder air is denser air and that allows the engine to produce more HP with the same AFR (I believe, this is where I start to get lost)

In the colder temps we should all be seeing less boost because the car is reaching its HP numbers at lower PSI because the ambient air is already colder and therefore denser. In the summer the ECU will up the boost to reach the same AFR due to the lack of air density.

I hope that helps, If anyone see's anything wrong with what I said above please feel free to correct me. I am just explaining it as I know and what I believe.

 

your close, almost right. the only thing you missed was your explanation of boost loss. Boost loss is due to denstiy change not increase in volume. there is more space in an intercooler but the space where the pressure sensor reads is the same size. pressure is relative to the largest restriction so even though the intercooler is larger once it fills it should be the same pressure.... right? the factor you need to take into account is pressure VS. Temp. as temp drops so does pressure. So the bigger intercooler cools the air. The cooler air has slower molecuels. the slower molecuels has less pressure but the same volume...... you get the idea.

You were close though everything elese makes sense.

 

That actually does make sense now that you say it. I guess then the reason why we are seeing loss of boost when an bigger FMIC is installed is actually the car's ECU; because the intake charge temps are lower (thus a higher air density) the car is reaching it's HP numbers at lower boost pressures and the ECU see's that it does not need as much pressure.

All I know is I need a tune

 

i was just being a smart *** sorry.

 

Almost... just a bit backwards. temps are lower, less boost same volume.but the second half is correct. The ecu is hitting power goals sooner, so the boost is limited. although it doesn't work as well as the hermans would like to admit, the system should make the same power everytime the car is turned on regardless of the weather.