[BobS]

What stg 2 are you running? Which version are you most happy with? I was running Cobb stg2 aggressive and hitting 19.4 or so psi, isn't that a little high for stock turbos? My car isn't my daily driver but I really don't want to buy a new set of turbos just yet. The car is now running Cobb stg 2 and hitting 16.5 psi, I feel better about that.

How many of you guys are running stg 2 aggressive and are you seeing the same levels of boost?

[enrita]

on low rpm is fine and in range with the flow map of the turbos. Do some logs and see exactly the boost curve.

[E90SoFlo]

stage 2 + aggressive.

daily.

98k miles.

[BobS]

Car is in the shop now getting a coolant flush but yea, I plan to log it soon. I had a weird thing happen the other day where I was driving the car hard on the freeway (Cobb stg 2 agg) and then came up on traffic that was bumper to bumper. I had to go stop/go for 10 min and the car started smoking a bluish color smoke like it was burning off oil/blowby. Maybe my turbo or turbos are on their way out, I dunno.

After I got back up to speed everything was fine and then I couldn't get the car to do it again....very weird

I'm having the shop do a check on the car but so far everything appears to be ok...

[335(EX)(EYE)]

im hitting 19psi on the stage 1 aggresive map v4.0..uv got me worried. is that ok?

[tscdennab]

Originally Posted by BobS

I had to go stop/go for 10 min and the car started smoking a bluish color smoke like it was burning off oil/blowby. Maybe my turbo or turbos are on their way out, I dunno.

Yes it is entirely possible that your turbos are on the way out. And don't believe that 19.4psi is fine, because it's not.

I would like someone to explain to me on the turbo efficiency islands graph how 19+ psi is fine. I read that entire sticky thread and no one seems to know how to interpret that graph in conjunction to the N54 engine.

[E90SoFlo]

Originally Posted by tscdennab

Yes it is entirely possible that your turbos are on the way out. And don't believe that 19.4psi is fine, because it's not.

I would like someone to explain to me on the turbo efficiency islands graph how 19+ psi is fine. I read that entire sticky thread and no one seems to know how to interpret that graph in conjunction to the N54 engine.

Please inform us how you know that its not fine.

Cobb is a huge company and I trust they know what they are doing, you on the other hand.....

Hitting 19 psi on stage 1 is more then likely just boost spikes during shifts. Not actual PSI while WOT

[BobS]

The turbos could be on their way out, car only has 50k miles on it, been tuned for 20k. They don't whine and the car doesn't burn through oil( I never have to add it), so I'm a little perplexed at the smoking issue I had...

Also the car hits boost rather easily so it seems the turbos are good. I do have a lot of wg rattle but everyone does right? Lol

[Lulz_M3]

Originally Posted by tscdennab

Yes it is entirely possible that your turbos are on the way out. And don't believe that 19.4psi is fine, because it's not.

I would like someone to explain to me on the turbo efficiency islands graph how 19+ psi is fine. I read that entire sticky thread and no one seems to know how to interpret that graph in conjunction to the N54 engine.

Heres a good read, wont give you the answers but you can put the leg work in if you would like to proactively do the research yourself.

http://honda-tech.com/showthread.php?t=142398

[RnmEvo9]

I used to see 18.5psi in the midrange, but lately I've been seeing 19.5psi in the midrange (this is WOT, not after a shift) according to my P3 boost gauge. I've had no issues and pulls very nicely on pump gas (117mph trap speeds consistently).

[335TWNTURBO]

I want to know the answer to this question too.

[marv85]

Originally Posted by BobS

The turbos could be on their way out, car only has 50k miles on it, been tuned for 20k. They don't whine and the car doesn't burn through oil( I never have to add it), so I'm a little perplexed at the smoking issue I had...

Also the car hits boost rather easily so it seems the turbos are good. I do have a lot of wg rattle but everyone does right? Lol

is it hot where you live?

The best thing to do is to log. then we can all take a look and make sure everything is in check (make sure to include all relevant variables in your log)

[marv85]

Originally Posted by 335(EX)(EYE)

im hitting 19psi on the stage 1 aggresive map v4.0..uv got me worried. is that ok?

that's probably a shift spike (when you release the throttle under full boost you'll see that high). It's not real...

[BMWsky]

I've got a 6MT and have seen 20.9 spike at shift point, about 14 or so sustained (on stage 1+). I'm having DP's put on the car as I type this so I'll log tonight and see what it looks like.

[Jeff@TopGearSolutions]

Any values at a shift spike are irrelevant as its an inflated number due to the throttle body closing.

You also have to keep in mind where boost is being read and if the throttle blade is open 100%.

Any throttle closure would inhibit a false inflated reading.

The only true way to determine if you in a safe zone is to post logs which include throttle blade.

These turbo's can handle more boost under 5000 RPM VS the amount they can handle at redline.

You should expect your peak boost near 4000 RPM and taper down after 6000 RPM to 12-14 depending on the map.

Until someone posts logs of actual boost and throttle blade this is not going anywhere.

[BMWsky]

Originally Posted by Jeff@topgearsolutions

...You should expect your peak boost near 4000 RPM and taper down after 6000 RPM to 12-14 depending on the map....

+1. This is pretty much exactly what I see.

[rader1]

I'm currently running stage 2+ sport. I was running aggressive but with ambient temps running ~80F during the day I swapped over to the sport maps just to go easy on the car.

Originally Posted by tscdennab

And don't believe that 19.4psi is fine, because it's not.

Turbos don't create boost the restrictions in the engine do. All a turbo does is spin so the big concern is shaft speed. I don't know what RPMs the turbos are turning to hold 19psi @ 4Krpm but I bet it's less than making 16psi @ 6.5Krpms like some of the other tunes are running.

[Jeff@TopGearSolutions]

It's also worth mentioning Cobb does not target boost, but actual load on the engine, depending on your area and conditions you may require more or less boost then others depending on how efficient your conditions are. There are ceiling limits on boost allotment too. If you feel your tune is too aggressive there is nothing wrong in dialing down to a less aggressive map.

[BobS]

I'll try and log when I get the car back. I'm just going to run a lower boost map for the heck of it, not really ready to purchase turbos and at 16 psi the car is still plenty fast so why take the chance. Its been 70-75 degrees here with 60-95% humidity FYI

[Jeff@TopGearSolutions]

Originally Posted by BobS

I'll try and log when I get the car back. I'm just going to run a lower boost map for the heck of it, not really ready to purchase turbos and at 16 psi the car is still plenty fast so why take the chance. Its been 70-75 degrees here with 60-95% humidity FYI

Unfortunately the Cobb is based off load, so as conditions worsen it will increase boost. Said another way, as it gets hotter out, with more humidity, its going to take more boost in theory to meet the same load target. The downside is you have to push your turbo's that much more in conditions that are not ideal for turbo's. All of this is so the car produces (in theory) the same power in any driving condition. The stock DME works in the same way.

The piggy's are not based on load but actual boost. So you can dial up boost if conditions are better, like in the winter, and in the summer you can dial it down so your not pushing the car so hard.

On my last car I used to run two tunes, winter and summer, that way I had the safety and performance all year round.

[marv85]

Originally Posted by BobS

I'll try and log when I get the car back. I'm just going to run a lower boost map for the heck of it, not really ready to purchase turbos and at 16 psi the car is still plenty fast so why take the chance. Its been 70-75 degrees here with 60-95% humidity FYI

Originally Posted by Jeff@topgearsolutions

Unfortunately the Cobb is based off load, so as conditions worsen it will increase boost. Said another way, as it gets hotter out, with more humidity, its going to take more boost in theory to meet the same load target. The downside is you have to push your turbo's that much more in conditions that are not ideal for turbo's. All of this is so the car produces (in theory) the same power in any driving condition. The stock DME works in the same way.

The piggy's are not based on load but actual boost. So you can dial up boost if conditions are better, like in the winter, and in the summer you can dial it down so your not pushing the car so hard.

On my last car I used to run two tunes, winter and summer, that way I had the safety and performance all year round.

If it gets really hot, and you're really worried just drop to stage2+ sport. Or get a meth kit

[BobS]

Or just don't don't push the car hard when it's real hot heh