Wont boost past 13psi from time to time.. !??!

[cobrAA]

Hello guys,

i'm having a weird issue that I can't figure out why and I'm starting to winder if its not electronic instead of mechanic. I explain:

When I drive normally/cruise and decide to floor it.. I would say 95% of the time when I hit 13psi it's like the car stop accelerating, theres no more G-force pushing you, no rush, no nothing. feel like I just popped a hose or something right ?

However, when I launch the car at 4-5k, I hit 23 psi perfectly fine. So I can't myself having a boost leak somewhere.

Do you have a clue what this **** could be ??

[Skym]

Any popping sounds from exhaust when it does this????

[dylanc]

Do you have a ROM tune or an independent tuning setup? I got this when I had stock ecu with ROM tune, ecu was detecting knock and wouldn't boost past 10-11 psi until I restarted car
Sent from my C625a using Board Express

[craftz]

How about the boost controller being suspect. Would you be able to try another? What would your boost be without the controller?

[cobrAA]

Any popping sounds from exhaust when it does this????

Don't think of any.

Do you have a ROM tune or an independent tuning setup? I got this when I had stock ecu with ROM tune, ecu was detecting knock and wouldn't boost past 10-11 psi until I restarted car
Sent from my C625a using Board Express

Could be, I'm with nistune.

How about the boost controller being suspect. Would you be able to try another? What would your boost be without the controller?

Could be but then why would it work when I launch ? And I barely drove the car this summer and was working perfectly fine in may.

The more I think about it, the more I think it's the tune went bad or something.

[cobrAA]

Any popping sounds from exhaust when it does this????

Don't think of any.

Do you have a ROM tune or an independent tuning setup? I got this when I had stock ecu with ROM tune, ecu was detecting knock and wouldn't boost past 10-11 psi until I restarted car
Sent from my C625a using Board Express

Could be, I'm with nistune.

How about the boost controller being suspect. Would you be able to try another? What would your boost be without the controller?

Could be but then why would it work when I launch ? And I barely drove the car this summer and was working perfectly fine in may.

The more I think about it, the more I think it's the tune went bad or something ecu-wise related.

[craftz]

If you have Nistune and suspect that, reload your map, run it off your pc. If everything is good burn it. If it still acts up it's not the tune.

[Skym]

Don't think of any.

Could be, I'm with nistune.

Stock GTR ECU has knock boost duty maps (can drop boost level and might feel similar to a popped intake hose joiner). I was just checking that it wasn't a intake airleak before MAF causing MAF to max out earlier thus causing ECU to hit boost cut alot earlier than it should.

Sometimes stock GTR ECU can switch to knock maps if run on a bad batch or old fuel (lower octane). In some cases it can be as simple as something knocking against engine, intake or exhaust leak, etc.

[cobrAA]

thank you guys. Now that I think, I swapped my intake twice this summer and now running the Apexi pwer intake, could this little change throw off the previous map ?

I will bring it to a mechanic early this week to perform some sort of leak-test and see if something is not sealed properly, but what your saying SKYM is pretty much what I feel when boosting. feel like I just popped a joint ( happened before, had bad clamp), but everything is fine lol

[Skym]

You're welcome. Boost level should rise by around 0.1bar with podfilters (engine runs leaner and is where the extra whp comes from). Did tuner give it some headroom with fueling??? (what's the A/F ratio on dyno chart???). If not, needs a retune.

Engine can feel very flat when running on knock maps (pulls ignition timing via knock igniton map, runs engine richer via knock fuel map, drops boost level via knock boost duty map).

[cobrAA]

Booked a tuning session next week. we will know for sure wtf is up lol