[AU335i]

Originally Posted by benzy89

If you look at COBB's dynos (in the map notes section of each tune), HP peaks around 5,000 RPMS and last until 6,000. Reving past 6500 is only good for noise as the powerband falls off substantially at that point.



Dumb question: are you sure its boost oscillation or are you leaking? Possible that at Stage 2+ that you've got a leak somewhere. You don't list any of your mods in your sig, but if you have any OEM bits left outside of the map requirements (upgraded intake, DPs & FMIC), that either the OEM DVs or CP is the source of your leak.

Boost hits peak ~18.5 psi consistently after the initial oscillation...


WGDC looks normal (~50-52 range) and no leak code... no codes at all lol so I don't think i'm leaking


but yes I do have stock DV's/CP

[benzy89]

Originally Posted by AU335i

Boost hits peak ~18.5 psi consistently after the initial oscillation...


WGDC looks normal (~50-52 range) and no leak code... no codes at all lol so I don't think i'm leaking


but yes I do have stock DV's/CP

The stock CP/DVs might not be responsive enough under WOT at that boost setting, can't forget that stock boost is less than 9 psi (so you're running about double the pressure/stress being put on the OEM bits). I'm not gonna tell you that spending ~$600 on aftermarket DVs + CP is "magically" going to fix the problem. Have you had COBB looks at your logs to see if maybe they know what's going?

[AU335i]

Originally Posted by benzy89

The stock CP/DVs might not be responsive enough under WOT at that boost setting, can't forget that stock boost is less than 9 psi (so you're running about double the pressure/stress being put on the OEM bits). I'm not gonna tell you that spending ~$600 on aftermarket DVs + CP is "magically" going to fix the problem. Have you had COBB looks at your logs to see if maybe they know what's going?

yeah... I posted a thread and a few people say its a known issue amongst certain cars on stage 2+ aggressive... thats why I'm wondering if there was a specific reason or just randoms.

[dfv2]

Originally Posted by AU335i

are there alot of known cases of boost oscillation with the stg. 2+ aggressive? I'm wondering if there are specific reasons for it or just random cars?

It's a well known issue that cobb has stated a few times (in this thread) that they are working to fix before v4 comes out of beta. I have it too, pretty much don't notice it at this point but it's very annoying when you pay attention to it.

[benzy89]

Originally Posted by AU335i

yeah... I posted a thread and a few people say its a known issue amongst certain cars on stage 2+ aggressive... thats why I'm wondering if there was a specific reason or just randoms.

I mean if your logs are getting the thumbs up, then its gotta be parts

[Bash]

Originally Posted by ihc95

Hi everyone Im considering getting the Cobb AP. Ive read that the AP increases the rev limit to 7200 RPM. Is this also true for the Auto trans or just the 6MT?

It's only raised on MT.

[new2the3]

How does the Cobb tune handle altitude changes? Being in calif. if I drive from sea level to 6000ft in a two hour period, will the Cobb safely adapt?

[benzy89]

Originally Posted by new2the3

How does the Cobb tune handle altitude changes? Being in calif. if I drive from sea level to 6000ft in a two hour period, will the Cobb safely adapt?

Cannot comment from personal experience, but the way the COBB works is that it re-flashes the factory DME for a higher performance setting (unlike a plug in system, which intercepts signals & then transmits a higher performance request back to the DME).

Since the factory DME adjusts to variables like elevation & quality of gas, it's safe to say that even w/ the COBB tune the car would be able to adapt as if there was no tune installed.

[COBB Tuning]

With our mapping, the car will compensate for altitude just like it will stock. Since the BMW uses load targeting (not boost targeting), you will probably see slightly higher boost pressures at altitude, though they will still be well within the turbo's efficiency range. The goal with load targeting is to provide consistent performance in varying atmospheric conditions.

The boost oscillation is typically isolated to specific ROMs. We should have a fix ready soon with v402 maps.

Ian

[2Times]

Originally Posted by COBB Tuning

...

The boost oscillation is typically isolated to specific ROMs. We should have a fix ready soon with v402 maps.

Ian

I just had this issue on I8A0S... is this one of the roms you're seeing it with?

[AU335i]

Originally Posted by 2Times

I just had this issue on I8A0S... is this one of the roms you're seeing it with?

most likely since i'm on same ROM

[ajsalida]

Originally Posted by COBB Tuning

With our mapping, the car will compensate for altitude just like it will stock. Since the BMW uses load targeting (not boost targeting), you will probably see slightly higher boost pressures at altitude, though they will still be well within the turbo's efficiency range. The goal with load targeting is to provide consistent performance in varying atmospheric conditions.

The boost oscillation is typically isolated to specific ROMs. We should have a fix ready soon with v402 maps.

Ian

I can vouch for this (higher boost), I live at 8k elevation and do most of my driving above that, to 12k. Car is 335xi auto trans.

Wanted to add some anecdotal info based on a recent 1600 mile road trip to lower altitude (1000 ft) and much hotter denser air, using stage 1+FMIC. My car has IJEOS dme, and many other owners with same # had issues. I had zero problems with v400, when v401 came out I tried it and switched back to v400. v401 seemed a little less crisp esp on tip-in as if the ST map had been dialed back to be less aggressive.

Anyway I ran v400 stage 1+ aggressive on 91 octane + octane booster, for weeks/months, no problems. Really liked it. Then I switched to sport mode and just 91 no octane boost. A little less oomph but still good. No codes no timing pulls nothing.

Getting ready for the trip I decided what the hell load up the v401 and v301 maps just in case and BRING THE COBB WITH ME (thank goodness).

So 800 miles in one day going from 8k ft elevation 75 deg daytime high under 20% humidity to 1k @ 96 deg and 100% humidity. Had executed a number of WOT passes coming out of the mountains but none until I need to merge onto a beltway.

Immediate stutter/bog, engine felt as if it was missing hard, or even tranny/transfer case busted. Felt awful and barely drivable. Literally 5 miles form where I was going.

Long story short the problems others were having with v400, I was now having under extreme heat soak, denser/hotter air, higher humidity. Re-flashed to v401, got some name brand gas just in case, some octane booster. Reset ECU though there were no codes. No more problems though I took it very easy initially. Drove back yesterday (800 miles) in similar conditions everything was fine.

Anyway relating this just for the general Cobb feedback/hive mind to process.

I still do not like the mid/high rpm range drop off o power, seems v401 stage 1+ ought to be stronger than v301 stage 1 (peak HP and TQ, not just peak TQ down low). And it isn't according to some dynos and my own impressions. Maybe someone at Cobb can comment on this.

[benzy89]

Originally Posted by COBB Tuning

The boost oscillation is typically isolated to specific ROMs. We should have a fix ready soon with v402 maps.

Ian

This means another beta map or we getting the final product??

[skim7x]

Originally Posted by 2Times

I just had this issue on I8A0S... is this one of the roms you're seeing it with?

I am running I8AOS but don't have the issue, weird.

[nafoo]

Originally Posted by skim7x

I am running I8AOS but don't have the issue, weird.

Same here.

[2Times]

Originally Posted by skim7x

I am running I8AOS but don't have the issue, weird.

Originally Posted by nafoo

Same here.

It is only once in a while... it's a very strange feeling but once it gets above 4k rpms, it's fine.

[AU335i]

Originally Posted by 2Times

It is only once in a while... it's a very strange feeling but once it gets above 4k rpms, it's fine.

on the LT throttle its usually not noticeable and can only see it in the logs.

[COBB Tuning]

We have just released a firmware update that resolves a known bug that impacts BMW N54 IKB0S IS ECU’s. When this bug is encountered, the AccessPORT no longer recognizes that it is in an installed state immediately after the AccessPORT has been Installed or after a Change Map routine has been completed, rendering the AccessPORT inoperable. Firmware release 1.6.5.0-4040 specifically eliminates this bug on IKB0S IS ECUs and we strongly recommend verifying your AccessPORT is up to date on the latest release firmware before installation. This firmware is compatible with all BMW AccessPORTs.

If your AccessPORT is experiencing the symptom of this bug, please contact a COBB Tuning Customer Service Representative at 866-922-3059 to assist in resolving this issue.

[Motastic]

so this might be a stupid question but i have updated my AP but it still says im on version 301, it wont update to 404 maps. I have "beta maps" checked. Do I have to manually load those in or what?

[Mangler]

Originally Posted by Motastic

so this might be a stupid question but i have updated my AP but it still says im on version 301, it wont update to 404 maps. I have "beta maps" checked. Do I have to manually load those in or what?

Yes you have to load them from the website > PC > AP manager

T

[3-Serious]

Question what is TPS Actual on the data log settings? Also I see on my logs that when I spike boost to 19 on some runs the TPS Actual drops? Im running stage 2+ agressive v301.

[Jonny954]

Hi all,

off topic...but I am planning on buying a COBB soon...I have catless dp's and therefore have CEL. Will I be able to get rid of the CEL with the cobb??
THX