Help, Cobb Stage 2 breaking up at high RPM

[Ruff Ryda]

Originally Posted by EVOXMAINE

mine does it with just stage 1 it doesn't have anything to do with stages or turbo-back / stock. It must just still be getting far to much fuel up top... wish I could get rid of this so I can haul ass all the way to redline!!!

Same here!!

[RobY]

Originally Posted by Ruff Ryda

Do you have any history with the AP?

Im bone stock flashed with stg 1 91 running on california pisstane. So far so good, pulls straight to redline with no hesitation in any gear in 110 degree central valley heat.

[RobY]

Originally Posted by EVOXMAINE

mine does it with just stage 1 it doesn't have anything to do with stages or turbo-back / stock. It must just still be getting far to much fuel up top... wish I could get rid of this so I can haul ass all the way to redline!!!

Put the stock intake and filter back in. Cobb noted that the current gen EVO's are very sensitive to intake changes. They developed separate maps for different intake configs.

Cobb has stated in the past that something as simple as a drop in filter caused a change of 0.5 AFR. This is pretty significant.

Diffrent diameter MAF housings and intake tubing throw the AFR so far off that it actually becomes unsafe to run a non specific OTS map.

[Ruff Ryda]

Originally Posted by RobY

Put the stock intake and filter back in. Cobb noted that the current gen EVO's are very sensitive to intake changes. They developed separate maps for different intake configs.

Cobb has stated in the past that something as simple as a drop in filter caused a change of 0.5 AFR. This is pretty significant.

Diffrent diameter MAF housings and intake tubing throw the AFR so far off that it actually becomes unsafe to run a non specific OTS map.

I'm running the HKS panel filter map.

[RobY]

Ya, i was referring to EVOXMAINE's problem. If the sig is correct he's running a custom intake setup.

[EVOXMAINE]

Have perrin inlet and a cone. This helped my problem. before when I was stock this problem was bad. I put an intake in because someone had said it helped and it did. seems as though an intake would lean, and I need as much of that as I can. I use the cobb map for use with sf intake. That intake is basically just a filter. Just explain if I am wrong!!! I would love to get this problem solved.

[mrMTB]

OP-

you're being a bit less than helpful with others here trying to give you some assistance. Let's take it from the top and see if you can fill in the blanks...

Original issue- running AP stage II map (which one?) with panel filter (which brand and type?), UICP, and removed boost pill. Experiencing breakup around 5500 rpm.

Troubleshooting 1- put boost pill back in. Same issue. (same map?)

Troubleshooting 2- you were requested to put the pill back in, and reflash to Stage I with HKS filter. Did you do this? What were the results? Did you log?

Troubleshooting 3- replace aftermarket filter with stock. Probably a good idea when you are doing this to clean the MAF as some filters will foul the sensor and cause issues. Intake sensitivity is well documented on this vehicle.

A few other things- you don't mention what kind or octane fuel you are running. If you are running a 93 octane map, you should also try the above steps with the 91 octane map to ensure it is not and issue with the fuel itself.

I'm interested in your statement that many tuners (Hollywood) have verified that the stage ii map is safer (safe at all?) on a car with a stock exhaust. Would you mind pointing out a few threads where this has been demonstrated?

[Ruff Ryda]

Originally Posted by mrMTB

OP-

you're being a bit less than helpful with others here trying to give you some assistance. Let's take it from the top and see if you can fill in the blanks...

Original issue- running AP stage II map (which one?) with panel filter (which brand and type?), UICP, and removed boost pill. Experiencing breakup around 5500 rpm.

Troubleshooting 1- put boost pill back in. Same issue. (same map?)

Troubleshooting 2- you were requested to put the pill back in, and reflash to Stage I with HKS filter. Did you do this? What were the results? Did you log?

Troubleshooting 3- replace aftermarket filter with stock. Probably a good idea when you are doing this to clean the MAF as some filters will foul the sensor and cause issues. Intake sensitivity is well documented on this vehicle.

A few other things- you don't mention what kind or octane fuel you are running. If you are running a 93 octane map, you should also try the above steps with the 91 octane map to ensure it is not and issue with the fuel itself.

I'm interested in your statement that many tuners (Hollywood) have verified that the stage ii map is safer (safe at all?) on a car with a stock exhaust. Would you mind pointing out a few threads where this has been demonstrated?

I'll start by telling you that just telling me the same thing that is stated on cobb website 5 times in a row is not what I call helping.

I am running BP 93 oct fuel. I have done all the steps that you stated above with similar results. I just installed Cobb ATR this morning and will be doing some logging with that later today.

[EVOXMAINE]

I just tried stg2 and it didn't pull as good as stg1... seemed pretty doggish. hoping that changes when I get the turboback. Also I took the possitive off the battery and held the brake to the floor for a while to reset everything. I then flashed back to stg1 and it seems to haul right now. I think that even with the AP the ecu learns to richen itself.

[Ruff Ryda]

I did some logging yesterday. My car seamed to be running ok but still the slight breakup. My car ran stage 2 fine at first but after the ecu made it's changes through learning it became a lil too rich up top.

All in all my car runs good, it's just a little embarrasing when you go WOT and cars start crashing behind me because they can no longer see because the black smoke.

[mrMTB]

Would you mind posting the logs? What map were you running, and what was the state of your hardware modifications at that time (boost pill, filter, etc)?

[Ruff Ryda]

Originally Posted by mrMTB

Would you mind posting the logs? What map were you running, and what was the state of your hardware modifications at that time (boost pill, filter, etc)?

Sure will. I'm at work right now, I'll try to post them later tonight.

[Ruff Ryda]

Here is a AP log that I ran yesterday morning. My ATR logs are a screwed up.

[mrMTB]

Hmm, you're overboosting @9.65, and it appears that the ECU is hiccuping for a second as it tries to get it back under control (this is happening around the 5500 RPM you mention previously). Your load cells move 174 > 238 (spike) > 192 (recover) > 210 (1.3 sec following spike) > 206 > 191.

Have you tried running the Stage II + HKS map? Cobb recommends the HKS intake maps for people who have issues running the regular stage maps with a panel filter. Yes, it'll enrich the fueling in those transition and spool areas, but this might be just what the system needs to keep the spike under control.

[Ruff Ryda]

Originally Posted by mrMTB

Hmm, you're overboosting @9.65, and it appears that the ECU is hiccuping for a second as it tries to get it back under control (this is happening around the 5500 RPM you mention previously). Your load cells move 174 > 238 (spike) > 192 (recover) > 210 (1.3 sec following spike) > 206 > 191.

Have you tried running the Stage II + HKS map? Cobb recommends the HKS intake maps for people who have issues running the regular stage maps with a panel filter. Yes, it'll enrich the fueling in those transition and spool areas, but this might be just what the system needs to keep the spike under control.

Yeah, that is what I am currently running, and was running during this log.