Cobb AccessPORT Discussion
Yeah I guess from a versatile and practical point of view, but if one is looking for the most gains I believe a more specific based tune would be in call for....which leads me to believe a Cobb stage 1 w/stock intake would outperform one of Jeff's NA tunes w/a aftermarket CAI????
Intakes on the '8 do nothing but lose peak power.
They "gain" power in ranges that have less than peak to begin with, that is how they can claim things like 15 HP.
There has never been a more perfectly engineered intake than the one on the RX-8.
That said, the way intakes on most cars work is by intentionally screwing with the MAF.
The AP uses the MAF to gain more precise control over the fuel and spark.
Garbage in - garbage out. If the MAF signal is FUBARed by your intake, you can't possibly expect the AP to make it right.
Now, if you had access to a pro tuner, they could read your fuel trims and produce a calibration that corrected much of the bad MAF output, but it would be easier (and produce more power) if you just put the stock intake back on.
It does nothing by make noise and change your peak torque point.
They "gain" power in ranges that have less than peak to begin with, that is how they can claim things like 15 HP.
There has never been a more perfectly engineered intake than the one on the RX-8.
That said, the way intakes on most cars work is by intentionally screwing with the MAF.
The AP uses the MAF to gain more precise control over the fuel and spark.
Garbage in - garbage out. If the MAF signal is FUBARed by your intake, you can't possibly expect the AP to make it right.
Now, if you had access to a pro tuner, they could read your fuel trims and produce a calibration that corrected much of the bad MAF output, but it would be easier (and produce more power) if you just put the stock intake back on.
It does nothing by make noise and change your peak torque point.
Last edited by Derex'8; Mar 18, 2008 at 12:42 PM.
jeff...im still running a/f ratios of mid to high 14's at wot....any suggestions....stft are still petty good and stay consistent.....i dont plan moving to stage 2 or 3 until my afr is in the 13's......thanks
If you are seeing high 14s at WOT, moving up a stage would make no sense whatsoever.
It not like there is magical power. It will just get leaner.
Stay where you are for a few days and let the trims settle and then see where you are. Where are they now?
It is normal for the A/F to be in the high 14's and low 15's at less than maximum load.
Cruising, you might even touch 16:1 in some ranges. That is your missing fuel economy!
It not like there is magical power. It will just get leaner.
Stay where you are for a few days and let the trims settle and then see where you are. Where are they now?
It is normal for the A/F to be in the high 14's and low 15's at less than maximum load.
Cruising, you might even touch 16:1 in some ranges. That is your missing fuel economy!
As long as it goes below 14:1 when you mash it, that isn't a problem.
However, I wouldn't mash it until I know where my trims are going to settle.
Remember people - we are removing the safeguards that are built in via an overly-rich mixture, so you need to be patient, methodical and careful.
However, I wouldn't mash it until I know where my trims are going to settle.
Remember people - we are removing the safeguards that are built in via an overly-rich mixture, so you need to be patient, methodical and careful.
Doppelgänger
Joined: Feb 2008
Posts: 3,192
Likes: 1
From: Florida
useless cels for modified cars, such as cat not working, or fuel too rich have been axed.
jeff can make a custom map that puts back, or removes cels for you though.
considering the limited amount of time he's had to work with, I dare say that the AP and his maps are impressive.
jeff can make a custom map that puts back, or removes cels for you though.
considering the limited amount of time he's had to work with, I dare say that the AP and his maps are impressive.
Registered User
Joined: Feb 2008
Posts: 249
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Ok, I took out the PCM and removed the Greddy harness and it's just hangin there now, and I plugged in all the original five plugs into the PCM. I flashed it to 3.0 base flash and the lights came on, the car with the squiggly tire lines on the top of the tach was on, and the dsc off light was blinking.
I double checked everything I did and did it all gently and don't think I pulled on any wires hard. after messin around with the flashes as the instructions say to get to a good stft, the dsc light eventually went off and so did the squggly tire light. one time the dsc off light would not come on even when i pushed the button, but now everything seems back to normal
When following instructions to see if i had a neg stft, my numbers are all over the place but mostly neg. So i went to 3.3b, minus 6%. Numbers are still all over the place so I guess i'll drive around for a few days, but I got the impression to just drive 'lightly' around the block till it warms up. Anyways, I think my numbers are all mostly in the high neg, but are really all over the place. AFR when under engine braking is like 20, but goes as low as 11 under light load accel. normal very light accel, it is in 13's to 14's, but when letting off throttle and engine braking it goes to 20. it's still backfiring badly and stalling at clutch in and car stop.
So i'm not sure what to do now, except wonder are these calibrations off for my car in particular? maybe i can get some moer custom map where the idle is increased so it doesn't stall? normal idle is mid 800's which seems normal, but for some reason when coming to a stop, it wants to dip really low then stalls and sometimes uncontrollably and even with throttle blipping I can't keep it on.
and one more thing, it will not go into boost so i'm very careful when driving now. when i accel, i do it very gently, if i don't, past 3 to 4000 rpm it bogs like crazy. what am i doing wrong?
I double checked everything I did and did it all gently and don't think I pulled on any wires hard. after messin around with the flashes as the instructions say to get to a good stft, the dsc light eventually went off and so did the squggly tire light. one time the dsc off light would not come on even when i pushed the button, but now everything seems back to normal
When following instructions to see if i had a neg stft, my numbers are all over the place but mostly neg. So i went to 3.3b, minus 6%. Numbers are still all over the place so I guess i'll drive around for a few days, but I got the impression to just drive 'lightly' around the block till it warms up. Anyways, I think my numbers are all mostly in the high neg, but are really all over the place. AFR when under engine braking is like 20, but goes as low as 11 under light load accel. normal very light accel, it is in 13's to 14's, but when letting off throttle and engine braking it goes to 20. it's still backfiring badly and stalling at clutch in and car stop.
So i'm not sure what to do now, except wonder are these calibrations off for my car in particular? maybe i can get some moer custom map where the idle is increased so it doesn't stall? normal idle is mid 800's which seems normal, but for some reason when coming to a stop, it wants to dip really low then stalls and sometimes uncontrollably and even with throttle blipping I can't keep it on.
and one more thing, it will not go into boost so i'm very careful when driving now. when i accel, i do it very gently, if i don't, past 3 to 4000 rpm it bogs like crazy. what am i doing wrong?
Doppelgänger
Joined: Feb 2008
Posts: 3,192
Likes: 1
From: Florida
Ok, I took out the PCM and removed the Greddy harness and it's just hangin there now, and I plugged in all the original five plugs into the PCM. I flashed it to 3.0 base flash and the lights came on, the car with the squiggly tire lines on the top of the tach was on, and the dsc off light was blinking.
When following instructions to see if i had a neg stft, my numbers are all over the place but mostly neg. So i went to 3.3b, minus 6%. Numbers are still all over the place so I guess i'll drive around for a few days, but I got the impression to just drive 'lightly' around the block till it warms up. Anyways, I think my numbers are all mostly in the high neg, but are really all over the place. AFR when under engine braking is like 20, but goes as low as 11 under light load accel. normal very light accel, it is in 13's to 14's, but when letting off throttle and engine braking it goes to 20.
So i'm not sure what to do now, except wonder are these calibrations off for my car in particular? maybe i can get some moer custom map where the idle is increased so it doesn't stall?
Jeff's maps allow you to adjust it so the trims don't need to be adjusted as much.
and one more thing, it will not go into boost so i'm very careful when driving now. when i accel, i do it very gently, if i don't, past 3 to 4000 rpm it bogs like crazy. what am i doing wrong?
Registered User
Joined: Feb 2008
Posts: 249
Likes: 0
When you disconnect the ECU, it will have you do the DSC steering wheel thing, turn it to the left all the way, then the right, and it will go away. I usually turn off the car, and start it up again, so the traction icon goes away.
If you can't tell, just drive around for a few days. Then look at your long term fuel trim to see where to go with it.
The car is constantly making fuel adjustments. At idle you'll see the STFT moving around. In the past when I was NA and reset the ECU, it would usually take 2-3 drive cycles for the car to learn how to idle properly. Some people don't have this issue because the trims are close to being what they should be, while others need a bit of adjustment.
Jeff's maps allow you to adjust it so the trims don't need to be adjusted as much.
Sounds like you need a better intake setup and to recirculate your BOV.
If you can't tell, just drive around for a few days. Then look at your long term fuel trim to see where to go with it.
The car is constantly making fuel adjustments. At idle you'll see the STFT moving around. In the past when I was NA and reset the ECU, it would usually take 2-3 drive cycles for the car to learn how to idle properly. Some people don't have this issue because the trims are close to being what they should be, while others need a bit of adjustment.
Jeff's maps allow you to adjust it so the trims don't need to be adjusted as much.
Sounds like you need a better intake setup and to recirculate your BOV.
Doppelgänger
Joined: Feb 2008
Posts: 3,192
Likes: 1
From: Florida
greddy intake setup is far from ideal, but it's better than the maf housing i had on earlier. the difference is like night and day though. So the importance of a properly setup intake cannot be underestimated or taken lightly.
the greddy emu setup uses a pressure sensor when you go into boost, so it isn't going to be as sensitive in boost as your car will be now using only the maf.
the greddy emu setup uses a pressure sensor when you go into boost, so it isn't going to be as sensitive in boost as your car will be now using only the maf.
Registered User
Joined: Feb 2008
Posts: 249
Likes: 0
greddy intake setup is far from ideal, but it's better than the maf housing i had on earlier. the difference is like night and day though. So the importance of a properly setup intake cannot be underestimated or taken lightly.
the greddy emu setup uses a pressure sensor when you go into boost, so it isn't going to be as sensitive in boost as your car will be now using only the maf.
the greddy emu setup uses a pressure sensor when you go into boost, so it isn't going to be as sensitive in boost as your car will be now using only the maf.