Dynoed with Detroit Rocker blower cams
03-12-2012, 08:34 AM
#13
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Join Date: Nov 2009
Location: PR
Posts: 329
The HP/TQ differences are probably due to both my car being an automatic, and the blower being a centrifugal. I bet you could get a pretty neat power curve with a twin screw blower and these cams.
03-12-2012, 06:22 PM
#14
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Join Date: Nov 2009
Location: PR
Posts: 329
One thing I haven't mentioned yet was that I was having some issues with the car stalling after shutting it off, and attempting to restart it. I would need to give it some gas for a few seconds so it wouldn't stall. Before bothering Brenspeed about it, though, I did the whole "clean throttle body, and MAF" thing that everyone recommends. Stalled occasionally still.
Then I found this post on another forum, from Chris Rose (AmericanMuscle.com) regarding some similar issues on the tuned 2011+ mustangs:
"Many people have been complaining about idle issues with a custom tune, and also even on a stock tune when they first return it to stock. There is a simple answer to this, and luckily... a simple fix!
First, the reason that this happens - your PCM calibration controls the idle, and memorizes certain driving conditions and mechanical conditions. This way it knows exactly what your car needs (air requirements, etc.) to idle properly. This is stored in the PCM, so any power interruption (battery disconnected, new batter, OR ANY PCM REFLASH INCLUDING CUSTOM TUNES) will result in a loss of these memorized requirements. Once the car has power to the PCM again or a fresh reflash, it MUST relearn these values or idle quality will be affected. Do the following procedure to fix it (from a cold start!) Here is the Ford owners manual text:
------------------------------------------
Because your vehicle's engine is electronically controlled by a computer, some control conditions are maintained by power from the battery. When the battery is disconnected or a new battery is installed, the engine must relearn its idle and fuel trim strategy for optimum driveability and performance. To begin this process:
1.) With the vehicle at a complete stop, set the parking brake.
2.) Put the gearshift in P (Park) (automatic transmission) or the neutral position (manual transmission), turn of all accessories and start the engine.
3.) Run the engine until it reaches normal operating temperature.
4.) Allow the engine to idle for atleast one minute. *AM note: one minute AFTER you get to peak temperature - probably about 5 minutes total from cold start.
5.) Turn the A/C on and allow the engine to idle for at least one minute.
6.) Drive the vehicle to complete the relearning process.
• The vehicle may need to be driven 10 miles (16km) or more to relearn the idle and fuel trim strategy.
• If you do not allow the engine to relearn its idle trim, the idle quality of your vehicle may be adversely affected until the idle trim is eventually relearned.
------------------------------------------
We're all about good customer service at AmericanMuscle. The idle quality issues sent us into panic mode. We tested our tune on over four different 2011 Mustangs overnight to try and hammer down if it was something inside our calibration just to be safe. We logged the 'idle integrator' (which is the correction for air requirements) and learned that it was unstable after reflash for a few minutes while it learned.
This is nothing new, we've logged this parameter on many vehicles that have camshafts, superchargers, etc. In 2011, the air requirements became a little bit more touchy, so this process needs to be done, while previous years responded much better."
I tried this, and surprisingly it worked! In my case I guess I never bothered to turn on the AC at all. The loss of vacuum from the cams must have really wonked up the "idle integrator whatchamathingy" that Chris mentions. Now my car starts pretty solid, everytime. Didn't even need to bother raising the idle, which I've set at 700rpm, to let my pony really trot.
Then I found this post on another forum, from Chris Rose (AmericanMuscle.com) regarding some similar issues on the tuned 2011+ mustangs:
"Many people have been complaining about idle issues with a custom tune, and also even on a stock tune when they first return it to stock. There is a simple answer to this, and luckily... a simple fix!
First, the reason that this happens - your PCM calibration controls the idle, and memorizes certain driving conditions and mechanical conditions. This way it knows exactly what your car needs (air requirements, etc.) to idle properly. This is stored in the PCM, so any power interruption (battery disconnected, new batter, OR ANY PCM REFLASH INCLUDING CUSTOM TUNES) will result in a loss of these memorized requirements. Once the car has power to the PCM again or a fresh reflash, it MUST relearn these values or idle quality will be affected. Do the following procedure to fix it (from a cold start!) Here is the Ford owners manual text:
------------------------------------------
Because your vehicle's engine is electronically controlled by a computer, some control conditions are maintained by power from the battery. When the battery is disconnected or a new battery is installed, the engine must relearn its idle and fuel trim strategy for optimum driveability and performance. To begin this process:
1.) With the vehicle at a complete stop, set the parking brake.
2.) Put the gearshift in P (Park) (automatic transmission) or the neutral position (manual transmission), turn of all accessories and start the engine.
3.) Run the engine until it reaches normal operating temperature.
4.) Allow the engine to idle for atleast one minute. *AM note: one minute AFTER you get to peak temperature - probably about 5 minutes total from cold start.
5.) Turn the A/C on and allow the engine to idle for at least one minute.
6.) Drive the vehicle to complete the relearning process.
• The vehicle may need to be driven 10 miles (16km) or more to relearn the idle and fuel trim strategy.
• If you do not allow the engine to relearn its idle trim, the idle quality of your vehicle may be adversely affected until the idle trim is eventually relearned.
------------------------------------------
We're all about good customer service at AmericanMuscle. The idle quality issues sent us into panic mode. We tested our tune on over four different 2011 Mustangs overnight to try and hammer down if it was something inside our calibration just to be safe. We logged the 'idle integrator' (which is the correction for air requirements) and learned that it was unstable after reflash for a few minutes while it learned.
This is nothing new, we've logged this parameter on many vehicles that have camshafts, superchargers, etc. In 2011, the air requirements became a little bit more touchy, so this process needs to be done, while previous years responded much better."
I tried this, and surprisingly it worked! In my case I guess I never bothered to turn on the AC at all. The loss of vacuum from the cams must have really wonked up the "idle integrator whatchamathingy" that Chris mentions. Now my car starts pretty solid, everytime. Didn't even need to bother raising the idle, which I've set at 700rpm, to let my pony really trot.
03-12-2012, 11:52 PM
#15
5th Gear Member
Join Date: Dec 2006
Location: Redding, CA
Posts: 4,552
It produces about 10psi of boost. But i barely see above 8psi most of the time. I guess those last 2psi are at the 6500rpm range, which I rarely dare go to.
The HP/TQ differences are probably due to both my car being an automatic, and the blower being a centrifugal. I bet you could get a pretty neat power curve with a twin screw blower and these cams.
The HP/TQ differences are probably due to both my car being an automatic, and the blower being a centrifugal. I bet you could get a pretty neat power curve with a twin screw blower and these cams.
03-14-2012, 12:16 AM
#16
5th Gear Member
Join Date: Oct 2009
Location: Maui
Posts: 4,752
Acerbus...... your post explains what happened to me the last time I disconnected my battery when I installed my leather skins. The idle was kinda screwed....very rough and kinda rich. I knew it had something to do with the relearning thing. It eventually fixed itself. Thanks for the post, learned something new today.
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