Multiple boost setting question...
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Twin Turbo Coupe
Joined: Apr 2005
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From: Frederick MD
Multiple boost setting question...
Those who are running a MAF and multiple boost settings.....how are you making up the difference in fuel between high and low boost?
I have been trying to decide on the best and most consistent way to proceed. Looking to run 11lbs low and 15lbs high...here are what I see as some options:
1)Thinking that having a different program for high and low. This would appear to be a bit of a PITA to flash thepcm to switch back and forth for settings and that I would also have to maintain/tweak two sets of tunes if I changes/add things down the road.
2)I was also thinking that I could tune for high boost and then run a rich low boost setting and pull back on the alky. Probably the most practicle and safest but I am not sure whether it would be too rich at the low setting
3)Use the roadrunner pcm/EFI live real time tuning but it just does not seem like many have tried this approach yet...I did not see where anyone tried this on this forum yet but who knows
4) Run SD but at the moment constant tweaking is not desireable. But I would be willing to go this route once I become more versed in tuning.
Thanks for your input!
I have been trying to decide on the best and most consistent way to proceed. Looking to run 11lbs low and 15lbs high...here are what I see as some options:
1)Thinking that having a different program for high and low. This would appear to be a bit of a PITA to flash thepcm to switch back and forth for settings and that I would also have to maintain/tweak two sets of tunes if I changes/add things down the road.
2)I was also thinking that I could tune for high boost and then run a rich low boost setting and pull back on the alky. Probably the most practicle and safest but I am not sure whether it would be too rich at the low setting
3)Use the roadrunner pcm/EFI live real time tuning but it just does not seem like many have tried this approach yet...I did not see where anyone tried this on this forum yet but who knows
4) Run SD but at the moment constant tweaking is not desireable. But I would be willing to go this route once I become more versed in tuning.
Thanks for your input!
Team Owner
Joined: Jul 2003
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From: Detroit
This is exactly what I do, although I usually just run my low boost setting pig rich as it still makes gobs of power.
Burning Brakes
Joined: May 2003
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From: Roswell New Mexico
St. Jude Donor '07-'08
This is the option i would choose. I have tuned my one time (took a few hours) and have never touched it since...working great. I am sure it will need some changes in the long run, but you are talking maybe once every few months...maybe
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Twin Turbo Coupe
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From: Frederick MD
Thread Starter
Twin Turbo Coupe
Joined: Apr 2005
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From: Frederick MD
Once I become more versed in tuning, I will probably go down this route to keep myself busy and try something new. I would really like to see if anyone gets the road runner pcm running realtime with EFI live as this would make adjustments to the tables based on real-time wideband readings...I would not think you could get more acurate than that.
Burning Brakes
Joined: Feb 2004
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From: over the water Cali
I have seen some here, i think with one of the twin turbo set ups move the ECU to the battery compartment(location). If this is done then buying a second ECU for 200 buck with a second tune would allow a 15 second swap if needed without the risk of frying the ECU. Just use a battery quick disconnect as well.???
Team Owner
Joined: Jul 2002
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From: This city NEVER sleeps! Frank's back yard!
LPE set mine up such that I flash the ECM with a custom tune for each of my two boost settings. 10 psi and 13 psi, with fuel and spark optimized for each. Their usual way is to be too rich at low boost and retarded timing on high boost with a single tune which compromises both settings somewhat. The SD solution is best, but I'm very happy with my two tune set up!
Supporting Vendor
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From: http://www.mphparts.com 800-364-1975
A few psi of boost is not really that much in the grand scheme of things, and other than the power output difference I doubt most of us could tell the difference between a car running at 12:1 vs. running at 10.5:1. You want two boost settings to have a "kill" mode and a normal mode, with normal mode having a reduction in power, right? I would tune for kill mode, and then dial back your boost pressure for normal mode until you've found the sweet spot where power output is about where you want it. Your car doesn't have to be running a perfect 11.5:1 or 12:1 to run well at WOT.
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Twin Turbo Coupe
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From: Frederick MD
A few psi of boost is not really that much in the grand scheme of things, and other than the power output difference I doubt most of us could tell the difference between a car running at 12:1 vs. running at 10.5:1. You want two boost settings to have a "kill" mode and a normal mode, with normal mode having a reduction in power, right? I would tune for kill mode, and then dial back your boost pressure for normal mode until you've found the sweet spot where power output is about where you want it. Your car doesn't have to be running a perfect 11.5:1 or 12:1 to run well at WOT.
Burning Brakes
Joined: Aug 2000
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From: Oregon City , Oregon USA
Help me understand the tuning issues involved here. Does the difference between high and low boost tune requirements have to do with the relationship between boost and throttle position and rpms? Why are the tuning requirements for an engine tuned for say 15 lbs of boost but only seeing 10 lbs at part throttle or full throttle at a lower engine speed different than an engine that is being limited to 10 lbs by a second setting on the boost controller?
Le Mans Master
Joined: Oct 2003
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From: PA
St. Jude Donor '08
A few psi of boost is not really that much in the grand scheme of things, and other than the power output difference I doubt most of us could tell the difference between a car running at 12:1 vs. running at 10.5:1. You want two boost settings to have a "kill" mode and a normal mode, with normal mode having a reduction in power, right? I would tune for kill mode, and then dial back your boost pressure for normal mode until you've found the sweet spot where power output is about where you want it. Your car doesn't have to be running a perfect 11.5:1 or 12:1 to run well at WOT.
100%i agree with tony, your AR dont have to be perfect.
tony is right, ive my car pig rich 10.0 high 9s @ 18psi and there is no way your going to complain about lack of power.
Last edited by NICK YOSKIN; Mar 29, 2007 at 12:25 PM.
Premium Supporting Vendor
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From: Knoxville Tennessee
YOU have run your car and made nine second passes?
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From: Knoxville Tennessee
Safety Car
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From: Valrico Florida
Thread Starter
Twin Turbo Coupe
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From: Frederick MD
Thanks Nick....Sounds like dialing high for the kill is the way....just was not sure about how loaw boost would turn out. Sounds like it will NOT be a problem.
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Twin Turbo Coupe
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From: Frederick MD
At my new power levels, I am sure I will be needing another set in a couple of months