Speed density with or without o2s?
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On The Tree
Joined: Jul 2012
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From: tulsa, ok
Speed density with or without o2s? Hey guys, what are you guys running on your turbo cars/trucks? I am almost finished building my turbo 5.3 build and I am wondering what other guys are doing on their street builds. I see running olsd you don't need front o2s some say it works well others say don't do it. But with clsd you use front o2s. What are you guys running and how is it working for you?
Also if you are running closed loop with a front mount turbo where did you put your o2s for good readings without burning them up?
Also if you are running closed loop with a front mount turbo where did you put your o2s for good readings without burning them up?
Pre turbo backpressure skews wideband readings considerably. I don't know how much it would affect narrowbands. I usually just do post turbo placement for tuning, then OLSD. There could, however, be many situations where CLSD would be preferable.
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Thread Starter
On The Tree
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From: tulsa, ok
Ive seen a few having good luck with olsd. Are you running it on a street setup?
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Verdad Gallardo OLSD can be great on a street setup, but only if you are willing to properly tune in any number of weather conditions. A quick and dirty OLSD setup that doesn't tune all of the modifying tables for different temperatures and traffic conditions just won't do for a full tune. A quick search of posts under my screen name will bring up a long term update on a turbo Escalade that has been running OLSD for over ten years with no problems other than blown transmissions. To be realistic, there have been many vehicles that ran an even cruder open loop alpha-n setup for years with few problems, but those are usually NA builds, and are mostly motorcycles. The perfection we tend to chase around these forums is a fun goal, but rarely a necessity.
Thread Starter
On The Tree
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From: tulsa, ok
Uego + emap Hi BB, the Gametech "tech" is CORRECT.
The UEGO is effected by EMAP with a higher AFR reported as pressure is increased.
Th EGO, four wire, is effected by temperature OVER 1500F with a higher AFR reported with temperature increase.
The Alpha-N mode is commonly used for SC engines when MAP-Comp is specified AND Mixed to allow for the correct PW.
I run Closed Loop as much as possible.
Lance
The UEGO is effected by EMAP with a higher AFR reported as pressure is increased.
Th EGO, four wire, is effected by temperature OVER 1500F with a higher AFR reported with temperature increase.
The Alpha-N mode is commonly used for SC engines when MAP-Comp is specified AND Mixed to allow for the correct PW.
I run Closed Loop as much as possible.
Lance
If you know what you are doing, you don't need narrowbands or closed loop. I daily drove all my previous cars pretty much open loop all the time- and got better economy doing it that way because I shot for leaner than 14.7:1 which is where the narrowband tries to hold you.
So, cliff for the narrowband, use or dont use, put anywhere you want, when you are making power it kicks into open loop anyways so any interference due to temp or pressure isn't a concern.
Wideband on the other hand, you want/need, in any performance car needs this or can use a wideband. It should be put away from the high temperature/pressure source i.e. downstream of the turbine a couple feet if possible. Some widebands have an analog output also (like the ever popular AEM I always use) so it will do a "narrowband simulation" for the oem computer to think you have the narrowband still. In many sensors you can program the narrowband output, I use for example: (15.2:1 @ 0.005v and 0.995v @ 14.85:1) So it holds mean lean as if I were in open loop programmed lean (except now the computer can keep correcting it lean)
So, cliff for the narrowband, use or dont use, put anywhere you want, when you are making power it kicks into open loop anyways so any interference due to temp or pressure isn't a concern.
Wideband on the other hand, you want/need, in any performance car needs this or can use a wideband. It should be put away from the high temperature/pressure source i.e. downstream of the turbine a couple feet if possible. Some widebands have an analog output also (like the ever popular AEM I always use) so it will do a "narrowband simulation" for the oem computer to think you have the narrowband still. In many sensors you can program the narrowband output, I use for example: (15.2:1 @ 0.005v and 0.995v @ 14.85:1) So it holds mean lean as if I were in open loop programmed lean (except now the computer can keep correcting it lean)
Thread Starter
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From: tulsa, ok
I've got all the stuff to run the narrowbands already so I figure I might as well add them on at this point. This build will be mainly a street setup. If it was a strip only I would probably just run OLSD and call it a day.