113 replies to this topic

[Harrison@Stage6]

To each their own I guess Chris. My stock bottom end engine at 105K miles looked sexy as hell when we tore it apart. The last 30K were boosted. I have never had any issues with part throttle fueling though. When it went into boost, it always richened up.

[Speedy]

To each their own I guess Chris. My stock bottom end engine at 105K miles looked sexy as hell when we tore it apart. The last 30K were boosted. I have never had any issues with part throttle fueling though. When it went into boost, it always richened up.

 

How what that accomplished in closed loop?

[legmaker]

harrison..... this^^^^^^^

 

the closed loop fueling is why i ran meth.  when i race, i do not run the meth.  my bigger fmic solved my issues with that, so i am with you on that harrison.  

[Harrison@Stage6]

Tuner secrets my friend...... ask Joel what he does. He's the tuner not me. .

[Speedy]

That would be interesting as I've not heard anyone that could manipulate closed loop fueling.

[Harrison@Stage6]

You're not manipulating closed loop at all.

[345_CHLNGR]

Tuners do fuel enrichment for PTB by making it go into Open Loop at a much Lower throttle %.

[legmaker]

yes, but the scenario is very real to see boost and 14.7 a/f on the gauges.  the "work-arounds" are not complete.  its gets worse when you find yourself in a situation of low rpm / high gear and suddenly need throttle input that would not necessarily put the car into closed loop. 

[Knownman]

This.^^

In other words when daily driving. I don't necessarily want to spook everyone around me when I'm just trying to get into a lane during rush hour. Sometimes I tip the peddle a bit to deep in 4th gear and it wants to drop into boost just a bit. This is where having some detonation protection on a stock 6.1 with stock compression makes sense to me.

It's not too complicated reasoning

[Speedy]

Ok so we're back to this again.  Harrison's statement was "I have never had any issues with part throttle fueling though. When it went into boost, it always richened up."

 

Either Joel is manipulating closed loop fueling, which I believe can't be done with what we have today, or he moved the PE point of the throttle way down so you'd enter PE as soon as you got in to boost  NOT desirable.

 

I have heard rumblings that something can be done with the VE tables to enrich fueling in closed loop but have never seen it actually done.

 

Would sure be nice to get a solution though.

 

Mike set my PE point at about 60% throttle and I didn't like it so he moved it back to about 80%.  As a result I get nice smooth transitions in to boost, but I also can see 5-6psi and the AFR is 14s.  I have to be aware of that and not drive the car in to that area and hold it there for long periods of time.

[sharkcohen]

AJ told me that if I did some logging of my part throttle boost that I wouldn't see anything to be concerned about. Well I did some logging, and he was right.

[Jerseyboy]

Ok so we're back to this again. Harrison's statement was "I have never had any issues with part throttle fueling though. When it went into boost, it always richened up."

Either Joel is manipulating closed loop fueling, which I believe can't be done with what we have today, or he moved the PE point of the throttle way down so you'd enter PE as soon as you got in to boost NOT desirable.

I have heard rumblings that something can be done with the VE tables to enrich fueling in closed loop but have never seen it actually done.

Ok, you need to think about what you just said. Part throttle boost is bad beacause you are lean but going into PE when you go into boost is bad. Huh? You just contradicted yourself Spanky...I mean Speedy.

J

[RonP]

^{I have been trying to follow all the PTB stuff for a while and quite frankly I gave up. I run the piss out of my car and there are often times...many times actually, that I am 3-4lbs maybe even 5 and the AFR is still 14.7 unless I mash the pedal further. I guess I was under the impression that you are either in closed loop or open loop and in closed, the tables couldn't be changed. But hell this is all new to me.}

[Speedy]

Ok, you need to think about what you just said. Part throttle boost is bad beacause you are lean but going into PE when you go into boost is bad. Huh? You just contradicted yourself Spanky...I mean Speedy.

J

 

Shouldn't be confusing for you sparky, I mean spanky, I mean JB   Neither situation is ideal.  Given the two I'll drive the car in PTB and just be "mindful".  Having a 600RWHP car go PE at 60% throttle is no bueno for me.  Car's been fine for 5 years driving it in PTB during normal driving.

 

I had the same problem on my supercharged 4Runner that I tuned myself.  With it I got a piggy back box that tied in to the O2 sensor circuit and "tricks" the computer in to adding fuel closed loop when boost is seen.  It drops the AFR from 14:7 to 13:2.  If I pushed it farther I got a CEL for the fuel enrichment being out of range.  It accomplishes the manipulation by intercepting the O2 voltage circuit and modifying it when boost is seen to make the car think it's getting lean, and thus it adds fuel from it's closed loop programming.  I've had that vehicle supercharged for 7 years and it's got 101,000 miles on it now.  Stock motor, 10psi boost, but factory 9:1 compression on that V6.

 

^{I have been trying to follow all the PTB stuff for a while and quite frankly I gave up. I run the piss out of my car and there are often times...many times actually, that I am 3-4lbs maybe even 5 and the AFR is still 14.7 unless I mash the pedal further. I guess I was under the impression that you are either in closed loop or open loop and in closed, the tables couldn't be changed. But hell this is all new to me.}

 

It's fine.  Just don't hold it at 6psi lugging up a hill for 10 minutes.

[ostmike]

^{I have been trying to follow all the PTB stuff for a while and quite frankly I gave up. I run the piss out of my car and there are often times...many times actually, that I am 3-4lbs maybe even 5 and the AFR is still 14.7 unless I mash the pedal further. I guess I was under the impression that you are either in closed loop or open loop and in closed, the tables couldn't be changed. But hell this is all new to me.}

 

Ron, you are correct, your car is either in "open loop" or "closed loop" there are no other options  

The trick is controlling when you are in either of those modes. With the SRT's that have working VE tables, "closed loop" becomes less important with a well tuned VE surface. On the other hand the RT's can be a little more difficult and it becomes more of a question of when to transition into "open loop" from "closed loop" as well as when to transition into PE.

 

I wouldn't sweat 3-4 psi in "closed loop" with the way I have your timing set there but if you want some more PE I can make it come in sooner for you.

[RonP]

Ron, you are correct, your car is either in "open loop" or "closed loop" there are no other options

The trick is controlling when you are in either of those modes. With the SRT's that have working VE tables, "closed loop" becomes less important with a well tuned VE surface. On the other hand the RT's can be a little more difficult and it becomes more of a question of when to transition into "open loop" from "closed loop" as well as when to transition into PE.

 

I wouldn't sweat 3-4 psi in "closed loop" with the way I have your timing set there but if you want some more PE I can make it come in sooner for you.

 

Mike,

 

I think I am good as far as I am concened for now, but I will take a look at it. That was the other thing I should have added to my post..."I trust my tuner"...Just looking forward to getting the new engine done and the car up to you.

[ostmike]

Mike,

 

I think I am good as far as I am concened for now, but I will take a look at it. That was the other thing I should have added to my post..."I trust my tuner"...Just looking forward to getting the new engine done and the car up to you.

 

Thanks Ron and I wasn't insinuating that you didn't trust me   - there is plenty I don't know so please always question things and assume nothing!

[toofart]

Can someone remind me what PE stands for?

[Speedy]

Can someone remind me what PE stands for?

Power Enrichment

[Jerseyboy]

So you don't want to be stoich with boost but you don't want to enrich. What do you want? What is your concern with going open loop in boost if you are saying you don't want to run closed loop in boost? You are kind of talking in circles here Speedy. ...

J