fast question

[vettetech]

What should I set the close loop low rpm to and the high rpm to.
I was wondering would it be a good Idea to have it operate trough out the whole rpm range. Right now I noticed it is set to 1500 and off at 1700. Its a Grand National with a t72 turbo. What are most people doing

Thanks Darren

 

[tazgn]

I have mine set to 1200 and 1000RPM. JUST above idle. I tried setting it higher, but the stoplight acceleration seemed to stumble initially by having closed loop come in higher for me. I needed the corrections to come in right away (couldn't get my VE table to work for me down that low in RPM all the time).

Derrick

 

[Craig Smith]

Darren, I think you may have your settings backwards. It has to go above the setting in closed loop high RPM to turn on, and then fall back below the low setting to turn off. Your description leads me to believe you have it the other way around. Just thought I'd mention that for you.

 

[bobc455]

Here is my current thinking on when to activate the O2.

I have a mild enough setup that the O2 sensor will work well at idle, so I am going to use it rhough the whole RPM range for driving.

When I go to the track, however, I am going to have it come on at 3000 RPM and shut off when it falls below 2000 RPM. My thinking is that if it is applying correction at idle/staging (at the starting light), it will carry that correction over when I nail the throttle - however because the engine is operating very differently at WOT, I don't think I want the correction carried over from idle to WOT.

If there were some way to reset the correction when there is a large change in TPS, I would do that, however the O2 correction is kinda dynamic and I want things to start anew when I go WFO.

Make sense?

That is only one persons opinion, there are some who run like Derrick at just over idle only, and some who run without it once they have an accurately tuned VE table (supposedly more consistent).

-Bob Cunningham
bobc@gnttype.org

 

[vettetech]

I was thinking that its better to turn it on until I have all the tuneing done then only allow it to operate during hwy cruse speeds.

Thanks

 

[vettetech]

Craig you are right my thinking was wrong. I assumed that the low was when it would turn on and the high was when it would turn off. So this morning I set it to 900 low and 6300 high and it did not work at all. Thats when I discoverd the errors of my thinking.
I set it to 800 turn off and 900 turn on and it worked. But now the Idle is unstable cause it is always correcting.
I think I will raise it to 1000 turn off and 1200 turn on. Cause I have the exact set up as tazgn and I have the exact hesitation he has.
87 GN Girdled/balanced 3.8, GN1R Ported/Polished Heads, T-72BB Turbo, 72# inj., F.A.S.T., ATR headers/DP/exhaust, Duel intank pumps, 214/214 Roller cam, roller rockers, 70mm TB, J&E forged pistons, H-beam rods, PTS 200-4R, Yank 3600 TC, FORD 9"

I am a newbe at all this. I know Its running rich I need to adjust all the VE tables but my question is What should I set my fuel pressure at, Right now its set to 50psi with out a vac hose connected to it. I am thinking I should proable set it to 45psi. What do yall think?