His dyno A/F already shows its running at a decient safe A/F. It could be leaned out a bit, but it's not bad at all for a FI setup. Usually, you run a bit leaner off the dyno then on, so i think you'll be right in the ballpark on the A/F at WOT. The O2's shouldn't make a night and day difference at WOT because there not in use at WOT. Now out of WOT, i could see a big difference there, but assuming everything is working normally, you should be running in the 14 to 15:1 range out of WOT.

Ken R.

 

I would imagine his car is running rich at part throttle/idle. BUT...

That is why I would buy a wide band to VERIFY. I never claimed he was running rich, but I think it is always helpful to know what the car is doing while you are not in a controlled environment. (or as controlled as a shop with a dyno.)

IMHO, the wide band O2 sensor is the best thing in the performance world since radial tires. Or something like that.

 

I did borrow a buddies wideband to test in my y pipe on the street and it started at 10.8 down low and creeped up to 12.1 at 6500.
I thought the same thing about the o2's not effecting wot but I only changed those and fixed the wiring issues on the fan so maybe the computer was seeing the fans acting up and pulling timing or going into some sort of limp mode or something?
Whatever it was, it was really holding back the car in performance thats for sure!

 

I have a 97 383 - D1 with 3.4" dia. drive pulley (Meth and spearco IC). I have tuned with a DynoJet WB O2 on the road. The car was pulling timing @ high rev. Re-tuned with LT1_edit v2.2 and zeroed the knock tables. That helped alot. Next, I'm converting the sensor to a line resistor (100kohm). Also, I am running (2) Walbro 255lph pump set-up on 72# Seimens injectors. The PE curve was fueling very rich @ 10.5:1. I knocked the cal curve down to achieve about 12.8/ 12.5:1. Helped alot. Now it is all over the road @ high rpm in WOT mode when the rpm rolls on with an M6. ALso, I have had many opti failures. Your description sounded very similar relative to lack of power on high. I recently changed to a Summit (added rivets to the rotor), and, quite a difference. These things need constant maintenance and cleaning of the wheel and high voltage contacts. My experience has been these LT1 engines like alot of timing even with FI(about 32* to 34* @ 100 kpa & 4k rpm). Sorry for the long rant. B.

 

I'll agree there, but you might reconsider zeroing your knock tables. You shouldn't have to assuming you don't have anything generating false knock. I'm running a Snow system with a FMIC. Just ran it last week on 12psi and a 150 dry shot. Started at around 20deg of timing. Ended the night at 27deg of timing and still wasn't seeing any KR through the entire pass from launch, even on the shifts. My tables are turned on. I was pretty happy with that. It's a 383 at 9:1 with stock ported LT1 castings. There definitly happy with timing on the right setup and safe A/F's.

Ken R.

 

Ran the car last Friday. Transmission issues made for a ****ty night and had a header gasket blow out
Good news is it picked up the driver side tire a few inches

 

Lifting a tire is never disappointing. Awesome job!

 

I've got alot of noise that has created alot of "false" knock sensor trigger. So, I deleated the knock ignition timing roll-back. I too have a progressive Snow M/H2O Inj and a large Spearco IC. Also, I have installed Evans NPG waterless coolant. This helps prevent detonation due to far improved heat transfer,and, wide open coolant flow over the EG water based coolant. The stock designed poppet/ bypass style T_stat is quite restrictive, and, will allow coolant to bypass the rad untill it is a full temperature. From my observation, the bypass does not seal the WP port The motor is happy now.