Dyno Tuning Pros A/F???

[LosLS2]

Hey Guys,

I have a question for some of the guys that are good at dyno tuning WOT. When trying to figure out what the best A/F is for the specific vehicle on the dyno, where do you add and subtract the fuel? Are you changing the VE table in the 95-105 KPA (NA) area or are you changing the PE? The reason that I ask is that in all of my reading and dialing things in, I have read that you are supposed to set the PE to what you want and move the VE values around until you get to the PE desired value. I know that 90% of the dynotuning that happens, happens in 2 hours or so. Unless you are running in OL, there is no way to properly dial in the VE table in that amount of time. I am running HPTuners in OLSD.

Thanks in advance!

[WS6FirebirdTA00]

You make sure you have no error for your VE, then you adjust the PE, this way the car will follow the fueling correctly.

[WS6FirebirdTA00]

Any those "dyno tunes" are half assed, most people only change the PE. I have yet to see a "pro" tuner at a shop around here change anything besides the PE.

[cjs27410]

I set the PE table @ 1.150 which equals a commanded 12.7 (14.62/1.150).
Then adjust the VE cells that correspond to the commanded cells that you hit.
You need a wideband to do that.

[LosLS2]

Well, any decent shop has a wideband on their dyno. It would be kinda hard to do any dynotuning without one. I also have one that is mounted to the car and I log thru HPT.
The problem is that my VE is dialed in to those (95-105KPA) cells by doing WOT runs in 2nd and 3rd as WOT runs in 4th gear are still near 135mph with my 28" tires and 4.10 gears at 6500RPM on the street. Is there a rule of thumb or something for the difference in load that I could calculate and adjust before I show up on the dyno?

[Russ K]

I do the wot afr tuning on my car by slowing the car down to ~1000 rpm in 3rd gear. Then flooring it till 7000 rpm. By slowing the accel rate, the afr graph & histogram have a better resolution and no tire spin.

Russ Kemp

[LosLS2]

I do the wot afr tuning on my car by slowing the car down to ~1000 rpm in 3rd gear. Then flooring it till 7000 rpm. By slowing the accel rate, the afr graph & histogram have a better resolution and no tire spin.

Russ Kemp

Great idea

[cjs27410]

Same here - I start in 3rd around 1000 - 1200 R's hold wide open until the revlimiter @ 6200 around 95 mph. Then push in the clutch to avoid any back pressure/lean a/f readings.