Running Rich AFR, anybody else with Dyno numbers?

**nomorefords** · 09-25-2007, 09:03 AM

I got my Z dynoed this weekend and I peaked at 313/337, which I didn't think was too bad because I have an A4 with minimum bolt ons right now. But when I was at WOT my peak horse was at 11.3 AFR and peak torque was at 11.5 AFR. I've been researching and even the dyno guys said I could probably expect a 15-20 rwhp gain with the AFR leaned out. So, i was just wondering if anyone has had this come up during a dyno run then been re-tuned and re-dynoed with the new AFR? I'll be getting my tune finished up this week so hopefully that will alleviate the issue, but I was curious about dyno numbers.

**67CamaroRSSS** · 09-25-2007, 11:57 AM

My 02 Z dynoed 343/357 at the rear wheels. I had a Volant CAI, QTP 1-3/4 LT's w/ 3" ORY and a QTP 3" E-Cutout in the I-pipe at the time.

I've since swapped the ORY and cutout for 2-1/2" true duals with an X-pipe and MagnaFlow's dumped at the axle. I had 3.42's (from an M6 car) but I've since swapped to 3.73's.

Haven't dynoed with new gears and exhaust yet but it feels sorta the same (SOTP) with the torque moved a little down (rpm wise) in the power band. My A/F was a pretty consistent 11.5:1 (give or take a percentage point) from 2500 to 5500 rpm.

I also have a "piggy back" program that a buddy wrote that runs lean during freeway driving at constant speed which allowed me to get 25-26 mpg at 75 mph when I went to Cali last July.

**nomorefords** · 09-26-2007, 07:07 AM

Originally Posted by 67CamaroRSSS

My 02 Z dynoed 343/357 at the rear wheels. I had a Volant CAI, QTP 1-3/4 LT's w/ 3" ORY and a QTP 3" E-Cutout in the I-pipe at the time.

I've since swapped the ORY and cutout for 2-1/2" true duals with an X-pipe and MagnaFlow's dumped at the axle. I had 3.42's (from an M6 car) but I've since swapped to 3.73's.

Haven't dynoed with new gears and exhaust yet but it feels sorta the same (SOTP) with the torque moved a little down (rpm wise) in the power band. My A/F was a pretty consistent 11.5:1 (give or take a percentage point) from 2500 to 5500 rpm.

I also have a "piggy back" program that a buddy wrote that runs lean during freeway driving at constant speed which allowed me to get 25-26 mpg at 75 mph when I went to Cali last July.

25-26 that has to be nice, even when I'm nice and light on the throttle through a whole tank i'm bairly seeing 17 mpg's, do you think that would be because I'm running rich?

**67CamaroRSSS** · 09-26-2007, 09:18 AM

Might be. I only get 12-13 mpg around town.

**nomorefords** · 09-26-2007, 10:07 AM

That's about the same as me in town, but I usually average about 15 mpg for a full tank, before I put my gears and stuff on it was like 18-19 max. My car runs great too, I guess thats what 346 cubes will do though right! Also, I see that you were at around the same AFR as me on your dyno run, should I leave it where it's at, will leaning it out give me more troubles then benifit. Also, when I hit the gas, even lightly there's a slight, slight knock i guess more of a ping. Not a rod or anything like that, but like the sound of low quality fuel, if you know what i'm saying, could that be because I'm too rich. Just figured i'd ask maybe get some feedback, if so thanks man. Oh, one more thing, that piggy back program your speaking of is that something i could have done when I finish my tune?