2002 Lightning
6# Lower pulley
Diablo chip
Denso IT 22 plugs

I went to the dyno today to get some A/F ratios to see if my chip is within safe peramiters. The thing is my power was way down and according to the wide band I was running EXTREMELY rich. It was only making a peak of 420 torque and 351 HP???

Now this trubles me for a few reasons.
1) it is 4 Degrees Fahrenheit outside (I live in Canada) so that should have leaned it out qiut a bit.
2) I ran a 12.9@105 mph in the summer with a 1.84 60 foot time so I would think I am running a good A/F ratio and making good power for my mods.
3) I decided to floor it on my way home to see if I hear any detonation because with it being this cold outside I would think it would run lean for sure. And sure enough I floored it at 60mph and as the RPM got near redline I could hear the crakling sound if detonation. I immedialtly take my foot of the gas to not do any damage. I try this one more time and again when the RPM gets close to redline I hear detonation. I am 95% sure it was detonation I was hearing. SO that would mean I am not running extremely rich as the dyno said I was. I would guess my A/F ratio was dead on because if it ran a bit rich in this weather it would be perfect in the summer.

4) I pulled one of my plugs and it was not black like I would expect if I was running very rich. It was a brown colour.

I have attached pictures of some dyno graphs showing my A/F ratios recorded by the Dyno as well as my max power. I also have attached a pic of a plug.

So tuners is it possible to run this rich on a dyno with a chip made for a 6# pulley? Is it because there is no strain on the motor from lugging the 5000 pound body or is the dyno messed up?

Help please.
Thanks Jason

The plug looks a bit blacker then it really is. It was a dark brown color.



I dont know if you could read the A/F's so I will post the extremes..

A/F is from 9.89-11.11


A/F is from 9.7-10.73

 

A/F is from 9.71-11.53



This is my best power chart
Max hp =351@5000
Max Trq =420 @4000 Could it be because we get max torque before 3000rpm? We couldnt floor it before 3000rpm because it would kick down into second.

 

Ouch, looks like its running a tad rich! You needa get that fixed.

-Mike

 

To be honest man i don't know how accurate that dyno is...Not bashing it just i never really seen 1 look like that..We can lean you down if thats what you want but its COLD! outside i'd rather see you rich and live thru the winter and when spring gets here we'll pick it up a notch...just let me know either way and we'll take care of it.....JLP

 

Is the plug really supposed to look like that?? I thought they had more of a "nub" on the end rather than the "needle" you have in your photo. Might want to check into that!

-Ollie

 

That is what the Denso IT 22 plugs (iridium) plugs look like.

 

Johnny, thats what I am saying. I mean with it being this cold out I should be running on the lean end of the scale. With all the facts that I showed you do you think its running as rich as the charts say? Also I am almost positive I heard detonation when going WOT on the way home. I would have never floored it in this kind of weather before because of the fear of running lean but after the dyno I had to see what would happen. Maybe I will take it to another dyno to double check everything. I just dont get it. Power is way down on paper but it ran 12.9@105 with a 1.84 short time so its making the power it should with a 6# pulley and chip. Man this pisses me off. Do you mind if I keep this chip for another month or 2 Johnny before I send it back for a re-burn fo rthe other stufh like torque reduction and shift points? That way I can maybe get a chance to put it on another dyno. I want to be safe and like you said I would rather run rich in this weather but I have a feeling I am not running as rich as the dyno says due to the detonation I heard. Any way let me know if you are ok with me keeping the chip for another 2 months or so till I get a chance to go to another dyno.
Thanks, Jason
SHP Racing

 

TTT

 

I have sent you an email Johnny

 

Was the truck warm or cold when you ran?

 

I run my a/f's very rich...10.x:1. I ran an 11.4 et with only 14 degrees of timing and 10.x:1 a/f's. I would rather run rich and lose a few HP, than lean it out and risk damage. Just my opinion...for what it's worth.

 

The truck was warm.

 

I would also rather run a bit rich and lose some HP to be on the sfae side. But isnt this a bit on the toooo rich side?

 

And I thought 11.2 was too rich when I dynoed last Feb. Going to the same dyno Monday....................

Dan