I recently had my car dyno'd at Gruppe-S. This dyno reading showed my AFR went up to 12.0:1 at about 6300 rpms. This obviously has me concerned and the reason I went with Works was to get headache-free mods. Now I have a few questions:

Has anyone dyno'd at Gruppe-S with a P2 flashed car and had normal / lower AFR readings in this rpm range?

Has anyone dyno'd at Gruppe-S with a P2 flashed car and had excessively lean readings like me only to do more pulls on a different dyno and find the AFR was really normal?

Finally, has anyone had a similar result as me on the Gruppe-S dyno, but then collected data during a road data logging session and found out the AFR was really normal?

Thanks for any info.
Gabe

 

You might want to contact some of the forum members who posted in the following thread.

https://www.evolutionm.net/forums/sh...0&page=1&pp=15

I'd be interested to hear how this works out for you.

 

I have. My AFRs were good up top. I will have to find my graphs to try and post.

What mods do you have?

 

I read that thread before, contacted one other person, and do not have an answer other than a lot of P2 flashed cars have this issue on the Gruppe-S dyno.

 

Interesting! I would like to see your graphs. I have an 05 Evo with the following related mods: Works P2, 3" ceramic coated DP, works hi-flow cat, works 3" IP, works axle-back muffler, and works air filter.

 

Almost the same mods I'm contemplating.......

It would be nice to get to the bottom of this little mystery.

 

Yes, it would be nice. I went with Works in the first place because I care more about having a setup that is conservative and worry-free. I spoke with Jamie about this several days ago and have yet to hear back. My request to Works would be to have them hook up their data logging equipment and perform some road pulls on my car. If it is found that my AFR is actually normal, then I will feel confident that I picked Works as my company of choice for mods. I was planning on purchasing Works cams etc. in the future.
Gabe

 

Are you close to Works?

I would hope that they might be able to run some diagnostic tests to put your mind at ease.

I'd also consider getting a wide-band AFR meter (e.g. PLX, Zeitronix).

 

Click on the pic for a bigger version.

 

Logging on the Road or a properly set up and calibrated dyno has show again and again that our AFRs are perfect. If anyone has any doubts feel free to come in and we will hook up all of our equipment so you can see the perfect AFR for yourself. Or head up to a dyno that is set up perfectly like the one at San Rafael Mitsubishi.

I'll quote my self from another thread:




/thread

 

Hey folks we would be more than happy to baseline dyno a couple of cars running various setups and show everyone that there is nothing either incorrectly calibrated or what have you with our dyno setup.

FWIW, I used to tune on a dyno jet and would see my AFR lean out up to one full point when on the street due to the lack of load so in fairness posting AFR graphs from a none load based dyno really is meaningless.

Sorry for jumping on your forum area Works just felt we needed to make sure no missinformation was being spread.

Mike

 

Hey Jan,

Show me some information about a Dynojet being load based.

 

interesting, about to get a p2 so i think i may watch this... as for anything and everything i've heard, works stuff is incredibly safe and incredibly good....

 

I am confused. Did anyone say that the Dynojet was load based?

 

Well, here's my dyno chart from the last dyno day at Gruppe-S. I have a P2.

EDIT: I have a high flow cat, which may or may not affect AFR readings at the tailpipe.