AFR is reading from the driver side bank, just below the 3" HFC.

I'm idling around 15.5 and cruising it stays between 15.5 and 16.

Light/medium acceleration outside of boost stays between 13.5 and 15.5.

Heavier acceleration approaching 0psi pressure (just before boost) it drops to 12.5-13.5

When boosting between 1psi and 8psi it seems to hold a steady 11.

Between 8.5 and 9.5psi is drops to around 10.5.

What do you guys think? Is this OK?

 

are you reading from before the cat or after it....i can't quite visualize it?

but it seems to be reacting normal...assuming the rest of the tune is good.

tom

 

i would tune mid 11s close to redline, and target high 11's after ~3000 rpms. Anything richer is a waste of gas and power, assuming reasonable timing.

 

What EMS?

 

It seems a tad bit rich under high boost,imo.

 

need more info..before or after cat bung for a/f gauge, what gauge, what ems and where were u tuned if u are tuned?

i was first tuned at aam and was very rich i think that may be where u were tuned..., made much more power and a much better tune on my last tune at vtr in long island..all around a more stable tune and much better a/f..everything seems ok but u seem a little rich under boost and i dont run that high of a /f when im just cruising im between 14.6-15.2 i beleive and idle around the same

 

hm.......def too rich for my taste up top.

 

too rich for my taste i run a steady 11.8 at WOT

 

Is it dangerous to run it lil bit rich? lets say around 10.8+ stock HR engine full boost (8.5psi) in a hot weather?

 

No.

 

no its just stupid and loss of power that u could be making, and a little rich is better than a little lean but there is a line to where u are too ruch and are causing ur cats to burn up or coating ur pistons etc...a good solit tune will be in the 11's

 

I have an AEM wideband hooked up in the bung just below/past the cat. UTEC ems.

When aam tuned it originally it wasn't this rich. It was since retuned and now I'm obviously richer.

On an ideal tune, what would I be seeing in each area of boost/preboost I mentioned?

 

kinda buzzed up right now so bear with me...ur bung for a/f gauge should be before cat..**** u should get rid of the cats and go test pipes for the fact that the cats are gonna fail eventually, trust me on that ive gone through 2 sets......at ur boost levels u should see mid to high 11's through ur full boost....im supercharged so its different for me since i have linear boost, but with a turbo car u should hold as close to 12.0 as possible without going over imo..11.8-11.9 steady would be a good safe tune under full boost..as far as pre boost that is not as important but will come with a good solit tune..as far as idle i am sitting at around 14.6-15.2 as well as cruising and part throttle will get to 12's and 13's depending on how much i am at, under full boost im 12's to a steady 11's when i get into some good boost

 

I have fairly large cats (3"), they are the same ones that AAM used on their 700+awhp GTR without issues so i should be good with my 'measly' 420whp. Stink pipes are out of the question for now, as these cats are working very well.

Could anyone else comment about the location of the AF sensor? I was told that cats don't change the AF reading and according to the AEM documentation I have it in the correct spot.

 

It will be more accurate before the cat, but I don't think it's a huge difference. The cats (if they are working) use oxygen during the catalytic process (more than they make via the reduction of nitrogen oxides), so a wideband after the cat will read leaner. How much leaner depends on how well the cat is working.

 

ok when the cats fail send me a pm and ill tell ya i told u so its not about handling power level its the heat where they are placed imo...anyway i wouldnt lie to u the bung for the a/f should be before cat, after the exhaust goes into the cat it is gonna alter the reading..and as far as test pipes, they are the way to go, less worry and with a motordyne xyz do not stink at all as well as no rasp..pure performance and a great mod with test pipes i made much more power than high flows.. good luck

 

HFC rated is not mean to me anymore. It is matter with how long that cats can hold with FI to me. One time mine read very off, without change tune or parts, it started read very lean and very rich... but figured i had to recalibrate after 3000milies.

 

If the cats fail I'll definitely let it be known because they were not cheap. I've got an EGT gauge and keep tabs on temps and haven't seen anything alarming.

As far as test pipes not smelling, I guess it's all relative. 9 times out of 10 I can tell you if the car in front of me has test pipes or not.

 

Cats can fail with other reason as well.

 

Well I am not sure about the rest of these guy but if any respects the guys over at GT motorsports they have my car set up rich. AFR @12 running 12psi and 500hp. You can run it leaner but it is your engine.