hi mates

recently I have installed for monitor reliability a afr Uego AFR wideband

this is my actual config:

- GT2560R
- FMIC (short route)
- WALBRO + wiring mod
- 200 cell cat + full Ø2,75 stainless steel exahust
- Bonalume dump valve

- live map (arund 300 hp but with stock exahust + 200 cell cat)

the wideband is on from 2 days so I haven't experience to judge...

in normal cruise conditions (1500 - 3000 rpm) I read from 13,5 to 15,5

in full boost after 3000 rmp the ratio goes from 8 to 10

please let me know your impressions !!

do I need a remap? can I trust to drive with such values?

many thanks

David

Is this the AEM gauge? You certainly need to check if the gauge is correct, because 8-10 AFR is not so healthy. Does the car boost correctly, no hesitation or misfire?

the gauge is this:

http://www.ebay.it/itm/121093036181?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

I'm really newbie about this wideband.

The car has a good boost but I have mapped before to upgrade the exahust.

what can happen with 8-10 afr??

for me is important now to know if I risk something with these values

does this guage need to be adjusted ??

many thanks Flea for your support

I'm surprised you see 8 on that one. I have the same gauge and it doesn't show 8, only goes down to 10 and the minimum.

Cruise conditions sounds fine and doing as it should, but as Flea says, 8 - 10 is a bit too rich when on boost.

tonight I will make some others shoots and I will give you new readings....

Definitely too rich at full boost, take it back to whoever did the live map and get them to adjust the fuelling.

Was the live map done while the car had all the mod's it has now?

no, as I told above the live map was made with stock exahust + 200 cell cat

now I run a full stainless Ø2,75"

what can happen? if the problem can be only bigger fuel consumption I don't care ...

In short term, nothing drastic, but in medium to long term the over fuelling will damage the engine.

How do the plugs look?

Take it back to the mapper to be checked and adjusted.

back to you with new (more accurate data) !!

during full boost from 3000 to 6500 rmp I read between 10.5 and 11

as above in normal cruise 13.5 to 16.5

I think they are regualar values and I feel much better toninght

but I still wait for your final verdict...

Please have a look to your exhaust clamp towards the turbo. Your values look a little bit suspect. Maybe your wideband shows wrong values due to ambient air from an untight clamp?

The range of 13.5-16.5 is within reason for normal cruise - it just depends on what the engine is doing at the time; accelerating a bit, slowing down a bit, running steady.

Under steady load and rpm the AFR will waver around 14.7; say 14.3-15.0.

Light acceleration: 14.0-ish to 13.0-ish.

Deceleration: from 14-ish, to high off the scale, as the injectors shut off on overrun (taking your foot off the accelerator)

At full load (boost) 10.5-11.0 is sub-optimal, but it's certainly not going to do any damage at all. In fact a lot of turbocharged cars (Coupes included) run like that from the factory because it's on the safer side of sub-optimal.

@kj16v: The values you stated are ok
But no 8-10 afr - there an engine is not running any more.
I personally would avoid all below 11.2
Below this value you will get significant bore washing.
Moreover you will lose a lot of power, because the engine efficiency is going down.

Juergen

8-10 AFR definitely isn't good, but Stichl's car isn't running 8-10, so that's okay.

As I mentioned above, 10.5 is sub-optimal in terms of making power, but whether it's doing damage depends 100% on how long it stays like that. If the AFR stays at 10.5 at WOT all the way from low rpm to the redline, and you spend all day doing WOT pulls up hills, then yes there potential for bore wash. But stock 16VTs and 20VTs can briefly hit anywhere from around 11.5 to around 10.5 depending on age/wear, usually at a particular point from peak torque upwards, and that certainly doesn't do damage.

So unless your AFR is sitting at 10.5 all the way from, like, 2k to the rev limit, that's nothing to worry about. Certainly losing power, but that's one of the things that's addressed when an ECU is mapped.

The AEM is a great budget gauge, works well to keep an eye on things. It does display richer the further away the fueling moves from stoich i.e. circa 0.3-0.4 compared to a calibrated high end lambda when in the 11-12 range so you can factor that into your readings.

Two cars, both standard factory turbo at 1bar pressure.

First car will run 13.2:1 under boost until conditions dictate it should drop to 12 then 11

Second car runs 9.8-10.4 under full boost regardless

Not all is as it would seem...