My air/fuel ratios.

[ion] C2 · 07-03-2008, 08:07 PM

So I got my AEM wideband installed today. Wondering how bad these AFRs are until I get some tuning with the new engine in it.

Idle:
14.2 - 15.2

Cruise:
14.0 - 15.4

WOT:
12.8 (cold, first run after getting wideband installed)
13.3-13.5 (warmed up)

I'm pretty sure 13.5 is far too lean for wide open on 7 PSI.

Also I noticed after my wideband sensor was installed that my narrowband AFR gauge (combo'd with my boost gauge) only reads lean to stoich, never goes past to rich no matter what. It seems like the wideband screwed up the narrowband's reading somehow.

I'll get tuned after the new engine is in and meth is active. Some people actually said methanol moved them from 13 AFRs in boost to like 11.8ish which is I think the ideal location. So meth may come soon.

Redog · 07-03-2008, 08:13 PM

Yeah you need to tune, I'm pretty sure the a/f ratio on a LA1 is around 14.1

[ion] C2 · 07-03-2008, 08:15 PM

Lol that wouldn't be good, AFRs should be in the high 11-mid 12s area under wide open throttle.

jabartram · 07-03-2008, 08:24 PM

Quote:

Originally Posted by Redog

Yeah you need to tune, I'm pretty sure the a/f ratio on a LA1 is around 14.1

huh???

[ion] C2 · 07-04-2008, 04:57 PM

Responses on j-body:

Quote:

Ya that's WAY lean, stay out of boost until you get that fattened up.

Quote:

I would look for 12.2's. Really need to get that tuned.

Quote:

Personally when I tune a boosted car, supercharger or turbo I always shoot for 11.5 A/F when in boost. It could be leaned out a bit more to get more power but I am not comfortable running things close to the edge. 12.8 is way to lean for what you are running and 13's well thats just scary.

Quote:

about what saw from mine , ran low 15's in the 1/4 with afr in the 13.0 range , once i dropped the afr to about 11.5 -11.8 my times dropped to low 14's

I remember reading once from some guy who ran where I was until he put 370cc Cobalt ones in, dropped his AFRs into the mid to high 11s and a second off his quarter mile.

I can pick up some 370s for like $70 but you have to mod the fuel rail somehow or something to make them sit right, I think they're shorter. I'll have to look into it, because if using the 370s still allows me to get regular RC engineering injectors in the future, these might be a great temp fix.

jabartram · 07-04-2008, 06:35 PM

do you have the ability to tune for different injectors?

[ion] C2 · 07-04-2008, 06:55 PM

If I borrow/buy HPTuners + someone who knows what they're doing, yes. I want to get RC Engineering 440cc ones and tune with em, but if I could spray some meth and tune with that for now (meth tends to richen things up) that'd work at least to get some times at the track with the rebuilt engine in.

Vinalero · 07-04-2008, 07:09 PM

Does that mean that there are strong chances that I am running lean also?

[ion] C2 · 07-04-2008, 07:13 PM

Get a wideband and find out, lol. This other guy ran really rich with the stock injectors and similar modifications, actually he has a lot of modifications now and still uses the 310s. He had to tune to lean it out a bit. It seems to differ car to car. But most people run lean with the supercharger kit injectors.

I have the 2.6" pulley and RSM 62mm throttle body so I'm pushing far more air in than the stock kit was but I'm using the stock kit's tune.

Vinalero · 07-04-2008, 07:20 PM

thats what I was thinking about, are you still on the stock fuel pump?

Im a bit noob to that part of tuning, but a wideband, is that the big device with a big screen that the dealer plugs under the car to check for codes and engine data?

[ion] C2 · 07-04-2008, 07:31 PM

lol no a wideband gauge is one that reads the output from a wideband oxygen sensor. the stock O2 sensor is a narrowband, it has to do with voltage ranges and accuracy. the wideband is extremely accurate and tells you exactly what air to fuel ratio you're running.

Vinalero · 07-04-2008, 08:02 PM

in other word, you have to replace your stock O2 sensor with the wideband that is wired to a gauge and also wire it to the existing wires that were with the stock O2 sensor.

AftermathAlero · 07-04-2008, 08:12 PM

Quote:

Originally Posted by Vinalero

in other word, you have to replace your stock O2 sensor with the wideband that is wired to a gauge and also wire it to the existing wires that were with the stock O2 sensor.

You dont have to replace the stock o2 sensor. You just get another o2 sensor bung and weld it in for the wideband o2 sensor. Some wideband air/fuel gauge comes w/ a bung for you to weld on.

------------------------------

Thats the same gauge i'm getting too. AEM air/fuel wideband is one of the best around.

[ion] C2 · 07-04-2008, 08:16 PM

Yep it comes with the threaded bung, take it to an exhaust place and they drill a hole and weld it in.

jabartram · 07-04-2008, 08:33 PM

i run innovate motorsports. LC1 and XD16. http://www.innovatemotorsports.com/products/MTS.php

AftermathAlero · 07-04-2008, 09:39 PM

Quote:

Originally Posted by jabartram

i run innovate motorsports. LC1 and XD16. http://www.innovatemotorsports.com/products/MTS.php

those are badass too!

Vinalero · 07-05-2008, 11:20 AM

thx for the infos guys. However this must be out of my budget for only a gauge lol. Maybe when I'll go with a bigger TB or if I can find a good deal on one.

By the way, do you have to place the wideband sensor before or past the catalytic converter?

Alerosaint · 07-05-2008, 11:36 AM

Something tell me i might be running lean and if not when I change the pulley i def will be running lean...I guess im gonna have to pony up for a wideband...hmm..or can I take it a tuner and have them check it out???

Quote:

Originally Posted by Vinalero

By the way, do you have to place the wideband sensor before or past the catalytic converter?

I would like to know this as well just in case i get a wideband

jabartram · 07-05-2008, 12:31 PM

wideband goes before the cat, and personally a wideband and tuning device would be a better investment than a throttle body. its amazing how much power you can gain with proper tuning. and once you learn to read a wideband compared against tuning software, you will know exactly what your car is doing. i notice a difference in my a/f via the wideband when the weather changes during the day.

and you can put a wideband in place of a stock o2 sensor, there are 2 analog(narrowband) outputs on the wideband setup that are designed just for that.

Vinalero · 07-05-2008, 12:43 PM

I might consider that. You mean that there are some widebands sensors that do both the job of reading precisely the A/F mixture and also acting like a stock O2?

What are some of the tuning device available?