running rich/lean

1Teggy

sleeper
Just recently installed a turbo in my car. When I down shift the A/F gauge says its running rich and when I accelerate it says I'm going lean. At idle it reads between 14.4 and 15.1 which is generally the right area. Any suggestions are appreciated. Thanks
 

Str8Boostin

Sleeper
Don't pay any attention while you're driving.

Don't know where your ratio is supposed to be at idle (SRT-4 engine is 14.8 ) but as long as your idle A/F ratio is where it's supposed to be at idle and WOT (wide open throttle) you're fine. Anything else that isn't WOT or idle doesn't matter.
 


1Teggy

sleeper
Don't pay any attention while you're driving.

Don't know where your ratio is supposed to be at idle (SRT-4 engine is 14.8 ) but as long as your idle A/F ratio is where it's supposed to be at idle and WOT (wide open throttle) you're fine. Anything else that isn't WOT or idle doesn't matter.
When WOT it leans out around 11.1 and the normal A/F ratio is also 14.8..are you sure that its normal to be rich when down revving
 

Str8Boostin

Sleeper
When WOT it leans out around 11.1 and the normal A/F ratio is also 14.8..are you sure that its normal to be rich when down revving
Yeah.

All my boosted cars' wideband would fluctuate like crazy when I'd blip the throttle or engine brake and the revs are coming down from like 4k or so. When I think about it, it normally jumps to rich then completely lean if the RPM's are coming down.

Like I said though, don't pay any attention unless it's at WOT or Idle.

Btw, is 11.1 where you''re supposed to be at@WOT?

New to the Honda scene but not new to turbo's at all. The sweetspot for my vehicle is 12.0, and pretty much throughout the RPM range it's from 11.7-11.9 and pulls nicely w/o knock.
 

1Teggy

sleeper
Its supposed to sit around 14.8 at idle. Dont know where its supposed to be WOT but i would assume the same at as idle.
 


Str8Boostin

Sleeper
Uhm no....

I'm not familiar with Hondas (honestly I just joined because I know nothing about Hondas) but a boosted car's a/f ratio is not supposed to be the same at WOT than it is at idle.

Most cars idle at 14.8, mine does.

Not all cars run at the same compression, though a lower compression vehicle is better/safer for adding a turbo. Anyway, most cars that are turbo'd or have a turbo added run at their best/safest a/f ratio of 12.0

If you ran anything above 12, you're running lean/too lean at WOT. There are many different reasons as to why one would run lean;
1. Running out of fuel. Get bigger injectors! Also, you'll want a fuel pressure regulator since adding bigger injectors isn't enough. You'll want to regulate the pressure the injectors are working at.
2. Too much boost. This goes with #1, but sometimes fuel mods alone aren't enough depending on your other mods.
3. Tune. Not sure how it works with Honda's but vehicles I've messed with (OBD-2 for the most part) require a rescale. PCM's can only adjust themselves so much when changing out parts for performance parts, but something like an injector swap will require a rewrite/rescale telling the PCM it has bigger injectors.

You also never posted what turbo you have.

Don't turn up your boost expecting more 'power'. Turbo's have a limit IE a TD04 is simply spinning for the hell of it if you push anything more than 17-18psi.

Btw, who's tuning your car?
 

blaketeg

I <3 Boost
The a/f's in idle should be between 16.8-17.5 i believe, my idle is right around 16

While under WOT in boost, you should be no higher than 12 and no lower than 11 for the best performance.

what tuning program and injectors are you using? sounds to me you need a better tune
 
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Str8Boostin

Sleeper
The a/f's in idle should be between 16.8-17.5 i believe, my idle is right around 17.2

14.8 is ray to rich for idle

While under WOT in boost, you should be no higher than 12 and no lower than 11 for the best performance.

what tuning program and injectors are you using? sounds to me you need a better tune
Boosted Teg's like 16.8-17.5? Damn that's lean as hell....that specific to certain Honda engines due to head swaps/different compression/etc?

To the OP, like blake and I said....who the hell's tuning your car?

I hope you didn't just throw in a turbo and expect everything to match up perfectly.
 

blaketeg

I <3 Boost
Boosted Teg's like 16.8-17.5? Damn that's lean as hell....that specific to certain Honda engines due to head swaps/different compression/etc?

To the OP, like blake and I said....who the hell's tuning your car?

I hope you didn't just throw in a turbo and expect everything to match up perfectly.
well i just know thats where its sopposed to be around for any honda, i may be wrong but ive had 3 boosted hondas all bieng b-series and all my a/f's were in that general area.
 

hidenplanvew

New Member
A stoichiometric mixture is the working point that modern engine management systems employing fuel injection attempt to achieve in light load cruise situations. For gasoline fuel, the stoichiometric air/fuel mixture is approximately 14.7; i.e. the approximate mass of air is 14.7 mass of fuel. Any mixture less than 14.7 to 1 is considered to be a rich mixture, any more than 14.7 to 1 is a lean mixture - given perfect (ideal) "test" fuel (gasoline consisting of solely n-heptane and iso-octane). In reality, most fuels consist of a combination of heptane, octane, a handful of other alkanes, plus additives including detergents, and possibly oxygenators such as MTBE (methyl tert-butyl ether) or ethanol/methanol. These compounds all alter the stoichiometric ratio, with most of the additives pushing the ratio downward (oxygenators bring extra oxygen to the combustion event in liquid form that is released at time of combustions; for MTBE-laden fuel, a stoichiometric ratio can be as low as 14.1:1). Vehicles using an oxygen sensor(s) or other feedback-loop to control fuel to air ratios (usually by controlling fuel volume) will usually compensate automatically for this change in the fuel's stoichiometric rate by measuring the exhaust gas composition, while vehicles without such controls (such as most motorcycles until recently, and cars predating the mid-1980s) may have difficulties running certain boutique blends of fuels (esp. winter fuels used in some areas) and may need to be rejetted (or otherwise have the fueling ratios altered) to compensate for special boutique fuel mixes. Vehicles using oxygen sensors enable the air-fuel ratio to be monitored by means of an air fuel ratio meter.

11:1 is alittle rich 16:1 is lean
11 parts oxygen to one part fuel ,and 16 parts oxygen to one part fuel
 

Str8Boostin

Sleeper
There you go^

Knew 14.7@idle was what one should generally see in a boosted vehicle :p

Too rich, and you're literally pouring gas out your window. :evil:

Too lean, motor goes POP. :shock:
 

blaketeg

I <3 Boost
yeah pretty much as long as your idle is smooth, it doesnt matter to much where your a/f's are. There is no load on the engine, your not going to damage anything
 
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