# Rich or lean???



## Sergei_dekker (Jun 4, 2005)

Which one is better? As my next scheduled maintainence is coming....I'll be plannign to advance my timing to 17BDTC and change the air/fuel ratio if possible...and yes....has anyone tried DOT 5.1 brake fluid??? will it improve my braking response??


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## ValBoo (May 19, 2003)

Sergei... Sergei... Sergei....

Neither too lean nor too rich.
Ideal for good continuous & complete combustion, an air/fuel ratio around 13 to 13.5 is very good. But this is pointless since dealers can't do anything about it, and that is where the air fuel converters (like Apex'i SAFC II) come in.
If your car's ECU set air fuel map is not so good then using the SAFC you can correct this and gain power. (see my earlier "how to" on this above)

Timing advance to 17 BTDC your dealer can do. :thumbup: 

brake fluid: I have not tried.


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## thetimster (May 6, 2005)

Too rich prevents the car from stalling. So manufacturers always have the cars come out of production with the ratio leaning towards the rich side. (Sorry, couldn't resist the pun.) However, additional power can be gained by readjusting the ratio towards the leaner side... but obvsiouly not TOO lean because it will cause the engine to stall. The SAFC-II (which will be my next project once I can get the headers install set) would be the best bet for adjusting air/fuel ratio. Its a complicated little gadget. I still don't understand most of its settings. ValBoo got it tuned to his liking and the settings he mentioned still sound cryptic to me. But I guess I'll learn about it a bit more when I finally get to install it. Its been sitting at home waiting for all the mechanical upgrades to get in. Now that the headers are in, I think I'm ready to do it once I get back home.

Timing advance is very easy. Let the dealer know, and they can set it easily. You can check the engine badge under the hood to see the factory settings. I think it should be at 15BDTC. Resetting it requires the mechanic to hook up the Consult II to your car underneath and beside the steering column. It only takes 2 minutes.  My ECU wouldn't take anything more than 17. Same as ValBoo's if I'm not mistaken.

Hmmm... sorry, nothing to add on the brake fluid either.


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## ValBoo (May 19, 2003)

I think they tend to go to rich side for emissions... (funny as it seems richer combustion reduces the sulphur dioxide emissions)

Also forgot to mention before: A thing to remember on going to more advance timing is to use premium/higher octane gas.


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## Sergei_dekker (Jun 4, 2005)

ValBoo said:


> I think they tend to go to rich side for emissions... (funny as it seems richer combustion reduces the sulphur dioxide emissions)
> 
> Also forgot to mention before: A thing to remember on going to more advance timing is to use premium/higher octane gas.


 No worries...as My country has RON98 and i use it all the time.....


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## Sergei_dekker (Jun 4, 2005)

thetimster said:


> Too rich prevents the car from stalling. So manufacturers always have the cars come out of production with the ratio leaning towards the rich side. (Sorry, couldn't resist the pun.) However, additional power can be gained by readjusting the ratio towards the leaner side... but obvsiouly not TOO lean because it will cause the engine to stall. The SAFC-II (which will be my next project once I can get the headers install set) would be the best bet for adjusting air/fuel ratio. Its a complicated little gadget. I still don't understand most of its settings. ValBoo got it tuned to his liking and the settings he mentioned still sound cryptic to me. But I guess I'll learn about it a bit more when I finally get to install it. Its been sitting at home waiting for all the mechanical upgrades to get in. Now that the headers are in, I think I'm ready to do it once I get back home.
> 
> Timing advance is very easy. Let the dealer know, and they can set it easily. You can check the engine badge under the hood to see the factory settings. I think it should be at 15BDTC. Resetting it requires the mechanic to hook up the Consult II to your car underneath and beside the steering column. It only takes 2 minutes.  My ECU wouldn't take anything more than 17. Same as ValBoo's if I'm not mistaken.
> 
> Hmmm... sorry, nothing to add on the brake fluid either.



So that means u cant use CONSULT II to adjust the air/fuel mixture??


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## jtanoyo1 (May 15, 2005)

Lean = engine detonation = melted piston rings, broken cylinder head, etc etc etc...

rich = too much fuel = lousy gas mileage = caked chambers = black gas fumes out of your exhaust = bad performance too, but hey, at your car won't blow up.


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## thetimster (May 6, 2005)

Sergei, I don't think Consult II will adjust air:fuel ratio. Only thing you can do with that for performance is advance timing. Air:fuel ratio is controlled by the ECU and would usually require something piggy-backed to it like the SAFC-II.


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