Running Lean..
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From: Las Vegas.. back in san jose..
Running Lean.. i have a friend who was telling me with any car an lt1 or ls1 when u r racing or really hitting the gas all the way to the floor....once u want to slow down is it better to completly let off the gas...or slowly let off the gas....he was saying that ur car runs lean and has the possibility of completly shutting off...???whats ur guys thoughts
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From: Los Angeles, CA
BS. You shouldn't have to worry about any lean condition on decel anyways, since there's very little load on the motor at that time. If your car ever dies on decel, it needs repair/tuning.
Originally Posted by whilte93lt1
well my buddy saw the post and was telling me that he was talking baout while u r racing W.O.T. completly letting of....
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From: Hazard Co. Maryland
Originally Posted by whilte93lt1
well my buddy saw the post and was telling me that he was talking baout while u r racing W.O.T. completly letting of....
The maf on a stock motor will more then compensate for a WOT to Closed Throttle decel. What you should be concerned with his hitting the factory fuel shut off instead. Unfortunate thing about the factory rev. limiters is they cut fuel to keep the engine from over reving which will cause a lean condition. That's why soft touch limiters work well, they cut spark instead of fuel so there isn't a chance to lean the motor, they will then fire the individual cylinders on the next cycle to keep them from loading up too much. BTW, what do you think road racing is? Drag racing with corners, and I don't see road race engines blowing up because of leaning out on a deceleration from 180 MPH into the corkscrew @ laguna seca.
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What if you drive a manual transmission? Every time you go to shift at WOT you run the risk of leaning out and blowing up your motor? No. It really dosnt work like that. The ECM is programmed to be very forgiving, always erring on the side of being rich, cause rich = safe. Youre in no danger of hurting your motor by letting off abruptly after WOT, unless someone gave you a **** poor tune.
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From: Hazard Co. Maryland
Originally Posted by GuitsBoy
What if you drive a manual transmission? Every time you go to shift at WOT you run the risk of leaning out and blowing up your motor? No. It really dosnt work like that. The ECM is programmed to be very forgiving, always erring on the side of being rich, cause rich = safe. Youre in no danger of hurting your motor by letting off abruptly after WOT, unless someone gave you a **** poor tune.
*One should be more concerned* It's still not really an issue either way on an OEM calibrated PCM. There is more of a chance that you will go lean due to a miss shift with the throttle blade is 100% open and the fuel being cut, along with some spark too, than there is when the the throttle blade is closed. The motor still is accelerating, or trying to accelerate in the first one which means that it's pulling in more air, with less fuel to compensate for it, again, less spark too. Obviously computers from the manufacture will produce a somewhat safe, rich, tune as fuel is generally cheaper than parts. Though that's not to much of the case any more.
Wonder if the electronic throttles in the DBW LS2s shut if you hit the fuel cutoff? Now that's a good question. It is my understanding that hitting the revlimiter disables alternating fuel injectors. While less fuel means a dangerous lean condition, in this case no fuel at all mean no fire at all. and even if you did have a lean condition, since it alternates cylinders it might not do the same kind of damage as if it were continually running lean.
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From: Kent WA
Originally Posted by whilte93lt1
i have a friend who was telling me with any car an lt1 or ls1 when u r racing or really hitting the gas all the way to the floor....once u want to slow down is it better to completly let off the gas...or slowly let off the gas....he was saying that ur car runs lean and has the possibility of completly shutting off...???whats ur guys thoughts
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From: Hazard Co. Maryland
Originally Posted by GuitsBoy
It is my understanding that hitting the revlimiter disables alternating fuel injectors. While less fuel means a dangerous lean condition, in this case no fuel at all mean no fire at all. and even if you did have a lean condition, since it alternates cylinders it might not do the same kind of damage as if it were continually running lean.
Much like a soft touch MSD limiter. Only done with spark instead of fuel. If that is the case. How ever, I thought the injectors on a factory PCM are batch fired...ie, one back to the other, every 180 degrees of crank roation. Perhaps I am wrong on that. Good thought thouh.