What have you done to your MS3 today?
- Thread starter ZoomVT
- Start date
With a carb? Sure. With runner injection? Maybe. With direct injection? You'd have to try hard to convince me that the fuel spends enough time mixing with the air for the temperature to have much of an impact.
this all sounded crazy to me so i looked it up. found THIS
it sounds like because their is less air particles entering your engine, it needs less fuel to reach the appropriate fuel ratio...
but being as we have turbo cars we should know that forcing more air, means using more fuel, resulting in more power. so knowing this we can assume we are producing less power than we would cruising at colder temps, and thus have to thottle more to maintain our usual speeds. so don't go selling your CAIs. plus if we were a bunch of MPG weenies we wouldnt drive MS3s
it sounds like because their is less air particles entering your engine, it needs less fuel to reach the appropriate fuel ratio...
but being as we have turbo cars we should know that forcing more air, means using more fuel, resulting in more power. so knowing this we can assume we are producing less power than we would cruising at colder temps, and thus have to thottle more to maintain our usual speeds. so don't go selling your CAIs. plus if we were a bunch of MPG weenies we wouldnt drive MS3s
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oaklandopen
Member
Hotter air also equals less oxygen content, therefor less fuel to reach the desired ratio. In general every 10 degrees ferenheit difference in air temperature is 1% hp difference. But that's just 1 factor in ambient sources affecting engine performance
Are there even enough registered cars in nebraska to care about how they run?
$25?
Are there even enough registered cars in nebraska to care about how they run?
$25?
stoichiometry! give that man a cookie
What do you think a MAF sensor is for? It measures the available oxygen and adjusts fuel accordingly. It's like having tiny little mechanics swapping out jets and turning the air screw thousands of times per minute.
Orly? I haz no idea!!1! I never knew a mass air flow sensor could measure the amount of air going into my engine! (hi)
My point was simply that with a DI engine hot air doesn't spend enough time with the fuel to atomize it appreciably better than cold air, whereas with a carb or runner injection it did. Not that I really buy that argument at all.
I buy the stoich argument: you get better fuel economy because the car can't make as much power and consumes less air and fuel. I buy it mostly because SWRI wrote that short paper on it, and SWRI has credibility.
I stand corrected. I guess my smarmy comment was directed at the person you were replying to. In a DI engine, fuel atomization is not dependent at all on any factor other than injector size and fuel pressure.
Stoichiometry is the only answer. I lived it when I raced and tuned my 2-stroke and the tune that was spot on in the morning sucked as soon as the temps rose a few degrees. Jetting (and mixing fuel/oil) for projected race time temps became the norm.
oaklandopen
Member
The actual oxygen content is really just a calculation by the computer. There are soooo many types of maf sensors. Ones that look like honeycomb, ones that are just a door, ones that use resistors that heat up (ours), etc.
The vane-type (like older miatas) uses the idea that the further open the door gets as air passes through, the more O2 content there is. It uses some kind of potentiometer or rheostat to get a voltage reading from however far open the door is
Some use microphones (expensive) to "listen" to how much O2 is passing. Some use light sensors (also expensive) to "see" how much O2 is coming in by how much its bending the light
The honeycomb ones have multiple sensors. The resistor ones like ours get a reading of how fast the superheeated resistor cools due to the amount of O2 passing over it
The vane-type (like older miatas) uses the idea that the further open the door gets as air passes through, the more O2 content there is. It uses some kind of potentiometer or rheostat to get a voltage reading from however far open the door is
Some use microphones (expensive) to "listen" to how much O2 is passing. Some use light sensors (also expensive) to "see" how much O2 is coming in by how much its bending the light
The honeycomb ones have multiple sensors. The resistor ones like ours get a reading of how fast the superheeated resistor cools due to the amount of O2 passing over it
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holy s***!! i mean holy s*** thats alot. Thats the lifetime membership with free towing loaner cars and get out jail free card right!?
- Oakland thanks for the clarifications on a fairly complicated issue. you sir are an asset to our forum!
_ Got my ETS 3.5 Top Mount back from warranty repair. i had it for almost 3 years and it cracked. They covered it completely. The folks at Extreme Turbo Systems welded brand new end tanks and shroud mounts, plus a new water jet cut shroud. looks fabulous! and i might be one of the few who have the big 3.5.
A happy day indeed. One more step closer to getting back on the road! Thanks ETS!!!
- Oakland thanks for the clarifications on a fairly complicated issue. you sir are an asset to our forum!
_ Got my ETS 3.5 Top Mount back from warranty repair. i had it for almost 3 years and it cracked. They covered it completely. The folks at Extreme Turbo Systems welded brand new end tanks and shroud mounts, plus a new water jet cut shroud. looks fabulous! and i might be one of the few who have the big 3.5.
A happy day indeed. One more step closer to getting back on the road! Thanks ETS!!!
