high mpg, low displacement, small cam, high boost?
03-23-2011, 02:39 PM
#41
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I average about 12 mpg towing a 50 ft enclosed. I ussually scale right at 26k. 12v, twin compound turbo, coated pistons, valves, combustion chambers, runners,three intercoolers, ddp 4 injectors with 3.54 gears and a nv5600 conversion.
Makes around 800/1300
I still want to see a hot air engine attempt.
03-23-2011, 02:57 PM
#42
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You are right,I had a hard time swallowing that fact when I found out.
I was actually going to buy a Duramax until I thought it through.
At least the Canadians are able to build a better car than the Mexicans.
I think my motor came from Wisconsin.
The variable cam timing stuff,dod,and hybrid stuff all is a good interesting way to save on gas.
If saving on money is the issue than getting it used is the way to go.
I was actually going to buy a Duramax until I thought it through.
At least the Canadians are able to build a better car than the Mexicans.
I think my motor came from Wisconsin.
The variable cam timing stuff,dod,and hybrid stuff all is a good interesting way to save on gas.
If saving on money is the issue than getting it used is the way to go.
03-23-2011, 07:59 PM
#43
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I pulled the oil cooler off a 2010 (for oil feed)Im turboing and noticed it says....made in USA. I was surprised and someone commented on thats why there so expensive. It was a little funny.
sorry thread hijack...
how bout a 4.8 crank in a ls2 block with dod and 11 to 1 with boost and l92's or ls3 heads.
sorry thread hijack...
how bout a 4.8 crank in a ls2 block with dod and 11 to 1 with boost and l92's or ls3 heads.
03-24-2011, 09:26 AM
#45
I pulled the oil cooler off a 2010 (for oil feed)Im turboing and noticed it says....made in USA. I was surprised and someone commented on thats why there so expensive. It was a little funny.
sorry thread hijack...
how bout a 4.8 crank in a ls2 block with dod and 11 to 1 with boost and l92's or ls3 heads.
sorry thread hijack...
how bout a 4.8 crank in a ls2 block with dod and 11 to 1 with boost and l92's or ls3 heads.
04-02-2011, 11:14 AM
#49
I have been thinking about this for my Silverado SS. Been towing a trailer a ton and thinking about fuel mpg. Losing the pumping losses is what I have been thinking, trying to run the engine with no vac and using boost for power. Right now with the 6.0 engine I run between 2 inches vac and 5psi boost with hills and level ground cruising. My rpm is between 2200-2600 most times with converter locked. I would like a small V8 with DOD and boost control on the throttle pedal. Leave the throttle at WOT when cruising and de-activate cylinders to slow down or add boost to climb. Those 12 hour rides get me thinking! I do run my intercooler pump only when I exceed 30% throttle as the hotter intake air helps MPG, I originally tried this in the Nova and it was worth .5 MPG.
Kurt
Kurt
04-02-2011, 06:25 PM
#51
thats a little over my head but the part i did notice is the hotter intake air helping mpg. i am trying to understand why hotter intake air would help mpg. seems like letting the iats go up would reduce the oxygen which would reduce the amount of fuel needed at a given rpm to maintain stoich. it would be a like having a smaller engine.
04-07-2011, 12:05 AM
#52
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There is a coolant temp vs pw adder type table (aka choke)- it goes flat around 180ish depending on calibration.
That's why you have to tune for a colder stat.-
Also, thermal efficiency goes up as CT goes up. Higher CT can lead to detonation at WOT though unless steps are taken - Evans coolant would be and example- reverse cooling ala LT1 is another-
Hot air = complete evaporation of all fuel. ie no "drops" to cause AFR dips/spikes in the chamber. "big" drop over here means lean spot over there in chamber. Leans spot needs more fuel added to cover it up (o2 sensor/short/long term fuel trim etc)
Also needs less spark advance so less counter torque etc.
VE goes down, but power/efficiency goes up iirc.
Smokey Yunick did a hot air motor back in the 80's. Used a small turbo and ~3psi. Basically ran engine coolant through an air to water IC with a mixer (turbo). Made lots of power relative to cid and good mileage too.
Tuning and temp control was the big issue from what I read. If temp got to far off target the motor went into hard detonation quick. Hot Rod covered it (again) last year IIRC when a book about Smokey was released. Some of us in this thread are old enough to have read the original article.
04-07-2011, 09:42 AM
#53
I do remember when those articles came out. Fresh out of college and struggling with dollar a gallon gas
. A friend even had one of those Fiero's like he used to test his theory. I remember that thing looking a whole lot faster than it actually was.
. A friend even had one of those Fiero's like he used to test his theory. I remember that thing looking a whole lot faster than it actually was.
04-08-2011, 09:34 AM
#54
No, not really. As soon as it goes into closed loop it listens to the O2 sensors (which only shoot for stoich) entirely (until going into Power Enrichment with enough throttle). Most GM PCMs go into closed loop between 93 and 131 degreesF coolant temp (For STFTs).
