Thread: EGR
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Old 05-06-2024, 05:33 PM   #11 (permalink)
Isaac Zachary
High Altitude Hybrid
 
Join Date: Dec 2020
Location: Gunnison, CO
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Avalon - '13 Toyota Avalon HV
90 day: 40.45 mpg (US)

Prius - '06 Toyota Prius
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Quote:
Originally Posted by racprops View Post
I have read many books that say tune your engine and drive train so that your engine is at or near your engines Torque Peek for best MPG at your preferred Speed.

BUT a torque peak of 2800 RPMs mean cruse below 2500RPMs will not give good MPG…


Yes, thus my looking into EGR to cause a more open throttle to cut “pumping losses”

I have NO boost of any kind.

Small low performance heads and valves are reported better for MPG.

WHICH is why I am running a STOCK TPI, no big tubes, stock 193 Heads with stock valves, and a stock cast iron exhaust manifold into low restrtive cats and mufflers.

Yes, at full throttle and max RPMS, but will them do 35 to 50MPG???


Yes efficient in their world…


Rich

PS Color to highlight my replies
Ok. And your point is???

If studies of the atomization and de-atomization of fuel in an intake system offends you because it was done by someone who builds race engines, well then so be it.

Agreed, peak torque RPM is something that will affect fuel mileage.

Agreed, EGR can help keep a throttle more open. But there are a lot more factors that help keep a throttle more open than just EGR. And there are a lot more factors that help fuel mileage than just keeping a throttle more open.

I never said you have boost, I was comparing differences and similarities between the goals of the racer's community and the goals of the ecomodder's community.

Yes, heads, valves, engine, etc. all should be sized according to power needs.

In no part of this did I say, "Put a 1,000hp formula race car engine in your car to get 50% efficiency." But there's no reason that a person can't consider whether the things that improve fuel efficiency in one engine could be applied to another with similar results as far as efficiency goes, even if the total power output and use case are completely different.

For an example:
  • Many air craft have twin spark plugs, but twin spark plugs can improve efficiency, espeically in engines that you can't put the spark plug right in the middle of the cylinder.
  • Many train and semi-truck engines roll along at low RPM's, part of the reason they get good efficiency. Again, lowering the RPM's can improve efficiency in an ecomodded car.
  • Likewise, race engines are about getting air and fuel in the most efficient way by engineering the flow through large valves for most power and efficiency. There's no reason you can't use similar geometry, only downsized, in order to keep the efficiency but lower the output power.

If you don't think so, then sorry for you.

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Last edited by Isaac Zachary; 05-06-2024 at 07:10 PM..
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