Future lean burn engine swap into 7th generation Civic sedan? CRX HF, HX?

[mpg_numbers_guy]

Originally Posted by Ecky

The hybrid system allows for the use of a smaller, more efficient engine than you could otherwise put in a vehicle, because it would be dangerously slow.

That makes sense. Similar to the new mild-hybrid system on the new Ram trucks where the electric battery just gives added power to the engine?

Originally Posted by Ecky

Probably $5-700? The Hondata ECU plugs right in where you old one was, but you need a tuner to program it.

If it's that much I don't see how it would be more beneficial than just doing an engine or transmission swap.

Originally Posted by Ecky

Pretty much. It helps to look at where the losses are.

Aerodynamics - A smaller car with a tapered rear end improves highway economy. People are increasingly buying larger, more boxy vehicles, despite more aerodynamic cars sitting next to them on lots.

Weight - Smaller, lighter vehicles improve city economy, since it's less mass to accelerate and stop. People want larger, heavier vehicles.

Transmissions - Manuals are less lossy than autos (usually). Nobody wants to shift gears, manuals are disappearing.

Engines - Smaller engines have less internal friction, and smaller parasitic losses. People want faster cars, and are buying bigger engines.

Tires - Narrower, lower rolling resistance tires improve economy. People want more grip for safer, higher speed cornering, and buy bigger, stickier tires.

True, true. Imagine where fuel economy would be otherwise.

Originally Posted by Ecky

Hybrid systems address a lot of these things, for various reasons. You can have a smaller engine without sacrificing power. You can have an automatic transmission with low losses (read about Toyota's planetary gearset in the Prius). You can use batteries to capture some of that energy lost in braking a heavier vehicle. You can get rid of some of the more lossy components in cars, such as alternators. It doesn't solve the aerodynamics or tire problems, but it helps.

If only the available hybrids within my price range had better reliability. Hybrid batteries are just so expensive to replace.

Originally Posted by California98Civic

Not only will the HX/EX Seventh gen engines and transmissions bolt up to one another, there is a chance that the manual Gen 1 Insight and the Gen 1 Civic Hybrid manual transmissions will too. See the manual transmission specs link in my signature file below. But the HX/EX swaps are painlessly simple within the 7th Gen.

Even better since the Insight has an even taller transmission.

sigh keep dreaming I guess.

[California98Civic]

Originally Posted by mpg_numbers_guy

...
Even better since the Insight has an even taller transmission...

Yup. Gen 1 Insights had almost precisely the RPMs of a VX when stock tire/wheel sizes are taken into account. Muast turn at about 2000-2100 RPM @ 60MPH.

But remember, I am just speculating it might bolt up. It might not. The various Civic transmissions from the 7th Gen will bolt up easy (hybrid is a question mark).

Dreaming is ok, too.

[mpg_numbers_guy]

Nice; that would be awesome if that were possible for me.

Jealous of the taller transmission in my parents' 2004 Toyota Sienna minivan - revs right at 2K rpms at 70 MPH. I can get low 30s mpg-wise driving it.

One thing though, is it possible to put in a transmission that is too tall? After all, if it were possible to use taller gearing for increased MPG, wouldn't the manufacturers naturally do that?

Dreaming is probably about all I'll be doing when it comes to the more expensive FE mods.

[hayden55]

Anybody else chime in to get your laptop out and start learning how to tune your current motor into lean burn? Only kicker is lean burn isnt really legal anymore since they hatdly ever pass emissions. So yeah you heard that right... you have to burn more fuel to pass emissions.

[oil pan 4]

As long as you're not in a smog problem area who cares. NOx is a local pollutant, CO2 is a global pollutant.
The EPA decided to be the DOTs' lap dog and wage a war on NOx ensuring lower fuel economy and higher fuel tax revenue.

[Ecky]

Originally Posted by mpg_numbers_guy

One thing though, is it possible to put in a transmission that is too tall? After all, if it were possible to use taller gearing for increased MPG, wouldn't the manufacturers naturally do that?

You'll find that in very new vehicles, transmissions have very reasonable top gearing. I want to say the newest Civic with 1.5 turbo motor have a CVT that can cruise as low as 1500rpm at 70mph? Balto would be the one to ask about that though.

It is possible to go too tall, but it's extremely unlikely you'll find any transmission that bolts up, which is too tall for your motor. You're not going to hurt anything, but you could, in theory, end up with a final gear which is so tall you can't actually maintain speed with it.

In my Insight, the 1.0L 3 cylinder turns around 1700RPM at 55mph, and even at those low revs I can at times see it at less than 50% load while cruising.

[California98Civic]

Originally Posted by mpg_numbers_guy

...is it possible to put in a transmission that is too tall? After all, if it were possible to use taller gearing for increased MPG, wouldn't the manufacturers naturally do that?
...

Agree with all said already in reply to this. I'll add that manual transmissions are rarer now because buyers don't want to work the gears, especially in the slug-lines of sprawled commuting. Those MTs that do sell are usually geared for high RPM power and such. So now you see auto transmissions and especially CVTs with tall gearing for the fuel economy set. The gearing on MTs, in other words, is not about technical practicality. Rather, it is just a marketing/profit thing. Always. Be. Closing.

[mpg_numbers_guy]

Originally Posted by hayden55

Anybody else chime in to get your laptop out and start learning how to tune your current motor into lean burn? Only kicker is lean burn isnt really legal anymore since they hatdly ever pass emissions. So yeah you heard that right... you have to burn more fuel to pass emissions.

This sounds interesting, as I love working with computers but the software is probably 100s of $$ and I'd probably program it wrong lol.

I really don't care about emissions lol. I drive more economically anyway which would offset any emissions problems.

Originally Posted by oil pan 4

As long as you're not in a smog problem area who cares. NOx is a local pollutant, CO2 is a global pollutant.
The EPA decided to be the DOTs' lap dog and wage a war on NOx ensuring lower fuel economy and higher fuel tax revenue.

And yet they're demanding more and more fuel efficient vehicles while doing this at the same time.

Originally Posted by Ecky

You'll find that in very new vehicles, transmissions have very reasonable top gearing. I want to say the newest Civic with 1.5 turbo motor have a CVT that can cruise as low as 1500rpm at 70mph? Balto would be the one to ask about that though.

It is possible to go too tall, but it's extremely unlikely you'll find any transmission that bolts up, which is too tall for your motor. You're not going to hurt anything, but you could, in theory, end up with a final gear which is so tall you can't actually maintain speed with it.

In my Insight, the 1.0L 3 cylinder turns around 1700RPM at 55mph, and even at those low revs I can at times see it at less than 50% load while cruising.

The 2015 Civic I rode in a few weeks ago cruised at 1500 RPM at 55 mph, similar to the '04 Sienna which is right at 2K rpms @ 70 mph. Still definitely a lot taller though.

If only the Insight could carry at least 4 people like the 2nd gen one did, and I could actually find a decent one, I would've bought one.

Originally Posted by California98Civic

Agree with all said already in reply to this. I'll add that manual transmissions are rarer now because buyers don't want to work the gears, especially in the slug-lines of sprawled commuting. Those MTs that do sell are usually geared for high RPM power and such. So now you see auto transmissions and especially CVTs with tall gearing for the fuel economy set. The gearing on MTs, in other words, is not about technical practicality. Rather, it is just a marketing/profit thing. Always. Be. Closing.

That makes sense seeing that pretty much all CVTs and even automatics are rated at better mpg than their manual counterparts.

Do you think paddle shifters on CVTs and automatics makes up for this?

[Ecky]

Originally Posted by mpg_numbers_guy

This sounds interesting, as I love working with computers but the software is probably 100s of $$ and I'd probably program it wrong lol.

I was just reading recently about the shop in Florida, LHT, which does Honda K20 swaps into Insights. Even with a very short transmission (probably 3000-3500rpm at 65mph as opposed to ~2100rpm) in the much larger 2 liter engine, they're claiming to see as much as 48mpg on the highway by tuning in lean burn with the Insight body, running as lean as 19:1 AFR.

Originally Posted by mpg_numbers_guy

If only the Insight could carry at least 4 people like the 2nd gen one did, and I could actually find a decent one, I would've bought one.

I don't have kids so I don't feel the need for back seats. If friends want to go out to movies with me, they can drive their own damn cars. I'm not paying the other 364 days of the year for them to ride around with me once in a blue moon.

Originally Posted by mpg_numbers_guy

That makes sense seeing that pretty much all CVTs and even automatics are rated at better mpg than their manual counterparts.

Do you think paddle shifters on CVTs and automatics makes up for this?

Not really. Paddle shifters don't let you run outside of the RPM range the transmission computer would allow, and CVTs normally maintain the lowest RPM possible anyway. Paddle shifters are really only there to rev the engine up unnecessarily.

My issue with automatics isn't as much the gearing, as it is the durability/reliability and the drivetrian losses. Someone has in their signature various transmission efficiencies, and I believe it was written that a manual is about 98% efficient, whereas a CVT is ~88 and a traditional auto is ~86. On top of that, you don't see any automatic transmissions with half a million miles on them; most cars I see in junkyards (that haven't been claimed by rust) are there because their automatic transmission failed long before anything else did.

[mpg_numbers_guy]

Originally Posted by Ecky

I was just reading recently about the shop in Florida, LHT, which does Honda K20 swaps into Insights. Even with a very short transmission (probably 3000-3500rpm at 65mph as opposed to ~2100rpm) in the much larger 2 liter engine, they're claiming to see as much as 48mpg on the highway by tuning in lean burn with the Insight body, running as lean as 19:1 AFR.

Even 48 mpg sounds nice to me right now since this current tank is down to about 36-37 mpg since most of my driving is short 5 mile trips on a cold engine, despite hypermiling. But then again, beating the highway EPA rating on a cold engine isn't THAT bad I guess on a stock Civic..

Originally Posted by Ecky

I don't have kids so I don't feel the need for back seats. If friends want to go out to movies with me, they can drive their own damn cars. I'm not paying the other 364 days of the year for them to ride around with me once in a blue moon.

Good point, but you can't really store much cargo in an Insight either.

Originally Posted by Ecky

Not really. Paddle shifters don't let you run outside of the RPM range the transmission computer would allow, and CVTs normally maintain the lowest RPM possible anyway. Paddle shifters are really only there to rev the engine up unnecessarily.

My issue with automatics isn't as much the gearing, as it is the durability/reliability and the drivetrian losses. Someone has in their signature various transmission efficiencies, and I believe it was written that a manual is about 98% efficient, whereas a CVT is ~88 and a traditional auto is ~86. On top of that, you don't see any automatic transmissions with half a million miles on them; most cars I see in junkyards (that haven't been claimed by rust) are there because their automatic transmission failed long before anything else did.

If a CVT normally maintains the lowest RPMs possible, how are they less efficient than manuals? I always thought manuals were more efficient than automatics just because one could "force" them to upshift sooner.