Transmission/gearing question

[Ecky]

Very true. Lightning can strike anywhere.

Maybe the LX transmission is a happy middle? Any way you could test drive a car with these various transmissions?

A very small turbo might be an option too. Small enough and it won't hurt economy, and will spool up very quickly. Not a cheap option but you could keep your power while gearing the car very tall for phenomenal highway economy.

[EcoCivic]

Originally Posted by Ecky

Very true. Lightning can strike anywhere.

Maybe the LX transmission is a happy middle? Any way you could test drive a car with these various transmissions?

A very small turbo might be an option too. Small enough and it won't hurt economy, and will spool up very quickly. Not a cheap option but you could keep your power while gearing the car very tall for phenomenal highway economy.

Great advice, thank you. I may see if I can find similar cars to test drive to at least get a feel of the gearing. However, the EX, DX/LX, and HX have different engines, so even if one feels faster or slower than the other, it would be hard to say if the difference is the engine or the gearing.

As for a turbo, great idea but no. I am going to eventually K swap this car, and the time and money involved in installing a turbo would never be offset by any fuel savings.

[Ecky]

I'm K swapping my Insight, and have put together what is possibly the tallest K series transmission ever assembled. I'll let the high level of torque take care of off-the-line acceleration and will be turning ~2200rpm (possibly less) at 70mph, hopefully allowing me to keep my 60+ mpg. Highway economy is really all about gearing and aerodynamics.

EDIT:



I'm actually less than certain about the 4.4 final drive in the EX. That's what California98Civic's Honda transmission guide says, but Honda says it can be either/or:

https://owners.honda.com/vehicles/information/2003/Civic-Coupe/specs#mid^EM2123PW

[California98Civic]

Originally Posted by Ecky

... I'm actually less than certain about the 4.4 final drive in the EX. That's what California98Civic's Honda transmission guide says, but Honda says it can be either/or:

https://owners.honda.com/vehicles/information/2003/Civic-Coupe/specs#mid^EM2123PW

Confusing. I got my data from Honda.com in 2013. But you are right for the link you offer for the 2003. Still, elsewhere, today, Honda.com lists only "Final Drive Ratio 4.41" for the 2002 MT EX. Oddly, their AT EX FD specs also change. See: https://owners.honda.com/vehicles/information/2002/Civic-Coupe/specs#mid^EM2192MW

Hard to confidently decide what is true without laying hands on the actual gears from an actual car.

??

EDIT: the Honda site also now labels the 2001-2005 EX as a "VTEC-E" engine and the HX as a "VTEC-E lean burn." But the EX was never vtec-e as far as I know. It's just VTEC. So I think over time, as they've updated that website, Honda may have introduced errors, which would be a bummer. Getting the original hard copies of the factory service manuals would be the way to resolve it.

[mpg_numbers_guy]

What program or website are you using to compare transmissions, Ecky?

[Ecky]

Originally Posted by mpg_numbers_guy

What program or website are you using to compare transmissions, Ecky?

This is what I use:

https://www.zealautowerks.com/transcalc.php

[EcoCivic]

Originally Posted by Ecky

I'm K swapping my Insight, and have put together what is possibly the tallest K series transmission ever assembled. I'll let the high level of torque take care of off-the-line acceleration and will be turning ~2200rpm (possibly less) at 70mph, hopefully allowing me to keep my 60+ mpg. Highway economy is really all about gearing and aerodynamics.

EDIT:



I'm actually less than certain about the 4.4 final drive in the EX. That's what California98Civic's Honda transmission guide says, but Honda says it can be either/or:

https://owners.honda.com/vehicles/information/2003/Civic-Coupe/specs#mid^EM2123PW

In a way having tall gearing sounds nice. Maybe it’s just me, but I don’t really like cruising at a high RPM for a long time because it sounds noisy and it feels stressful on the engine, even though I know it’s fine. If I regularly took long road trips I would probably get sick of the EX transmission’s short 5th gear pretty quickly. The idea of cruising at 4000 RPM all day doesn’t sound appealing to me.

But I also like to push it hard sometimes, so I think the best option for my needs may be to get the EX trans and swap to the HX 5th gear, and possibly the DX/LX 1st gear for more off the line power.

Call me crazy, but I am starting to think about the possibility of installing a CVT from a Civic Ferio 1.7. It would probably be the most fuel efficient, and also possibly the fastest since it could hold the RPM high for maximum acceleration at full throttle and there would be no shifting.

But one major problem with a CVT is I am not sure how well it would handle the extra power that this engine is making. From my understanding CVT’s are problematic enough as is, and I’m sure pushing more power through it than it was made for wouldn’t help.

[Ecky]

My understanding is that Honda's early CVTs didn't do well with high torque, and typically didn't last very long even with stock engines; failures before 150k weren't rare. They're also not very quick to "shift", giving a noticeable delay in power while the engine revs up and the belts find their new positions. Newer CVTs are faster to shift and more durable. Dunno about the 1.7's.

[racprops]

I am thinking that a second overdrive added to a stock 4 speed auto with a OD gear can work and in fact greatly increase a stock car/van’s MPG, just by lowing the cruse RPMS from around 2400 RPMs to 1700 RPMs.

This seems to be the best of all worlds, stock gearing until the added Over Drive is engaged then the advantage of super highway gearing.

Your thoughts and knowledge is invited.

Rich

[Ecky]

Originally Posted by racprops

I am thinking that a second overdrive added to a stock 4 speed auto with a OD gear can work and in fact greatly increase a stock car/van’s MPG, just by lowing the cruse RPMS from around 2400 RPMs to 1700 RPMs.

This seems to be the best of all worlds, stock gearing until the added Over Drive is engaged then the advantage of super highway gearing.

Your thoughts and knowledge is invited.

Rich

The devil is in the details. Do you mean turning a 4 speed into a 5 speed, or just swapping the 4th gear for a taller one?