Lack of engine braking on MT?

[TegGSR2CivSi]

TL;DR: Does the Gen 10 MT Civics coast too much and lack engine braking while in gear?

*disclamer* This is not a thread to debate if engine braking for your car is good or bad or a brakes v. clutch and rev matching discussion. I'm going to assume we're driving down a really steep ass hill and the brakes should have been replaced, so we need the engine's help */disclaimer*

I just recently got a 2017 Civic Si after driving a 97 Integra for 12 years.

After driving my 5-speed for so long, I'm incredibly used to my 'Teg engine braking IMMEDIATELY when coming off the gas to the point that I could get substantial life out of my brakes. But in comparison...

I'm finding the Civic to drive half like a manual and half like an automatic... fun to accelerate in and shift gears with, but HORRIBLE to slow down in....it feels like in gear it's actually coasting like an AT. Going down hills at highway speeds is pretty sad too. With my foot off the gas and being in gear, my integra can slow down in 5th from 80 to 60 in probably 10-15 seconds. The Civic in 4th gear, even, either slowly picks up speed or just barely holds constant speed. What gives? Is this transmission gearing or how the engine is working?

I noticed the Civic also has substantial 'rev hang', and there's a bunch of threads on how to tune your car to reduce the 'rev hang' and make your car go faster.

...Can you also tune your car to, essentially, go slower?

After doing a little half-assed, two-beers-in research, I believe the ECU or MHEC (magical honda engine computer) while at speed leaves the throttle full open while you take your foot off the gas and leaves the injectors spraying next to nothing, eliminating compression? Did I read this right? Is there a way you can reprogram your MHEC to make engine compression when no throttle input detected!

At the end of the day, would it be possible to tune a Civic to drive like a non DBW throttled manual? Or are things like Hondata and KTune only for improving going forward stuff?

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[l15b7allturbo]

If you turn off rev hang then engine braking will be more prominent

 

[turbo lover]

It's a low displacement engine with low friction, low pumping loss, and other efficiency tweaks. As a result, there isn't much engine braking.

 

[CivicChina]

the first time i went down a hill i was shcked by the lack of engine braking, it was a very steep and narrow road, in some sections i could only go down slowly in 1 st gear and holding the brakes. I was upset because engine braking was one of the reasons i switched back to manual after 2 automatic cars and I had never experienced similar behaviour on other cars in 20 years of driving, including many smaller displacement engines even though we had four 1.2l cars in the family during this period.
Fortunately i dont need to drive down mountain roads often.

 

[TegGSR2CivSi]

Sooooo, does anyone know of or heard anything about tuning their car to get better braking performance?

If you turn off rev hang then engine braking will be more prominent

Is this something you've tried or read up on?

It's a low displacement engine with low friction, low pumping loss, and other efficiency tweaks. As a result, there isn't much engine braking.

Yeah, its shockingly noticeable. Not a favorite feature IMO.

the first time i went down a hill i was shcked by the lack of engine braking, it was a very steep and narrow road, in some sections i could only go down slowly in 1 st gear and holding the brakes.

Hearing this is troubling. I wish Honda had considered this and included some sort of engine braking in their tuning (switch between efficiency and braking or something).

 

[l15b7allturbo]

Sooooo, does anyone know of or heard anything about tuning their car to get better braking performance?



Is this something you've tried or read up on?



Yeah, its shockingly noticeable. Not a favorite feature IMO.



Hearing this is troubling. I wish Honda had considered this and included some sort of engine braking in their tuning (switch between efficiency and braking or something).

Rev hang keeps about 6 percent of the throttle body open. If turned off then you end up with 2 percent so you're under more vacuum

 

[TegGSR2CivSi]

Rev hang keeps about 6 percent of the throttle body open. If turned off then you end up with 2 percent so you're under more vacuum

That's awesome and impressive you know that - where did you get that information? Also, where can I learn more about it and/or turn off rev hang?

 

[maddmatt02]

That's awesome and impressive you know that - where did you get that information? Also, where can I learn more about it and/or turn off rev hang?

Using a tuner. Not sure of hondata options but with ktuner you have a few settings on how aggressively it cuts. From the factory when you let off the tps command would only fall to maybe 12%, then shortly after softly fall to 3 or 4, where after rev hang fix now it will drop much quicker so you can actually feel the transition to engine breaking where before it was really smooth.

 

[choo]

Throttle will stay open as much as 10% during decel on the stock ecu.

 

[maddmatt02]

Throttle will stay open as much as 10% during decel on the stock ecu.

Damn, you're right. I forgot how bad it used to be. I just checked an old log where I let off around 110 and it fell to 15, then 12 right after, then took about 3 seconds to fall to 9.5 then the log ended because that was back when I used the auto-log.

 

[choo]

On the 1.5t it continues to inject fuel for a second or two after you let off the gas.

Sorry for the 70s color graph (was default I guess) but you can see the Injector Pulse Width still above zero after the TPS is at 0.

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