[SmartCat]

My Honda Civic's engine idle speed is 800 RPM. My old Chevrolet Optra's engine idle speed was 1000 RPM, and had excellent in-gear driveability.



When I say "driveability", I mean the responsiveness of the car when I get off the clutch after changing gears. In other words, you can call it the ease with which I can go over large humps in say, the 2nd gear.

1) Is there a relation between idle RPM speed and driveability of the car? If the engine idle RPM is higher by 25 to 50%, won't this automatically improve the "bumper to bumper traffic performance" of my car because the engine produces higher torque at 1200 RPM when compared to 800 RPM?

2) Can a Honda service engineer increase the idle RPM to something like 1000 to 1200 RPM?

[VW2010]

1000 to 1200 shouldnt cause a major concern with respect to wear and tear or other issues. Fuel efficiency will take a hit for sure but benefits are plenty as well. More power on hand to run accessories, faster cooling or heating as the engine warms up faster.

I also think the engine is going to be noisy. Will there be a proportional increase in performance, i doubt it. Even with 25% increase i am not convinced you will see a drastic difference in back to back traffic. Unlike a motorcycle where this can be converted to nice torque(like my bull running in Idle without using any acceleration that too at times when the throttle cable fails ).

But on a car i am not convinced the change in RPM will have enough change in torque to move that massive mass. You may see 5-10% improvement.

[dhanushs]

Originally Posted by smartcat

My Honda Civic's engine idle speed is 800 RPM. My old Chevrolet Optra's engine idle speed was 1000 RPM, and had excellent in-gear driveability.

More than the 200 rpm difference, this is mainly because the Optra has better low end torque than the Civic.

2) Can a Honda service engineer increase the idle RPM to something like 1000 to 1200 RPM?

Nope. I dont think a Honda Engineer can that, May be remap guys can, by tricking the o2 sensor or something (basically the ECU).

1) Is there a relation between idle RPM speed and driveability of the car? If the engine idle RPM is higher by 25 to 50%, won't this automatically improve the "bumper to bumper traffic performance" of my car because the engine produces higher torque at 1200 RPM when compared to 800 RPM?

The problem in setting a high idle rpm is:

• You burn your clutch much faster.
• Probability of running a hotter engine.
• Obviously lower FE

Meanwhile, I dont think a couple of 100 rpms will do the Civic any good. The low end is really bad. Anything close to 1500 rpm might make a difference, but the above points I mentioned will come into play.

[SmartCat]

Originally Posted by VW2010

Will there be a proportional increase in performance, i doubt it. Even with 25% increase i am not convinced you will see a drastic difference in back to back traffic.

But on a car i am not convinced the change in RPM will have enough change in torque to move that massive mass. You may see 5-10% improvement.

I will do a "Torque Vs engine RPM 2006 Honda Civic" Google Image search and see if I can find anything interesting.

Originally Posted by dhanushs

Nope. I dont think a Honda Engineer can that, May be remap guys can, by tricking the o2 sensor or something (basically the ECU).

I was hoping it would be a simple "tighten screw gently" or "twist the bolt" kind of job.

The problem in setting a high idle rpm is:
[*]You burn your clutch much faster.[*]Probability of running a hotter engine.[*]Obviously lower FE

I'm probably burning the clutch (and getting lower FE) anyway in heavy traffic.

[2000rpm]

Dont even try this for the Civic. The Civic has poor low end torque hence you cant expect the same performance as an Optra. The FE will definitely go for a toss.

The two vehicles are very very different. You can look at the Civic Mods thread to get an idea of what to do.

[SPIKE ARRESTOR]

Originally Posted by smartcat

My Honda Civic's engine idle speed is 800 RPM. My old Chevrolet Optra's engine idle speed was 1000 RPM, and had excellent in-gear driveability.

1000 I find it slightly on the higher side, which emission level was it ? Newer cars have lower LIS to reduce FC and emissions while idling (driving cycle).

1) Is there a relation between idle RPM speed and driveability of the car? If the engine idle RPM is higher by 25 to 50%, won't this automatically improve the "bumper to bumper traffic performance" of my car because the engine produces higher torque at 1200 RPM when compared to 800 RPM?

Yes there is, engine T Vs N curve, then depending on the parasitic loads (AC etc) and a lot of other factors you get a torque output.

2) Can a Honda service engineer increase the idle RPM to something like 1000 to 1200 RPM?

Yes / No. Depends on the service engineer.

Spike

[paragsachania]

I am not really sure if increasing the Idle RPM for a ECU equipped car is an easy one to do. There is an adjustment on the Throttle body that will increase the Idle RPM but from what I understand is that the ECU will also have a reference RPM referred to as "Desired Idling speed" against which it keeps the IAC working when this desired idle drops.

By increasing the RPM for idle, the next time you crank your car, it is more likely that the RPM will again settle at 800 (And not where you had adjusted before).

Few years before in my WagonR when RPMs were dropping significantly under Electric Load at idle speeds (Specially headlights) it eventually was a weak alternator belt that solved it and in the interim when we tried increasing the idle RPM it worked only till the next crank where the RPM dropped back to the Factory setting.

IMO, more than just adjusting the Idle speed, you might even have to make changes to the ECU settings in case you are attempting to do this.

Regarding the driveability aspects posts this tweak, owners & others have already responded.

[Sheel]

Bro,

I think you need to change your car IMO, you are not enjoying driving it any longer. Reading this thread, I couldn't help but search for this

[SmartCat]

Originally Posted by Sheel

Bro,

I think you need to change your car IMO, you are not enjoying driving it any longer. Reading this thread, I couldn't help but search for this

Somewhat agree. I like the car, its only the transmission I have issues with.

I spent all my money on A-star AT that I own now. No more cash to spare.

But couple of weeks back, I went to a few used car dealers looking for a swap (giving away my MT Civic and buying an AT Civic).

But the exercise is not worth it - my Civic has just got a 80,000 kms service (costing Rs. 20K) done, new battery, new tyres, recently renewed insurance, scratch free body etc. All this work done will be transferred to the new owner. If I swap, its very likely that I have to spend more money to bring it up to my current Civic's levels.

[IshaanIan]

The Civic was always poor when it came to low rpm drive-ability. Electronic throttle body will mean that it's not a simple job to fiddle around with you will need a remap and modifications to the intake and exhaust. If you are considering swapping your car but don't mind going for another manual, do check out the Mitsubishi Cedia. Severely underrated car that came with extremely good low-end response making it easy to drive in the city, good ground clearance for a sedan with a rally bred chassis meaning it could take a bit of abuse, spacious interiors including a large rear bench, and excellent high speed dynamics with far better stability and handling than the Civic

[GTO]

Why don't you get a remap or power box that focuses on low-end torque? Tell the tuner to focus on driveability only. I'd gotten one for my Civic and it did make a noticeable difference. Still wasn't a Corolla in traffic, but better than stock Civics.