Excellent performance when cold (all of a sudden?)

[jawn101]

So today I took the D out after work. It was the first time in a week or two, so she was well and truly asleep. It was about 65 out this afternoon. When I got on the road, I noticed that the car was performing better than I ever remembered it doing before. Throttle response was very snappy and easy and everything just felt really good.

Is this in my head or is there a reason why I might be seeing this difference?

For what it's worth, it's gotten cold here overnight lately - in the mid 30's. I have 20w50 Dino oil in the motor, same as always. Nothing has changed during the past couple weeks she's been sleeping.

[sdg3205]

Jon,

I'm glad you brought this up. I've often felt my car has run better the first 20 minutes (after a 5 min warmup) than after 2 hours or a full day. No clue man. Fuel pressure? Weakening spark? Driver being velocitized? At any rate the car was running nicely and problem free so i left well enough alone.

[jawn101]

Jon,

I'm glad you brought this up. I've often felt my car has run better the first 20 minutes (after a 5 min warmup) than after 2 hours or a full day. No clue man. Fuel pressure? Weakening spark? Driver being velocitized? At any rate the car was running nicely and problem free so i left well enough alone.

Yeah, there's always a slight improvement when it's fresh out of the garage, which I always chalked up to the old 'a cooler motor makes more power' chestnut. But this was really significant. Seriously it was like driving a race car for some reason :)

Not complaining - I want to figure out how to make it feel like that all the time!

Also, I should say there is nothing known wrong with the car. Runs fine all the time. The vital stats were all perfect during today's cruise (temp, oil pressure, voltage, etc) as they always are. Only tangible difference was the lower ambient temp and the fact that the overnight temps have been comparatively much lower than normal.

[rockola1454]

I've noticed both as well. My car seems to have more power (a) in Summer for the first 10-15 minutes and (b) overall in colder temperatures. I figured there was something wrong with it, but it sounds like this is normal?

[vwdmc16]

Its those low quality new Hondas you drive regularly Jon, they are lowering you standard of driving for when you get around to the D;)


Im not sure why that is Jon, Your car is just awesome! DEAL WITH IT!

[jawn101]

Its those low quality new Hondas you drive regularly Jon, they are lowering you standard of driving for when you get around to the D;)


Im not sure why that is Jon, Your car is just awesome! DEAL WITH IT!

LOL! That new CR-V is actually way fast.

I'm happy to admit my car is awesome... But it felt EXTRA awesome and I was hoping there might be a reason I could identify and make it this good all the time :)

[David T]

During Warm-Up the motor is running a little richer (more fuel) than when it is warmed up and is running "Closed Loop". That will make it feel a bit "peppier". Also helps it warm up a bit faster. Other factors, the fuel is very slightly denser and the air is denser so you get a slightly bigger charge in each cylinder in cold weather.
David Teitelbaum

[Jonathan]

Any chance it is the car (and possibly the driver) being a bit stiff initially... but as it warms up, it loosens up? And I don't mean fuel mixture, I mean like 'cold = stiff' and 'warm = loose'. Much like the properties of most materials. Same goes for you the athlete before a game. Your muscles are like the toffee... stiff initially, especially if cold, and bendable when warmed up.

What I am getting at is possibly the suspension components, whether it be the gas in the shocks, or the grease in the boots. Many of these things don't get appreciably warmed up along with the car, but if the ambient temperature is cooler, they might stay cooler and stiffer? That could account for part of the reason your steering feels tighter, but could also relate to the throttle spool and how easy it moving around. If it is snappy, it might just be feeling tighter for when warm it gets loose and sloppy.

[jawn101]

The throttle actually felt easier to push and more responsive than usual. Weird.

[sdg3205]

The throttle actually felt easier to push and more responsive than usual. Weird.

Ah ha! Maybe you broke a throttle spool spring? This would give the perception of increased throttle response.

[jawn101]

Ah ha! Maybe you broke a throttle spool spring? This would give the perception of increased throttle response.

I thought of that too, but I checked and the springs all look okay. I removed my main return spring once before and I know what it feels like not to have it installed - it feels stiff still, just... Better. I guess this is all subjective and probably in my head. :)

[vwdmc16]

yeah we removed his extra throttle spring a while ago, that did tremendous wonders for the feel of the pedal on his car. It's still out right Jon?

I think David T is probably right, cool fuel, dense air, richer mixture, it can totally add a few more hp over a hot and loose engine. Also it really could be the Hondas Jon, you are using electronic throttle compared to the cable, also your hondas arent stick shifts, so there must be an element of sensory change to a more a more direct feedback, analog vs digital etc.

[jawn101]

I put the spool return spring back a while ago as the throttle was sometimes not going 100% back to idle without it. I liked it a lot better removed but it ultimately had to go back.

You are probably right. Might all be the change from drive by wire to mechanical. The RSX handles worlds better than the D, but damn if the D isn't a more satisfying drive.

[WelmoedJ]

Lower temperatures (cold air) can take more fuel (think of a kind of intercooler).
The mixture now will be richer with the same mixture settings that work in warmer (summer) temperatures.
This makes for feeling a better performance of the car.

If your car still has the heat riser, remove it and replace it with a cold air intake.
Thereafter you will more or less have the same results in summertime temperatures.

The heat riser has a wax element that is supposed to close a valve once the engine reaches operational temperatures.
However this valve doesn't always function properly and may stay (a bit) open.
Extra hot air from the exhaust manifold then is mixed with the outside air and is saturated with fuel quicker than with colder air.
This causes the summer performance being influenced negatively.

[DavidProehl]

Have you thought about re-routing your A/C to dump into the engine bay to keep it at 30 degrees? It will give you that oh so fresh feeling all day long! :jk:

[vwdmc16]

I'm told that for a few years, Porsche connected a secondary air conditioning evaporator to the oil cooler instead of running cooler lines to the front of the car. that would give more consistent cooling performance, but not help intake temps

[pezzonovante88]

Mine also feels better at certain times than others. A few weeks ago when I got it back from it's oil change and check over, power delivery and engine response was noticeably better than I've felt for quite some time (or ever). After a about 5 or 10 mins, though, it went back to normal - which isn't bad, but not as good as it was. I don't know the reason behind this, but I'd like to find out. Next season, I plan on looking into it.

[David T]

My car always seems to run better after it gets washed. Probably more of a psychological effect then a real effect!
David Teitelbaum

[DCUK Martin]

If the lambda sensor is putting out nonsense, the car will operate properly for that warmup period where the ECU ignores the sensor. Then as soon as it switches in, you lose a load of power. This happened on my old #1458.

[jawn101]

If the lambda sensor is putting out nonsense, the car will operate properly for that warmup period where the ECU ignores the sensor. Then as soon as it switches in, you lose a load of power. This happened on my old #1458.

Wouldn't this affect idle quality too?

[Victor]

I feel pretty much that so many engine (and people_including me) are not getting enough air. I could certaily see the difference when I equipped my D with a K&N air filter, a cold air intake (remove the stove) and a removed cat. Now I'm flying. I don't know if it is the air filter, the cold air intake or else but...(maybe a combination of all this ..) On highways, I always though my speedo was faulty because I am mostly in the 130-140 km/h. Recently that speed was confirmed acurate by my girlfriend who drove her car along with me to a car show.
It's definitely faster than the previous D (automatic) And I find the 5th speed to be very long, which makes this car a very potent highway cruiser.
The only thing is that sometimes, the Lamba light goes off from time to time. The oxygen sensor is now quite close to the header. This however does not seems to affect the performance.

[Jonathan]

The only thing is that sometimes, the Lamba light goes off from time to time. The oxygen sensor is now quite close to the header. This however does not seems to affect the performance.

The trigger for the Lambda light to go off in the instrument cluster is coming from the service counter aka lambda counter and is only getting information from the speedometer cable. It doesn't actually communicate with the oxygen sensor directly. It is supposed to count to 30,000 miles and then the light gets a signal to tell you to replace the oxygen sensor. There is no information fed back from the sensor though to make the alarm go the other way. If your light is going off, it means your service counter has reached 30,000 miles. If it is coming on and off intermittently, it means something goofy is happening with the signal wire from the service counter to the back of the instrument cluster. Whether you really need a new oxygen sensor or not is another matter.

[jawn101]

I feel pretty much that so many engine (and people_including me) are not getting enough air. I could certaily see the difference when I equipped my D with a K&N air filter, a cold air intake (remove the stove) and a removed cat. Now I'm flying. I don't know if it is the air filter, the cold air intake or else but...(maybe a combination of all this ..) On highways, I always though my speedo was faulty because I am mostly in the 130-140 km/h. Recently that speed was confirmed acurate by my girlfriend who drove her car along with me to a car show.
It's definitely faster than the previous D (automatic) And I find the 5th speed to be very long, which makes this car a very potent highway cruiser.
The only thing is that sometimes, the Lamba light goes off from time to time. The oxygen sensor is now quite close to the header. This however does not seems to affect the performance.

I do have the cold air intake (no stove) and a K&N filter, which is already pushing the limits of modification allowable here in CA. Removing the cat is 100% not an option. I did notice improved performance when I deleted the stove since my air flap assembly was stuck, but that was a long time ago.

The O2 sensor doesn't actually impact the functionality of your Lambda light at all, unless you've modified the wiring - if that light is flickering it's a problem in your wiring or in the Lambda counter box under the dashboard.

[Victor]

The trigger for the Lambda light to go off in the instrument cluster is coming from the service counter aka lambda counter and is only getting information from the speedometer cable. It doesn't actually communicate with the oxygen sensor directly. It is supposed to count to 30,000 miles and then the light gets a signal to tell you to replace the oxygen sensor. There is no information fed back from the sensor though to make the alarm go the other way. If your light is going off, it means your service counter has reached 30,000 miles. If it is coming on and off intermittently, it means something goofy is happening with the signal wire from the service counter to the back of the instrument cluster. Whether you really need a new oxygen sensor or not is another matter.

Oh ok, Thank you, I did not know that. I thought it was mostly about the oxygen sensor because I beleive that signal (0) lighted up shortly after the cat was deleted and the new exhaust installed. Must be a coincidence.