Cooler air = Better boost.... Right?

[CMull123]

Lately, sumthins been naggin at me... 2 things actually.

 

It just started to get cooler around here, about 20-30 degrees cooler, down into the 40's at night, and I was wonderin at what temperature they test and tune these cars at in Japan? I figure if they do an average say 70 degree test to get the psi and tune right, when it drops colder, we'll be gettin cooler, more efficient boost. Does anyone know what kinda hp/tq numbers extra this could mean?

 

And as a footnote, wtf does a grounding kit do?

[John M]

There's more oxygen in cold air so the ecu compensates with more fuel. More air + more fuel = more power, even at the same boost level.

 

Grounding kits just put money in somebody's pocket. I can see *maybe* upgrading the existing straps to larger gauge wire but even then, don't expect much difference.

[automaticsti]

ive seen 5 HP on my buddies EVO dyno sheet after installing a sun grounding kit but for the $ its porbably not worth it.

[-TT-]

There's more oxygen in cold air so the ecu compensates with more fuel. More air + more fuel = more power, even at the same boost level.

 

i am by no means an expert, however, it is my understanding that when the air is cold (prone to less likelyhood of detonation) the ecu leans out the mixture. meaning less fuel. but of course since cold air is more dense, it is easier to accumulate more air in the cylinder, thus yielding more power.

 

correct me if i am wrong.

[LittleBlueGT]

ive seen 5 HP on my buddies EVO dyno sheet after installing a sun grounding kit but for the $ its porbably not worth it.

 

Dyno variations. If it was 5 hp for real that would be very cheap hp.

[Vimy101]

Denser air means more 02. Cooler air means timing is advanced. Longer stroke with more 02 means more power. Mixture can be leaned out for a more complete burn.

 

At least that's how I figure it. I heard somewhere sometime that engine power can increase by as much as 20% over nominal (say 72F/22C) when you get below 0F/-18C with dry air. Water takes up O2 space.

[CMull123]

Thanx for the replies.

 

I never had any assumptions that a grounding kit did all that much, my buddy has one on his shoebox xB, he also has a laser-cut battery tie down (crazy hp with that mod.) I was just wondering how they would actually make any more power or free up any power, wondering about the workings of them.

[AKLGT]

when i go to the track and it's warm and the sun is out (60-80 F), my times are much slower than when it's cool and the air is about 36-46 F. I like to get in as many runs first thing in the morning (if it's a weekend) or a bit later in the eve (at night). my first set of runs at the track w/ mods was 72 F outside, sunny and i hit 13.93 ET. then the next 2 times I went, the air was much cooler, probably 40-50 F and i was hitting 13.63-13.7 consistently. we don't have a dyno, so i can't tell you what that would equate to, but you can definitely tell the power difference just in the launch.

 

as for grounding kits, i've never done one, so don't know if they actually do anything other than look pretty.

[flyboy333]

Import Tuner just ran an article about grounding in which they gained around 5 hp for under a dollar on a Civic (it isn't on their site yet but may be there soon) . The thing is about grounding, you dont need a kit if you know how to do it yourself.