shrockworks xterraparts
XOC Decal
Newest Members
Glim, ChossWrangler, Patman, ChargedX, Randy Howerton
10084 Registered Users
Recent Posts
ECXC 2024!
by Tom
23/04/24 04:27 PM
2002 Door Opening Trim
by OffroadX
01/04/24 08:32 PM
XOC Still Lives
by OffroadX
01/04/24 08:31 PM
Shout Box

Who's Online
0 registered (), 113 Guests and 0 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#644148 - 28/12/05 08:50 PM What the HELL??
Anonymous
Unregistered


Ok, sorry, very new to this world, but want to get it right....so I just bought a 02 SC. Love it to death, only run Premium cause that's what it says and the gist I get from everyone here...

But what the HELL does Pinging mean?? Just so I can watch for it if it ever happens. Just want to educate myself on it. It's my first car I've ever owned and paid for myself so I wan to take care of her!!

Top
#644149 - 28/12/05 09:01 PM Re: What the HELL??
Anonymous
Unregistered


sounds like some little idiot with a cmall hammer hitting the block, as fast as the engine is turning.. also called knocking..

Top
#644150 - 28/12/05 09:11 PM Re: What the HELL??
TJ Offline
Member
*****

Registered: 08/03/01
Posts: 7756
Loc: Lawrenceville, NJ, USA
Pinging is the term for the fuel being ignited just a smidgen early (Timing too advanced)...

Imagine pushing a kid on a swing...the piston is the kid...

Essentially, the piston is heading back to get another push...but we start the push before he's completely finished coming towards us, jolting him a bit. (Pinging him)

If we have the right timing, we push just after the kid reaches the apex of the swing to us, and is just starting to swing away again, so we get a smooth transition of momentum. (No ping, happy kid...)

If we push the kid when he is coming to us, but not even slowed down enough yet, we can knock him right off the swing....that's knock, a more severe ping.

Octane just describes the speed of the flame propagation, think of it as how fast the fuel burns...the higher the octane, the slower the burn.

Higher octane burns more slowly, so it needs the spark to be delivered a bit sooner to give it time to burn all the fuel, and give the kid (Piston) a good long hard push....

If you use a lower octane fuel than your timing is set for, it burns more quickly, and pushes a bit early, essentially advancing your timing...and that of course can produce ping....or, in extreme cases, knock.

X's tuned for regular on the other hand, if you put hi-test in them, just blow extra hydrocarbons/unburned gas out, and start their push too late in the cycle.

Modern engines have a knock sensor system, and when they detect knock, they back off the timing until its gone...but keep it right up against the limit if they can.

So - if your engine calls for premium, you get better performance with premium....and your knock sensor will back off the tiing to prevent damage if you use lower octane than its designed for.

If your engine calls for regular, you get better performance with regular....and no benefit from premium unless you change the engine timing, etc.

There are exceptions, such as if your engine is out of tune, you can correct for the wrong timing by using the wrong gas to compensate...and at high altitude, you need lower octane or you lose power in the mountains....and in death valley, etc....you may need higher than normal octane, etc.

So - if you are watching for ping...so is your knock sensor....and it likes just a tiny tiny hint of ping to feel secure.

laugh
_________________________
- TJ

2001 Xterra '03 VG33, SE 5 spd, 305/70/16's, Revolvers, UBSkidderz, Doubled AAL's, 3"SL/2"BL, winch/bumpers, skids, sliders, OBA, Snorkel, pine stripes....

Friends don't let friends drive stock.

http://www.gifsoup.com/view/501230/tj-tackling-crawlers-ridge-o.gif

Top
#644151 - 29/12/05 05:46 AM Re: What the HELL??
Anonymous
Unregistered


So if I'm in Wyoming, and may cruise up into the mountains getting close to 9,000 ft. or more, is htis going to affect anything. I'm at around 6000 ft where I live.

Top
#644152 - 29/12/05 03:41 PM Re: What the HELL??
Anonymous
Unregistered


you should be ok if you are running premium fuel regardless of elevation, because the ECM will detect the thinner/ colder air and should correct the fuel mix to compensate. pinging in modern engines is a relatively uncommon occourance. more commonly found with older vehicles with carburetion and non-computer controlled equipment. also, if i'm not mistaken, the SC shold have spark knock detection for pinging because of the higher combustion temps of the huffer.

Top


Moderator:  krisjon, sky 

shrockworks xterraparts
XOC Decal