Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[lilpooh21186]

Ive been reading on how to better fine tune ignition while street tuning. It seems the only way is to have your load and then turn the key of at certian rpm's to read the last burn on the plugs. My question is how safe is it to be doing a pull say 3rd gear full boost what ever it my be, in my case anywere from 15-20psi and just turn of my ignition. To read the plugs.

[mrgreengenes]

i'm wondering too; do people just turn off the ignition and leave it gear, or full out off without the engine braking?  Would the engine decelerating (no fuel/ignition) wash out any last-burn "info" on the plugs?

curious.

phil

[lilpooh21186]

i understand it to be killing ignition in midpull if you let off the gas most cars create a quick rich condition which would mess with the plug reading.

[stealthiskey]

people will tell you otherwise, but i'll say it doesnt matter much. 

What you're really looking for is signs of detonation from overly advanced timing.  If you have det, it will put specs of aluminum on your plugs.  And those specs will still be there when you shut the car off.  Even if it went rich, idled, engine braking, whatever.

I would say the "correct way" is to do a pull, put the clutch in, kill the ignition coast to a stop without the engine moving.

[fuse]

I made this think. Works for about 6 tunes. Need to make it a bit better next time. Don’t use the foil tape makes a kink craps out. Put both mikes on one side of the clamp. Ya I read plugs too turn key off still on the gas. I don’t care much for reading the plugs for fuel I just use my wide band.

I use the ground strap try to hit the bend some time I will run it all the way down to the threads (n/a builds) don’t hear any knock no aluminum specks. I don’t know.

http://www.talkjdm.com/showthread.php?t=3284

Dyno is the only way to get it 100% I have also played with G meters. That kind of works have to use the same street, same iat, same ect still you spin a tire done. Or just run track a few times and mess with it.

Thats all I got Im a noob.

[d112crzy]

English please.

[Atticus]

isn't this why we have det cans?

[stealthiskey]

minor indicators of detonation will show on plugs before you can hear it through a det can.  There is almost always some detonation going on at the very end of the burn.

[lilpooh21186]

i was basicly talking about reading the strap without contaminating the burn with a rich condition

[turbo4life]

key OFF 

CLUTCH IN

NEUTAL


pull off and BREAK , stop

pull plugs

[Joseph Davis]

minor indicators of detonation will show on plugs before you can hear it through a det can. 

It shows up on piston surfaces long before you see it on the plug itself.

There is almost always some detonation going on at the very end of the burn.

No, there is not.  Have you ever looked at a graph of combustion pressure?  It's a bell curve, and besides the exhaust valve opens at the very end of the burn and everything vacates to a lower pressure environment.

[lilpooh21186]

key OFF 

CLUTCH IN

NEUTAL


pull off and BREAK , stop

pull plugs

good lookin out

[92CXyD]

yeah it shows on the piston. :yes:

I'm breaking in the new borescope with color LCD to check out the pistons while tuning. ;D

[98vtec]

i was looking at that in my snap on catalog...very tempting i must say lol

[92CXyD]

i was looking at that in my snap on catalog...very tempting i must say lol

I got one for work to inspect blind section of castings the one I'm using came with a 17mm head for around 270usd then another 75usd for the 9mm head and flex cable. ;D

But the foundry paid for it. ;D