azoufan

So previously I posted that I have a Diablo tuner. I run the 87 octane tune with the timing advanced 2 degrees on 89 octane fuel to prevent detonation. We can't get 93 octane out here, so I said the heck with it and have been running it on the weenie tune.

So today it got up into the 90's and leaving for lunch I got on it a bit, and wouldn't you know it, I got some detonation! [img]style_emoticons/<#EMO_DIR#>/banghead.gif[/img] Besides the JLT II and SCT2 I'm ordering from Doug, what the heck can I do here? I'm headed to Vegas for a day so I'll throw some 91 octane in for the trip to be safe, but this is sure hacking me off here.

Anyone else having issues like this? This is driving me nuts!

SixtySix

Have you used any Octane boost recently?

Cleveland

you'll have to use several bottles of octane booster to actually get 2 full numbers out of em.

-Dan

azoufan

No, I've never used any octane boost. I run an 87 octane Diablo tune with the timing parameters advanced 2 degrees, and fill it with 89 octane fuel every time. During the winter months here it's been fine, but now that it's gotten warmer I seem to be getting detonation again.

SixtySix

<div class='quotetop'>QUOTE(azoufan @ April 14, 2006, 6:35 AM) Quoted post</div><div class='quotemain'>
No, I've never used any octane boost. I run an 87 octane Diablo tune with the timing parameters advanced 2 degrees, and fill it with 89 octane fuel every time. During the winter months here it's been fine, but now that it's gotten warmer I seem to be getting detonation again.
[/b][/quote]

I haven't had those problems, at least not constantly. I run the 91 Octane tune, and use 91 Octane fuel with no problem whatsoever.

Now when it's really hot out, like 110+ and I sit in stop and go traffic for awhile, yeah, it'll detonate if I get on it, and of course the computer pulls timing big time when that happens.

If it detonates more regularly I'll take out a couple of degrees of timing and that usually does the trick.

Don't ever use any octane booster... I fouled my plugs using some, and it caused misfires in the upper RPM range.

94tbird

can someone explain detonation to me? what is it and how can you tell if it is happening?

tech

<div class='quotetop'>QUOTE(azoufan @ April 13, 2006, 11:59 PM) Quoted post</div><div class='quotemain'>
So previously I posted that I have a Diablo tuner. I run the 87 octane tune with the timing advanced 2 degrees on 89 octane fuel to prevent detonation. We can't get 93 octane out here, so I said the heck with it and have been running it on the weenie tune.

So today it got up into the 90's and leaving for lunch I got on it a bit, and wouldn't you know it, I got some detonation! [img]style_emoticons/<#EMO_DIR#>/banghead.gif[/img] Besides the JLT II and SCT2 I'm ordering from Doug, what the heck can I do here? I'm headed to Vegas for a day so I'll throw some 91 octane in for the trip to be safe, but this is sure hacking me off here.

Anyone else having issues like this? This is driving me nuts!
[/b][/quote]

Yes, I have this issue as well. I have used the 93 C&L tune with 93 octane fuel and have experienced detonation under hard exceleration.

I used the supplied 91 octane tune and it works fine, with very rare pre detonation problems.

What I was wondering is.....Autolite has the new colder plugs for the 4.6 3v, so would this prevent the detonation problems? In theory, that would make sense since the plug stays colder and requires higher temps for pre detonation. Any ideas folks?

Gunslinger

<div class='quotetop'>QUOTE(94tbird @ April 14, 2006, 10:52 AM) Quoted post</div><div class='quotemain'>
can someone explain detonation to me? what is it and how can you tell if it is happening?
[/b][/quote]

You know, pre-ignition, spark knock, pinging... it's how diesels operate, but our engines aren't diesels. The air/fuel charge is supposed to be ignited by the spark plug, but instead it combusts too soon and the expanding gas smacks into the piston which is still moving upwards. Many causes and not good if it happens too often.

tech

<div class='quotetop'>QUOTE(Gunslinger @ April 14, 2006, 12:57 PM) Quoted post</div><div class='quotemain'>
You know, pre-ignition, spark knock, pinging... it's how diesels operate, but our engines aren't diesels. The air/fuel charge is supposed to be ignited by the spark plug, but instead it combusts too soon and the expanding gas smacks into the piston which is still moving upwards. Many causes and not good if it happens too often.
[/b][/quote]


Still looking for input on switching to colder plugs.

mikem

Switch to Autolight H2O,s
Problem Solved