Detonation w/ 2.80" pulley and Predator Diablo Pulley tune

[Pyro]

Well, I put on the 2.80" pulley w/ 100mm Metco Idler. Big difference compared to the 2.93" pulley. I then loaded the Predators "Diablo Pulley" tune and got some minor detonation at WOT below 3K rpms. Just to be safe, I adjusted the fuel curve richer by 5% with only very slight (if any) improvements. I then realized that the 5% adjustment was too small taking into account that the full 15% only equals 1 a/f point. At lunch I will go the full 15% (1 a/f point) richer just to be safe until I can get it dyno tuned. 1 a/f point richer cant hurt considering the known alternative (detonation).

If anyone has any suggestions, I'm all ears! My only other mods are 9" powerstack filter, ram air duct, Flowmaster 2-chambers on stock plumbing, hood mod, and other non-engine goodies.

 

[postban]

How warm is it there?
50 degrees here and nothing but smooth running?

91 octane?

I always use 93-94 too.........

 

[MJ32V]

Is that tune setup for 91 or 93 octane? How much timing are you running down low?

MJ

 

[03DOHC]

Pull the timing.

 

[Pyro]

The only times I tested it was at night and this morning at 5:00 am so it's not the temp. I'll try retarding some timing and richen it up. I guess every car is different because others have no detonation.

 

[fastgascar]

In the pulley tune setting what is the standard A/F and Timing? What RPM? Are the settings constant or variable?

 

[Pyro]

Originally posted by fastgascar
In the pulley tune setting what is the standard A/F and Timing? What RPM? Are the settings constant or variable?

:shrug:

 

[Poisonous Mods]

Randy...finally ur dream came true ;-) :beer:

I have to say that every car is different ;-). Timing & Richer might fix it, hopefully.

:thumbsup:

 

[Pyro]

Originally posted by Poisonous Mods
Randy...finally ur dream came true ;-) :beer:

I have to say that every car is different ;-). Timing & Richer might fix it, hopefully.

:thumbsup:

Well, just got back from lunch and I spent it adjusting my "Diablo Pulley" tune. I really didn't do anything major....Just took back some timing and richened up the fuel a bit. Now there's no audible signs of detonation/pinging. It's very interesting to make changes and see actual results so quickly. Some of you may be freaking out that I'm "tuning" solo without a dyno tune. IMO, it scares me more to have detonation than to make changes to my tune to make it safer until I dyno tune it. Remember, it's the same thing as the good'ol days using the timing light and turning screws on the carb. This is just a lot more horsepower and a more expensive car. In that light, Yes, I'm nervous but I dont venture to the track either...actually, never have.

To be honest with you, during my test runs on the highway, WOT is no joke now that I have the Predator and the 2.80" pulley. It's a monster now.