Running lean and detonation

[Kong76]

Google it. Same sensor for GT and GT350.

I trust you. Worth a shot.

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[accel]

As you mention you are both running a "canned tune". So you get what you get. Not every engine is the same regardless of being built on an assembly line. Best of luck to both of you.

Yes, we got what we got. Unfortunately this is the only tune I'm aware of that is CARB legal. So, no alternatives other than some forced induction applications. But those are expensive.

So, we are given the tune - Ford Racing Power Pack, the fuel (91) and our cars. All cars are different, but we try to figure out what exactly is different. Ford racing was supposed to come-up with the tune that works for all.

 

[ugstang17]

***Goes with the terrain you live in.

 

[accel]

Kong76, you've mentioned spark plug replacement. What spark plugs did you use for a replacement?

Thinking of the situation when the more I drive the car during the same ride the easier it is to achieve detonation I wonder if this could be signs of pre-ignition as things heat up.

And so maybe colder spark plugs would be worth a try.

 

[Kong76]

Kong76, you've mentioned spark plug replacement. What spark plugs did you use for a replacement?

Thinking of the situation when the more I drive the car during the same ride the easier it is to achieve detonation I wonder if this could be signs of pre-ignition as things heat up.

And so maybe colder spark plugs would be worth a try.

I replaced with the same stock oem plugs. I believe they were sp 548 cyfs-12-f1

 

[ugstang17]

Still does not explain the lean condition on both banks while driving. Put it back to stock. Sell the kit, save some money, refuse to buy the old lady her boob job for Christmas (inside joke from another website) and drop the hammer on the Edelbrock or Whipple CARB package. OR just trade in for a 13/14 GT500. Better platform IMHO anyway.

 

[accel]

Still does not explain the lean condition on both banks while driving. Put it back to stock. Sell the kit, save some money, refuse to buy the old lady her boob job for Christmas (inside joke from another website) and drop the hammer on the Edelbrock or Whipple CARB package. OR just trade in for a 13/14 GT500. Better platform IMHO anyway.

My plan was just the tune until 5 years of ownership, and only then some sort of an FI.

But I cannot make my mind as to which one.

I'm a bit surprised that there isn't much info on superchargers besides how much hp/tq they make and quarter mile times. I'd be interested in in-depth reviews of them - pros and cons Daily driving, track reviews, autocross, etc.

All I know is I need a conservative one (stage I?) as I really like the car and plan on driving it for many years.

Honestly, if this damn tune worked maybe I wouldn't need anything else. All I like in it is character transformation - more direct gas pedal feel, higher redline etc. If they reduced power gains but make it work with 91 I'd be happy.

Regarding the lean fuel conditions - I think it was a common knowledge that this tune makes fuel mixture very lean, but still useable... the car is not throwing codes and there's no feel of power loss.

 

[ugstang17]

My plan was just the tune until 5 years of ownership, and only then some sort of an FI.

But I cannot make my mind as to which one.

I'm a bit surprised that there isn't much info on superchargers besides how much hp/tq they make and quarter mile times. I'd be interested in in-depth reviews of them - pros and cons Daily driving, track reviews, autocross, etc.

All I know is I need a conservative one (stage I?) as I really like the car and plan on driving it for many years.

Honestly, if this damn tune worked maybe I wouldn't need anything else. All I like in it is character transformation - more direct gas pedal feel, higher redline etc. If they reduced power gains but make it work with 91 I'd be happy.

Regarding the lean fuel conditions - I think it was a common knowledge that this tune makes fuel mixture very lean, but still useable... the car is not throwing codes and there's no feel of power loss.

I'm on my fourth FI setup. I can give you some insight from my personal experience if you wish to PM me so as to not alter any further the direction of this thread.

 

[accel]

I'm on my fourth FI setup. I can give you some insight from my personal experience if you wish to PM me so as to not alter any further the direction of this thread.

Thanks for the offer, I'll PM you

Back to the topic - I do not think there's a problem with fuel supply. The reason is - neither mine nor Kong's car detonates until the engine is completely and stably hot. So somehow overall the tune manages to supply detonation free mixture until then.

 

[Kong76]

Thanks for the offer, I'll PM you

Back to the topic - I do not think there's a problem with fuel supply. The reason is - neither mine nor Kong's car detonates until the engine is completely and stably hot. So somehow overall the tune manages to supply detonation free mixture until then.

Wonder if its our thermostat. Engine is getting too hot?

 

[accel]

Wonder if its our thermostat. Engine is getting too hot?

Lean fuel burns at higher temperatures.

I wonder if standard plugs might be at the edge of beeing too hot and what we hear is pre ignition.

I wonder if colder spark plugs could help.

Still unexplained is why boostain does not help you. I mean, if you have pre ignition you'd hear detonation sound even on high octane fuel.

But why pre ignition occurs then? You add bostain, fuel should become reach, temperature goes down. I guess 91 plus octane booster is not producing true high octane fuel and its burning characteristics are unknown.

 

[Kong76]

Lean fuel burns at higher temperatures.

I wonder if standard plugs might be at the edge of beeing too hot and what we hear is pre ignition.

I wonder if colder spark plugs could help.

Still unexplained is why boostain does not help you. I mean, if you have pre ignition you'd hear detonation sound even on high octane fuel.

But why pre ignition occurs then? You add bostain, fuel should become reach, temperature goes down. I guess 91 plus octane booster is not producing true high octane fuel and its burning characteristics are unknown.

Im only adding a few oz to 12 gallons. I am going off their mixing chart. I was aiming for 93-94 octane. I could dump what I have left which is about 6 oz see if that works.

Oddly headed to work yesterday morning about 615am there was a bit of fog/ mist in the air 47 degrees. The car loved it. Very responsive and quicker than I felt in quite sometime and no pinging from what I could hear.

Prob good DA.

 

[accel]

Kong76, have you tried relearn and MAF sensor swap yet?

I was afraid that I reported success too soon and the detonation will be back, but (still) carefully saying this, so far the detonation is pretty much gone. I've done a couple more things after MAF swap, but not sure they matter.

Before MAF swap I very moderately accelerated in first gear in my neighborhood and it detonated out loud.

Today I was driving around with windows open next to obstacles, sharply flooring it on purpose with wheel spin, tried it in all gears and sometimes I can achieve very short and faint sequence and then it's gone.

All this is on the same tank of 91 fuel from Costco. I'm still paranoid and scared it would come back.

P.S. Extra things I did after MAF swap - driver's side JLT catch can - relocated it into a cooler spot and shielded with heat insulator. This might slightly improved something actually. Also, I suspected air leak at manifold where plastic connects to a rubber band that clamps to throttle body. There's some irregularity at mine and I mask taped it. But I think this is just my paranoia.

 

[Kong76]

Well been a bit but I may have figured out the reason for the leaner condition and possibly related preignition. Doing some reading on where vacuum leaks come from I stumbled upon the brake booster. I crawled under the dash to take a look at the piston area behind brake pedal and there is some wetness when wiped with my finger. My booster diaphragm may be failing or has failed. There are no drips on the floorboard. I don't notice any rpm drops when pressing the brake pedal nor does the brake pedal seem stiff or hard. Seems to work ok. They have been clacky a bit but just assumed that was the brake pads moving.

I am going to do some tests after work to check the booster. If this is the problem causing a vacuum leak in the intake manifold.... halleluiah!! Bad thing is I don't know how long it's been running like this 1-2 years?

 

[ugstang17]

If your vacuum gauge is showing greater than 15" of Hg or more you have no vacuum leak. Most Coyote engines with stock cams run 17-19" Hg at an Idle of 750 after warmup. This is assuming that VCT is tuned correctly. If VCT strategy is creating overlap effect vacuum will be closer to static. For those reading who don't undcerstand VCT basics or cam basics...disregard.

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