Ok this truck is aggrevating me.

I installed a 6lb pulley a week or so ago and got a custom tune for my predator. I noticed that I was getting some tip in detonation on that program because the tuner advanced the timing 2 deg at part throttle.

We talked last night and he emailed me another program leaving the stock timing at partial throttle and its still doing the same thing. I am useing 93 Amoco gas and the detonation is gone in just a plit second but its there for sure

If i roll into the throttle its fine but if I just stab it to half throttle in drive or overdrive it detonates badly before it kick down a gear. This is 03 L with 19k on it and new fuel filter. I have my fuel press gauge installed and it goes up immediatly into the 45+ psi then to 50+ at full boost.

Any ideas?

Bob

 

Bob, I should have your custom tune to you later today. Give that a try. .

 

Sweet I wil give it a try Sal... It runs fantastically but the detonation is bothering me. I understand the affects of detonation and dont want to pony up for a short block anytime soon.

Bob

 

Could you have a bad spark plug?

 

I'd also *NOT* assume the gas is what you think it is.
Back in my stang days I had my timing on the ragged edge. I learned that some stations will differ from time to time. Don't know how or why but some tanks would knock and some would'nt from the same station / pump. Maybe your just on the edge like I was?

Rich

 

Its not a bad spark plug, I just put TR6's in it last weekend gapped at .035. It has no other "issues" other then the tip detonation.

It may be the gas but I always use the same Amoco for all my boosted cars since 1996 and never had detonation problems. I just filled it up at different station so well see if it gets better on the way home. I think its in the tune with regards to tip in. At wide open throttle it is just fine as well as just rolling into the throttle it does not ping.

The 6lber makes boost so fast I think its too fast for the computer to yank enough timing wih regards to sudden load.

Bob

 

I highly doubt that a mechanical supercharger makes boost faster than a computer can react.

--Joe

 

What was causing the Lean code you posted about the otherday ? Maybe there is something wrong with your truck like a vacuum leak ? Use the predator and monitor your fuel trims to see what the computer is doing.

 

Bob,

I am running the 6#er also, and I am running the BR7ef's
instead of the TR6's ... Haven't had a whisper of detonation.

Ask Sal how your's and my tunes are different on the 6# version.

Mines in position 2 and 3 on the 4 way.

One Street, and the next one strip ....

Hope you figure it out ...

Cliff

 

The breather cap was causing the lean code. Everything has been fine since removing it.

The truck runs strong the only detonation im hearing is at tip in, every other thing (WOT - cruise - idle) is just fine.

Soap -

What I mean to say is that the load tables in the ecu may not be able to handle 10psi of instant boost at tip in. The truck makes that easily is I just stab the gas. The stock pulley would not barely make 10psi at redline.

That why I think its just tuning issue but im no "tuner" thats for sure

Bob

 

I have a 6lb with chip and the tr6. gapped at .040 and I have no detenation .

 

Tip in detonation occurs because the MAF sensor can't adjust fast enough. At the heart of the MAF is a "hot wire" that the MAF is trying to hold at some temperature above ambient. The amount of energy needed to hold that temp is translated into air mass flowing past it (since every molecule absorbs a constantant amount of heat).

When you hit the throttle, the amount of energy needed to keep that wire's temp up skyrockets. The MAF will try like crazy to adjust to it as fast as it can, but some amount of air goes pretty much unmetered. Unmetered air = lean. Lean = heat. Heat = detonation.

So while the mechanical SC isn't creating boost faster then the computer can react to it. The SC is creating flow faster then the MAF can react to it.

 

UPDATE!!

I filled the truck up with 93 again at lunch time being I was below a 1/4 tank of gas. That alone has seemd to cure the detonation problem at tip in.

Very strange indeed, must have been a bad tank of gas.

Bob

 

Sometimes if your low on gas, you will get some pinging because your starving the pumps for fuel at wot. the gas floats to the back and your pumps are not far enough back to pick up the fuel. .....I'm no pro., but mines done the same thing before.......also, in cold weather i switched from tr6's to denso it22's and that cured my winter pinging.