Stubborn Pinging with my Vortech 8 lb boost

93BlkMustangGT · 07-17-2004

My '93 GT pings at WOT starting around 2500rpm at freeway speeds. The pinging is most evident when driving normally on 5th gear; 1/4 - 1/2 throttle then WOT as the RPM's build. My Mustang is not under boosting according to my boost guage.

My setup is this: Vortech 8lb S-Trim, 75mm MAS; 65mm TB; Vortech Instake Manifold; 190lph pump; T-Rex; 30lb injectors; TF Stage II CNC-ported heads; Stage II cam; MSD Ignition w/ retard; JMS Autologic chip; 91 octane gas. I pour in 104+ octane boost every now and then. The engine timing is at 10 degrees. TPS sensor is at .95 volts as recommended by JMS Chip.

I believe that my setup is where is should be but i can't pin down as to where the problem lies.

My gut feeling tells me that the problem has to do with fuel. Fuel pressure is currently at 45-46 psi at idle. Fuel filter had been changed 3 months ago. Should i go with 36lb injectors? Chip Re-burn?

I need some advise on how to get rid of this pinging.

Thanks.

glenn · 07-18-2004

what plugs are you running?

93BlkMustangGT · 07-19-2004

Sparkplugs are Autolite 3924 gapped at .022

Gap too small?

After reseaching, i've read the .032-.035 is the desired range for a supercharged mustang.

Will this resolve the pinging?

glenn · 07-19-2004

try 3923's gapped at .030.

BlueStreak03 · 07-20-2004

If changing the plugs doesn't cure it, have the A/F ratio checked. A lot of guys are using a 255 lph fuel pump, I don't know if your pump is limiting the fuel flow and leaning you out. Sounds like your problem is pretty much in the entire RPM band so plugs are a good bet.

Mana4Real · 07-20-2004

Sounds like it's running too lean. Fuel pump may be too small. I personally would run a 255LPH pump and at least 36lb injectors. But you need to change out those plugs... Run at least a 3923... You may even want to try a 3922. Like BlueStreak suggested, you may want to put it on the dyno to see what's up with the AFR.

I run two steps cooler gapped at .035"

JUSTNLX · 07-20-2004

Your fuel pump and injectors are fine for 8psi SC boost. Going to a larger pump could hurt more then help. Running more fuel through the system then you need could heat the fuel up causing lost hp.

At least one step cooler on the plugs gapped .032-.035

What is the boost retard set to? What is the timing/AFR on the chip?

Black 93 LX · 07-20-2004

Might be EGR not funtioning correctly........

66stang87 · 12-09-2008

this will solve the problem go now and get a set of bosh platinum 4 plugs part number bch-4457

spdjnky_42 · 12-10-2008

DOnt use platinum plugs. Get the number for autolite plugs for your head app then go one number less. This will be a cooler plug. Your timing should be set around 6*. Set your plug gap @ .030-.035 and you should be good to go. Bad timing causes detonation which will ruin your motor. You should definetly have your car custom tuned for this app.

66stang87 · 12-10-2008

your setup looks almost the same as mine i have gt40 heads and the plugs you say you were looking at were 14mm .750 and the two that you were saying and that other guy was saying the heat range was v rery hot the bosh plugs are the coldest heat at 9 thats what i run in my car and i never have any pinging . let my know