If race gas cures knock......

[Pats-GN]

Added 2 1/2 gallons of 110 to 1/2 tank of 93 and this cured my knock problem. So this takes away the possibilty of false knock. What should I start focusing on next? Plugs, wires, coil pack? I'm running 15psi and have tried thrasher92 and Reds93 still get moderate knock on 93.

thanks

 

[newtowner]

RJC power plate will help reduce knock at that boost level. I am running 17 psi boost with 93, but before that could only get away with 15 psi max with a little knock. When I add 108 to the 93 I can run 20 psi with no knock. I wouild also look into the SMC alky kit. I have a friend that runs 22 psi on the street, and I am sure he could get away with more boost.

 

[bruce]

Originally posted by Pats-GN
Added 2 1/2 gallons of 110 to 1/2 tank of 93 and this cured my knock problem. So this takes away the possibilty of false knock. What should I start focusing on next?

Direct Scan so you can datalog, and see what's going on when.

Without much diagnostics, you'll just be throwing parts at it. Not just for this. Diagnostics help to rule out what the problems, aren't.

If you in an oxygenated fuel zone, there may be not to much to do without getting into the chip.

 

[salvageV6]

What is moderate knock?

What outside temps.? What gear? What speed?

Just wondering.

 

[Pats-GN]

I'm getting between 3-8degrees of retard on the scanmaster. This is in cool temps. This happens under 60mph (2nd gear kick)then I let off. I sometimes get the audible "ping" for a few seconds when I first nail it. Also, I can boost it up in OD around 60mph and I start getting some knock. This knock came on all the sudden. I used to be able to run 16psi and 93 with no knock at all. I tried increasing fuel pressure, didnt help. I've got an old laptop, guess the direct scan would be a good idea

thanks

 

[Cleaner13]

Im sure you already knew this but I thought it would be an easy way to start eliminating things


the thrasher chip requires 45psi of fuel pressure line off
do you have that set?

Carl

 

[Pats-GN]

Yes, i've keep it at 45, and have raised it up a bit to see what happens, even tried switching regulators and filter.

 

[salvageV6]

I'd try that fuel pressure (45) with both chips.

What injectors? Stockers?

Yeah I know more questions than answers.

 

[Pats-GN]

Thats ok yes stock injectors, no leak down problems. Car runs great, other than a slight "jerk" at 45-50mph

 

[salvageV6]

Well there are several things you can "try" as tests.

1. One gallon of xylene to 4 gallons gas, no not to make more octane but to help clean the stock inj.

2. Fuel pressure gauge on the wiper blade to look for problems from static pressure to boost pressure.
Prolly not the problem but should be checked out.

3. Professionally clean and flow the stockers at which I would simply upgrade them to new ones. Yeah $$$.

4. Add a Power Plate, might want to consider having the throttle body mods. from Jay Jackson done at this time also too. Yeah more $$$.

5. Alky injection covers up a lot too.

6. Top engine clean might help if carbon is built up in the motor much cheaper to do as a test.

7. Try to find some 94 Sunoco or change brands of 93 gas to see if it goes down or away.

Not sure of your financial situation but throwing money at my car has always worked eventually.

 

[Tony sy2356]

Pats-GN,

Where are you from? If the AL under your name means Alberta that may be the cause of your knock.

I have found that the fuel here in alberta requires quite a bit less timing than our freinds down south can run.

Apparently the oil companies use some sort of different octane additive in canada compared to fuel in the USA.

If you aren't from AB, then ignore everything I just said


Tony

 

[salvageV6]

I think Jasper is in Alabama.

"They call Alabama The Crimson Tide,

They call me Deacon Blues."

 

[scottyb]

Originally posted by Pats-GN
I'm getting between 3-8degrees of retard on the scanmaster. This is in cool temps. This happens under 60mph (2nd gear kick)then I let off. I sometimes get the audible "ping" for a few seconds when I first nail it. Also, I can boost it up in OD around 60mph and I start getting some knock. This knock came on all the sudden. I used to be able to run 16psi and 93 with no knock at all. I tried increasing fuel pressure, didnt help. I've got an old laptop, guess the direct scan would be a good idea

thanks

Read salvage's suggestions. I agree that if it happened "all of the sudden", then start by evaluating fuel delivery. What are the o2's like? Fuel pressure, filter, pump....... You should be able to run 15lbs all day long on a Thrasher 92 with 93 gas.

 

[Pats-GN]

Yes, its alabama , thanks guys, i'm going to rig up fp guage so I can watch it under boost and see whats happening, thanks for the help

pat