Tuning questions?

[WOOSHH]

I recently installed a scanmaster and the instructions say not to go over more than 3 on the knock retard.The prior owner has Turbo Link version 2.13 installed,there directions say less than 6 on the knock retard.Which is a safe level of knock retard? I have the stock turbo and injectors,93 chip and am running 17psi of boost.At wide open throttle she stays at 17 but I seen the retard go as high as 10 and heard two pings and then quickly let up.I'm going to increase the fuel pressure-this should bring the retard down. Is this correct and anything else that should be done? Thanks

 

[Danster]

You should tune for no knock period.


Dannyo

 

[2QUIK6]

As Danny says, no knock is safest. At lower boost, a few degrees can be tolerated for a short amount of time, say 13#, but as you increase boost, the same few degrees become more harmful. For example, you might get 2 degrees at 13# of boost....your motor may tolerate that for a few hundred blasts....but getting 2 at 20#...it may not last long... So to be safe, no knock is the goal.

Now, increasing fp may get rid of the knock, specially if you are lean, and your O2s are below 800mv. But if you are a tad rich already, increasing fp will not help, you must lower the boost. Today's pump gas is crap, so I would not be surprised if you have to go down to 15-16# with stock turbo before no knock is achieved...it will pull harder with no knock since the timing is not being retarded.

Oh, and more than 3 degrees at any boost level is asking for trouble. If you can hear it, you're lucky you still have the headgaskets

 

[WOOSHH]

I'm all EARS! How would I tune for no knock period? I'm not getting knock on part throttle only WOT. Will raising the fuel pressure reduce the knock?

 

[WOOSHH]

Thanks I won't be doing any WOT runs until after I re-tune.

 

[XLR8]

Raising fuel pressure MAY reduce knock if the knock was caused by the car being lean. Most likely you will need to reduce boost or timing or raise octaine (alky) to eliminate knock.

 

[WOOSHH]

That's what I think it is,just a matter of raising the fuel pressure.I had tuned her up and the plugs looked great.I"ll also keep in mind whay everyone else said.

 

[Ormand]

Be careful about "just raising fuel pressure", you may have rich knock, and raising fuel pressure will not help. If the O2 readings look like you need higher fuel pressure, THEN raising fuel pressure may help. But if the O2 readings look rich already, you probably have to lower boost, or add alky.

 

[WOOSHH]

Low fuel pressure!

I had 29psi 's of fuel pressure,raised it to 40-seems better.I'm gonna try 43 and see what happens.My adj. reg was leaking.I had went to Kirban's get together and seen a little sweat around the the flare nut going to the reg.I tightened but I should have checked the pressure.I was the only car w/ NY plates for anyone that went that day.