antoine

I'm getting a 3/4 throttle ping from my motor with supercherger on or on motor i'm using 91 octane also, i had 30 pound svo injector still same thing custom chip made still i broke the crank because of the pinging but full throttle will not ping if i stay in it.how does the egr work under boost.?

xpndbl3

iTrader: (5)

if it's pinging why did you continue driving it instead of pulling timing out of the motor?

junkcltr

iTrader: (1)

This only applies if this engine is setup using the mods from your username engine description.

With a stock PROM and modified engine you will probably have some detonation/ping. Using a non-boost PROM creates a problem due to how it does fueling. At about 60-70% throttle it will not be in power enrichment (more fuel) mode. This can cause some detonation and timing may have something to do with it. You didn't mention if you use a timing retard box & FMU for fuel.

I had a similiar problem when I went with boost using a stock 1992 MAP ECM. At about 50% throttle I could make about 3 PSI of boost and the engine would start to ping due to it using the normal (stoich) fueling. Going WOT would make the ping go away because more fuel was added and timing is pulled. The only way to see this is to datalog. I then moved onto using the GM Syclone code and it is tuned much better for part throttle and WOT throttle.

How much boost are you running? Are you using an FMU? The 30#/hr are typically only good for 375-425 HP on a typical boosted engine (.55-.65 BSFC) without an FMU.

To get to the bottom of it you need to data log using the ALDL datastream. You can build an ALDL cable for less than $20 including an RS-232 cable and battery. There is software available for free that will run on a 386 or high laptop (cheap).

junkcltr

iTrader: (1)

EGR is on or off according to road speed, TPS opening, etc.
At road speed and 3/4 throttle the EGR would be off in a stock PROM.

antoine

I had a chip made and it still had pinging problems. Will an FMU work?

antoine

also i remove 4degrees of timing if i hit it you canb hear alittle for a second.