Pinging at 15lbs

[87we41087]

I am running 15lbs with 100 octane and i am hearing alot of pinging,( sounds like static). Is this normal? am i boosting too high for 100? If not, what is the recomended octane to boost ratio. thanks alot.

[kenmosher]

You should be fine running normal pump gas with only 15psi.

Are you sure of he accuracy of your boost gauge?

Has the motor been rebuilt (maybe with higher static compression?)

Is the fuel pump new/replaced? Check the fuel pressure under boost ... if it isin't rising 1 psi for each psi of boost, the pump is shot or the fuel filter is plugged.

Do you have any scan tool numbers?

[87we41087]

I am pretty sure the guage is accurate. The motor is rebuilt 3000 miles ago with all the goods, i have a scanmaster but for some reason it turns on for a second then shuts off. It says on the box itself, Retard degrees recall. I also have a speedpro computer with wideband installed. I will check the fuel pressure guage when running boost. I usually have my eyes on the boost pressure making sure i dont over boost. Other than that, i will have to go get it re-tuned. It hasnt seen the track or over 9 lbs in about a year. Tanks alot. :cheers:

[87we41087]

Its not the fuel pump, pressure rises w/ boost as it should.

[arthdgls]

I agree the static compression may be too high, or it may have an egr problem. egr will cause an engine to ping especially a engine already close; due to boost ,or high static compression . Also check fuel trim and make sure its not being leaned out . DOUG

[Keller]

Make sure the boost gauge isn't installed behind a restrictor. The boost may be higher that it is reading. I've seen this before. A mis-pumbed gauge can confuse you.

[PaCemkr86]

The motor was rebuilt , what pistons were used, was the block decked, heads shaved, what do the heads cc ?
have you done a compression test ? if so what were the readings ?