spark knock

[ntd]

Yesterday I stopped at one of my normal gas station added 3/4 tank of 93 octane drove home and parked it. Today I'm out running around and decide to let her inhale some air and at @4500 rpms it starts to spark knock and cars is pulling timing. Just so happened to have my SCT tuner handy;) pulled 2 degrees from the normal 18 degrees and stopped got some octane booster drives fine now. Seems I got some bad gas next fill up I'll set the timing back to 18 and hope that was the problem. Anyone ever had this happen sucks when you pay for premium and get economy:mad:?

[BlueFusion]

I'd go back to the gas station with the receipt and explain that their premium fuel was of lower quality and that you want the difference refunded.

It's worth a shot, atleast.

[SpartaPerformance]

Worthless effort because you can't prove it. You have to find a gas station thats busy and the gas doesn't sit. There is Mobil by my house with 12 pumps that are 90% packed all day every day and I've never had a problem.

[Zack]

I had a Vortech for years... on 2 cars.

18 degrees of timing is SUICIDE. .
Either you got the number wrong or you are just really lucky the engine is still in one piece.

[burtreynolds]

I fill up late at night and all the stations with 93 are closed at that time around here. I have been dumping about 4 gallons of VP 100 unleaded in the tank with every fill up and seems to take care of any issues. I had a little knocking on some crappy 91 I got at our local station and started doing this, seems to have fixed it.

I did go back to the station and let them know, the guy working there has a NICE termi and informed me he would never buy gas at that station. He gave me a free 52oz fountain soda however for my troubles.

[ntd]

I had a Vortech for years... on 2 cars.

18 degrees of timing is SUICIDE. .
Either you got the number wrong or you are just really lucky the engine is still in one piece.


Using my Aeroforce Gauge it measures 18 degrees on a pull and this is the first time Ive heard any detonation at all, so it seems I'm just really lucky What is the normal timing on a centrifugal setup?

[LANDY]

I run about 13* on the street

[Zack]

I never safely got more than 14 degrees in the car at 10psi.

if it doesnt detonate at WOT, that doesnt mean its not detonating at other rpm's.... the biggest problem are on these cars is with a locked converter in 4th gear.

[RR|Suki]

I never safely got more than 14 degrees in the car at 10psi.

if it doesnt detonate at WOT, that doesnt mean its not detonating at other rpm's.... the biggest problem are on these cars is with a locked converter in 4th gear.

Are you talking running that timing just right across the upper timing table sections? I'm just still curious about how other people's tables look. starting at like .7 load till full I have mine at like 8 @ 3K then stepping up to 15 by 6k @ 15psi now. not that my numbers really matter since my motor is different. Still curious though.

[Zack]

Timing always decreases as you move left to right on the table (in the higl loads and rpm's)

[ntd]

the SCT Tuners split it up in three section low, mid, and high rpm's that you can make adjustments in. I was only hearing the spark knock 4500 rpm's and up so I adjusted that table down 2 degrees (that's much as I could). I called the manager of the gas station and informed them that they may have a problem with there gas he didn't really seem to care:shake:. Call Livernios to discuss this timing issue but no answer I left a message I'm not happy

[RR|Suki]

Timing always decreases as you move left to right on the table (in the higl loads and rpm's)

I agree with that, and that's how it seemed like it should work in my mind, as boost increased timing should be falling, but for whatever reason the templates had it starting low then going up, and out of paranoia I've never deviated from that, wasn't sure if there was something I was missing.

so the lowest point for your timing is really high rpm high load. So really I'm missing all kinds of power by running small amounts of timing when the boost isn't even really kicking yet :shake: I fail.