87 octane + 9-1 pistons + 12# boost on my rx1...

[mulot30th]

For those who read my last thead on gaz starvation, I just changed fuel pump for a new one and was out for testing tonight...

Equal 4 molten pistons...

No knock at all on knock sensor, no blown gasket, nothing...



Only thin I noticed is after 7 or 8 seconds WOT it would consistently lose about 1000 rpm (probably due to high enough temperature tu melt pistons) --- about same time it previously starved for gaz with my old fuel pump.

And as soon as I let off throttle, I could go wot again and rpms went back to normal 10500rpm but quickly falling down to 9000 again.


I stopped engine, check in engine bay for anything wrong and all is okay so I did a quick last trial wot run so see if it would do it again...


When I re-started engine I noticed it was much harder to start than normal (9-10 seconds crank time).

I alsonoticed it was much less immediate throttle response ... from a idle start is now take about 1 full seconds to reach 10500 rpm instead of almost instantly... so something must be wrong that I though.


Back in my garage... I pulled the spark plugs... 2 of them were wet to molten alunium the other two were completely gray (molten aluminium).

a quick compression test revealed 90-115-120-90.... instead of usual 145 to 150 across the board....


so all 4 pistons are definitely toast..



so do not even try 87 octane at 12# boost even on 9-1 its a very bad idea.

I should have stayed with 91 or 93 octane

 

[BOOST]

Why would you even try that low of octane??? Sounds like your nock sensor may have been setup so it would not read your nocks???

 

[mulot30th]

Why would you even try that low of octane??? Sounds like your nock sensor may have been setup so it would not read your nocks???

only to insure max hp out of it... I was assuming knock sensor would tell me if knock heppened..


I guess there was to high conbustion temperature with no knock...


anyway... that was a so stupid error....

 

[Need for Speed 2]

The knock sensor is a bad crutch to lean on. Moluth you know better than that you were just pushing the outer limits werent you. also with 87 fuel it probly was so fast you or the sensor could not keep up but 7-8 seconds wide open ?

 

[visegrip]

i don't understand why people want to turn up the boost and run cheap fuel if ya can't afford the fuel don't boost .

 

[gsxr]

At least start with good fuel !!!!!
I don't like 87 in a stocker.

 

[Turk]

I had 10:1 pistons plus an extra head gasket & no way no how would i run regular(87) in mine at even low boost. If you didn,t damage the head you should walk away from this at under $1500!

 

[mulot30th]

i don't understand why people want to turn up the boost and run cheap fuel if ya can't afford the fuel don't boost .

Not because I can't afford good fuel, I have a 54 gallons c16 barrel on my garage...

I only wanted to extract every last ponies from it...

But what buzzz me the most is the fact it never knocked....

 

[TurboJamie]

If its a parker box, which has adjustable sensetivity I wouldn't trust it for anything.

 

[HYFLYR]

Your ballzy, I wouldnt have done that.

Is every last ponie like you say worth a 1500-2k bill for pistons? Not to me, i would rather pay a few extra bucks for gas and peace of mind and maybe miss out a few hp.

 

[rxrider]

Ouuuucccchh - that hurts. Hope you have not done harm to the valves and cylinder walls.

 

[sledheadgeorge]

Thats why I turn down the boost when I go on a long trip. 6-8 lbs max, you never know what kind of fuel you get when you go on a trip.

 

[HURRICANE]

I have absolutely NO USE for the parker knock box AT ALL.Cannot rely on it at all

 

[lakercr]

I have absolutely NO USE for the parker knock box AT ALL.Cannot rely on it at all

I talked to FJO about incorporating a knock sensor into their wideband last year. Technically, it would be very simple to do. However, unless the actual sensor is designed for the harmonics of the engine it will be used on, the end product will not be a useful tuning aid. End of the day, they wouldn't put their name on it.

 

[rxrider]

I have absolutely NO USE for the parker knock box AT ALL.Cannot rely on it at all

HURRICANE - Thank you for putting it straight. I have been thinking of buying the Parker Knock Box, I'll be better off spending my dollars on good fuel then I guess.