Plugs covered in carbon can become a hot spot. A factor that can propagate detonation. But who knows for sure at this point. The VQ does propose a volatile formula for detonation. The high compression along with our crappy gas means even at low boost we're running rather close to the edge. While I am offering my opinions, I would like to hear all the possibilities. So many opinions about the VQ bottom end are negative when it comes to FI. And while it may be true, I'd like to get a better idea of how well the stock internals stand up to boost when everything is running as it should. My Turbo KA ran 6.5 PSI and on occassion it would detonate and it had no problems staying in one piece. And while I had confirmation of much higher boost levels than I chose to run, which gave me more confidence in the bottom end, the KA was also a cheap replacement as so many were swapping in the SR. I don't think I can find a complete VQ for our cars for $500 a pop.

 

lol, gone are the days of replacing a four-banger! ls pistons for a gsr motor grew on treez! you think forged pistons for our car will ever cost $350 a set? they are up to a couple a grand right? wat grade fuel u guys running that its crappy? we got 94 ox over in NY. u ever think about running additives?

 

Octane boosters tend to be a waste of time. Considering the actual volume you put in(the bottles are pretty small), the boost in octane spread out over so much fuel(20 gallons) does very little. Someone did the calculation and the effect was much less than 1 octane point. Here's a post I found on NICO about it, but I'm not sure how valid his numbers ot any technical data are, but the reasoning is correct:

http://nicoclub.com/zerothread?id=10479

 

Damn that doesn't look pretty at all. What's a steady fuel ratio for a boost G? I'm not too sure on how it works with a G, but my car runs around a 12 a/f ratio and that's perfect. First time i dyno'ed my first car to tune it, fuel ratio was at 10-11 and nothing but smoke would come out and bad #'s to boot. But yea, back to your motor. Looks like that piston took one hell of a beating, any word yet on what exactly caused it?

Devon

 

the additive i'm talkin bout is not sold on the shelf as an octane booster and effectively can boost octane over 100 depending on the dilution ratio. they keep this stuff federally regulated now since people are puttin it in their gas tanks instead of using it for what its intended purpose is.

 

Well, if there is such a thing, please share. I'm sure several people would like to know what it is you are referring to.

There are plenty of additives that could be used, but aren't for different reasons. Leaded gas is a cheap way to have high octane fuel, but it is also poison to us and the environment. It will kill any catalytic converter it runs through as well. Lets keep the discussion realistic and not so much on the unobtanium in this world.

 

u've got questions, i've got answers. its called toluene. i'm pretty skeptical about the safeness of using it on a newer car, but i know alot of turbo ppl that run it with good results. I'm pretty sure its not good for the enviornment and people to sniff away at, but if your worried about the environment, then u shouldnt be turboing or supercharging your car anyway. here's an example of raising the octane of 92 octane premium gasonline to 98.6 octane...do a 30% dilution ratio of toluene(30%) to gas(70%). since we have a 20 gallon tank, that would mean you put 6 gallons of toluene and 14 gallons of gas. Its a common ingredient in Octane Boosters in a can. 12-16 oz. will only raise octane 2-3 *points*, i.e. from 92 to 92.3. They often cost $3-5 for 12-16 oz., when it can be purchased for less than $3/gal at chemical supply houses or paint stores. Go onto an STi forum, they have discussions on this stuff and the majority of them ok the use of it. But don't believe what i say, research it.