Re: [Chrysler300] Octane Booster For Real Gas And 10% Alcohol Gas

Another solution is to look for ways to avoid having to resort to an “octane booster” or other additive. I’ve had very good results from using NGK racing plugs to reduce detonation (ping) on the 413s. They are a colder plug which works better with today’s crap gas (ethanol or not) and by design they tend not to foul as one might think being a cold plug. This was a suggestion several years back from Tony Rinaldi and he offered a detailed explanation from his mechanic on why it works. I even use them on my ‘63 Imperial now with 10:1 compression, even though it is not a hi-po 413. I run a Mopar electronic ignition on that engine with too much vacuum advance and timing set at a stock 10 degrees BTDC and still no ping and no fouling on 91 octane non-ethanol. On the J, with “alleged” 9.6:1 compression I had a huge problem with ping but the NGKs in an even colder range have helped a lot along with timing set at 12 degrees BTDC, maybe 1/2 degree at most from stock and 91 octane.

I would think that mixing 93 octane 10% ethanol with 91 octane pure gas shouldn’t affect detonation too much. The ethanol raises octane. My understanding is that the 93 octane is achieved by adding ethanol to 91 octane pure gas. Another possibility is to check your actual engine running temp with an infrared thermometer on those hot days. If the engine is running a little too hot, it can increase detonation. Detonation can also be worse on very dry hot days (i.e humid air is better). Just some thoughts.

Carl B.

From: mailto:Chrysler300-noreply@xxxxxxxxxxxxxxx

Sent: Friday, August 21, 2015 4:43 PM

To: 300 Club Listserver

Subject: [Chrysler300] Octane Booster For Real Gas And 10% Alcohol Gas

Hi all,

Thanks to a member in Pa., we've now located non-alcohol gas at a reasonable price about an hour away from where we live.

But now we have another problem:

1. How to keep 10% alcohol 93 octane from pinging our F's engine, especially on hot days (which is when we drive it).

2. How to keep this "100% real gas" with lower octanes from ping our F's engine too.

What to do?

Recall that all gas octane today is what the Fed. calls "research octane", not what it was when we were driving our 300's back in the 60's with no 413's pinging at all.

So even when one is lucky enough to find local non-alcohol gas it is often not today's "higher test" motor fuel. It is more often today's "regular" [say 87] or maybe a "mid grade" octane say [91.5].

Those of you who are octane boosting alcohol and/or non-alcohol gas - what works best for you with BOTH of these fuels? A product that is readily available at local car stores is best but Internet orders can work too. Let's hear from you back to the server on what you are doing that works well, especially on hot days. We can all benefit from your experiences.

Thanks a lot to everyone who contributes to this discussion.

Maybe we can somehow beat this corn/octane disaster yet!

A&G