964russ

Goin santa pod nxt week, quarter mile drag strip.
Is a octane boost adative worth a go?

gchristofi

Not sure it will add any go over premium unleaded..... but do share how you get on!

Paulie964

From what I've read, octane boosters barely do anything (if anything at all). You're better off spending your money on higher octane fuels.

you can use something like this to get a rough estimate of your mix http://www.bazellracefuels.com/Calcs/OC1.htm

Once your computer adjusts for higher octane, you'll get a little more "umph" out of your engine. Can't hurt to try and see if you get any better numbers on the strip before and after.

Marc Shaw

Use with care as most octane boosters (MMT or Toluene) will damage emissions-control hardware, such as spark plugs, injectors, oxygen sensors and catalytic converters.

See here.

Marc

raspberryroadster

higher octane does not add "power" - it does allow you to "run more power" (which does create more heat (& potentially cause pre ignition) and is particularly important as part of heat mgt. system with a forced induction engine for example.
pre ignition in a "normal engine" causes pings/knocks....in a race prepared engine pre ignition will result in burnt/scorched top end (pistons valves).
if your car has power adders & has been tuned to run at higher octane then you should consider them (or buy race gas....expensive, but 113 octane). if your car is operating within normal power bands no need 94 octane is adequate.

as for boost enhancers in my last car (04 cobra, all forged internals, s'charged, dyno'd at 575rwHP) i often added lucas octane boost....if i considered i would be engaging the supercharger much. calculated to get me to 98 octane.

964 series imo are not particularly well suited to drag racing.....but in the event you are interested
Car & Driver in a july 1992 road test (rather brutally) obtained some pretty outstanding numbers from a 964 cab.
their methodology, QUOTE (scroll down as cut & paste was not a success!!)


results:
0-60mph 4.9 sec
standing 1/4 mi. 13.6 sec. @ 103 mph.

good luck & looking fwd. to hearing your times....my estimate hi 14's.

Indycam

"Toluene, an aromatic circular hydrocarbon chain, is a regular component of pump gas and is available in various grades at chemical supply stores. Premium street gasoline carries roughly 3- to 5% toluene, which partially helps octane characteristics. Unocal's 100-octane race gas has almost 25% toluene."

springer3

I don't think the computer adjusts for higher octane. "Adaptation" applies to idle control only.

As a safety feature, the spark timing is retarded if the knock sensors detect detonation. You will feel a significant power loss if the safety system activates, but it should not activate unless your fuel octane is too low, or if you lug the engine on a hot day.

Paulie964

I'm not saying you will see dramatic HP gains. But if the knock sensors don't trigger, you ignition will advance. Porsche tunes its cars to run on 93. The info I got from several pro's in the industry is that this advancing results in a difference you can feel in the seat of your pants.

I'm just passing on knowledge that was passed on to me from people involved with this sort of thing for years. If my sources are wrong, then sorry about the bad info. But I feel like those involved with engine building and tuning for 20+ years would have some credible insight on the matter.

964russ

Thanks for the reply,s.
I wont bother with any adatives, dont think it will be worth the effort.
And iam not goin with the aim to break the land speed record, just for a laugh with my mates.
Ill be in good company, 94 m3 + 95 sub + 02 type-r and my 64
Which is the quickest?

boxsey911

Of course it will depend on what sort (if any tuning) the other guys will have had done on their car. But assuming not much, I would think that it will be between you and the Scoob. Good luck

Marc Shaw

"There is an optimal window of effectiveness for toluene additives. Beyond that, the increased fuel density begins to have detrimental affects on proper fuel carburetion and also retards combustion. Toluene-laden fuels burn slower and make less power on high-revving engines."

Marc

-nick

In theory, you want the lowest octane that doesn't give you preignition on your particular engine. Oddly enough, lower octane fuel actually has more BTU's = more power. In practice, you want a decent margin of safety.

The only reason to ever increase octane over the stock recommendation is if you've either raised the compression or advanced the ECU's ignition curve. Those bottles of octane boost might come in handy on a road trip where the recommended minimum octane isn't available at a filling station, or if you want to add a couple psi on a turbo for a fun run. Otherwise they're worthless.

Have fun in the 1/4. Best of luck to your clutch!

964russ

Pod was great fun
Car performed spot on, no problems either with the 3 hour drive there or the several 1/4 mile runs.
My car did ok, best run was a 14.2265! 101mph!
And out of me and my mates, the m3 was the best.
He was allways 1 or 2 mph behind, v close .

The fastest i saw was a turbo hiyabussa (i didnt spell that right)
Did the 1/4 in 6 sec, 198mph

964russ

Sum pics.

964russ

964 vs US muscle.

Who won?