paradocs98

Great PCA HQ Tech Tactics video posted on YouTube earlier in the week describing gasoline octane, quality, "tiers" and additives. It's long and somewhat technical, but pretty fascinating. The discussion reinforces some long-held beliefs/practices, and debunks others. Among the highlights:

• The 10% ethanol in most unleaded gasoline is a relatively cheap way for suppliers to achieve octane ratings
• "Top Tier" gas is strongly preferred, especially for modern, high-performance engines, due its specific additive package that minimizes carbon deposits on engine internals
• An oil analysis comparing the health of a "babied," short-drive daily commuter car's engine to a track car's engine most often shows that the track car is in much better shape; the short-drive daily car's engine rarely gets up to operating temperature for a long enough time, so the pistons don't become warm enough to expand and prevent blow-by of fuel, water and contaminants into the crankcase; the track car, on the other hand, spends most of its time at high revs and optimal operating temperature (assuming it's not overheating), running in the conditions its engine was designed for--moisture in the system evaporates, and engine internals operate smoothly. The guest expert summed it up nicely: "Thoroughbreds are designed to run, not walk."
• The above leads to two important suggestions: 1) Especially in cold temps, don't let your engine idle for a prolonged period of time before driving off (idle for maybe 2-3 minutes max, rather than 10+ minutes), as idling doesn't get the engine warm enough to expand the internals and prevent piston blow-by; prolonged idling increases the incidence of unspent fuel and water washing away the oil layer between piston and cylinder liner before the piston gets warm enough to expand; this oil layer loss can then cause bore scoring; and 2) If you temporarily store your car during winter months, do not start it periodically, unless you plan to drive it for at least 20 minutes to get the internals up to temperature; just letting it idle for a few minutes every couple of weeks is one of the worst things that can be done to the engine, due to the reasons above; instead, top up the gas tank with ethanol-free fuel if possible prior to winter storage, attach the battery maintainer, and leave the car alone, unless it can be driven for a prolonged period
• A good fuel-system cleaner or additive is recommended once a year, but make sure it contains polyether amine (PEA), as this is the chemical that actually does the meaningful cleaning
• And something that I always suspected: if you see a tanker truck refilling the tanks at the gas station, keep driving--those station tanks will have all of the water and sediment from the bottom of the tank stirred up for the time being due to refilling, and you don't want that getting pumped into your car

A lot of this might be obvious to some here, but I found it pretty interesting. I posted this the other day in the 992 GT3 forum, but that was probably the wrong audience. Racing & DE is a much more technical-focused forum. Hope some find this helpful.

TXE36

Ever since the coof has been around, a lot of my vehicles sit. The street M3 in particular. I started it every few months with the battery disconnected in between. It developed a really loud, multi-cylinder valve tick doing this. Now, the S52 motor is notorious for developing valve ticks from the hydraulic lifters on the track and in autocross, but never from just sitting there idling. Last week, I actually needed to drive it, so I took it out very gingerly, never going above 1500RPM and within a 1/4 mile the tick was gone. Idling for 30 minutes wouldn't do it, but about a minute driving under 25 MPH, and it was happy. Perhaps gently jostling the motor while it was running got the air out of the lifters.

Cars like to be driven. Storage can be hell for a car.

okie981

Yes, for storage ethanol-free fuel is best, but it's also recommended to put a fuel stabilizer in the fuel, amount per the directions on the bottle. Prevents oxidation of the fuel just sitting in the tank.

Mike Roblin

^This. I have a ‘79 911 and it doesn’t get driven anywhere near enough but I always make sure it is topped off with fuel and has stabilizer in the tank before I leave the station. That way the stabilized fuel makes it all the way back to the injectors.

Combined with a battery tender the car starts up on the first try every time and runs great!

lcjhnsn

The talk was presented by Lake Speed Jr. I've seen him at the in-person Tech Tactics East events a couple times and I'm always fascinated by his talks. He is a certified tribologist (friction & lubrication expert). His Dad, Lake Speed Sr. was also a competitive Winston Cup Driver in the 80's.

paradocs98

I knew that name sounded familiar!

sparks259

Any recommendations as to which additives are the best? I have used Seafoam from time to time and my butt Dino can tell (yea right) the difference.

okie981

LN Engineering (Charles Navarro) recommends Driven Injector Defender and Liqui-Moly Jectron.

lcjhnsn

and BTW, Driven Racing Oil was founded by Lake Speed Jr. and Speediagnostix Oil Analysis is run by his daughter... small world :-)

696

There are a bunch of techrons. Any input on which is best? I know on the tech tactics that they just said to use one with a polyetheramine.

sobiloff

My tribologist prefers Berryman's B-12.