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, Fri, 31 Mar 2006 09:11:29
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The Idaho Corvette Page acquired octane booster test data from an independent research laboratory. The first test was straight 92-octane unleaded gas from a Chevron station in southern California. It tested at 96.3 RON and 88.3 MON for an R+M/2 rating of 92.3, 0.3-oct. higher than the rating on the pump. To a second sample of Chevron 92 from the same station, the lab added “104 Octane Boost”. The octane of the gasoline modified with this booster was unchanged. The lab tested a third sample of Chevron 92 and NOS brand “Street Formula”, a MMT octane booster, mixed 1:170 (12-oz. bottle in 16 gal. of gas). The results were: 96.8 RON, 88.4 MON and 92.6 R+M/2, a measurable change but, clearly, as the MON went up only 0.1-oct, not a practical improvement. NOS’ most potent booster, “Racing Formula”, another MMT-based product, in Chevron 92, tested at 98.5 RON, 90.4 MON and 94.5 R+M/2, a credible but modest improvement.
Before we get farther into testing, we should advise the reader that some of the research for this article was done in 2001, just before a change in premium unleaded fuel in the western United States from 92-octane to 91-octane. Some of the testing done for this article was with 92-octane fuel, however, some additional testing and price research was done, later, with 91-octane fuel. We apologize for the confusion but, unfortunately, we had no control over it.
That NOS octane booster lab-tested reasonably well intrigued us enough to give it a practical test. We picked a 1995 ZR1. In hot weather, the ZR1’s LT5 engine, when run on premium unleaded pump gas, will detonate under high load and, thus, will have spark retard as a result of knock sensing by the engine computer. We demonstrated this by running the car on a Super Flow SF-840 “Auto-Dyn, dual-mode chassis dynamometer at Westech Performance Group in Mira Loma, California while monitoring the engine controls data with a Vetronix Mastertech scan tester. The engine intake air temperature (IAT) was 108 degrees F. Between peak torque and peak power, the Mastertech showed 5-8 degrees spark retard on each of several dyno tests.
The car had 15 gallons of Chevron, premium unleaded in it when we added one bottle of NOS “Racing Formula”, drove it 5 miles to mix the booster thoroughly then put the car back on the Auto-Dyn. This time, in spite of the IAT climbing to 115°F, the Mastertech showed a maximum of two degrees retard and, on three of six passes, it read no spark retard at all. Run #5 was the best with power at the rear wheels up almost nine horsepower because the gasoline’s octane was, now, just high enough to tolerate full spark advance.
Clearly, boosters with enough MMT to be effective are good for occasional, limited increases in octane
If you want to make pump gas into “racing gas” for engines with 11:1 or more compression, high-boost superchargers, big doses of nitrous or any engine run on a race track at sustained high-speed/high-load; forget it. No canned octane booster in any quantity will fail to stop detonation under those conditions.
If you “read” spark plugs to tune your engine, the redish-brown MMT residue makes useful readings impossible. Levels of MMT octane boosters just moderately beyond the recommendations of booster manufacturers will foul spark plugs, damage oxygen sensors (O2S) and plug catalytic converters. High percentages of MMT contaminates engine oil and leaves hard metallic deposits in the combustion chambers, piston tops and upper end of the cylinder walls such that engine wear is greatly accelerated. Do not use them in concentrations higher than suggested by their manufacturers.
hat some automotive manufacturers believe MMT causes problems with the second generation on-board diagnostics (OBD 2) on ’96 or vehicles has us concerned about long-term use of MMT boosters in OBD2 engines. We would not use a MMT octane booster in a Corvette with OBD2. In fact, we’re not even comfortable with long-term, regular use in any engine with 02Ses and cats, OBD2 or otherwise.
posted by 65.118.125...
, Thu, 30 Mar 2006 04:30:29, Fri, 31 Mar 2006 04:16:59, Thu, 30 Mar 2006 17:24:57, Thu, 30 Mar 2006 09:27:50, Thu, 30 Mar 2006 07:09:51, Thu, 30 Mar 2006 12:03:42, Thu, 30 Mar 2006 07:43:06, Thu, 30 Mar 2006 11:42:47, Fri, 31 Mar 2006 09:11:29, Fri, 31 Mar 2006 14:35:51
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