HP IN A CAN
If you're into cars, chances are you have thrown a bottle of octane booster in your fuel tank at one time or another. But could you feel a performance increase? To find the answer, we carried out our own testing.
— Zoom Magazine - January 2004
Story and Images by Martin Donnon
Ever been caught short out in the sticks with your turbo car? You know the scenario: miles from nowhere, a tank of crappy unleaded you just fed it causes it to ping its ring off.
That's when it's time to reach into the glovebox and pull out that handy bottle of octane booster you had stored for just such an occasion. Instant ping relief in a bottle, modern octane boosters claim to do a whole lot more than simply stop the knock. It's a competitive market alright, so competitive in fact that the humble octane booster has now evolved into a street fighting, injector cleaning, fuel system revitalising wonder drug.
That sort of stuff I don't mind, but when the manufacturers of these wonder brews start to claim additional power, that's when my ears prick up.
There are many different brands and types of octane boosters on the market and the one thread that ties them all together is the promise of more engine power.
The purpose of this article was to see if there were any power gains by filling your tank with a bottle of octane booster. The twist was that with each sample we tested, the ignition timing would be advanced to take advantage of the increased knock resistance.
Whether or not these products increased fuel economy or cleaned injectors was simply outside the scope of this test. We are just interested in one thing, and that's a power gain.
None of this was my idea, though. Rather it was a directive from he who must be obeyed 'Warney'. He sent down a number of octane boosters and then sent me to the local speed shop to buy the rest. That way, we laid our hands on the stuff that any of our readers should be able to access at their local speed shop. No special cocktails made of 'unobtanium' here.
Now we had a field of 'test boosters' that we had to extract reasonable performance data from.
The first thing we had to do was lay our hands on a repeatable dyno performer.
There is also no point using a car in a testing procedure that can't back its actions with solid, accurate power runs, time after time.
There is also no point in using a car that has so much stodge in its delivery that it won't even begin to need octane help of any kind.
In other words, a turbocharged car would have to be on the menu, but not some mental, on-the-edge thing, rather a mildly boosted, stock-internal type; the kind that you and I drive almost every day.
Imagine our surprise when Ben Ellis offered up his HPI Silvia as the test mule. Why? Because it's a stock turbo/engine combination, running double the factory boost pressure and making excellent power (for what it is).
We ran the car several times to check its consistency and found that if the engine's water and oil temperatures were stabilised at both 70°C and 80°C respectively, it would make its 166.5 rear-wheel kilowatts with only a variance of some 0.5 percent. At no stage did it want to vary by more than a kilowatt, which gave us good hope that our results would be as accurate as possible.
What happens if you throw two or three bottles of octane booster into your fuel tank? Why not pour every single booster into your tank and run the engine solely off the resulting mix?
While it might sound stupid, we're pretty sure that it's more than likely crossed the minds of many people. The simple answer is that your engine probably won't fire up and run... let alone make power. Why?
There are many reasons, but the simplest one comes from understanding the true nature of an octane booster. Beyond making power and cleaning injectors and such, the primary function of any octane booster is to slow down the burn rate of the fuel and make the combustion mixture less likely to self ignite.
Overdosing with booster may result in the engine making less power due to the burn rate being too slow, or the additional included chemicals having an adverse effect on combustion.
Regardless, the logical way of making power using octane booster is to advance the ignition timing of the engine to a point higher than standard (to compensate for the slower burn of rate of the booster-affected fuel), but less than that where pinging occurs. As you have no doubt read the accompanying text, this is exactly what we did in our testing.
It would be almost crazy and take an awfully long time to add the prescribed amount of each booster to the Sylvia fuel tank for testing. We would either have to drain the tank between tests or simply run the fuel out, as adding each booster to the same tank of fuel would only prove how stupid we were more than anything else, not to mention cost a fortune.
We needed a plan - a way of using only a small amount of fuel for each test and one that gave no chance of contamination between booster samples.
Peter Hall from Willall Racing came up with the solution, carefully screwing together a complete external fuel system that held on a paltry 2L of fuel (enough we worked out for about eight or nine dyno passes, if need be), with its own dedicated feed and return system.
Consisting of nothing more than an external Vortech Trex fuel pump, a feed/return hose and some wiring, it hooked straight up to the Silvia's fuel rail inlet and return from the regulator. Happy with that, we then turned our attention to the testing.
The key to making power with any of the products we tested - and something that none of them actually tell you - is via ignition-timing adjustment.
Rather than muck around with programmable computers and erroneous knock sensors, we went back to basics and used simple crank-angle sensor adjustments for timing control and watched for the telltale 'puff' of unburnt fuel from the tailpipe to signal the onset of detonation.
There is no better way of picking up ping than watching the exhaust, I stand by that.
Testing was a fairly simple procedure. Mix up the brew of fuel and octane booster in the 2L container (using a burette and measuring jug to ensure accuracy), hook it up to the Sylvia and then perform a run at the car's 15° ignition timing setting. This would compare to our initial baseline figure for the car.
Then, all things being fine, we would 'power time' the engine by holding it at a fixed rpm point and winding ignition advance into the engine until it made the peak number. As it turned out, our adjustments were only ever very small.
Fuel used in the test was an off-the-shelf high-octane unleaded. I won't name the brand of fuel used, not through any concern as to its performance, but more to take the emphasis away from the base product itself and put it squarely on the boosters we used. None of the boosters we tested specified a particular base fuel. Instead, they all weaved their magic regardless of the original fuel stock.
Octane booster dilution was always for 'maximum strength'. Several of the products tested indicated that certain mixing ratios would give more octane or power improvement, so we went for the biggest brew possible.
However, some simply specified to 'add complete bottle to a single tank', which could give two fairly different results, say for a 30L tank-equipped Datsun 1200 and a 65L tank-equipped Commodore. So in these cases we used an assumed 60L tank capacity and worked our sums from there. Enough of the theory and mathematics, let's get down to business.
1st NF SUPER STREET (+5.0kW)
Manufacturer's Claim: "With Viscon!" whatever that might be! All the other usual claims like excellent economy and improved everything apply here.
Point of Interest: I don't like pictures of flames on my fuel additives... the two simply don't mix!
Mixing Ratio: 250ml/60L
Results: NF Super Street didn't enjoy a whole heap more ignition timing than stock, with only 2° being added before it generated peak power. The figure it came up with, 171.5rwkW, made it our winner for the day.
2nd NULON PRO STRENGTH (+4.2kW)
Manufacturer's Claim: "Boost Horsepower"
Point of Interest: Nothing particularly stands out about the Nulon product, other than the result.
Mixing Ratio: 500ml/60L
Results: While the Pro Strength didn't do an awful lot with stock ignition timing (notice the odd dip in the air/fuel ratio curve?) it did respond soundly once another 3° was screwed into place. Its 170.7rwkW was a good result.
3rd NITROX STREET LEGAL (+3.5kW)
Manufacturer's Claim: Lifts fuel rating up to 20 points. For those who read the fine print that's actually only 2 octane.
Point of Interest: Has "Advanced Manganese Technology".
Mixing Ratio: 300ml/50L
Results: Stock ignition timing showed this product to be a potent power producer, giving a maximum figure of 170.0rwkW. Not bad.
4th NITROX HOT SHOT (+3.4kW)
Manufacturer's Claim: Improves acceleration and power output by 10%. While it might do the first, it struggled a bit on the second.
Point of Interest: Big claims on the bright orange and yet again flame-encrusted bottle. It contains methanol and toluene.
Mixing Ratio: 500ml/15L
Results: Power did improve using Hot Shot, but not as much as we initially thought it might. Being the most 'aggressive' mix product on test, we figured it would give a strong result. While 169.9rwkW was good, it wasn't as good as the Street Legal.
5th WYNN'S RACE FORMULA (+2.1kW)
Manufacturer's Claim: Boosts engine power, lifts octane rating and stops engine pinging.
Point of Interest: Wynn's is a household name when it comes to octane boosters.
Mixing Ratio: 500ml/60L
Results: Wynn's proved that its booster gave some power gain by recording a peak power figure of 168.6rwkW. In this company, it placed midfield.
6th NF 1 SHOT (+2.1kW)
Manufacturer's Claim: Replaces leaded fuel. Simply pour a whole bottle of 1 Shot in your tank and no more need for AvGas. Boosts octane by 3 octane.
Point of Interest: It's a smaller package than the other NF competitor and doesn't look as flash.
Mixing Ratio: 200ml/50L
Results: Another midfield performer, with none of the zing present that its 'NF Super Street' brother displayed. 168.6rwkW once again for a midfield finish.
7th PURE POWER 33 (+0.5kW)
Manufacturer's Claim: Raises octane number by 33 points. What I want to know is, is this the same as the 20 points that Nitrox claims?
Point of Interest: One of the guys helping out on the test actually thought it was weed killer.
Mixing Ratio: 250ml/50L
Results: Marginal improvement in power over the stock baseline set-up showed 167rwkW was a positive result. It could also take an additional 4° of ignition timing without detonation.
8th 104 RACE (+0.4kW)
Manufacturer's Claim: Just about everything. Reduces internal engine wear amongst the other power-boosting properties.
Point of Interest: New easy-to-pour bottle design.
Mixing Ratio: 473ml/60L
Results: For some reason, stock timing gave the best power, which was very close to our baseline, but advancing it any further from there made the power output go backwards. Couldn't make it ping though, which is a good thing.
9th 104 STREET (-0.3kW)
Manufacturer's Claim: Probably the best known of all commercial octane boosters, the red bottle is highly visible. "Feel More Power?" is the claim.
Point of Interest: Yet more flames.
Mixing Ratio: 473ml/60L
Results:Not the strongest here, that's for sure. The 104 Street struggled to give the same power as the baseline run. Tweaking the timing a massive 5° nearly got us there.
All of the octane boosters tested performed their primary function of reducing detonation in a 'timing advanced' engine. However, the overall feeling is that in the race for more sales, the trend is to claim a little too much.
There were some standout performers here, gaining a reasonable, if not highly tangible, amount of power. While our testing procedure was fairly in-depth and not something many of you will spend the time and money to replicate, it shows that octane boosters can, and do, increase horsepower.
After all the data was collated, it was time to determine our podium finishers. Competing under our testing procedures, the winner of the day was NF Super Street with 171.5kW (a 5kW peak gain over standard), followed closely by Nulon Pro Strength with 170.7kW (a 4.2kW peak gain) and taking out the bronze was Nitrox Street Legal with 170kW (a 3.5kW peak gain).
As you can see. the results were quite close overall. At the end of the day, any horsepower gain is a good gain and one we will more than happily take.
Would the test results have varied on a different car? Maybe. However, that's not our, or your, problem. We tested within the limits of the products and gathered our data from there. These are our results, carefully measured in a controlled environment and we stick by them.