'Premium' (unleaded) petrol in Malaysia and most parts of Asia is rated at RON97 by the petroleum companies. For 'hardcore' type enthusiasts with modified Hondas like me, it means when I modify my engine, I tune it to run with this grade of petrol. For my case, running a turbo means limiting the boost level and tuning the ignition timing map to avoid detonation. I did not lower the CR on my B16A by a lot in order to maintain good throttle response so this limits the boost level I can run at. The weather conditions in this part of the world also tends to be hot and humid which means I need to run with a compromise between the highest boost I can consistently run, and avoiding detonation by running with richer AF ratios and retarded ignition timing. So if I can get petrol with higher RON rating (at the minimum), then I can run with higher boost plus more aggressive - typically more advanced - ignition timing. E.g. I might be able to tune for optimum timing now instead of retarding for knock elimination. Directly from this, I get more power. The same situation really applies to virtually all owners of heavily modified Honda (and non-Honda) cars as well, even NA ones. The route often taken to extract very high amounts of power from heavily modifying a Type-R engine for e.g., almost certainly means a high octane petrol/fuel is required.
In order to get higher grade petrol/fuel than what the petroleum companies supplies off the pumps in their stations, one of the most popular way is to add fuel boosters - chemical additives that modifies the properties of the normal petrol. The most common modifier is to increase the octane rating of the petrol/fuel and thus 'Octane Boosters' are the most popular fuel additive used by enthusiasts.
I myself have tried numerous fuel modifiers on my Honda Integra. When I first modified my Integra (almost 15 years ago), the first additive I used was Jungle Juice. Jungle-Juice is a pure octane booster. It modifies the octane rating of petrol but by itself, is not a combustible. Meaning, engines cannot run on pure Jungle-Juice, it must be mixed with ordinary petrol/fuel. My tuner, Rennie Khoo of Aerotech supplied it from barrels and it was troublesome to use. I needed to top-up to full tank and then head over to Aerotech to add Jungle-Juice as soon as possible. This was to ensure I get the correct mixture ratio. Obviously if I delay too long, then I will end up with too much Jungle Juice when I eventually add it in.
But the benefit of driving with Jungle Juice was most additive indeed. By properly modifying the octane rating of the petrol to around RON99, power delivery from the little B16A turbo was a fantastic feeling as the engine runs super smoothly, with only a little bit of throttle response lag. Unfortunately Rennie stopped supplying Jungle-Juice when he shifted focus fully to his Dynojet Far East operations.
Consequently I also tried other types of octane boosters, including the ones commonly tried by enthusiasts and available from the supermarket shelves or from the accessory shops. But none of them worked as well as Jungle-Juice. Actually very few of them worked at all.
Some time ago, HKS introduced DHOB which stands for 'Drag High Octane (Fuel) Booster'. HKS DHOB is not an octane booster but rather is and additive that is designed to improve the combustion of the air-fuel mixture. It worked quite well on my engine. Local tuning shop Aerotech then analyzed it and it is from there that they developed Afterburn which gives similar effectiveness but at a much more affordable price. Afterburn too worked well on my engine. I dyno'ed slightly more power in a before-after direct comparison dyno test. The added bonus was that eventhough Afterburn is not an octane booster it was still able to reduce detonation. I use Afterburn whenever I attend 'track-days' in my local Sepang race-circuit and quite often for normal road use as well. Afterburn has been one of TOVA's main sponsors for the last few years.
A few months ago Tony of Cosmo Elite, the local TORCO distributor (also a TOVA sponsor) passed me a can of TORCO's latest product - a fuel additive called TORCO Accelerator. TORCO Accelerator is very different to fuel additives I tried before - Jungle Juice, DHOB, Afterburn, etc. It is actually pure high grade racing fuel concentrate. In fact, pure TORCO Accelerator alone can be used to run our car - IF the engine can cope with its ultra high octane (over 111 Octane from what I understand). The idea of TORCO Accelerator is to use it to mix with normal pump-gas (i.e. petrol from the petrol station) in varying degrees of mixing ratios. By using more or less amount of TORCO Accelerator, I can actually get the RON rating petrol I want, up to the native octane of Accelerator of course. As Accelerator is really just high-grade racing fuel, it has additional benefits of improving the quality of the fuel, not just the octane rating. This is a very nice side benefit as the local petrol quality is not that high to begin with. TORCO says using Accelerator will lower the end-burn temperature of the fuel mixture which promotes more complete burning of the fuel mixture.
TORCO's instructions on how best to use Accelerator is to simply add it to the petrol/gas to increase its octane rating. On their website, they publish a mixing chart (shown on the left) listing various mixture ratios for petrol of different octane rating and the resultant octane rating after adding Accelerator. The chart uses U.S. units (gallons and ounces) of course. Nevertheless from the charts, it can be estimated that a mixture ratio of 1% (1:100) will increase the RON rating by approximately 2.4 'points', i.e. bringing up the RON rating from 97 to between RON 99 to RON 100. Now, the typical petrol tank size in a Honda is around 50litres. And TORCO Accelerator is supplied in approximately 1-litre cans (actually 1 U.S. quart or 947ml to be exact). So adding the whole can into a full tank of petrol will give a mixture ratio of 2% and this theoretically increases the petrol octane to around RON102 !
With just 'plain' RON97 petrol from ESSO, I encountered mild to moderate knocking from 5,000rpm onwards in 3rd gear. The maximum amount of retard by the ECU was 4-degree, which to me, is quite drastic. |
With a mixture of around 330ml added to the full tank (50litres) to get approximately RON98 petrol, all detonation was eliminated. Later I actually increased the ignition timing by 1 degree across the rev-range and reduced the AF to slightly over 12:1 and got slightly more power. For this type of tuning, HONDATA S300 rules ! |
With the approx 1-litre can of TORCO Accelerator I got from Tony for testing, I tested using both approximately a quarter of a can (~250ml) as well a third of the can (~330ml) to a full tank of petrol. These gives an approximate RON increase of 1 (for RON98) and almost 2 (for approx RON99) respectively. I would have loved to try RON100 (half can to the full tank) but I only had 1 can to test. RON100 would surely have been incredible to drive !
Even with the best of my efforts, I have never been completely successful in eliminating detonation from my Integra when using the standard petrol (RON97) from the pumps. On the dyno, the engine would rev till redline without any hints of detonation. But once on the open roads I almost always get some amount of detonation from the engine. The weather conditions here in Malaysia are just too hot and humid. This necessitates me to run with a higher than normal amount of ignition timing retard than is optimum for the engine and this is because I need to cater for the worst case conditions - e.g. super hot & humid afternoons where outside ambient temperate approaches 37degC (100degF). Under such conditions, if I am to drive with anything heavier than a very light throttle, ECT will quickly creep towards the 100degC mark and IAT climbs to high-50s, often even approaching 60. This is fertile teritory for detonation - lots of it and the frustrating thing is I always get it right at the upper limit of the rev-range :- 7000-8500rpm. As all VTEC fanatics would know, doing WOT runs but aborting or even easing off when approaching the redline is probably the most un-fun thing to do !
So for my own personal evaluation criteria, the key improvement I wanted from TORCO's Accelerator is not going to be some exotic scene where I add TORCO Accelerator whilst on the dyno and gets a huge jump in power. Rather, my key objective was to reduce or even eliminate detonation in real world conditions, i.e. when doing balls-out WOT runs on the roads. So the ability of using TORCO Accelerator to improve the quality (RON rating and otherwise) of regular pump petrol so that the engine runs without any detonation was, to me, the prime measurement. If TORCO Accelerator can do that, then I am sold.
My HONDATA S300's on-board datalogging feature was priceless in my evaluation. Prior to trying Accelerator, I have made enough datalogging runs to know that I will get detonation practically everytime I do a WOT run unless its late at night or on a cool rainy day, as measured by the stock knock sensor (which is not exactly very sensitive to start with). Now, with the proper mixture of Accelerator in the fuel, datalogging results showed that I have practically eliminated detonation in all but the most extreme of weather conditions especially with ~RON99 mixture ratio. Accelerator was so effective in eliminating detonation that I eventually ran with slightly higher boost and dailed forward my ignition timing. The extra 'oomph' from the little B16A (turbo) when using Accelerator was most satisfying indeed.
For this article, to demonstrate the benefit of TORCO's Accelerator on my Integra, I datalogged the standard 'before-after' comparison WOT runs, 2nd to 3rd gear till red-line (around 8000rpm). I performed those runs over as identical conditions as possible. Basically, I pumped a full tank of petrol from one of the ESSO stations I regularly go to. This station is conveniently located on a 5 lane-highway. So after exiting into the highway, I was able to select a spot to do a 2-3 gear WOT run. Just a little way ahead is an exit where I did a U-turn. Once I re-enter the highway again, I did another 2-3 gear WOT run, obviously this time in the opposite direction. Now further ahead was another U-turn so I now get back into the original direction and section of the highway I did the 1st run. Now I turn into the petrol station and put in the approximate amount of TORCO Accelerator (I used a cleaned empty bottle from Honda's Engine Cleaner to pour the Accelerator into before pouring them into the petrol tank). Then I would exit and do the two back-to-back 2nd 2-3 gear WOT runs again.
All these runs were datalogged using the on-board datalogging feature of my HONDATA S300. From the two pairs of runs, I selected the pair with the closest match in ECT and IAT, i.e. where the conditions are as identical as possible. Obviously the 2nd pair of runs (with Accelerator added) was slightly disadvantaged as the water and air temp were slightly higher after the first runs and this is clearly seen in the HONDATA datalog charts on the left. Both ECT and IAT were in fact around 2-degrees higher in the 2nd run.
The total elimination of detonation can be clearly seen in the 2nd run, i.e. with TORCO Accelerator added to the petrol to bring the RON rating up to an estimated RON99. This is actually what I expected/hoped TORCO Accelerator would do and it did deliver with splendid results. This is important because it means on the varying and often less than kind conditions on the open roads versus on the dyno, I now have a means of being assured I get little to none detonation whenever I felt the urge to WOT the engine.
At the moment, Tony said he has not decided whether to market TORCO Accelerator here in Malaysia or not. As Accelerator is a combustible liquid, he had to ship it in as 'hazardous material' which incurs a very hefty penalty in shipping cost. This artificially inflates the selling price of TORCO Accelerator to what he feels to be a prohibitive level (approaching RM200 or USD57 per can). So, even if used for only 0.5% mixture on Hondas, it means the cost of Accelerator would be more than the cost of the whole tank of petrol ! With the economy in the state it is now, Tony is sceptical if it will get good reception in the Malaysian market.
Nevertheless, it is indeed gratifying to know that there indeed is a petrol additive which really works well. If it is available on the market, I think I might end up using it regularly despite its price. I really think it is that good.
WongKN
August 2009
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