In the last installment of the Retro 5.0 dyno testing, we made 829 horsepower and 673 lb-ft of torque, thanks to our Vortech Si-trim supercharger. That number was on Boostane Race E85, and we were being conservative, since the threat of splitting the stock block was ever-present in the dyno room. While a broken block wouldn’t have been the end of the world for the project, it would have prevented us from conducting the next test in sequence — comparing those numbers to pump 93 treated with Boostane Professional.
Boostane Race E85
First, let’s recap the details of the E85 pulls, since they happened first, chronologically. The Retro 5.0 engine is a 302 cubic-inch small-block Ford, running forged 2618 flat-top pistons, with a stock crankshaft in a stock ’93 Thunderbird engine block. A Trick Flow Twisted Wedge 11R170 Top End Kit (TFS1 cam, 170cc 11R heads, aluminum 1.6 roller rockers) caps off the short-block, with a Holley SysteMax II intake manifold. All of that runs through a set of JBA 1-5/8-inch-primary, unequal-length shorty headers. A Holley Terminator X controls the combination.
After tuning the combination ourselves at 11psi of boost, the real tuner — Tommy Keeter of KPE Racing — took over several days later and wrung out the combo, spinning the engine up to 7,000 rpm and making 17psi out of the Vortech Si-Trim supercharger. A quick note here, is that everything on the blower was exactly as it would come in a ’87-’93 Mustang kit, including the 3.33-inch blower pulley. On Boostane’s Race E85, fresh out of the drum, we made 829 horsepower and 673 lb-ft of torque, at 20 degrees of timing at peak boost. (Fun note, Keeter said he didn’t really have to touch the tuneup for those numbers, he just had far more confidence to spin everything harder. I’ll take that as a compliment.)
Our test engine for this is our Vortech-supercharged small-block Ford dubbed Retro 5.0. Stock displacement, stock block, and stock crank, meant we were a little worried about surviving the test at all.
Boostane Professional Additive With 93-Octane Pump Gas
With our E85 numbers cemented, Keeter drained the fuel system of corn juice and replaced it with some of Wichita Falls’ finest premium pump gas (no jokes here, the Sunoco 93-Octane E10 gas really has proven its mettle on this engine dyno many times over). We went to Boostane’s website to open up the mixing calculator and found that to elevate our five-gallon jug of 93 to 104 octane, we’d need 32.75 fluid ounces. The cans of Boostane Professional are 32 fluid ounces, so we decided to just use one full can. Just for a fun calculation that got us 5 gallons of right at 104 octane fuel for just under $50, or $10 per gallon — just under half the cost of 104 unleaded at the time.
Keeter started of safely, pulling a significant amount of timing and only making short pulls. It was clear quick, fast, and in a hurry that the engine was more than happy with the mixed fuel, so RPM was brought back up to match the 7,000rpm limit of the E85 pulls, and timing was slowly reintroduced. Keeter was running his normal procedure for tuning an engine, not referencing the previous results, and by the stopping point we had some interesting information.
Boostane’s Race E85 is composed of 85-percent high-purity ethanol and the remaining 15-percent is high-grade petroleum distillates that can safely be called “race gas.”
The first, was that we actually had one degree more timing in the gasoline runs than we did with the E85. The second interesting result was how much power it made. The final dyno showed 786.8 horsepower and 647.6 lb-ft of torque, on pump gas, with Boostane Professional. That’s within 42 horsepower and 26 lb-ft of torque of our Race E85 results. Now, if we’re going to compare apples to apples here, looking at these results, we probably could have pushed the E85 tuneup a bit harder. Remember though, we’re doing all of this on a stock-block and stock-crank 5.0. We were at 74 — yes SEVENTY-FOUR — pulls on this engine, and decided that discretion is the better part of valor, and called it quits.
For the pump-gas portion, we added a full 32-ounce bottle of Boostane Professional to 5 gallons of Sunoco E10 93-octane gasoline from the local station. That works out to a mixture of just under 104 octane.
Breaking Down The Results
So, what does all of this data mean? Well, as expected, the engine made more power on E85, due largely to the ethanol’s increased latent heat of evaporation, and the cooling effects it has on the air-fuel charge. We didn’t quite expect to see that we were able to run just as much timing (a little more, actually) on the pump gas plus Boostane mix, but there it is, in black and white. These results happened before our giveaway engine dyno, and were a large part of the reason we were so confident in the Boostane in that testing.
Were this engine staying together and going into the car, as-is, we would likely accept the small tradeoff in power for the convenience of keeping a few cans of Boostane Professional in the trunk and being able to fill up at any gas station in the country (obviously, having to adjust for the peasant 91-octane we get in my part of the world). However, this engine isn’t staying together, as we are planning a full teardown and inspection to see what, if anything, is wrong, and assess the overall health of the mill. So make sure to stay tuned for that, as the article and video will be released soon.
As you can see here, at about 4,400 rpm there is almost no difference between the 93+Boostane and E85. However, as both the engine speed and boost increase, the ethanol’s latent heat of evaporation advantage really becomes apparent. The final peak numbers were 829 horsepower and 673 lb-ft on the E85; 787 horsepower and 648 lb-ft on the 93-octane + Boostane Professional. That’s about 42 horsepower and 26 lb-ft difference between the two fuels.
