SO YOU’VE ALREADY MADE the conversion from pump gas to E85 on your forced induction car and you love it. For less than the price of pump gas, E85 allows you to run race gas levels of boost for maximum performance. On top of that, turbo response and midrange torque are even better on pump E85 than on race gas. However, there were some tradeoffs. You spent a few bucks on upgraded pumps and injectors to meet the increased fuel supply demands. The changeover also decreased your vehicle’s range from 250 miles on gasoline to 200 miles per tankful on E85. These compromises were well worth the gain of an additional 10-to-20 percent horsepower. E85 is awesome. But, what if there was something even better for the times when you wanted even more power? VP Racing recently released a Red Bull energy drink infused version of E85 for racing purposes dubbed C85. While it’s not for pregnant or expectant mothers (or anyone running fuel injectors incompatible with MTBE), it will deliver significant gains for about $10 more per gallon.
Text by Michael Ferrara // Photos by DSPORT Staff // Illustration by Paul Laguette
DSPORT Issue #147
VP Racing Fuels C85 uses MTBE (Methyl Tertiary Butyle Ether) as one of its components. For a number of years, MTBE was used in gasoline sold at the pump. It has since been replaced by ethanol and other additives. Today, MTBE is only found in some blends of racing fuel (Q16, VP Import, C85.). Any fuel containing MTBE will have compatibility issues with a certain family of fuel injectors.
A few years ago, extremely high-flow, high-impedance injectors became very popular in the performance aftermarket. These injectors performed very well, especially in high-horsepower small displacement applications. However, this family of injectors was not engineered to be used with gasoline. Instead, these injectors were engineered to be used on Compressed Natural Gas (CNG) applications. As such, some of the internal components were made from polymer materials. These particular polymer materials have compatibility issues with certain chemical compounds. In the case of this family of injectors, MTBE, nitromethane or nitro propane causes the polymer to swell and the fuel delivery through the injector to be significantly decreased. Hence, those 2,200 cc/min ID 2000 injectors may be only able to deliver 1,400 cc/min or less once MTBE swells up the polymer materials inside the injector. Having an injector deliver less than its predicted fuel flow will lead to fuel lean conditions. Those fuel lean conditions can torch your engine internals and destroy your engine.
Today, a number of high-performance injector manufacturers are addressing this issue by introducing a new generation of injectors. These new injectors offer many of the performance characteristics of the CNG injectors, but utilize stainless-steel internals for superior fuel compatibility. Our Project R35 test vehicle currently features such a set of injectors. It is running a set of Injector Dynamics ID1300s that feature all stainless-steel internals. This injector has been tested with all know fuels and it offers superior corrosion resistance to alcohol-based fuels.
The Car: DSPORT Project R35
Our 2012 Nissan GT-R project vehicle sports a completely stock engine with a host of high-quality bolt-on upgrades. Exhaust, intake, fuel and engine management system upgrades allow maximum power to be extracted from the factory turbochargers. The exhaust system still includes the factory “catted” downpipes, but now those cats feed a GReddy 94mm titanium exhaust. As with any turbocharged vehicle, reducing back pressure downstream from the turbochargers is key to maximizing power, response and e iciency and that’s exactly what the GReddy exhaust accomplishes. A set of Got Boost 3.0-inch intake pipes reduces inlet restriction to the turbochargers to again aid in power, response and e iciency improvements. To meet the fuel demands of an engine making about 200 additional horsepower over stock and using an alternative fuel, fuel supply and delivery upgrades were made. A T1 Race Development fuel rail kit, ID 1300 fuel injectors and a pair of Walbro “267” E85 pumps now keep up with the delivery demands. All aspects of engine control fall under the direction of a MoTeC M1Plug-in ECU system. The MoTeC M1 system features full integration with all factory systems while providing traction control, data logging and engine control beyond the capabilities of a reflashed factory ECU.
The DSPORT Project R35 generates 629 horsepower at 18.4psi and 5,450 RPM with peak torque checking in at 663 lb- at 21.0 psi and 4,500 RPM when running on E85. For comparison, this same vehicle produced 461 horsepower and 449 lb- of torque on the same dyno when in pure stock form running on 91-octane pump gas. Our upgrades and the switch to E85 have increased peak power by 36.4 percent and peak torque by 47.4 percent. This begs us to ask…will VP Racing C85 allow us to get any more or are we already maxed out?
