The MSD injectors utilize...
The MSD injectors utilize traditional Bosch harness connectors, while the LS2 uses the more modern EV6 style. Eight of these simple adapters fixed me right up.
These parts from Nasty allowed the MSD injectors to be mounted to the FAST intake without the spacers required when using the stock fuel rail. That cleaned up the install considerably. The red and blue anodized fittings and stainless lines also added a racy look to the engine room, something D6C desperately needed. These parts look so good that I have to have more. Keep an eye out for more finery from Nasty and MSD in a future installment.
On the Dyno
With the hard parts in place, it was time to retune for the MSD injectors. On paper, this should be a simple matter of rescaling the injector sizing in the tune. Sometimes, it doesn't work out quite so smoothly, as some injectors are very non-linear in their fuel delivery across the rpm band. In the case of the MSDs, no such problems existed, so the car was right back to 430 rwhp on just the second pull. There was definitely a noticeable improvement in the idle, with a bit less lope evident.
Ten gallons of E85 were added...
Ten gallons of E85 were added to an almost empty tank to keep dilution to a minimum. One other upside of E85 is its pleasant, slightly sweet smell. While it doesn't smell quite as good as race gas, it doesn't reek like the pump stuff.
It was now time for the moment of truth. The fuel gauge was hovering at 1/16 of a tank, so there was no reason to be concerned about significant dilution of the E85 by the existing 92-octane gasoline. Ten gallons of corn juice were added, and EFI Live was once again called to action. Wittmer told me a simple arithmetic equation was all that was required to adjust the tune for the E85 now flowing through D6C's fuel system.
The first dyno pull on E85 showed a gain of 8 rwhp, with a significantly rich AFR of around 11:1. This power gain was the result of the LS2's ability to accept more timing without detonation, thanks to the additional octane provided by the ethanol mixture. A few more tune/pull cycles were completed on the Dynojet to touch up the AFR in a few spots. Interestingly, Wittmer experimented with advanced WOT ignition timing well past 30 degrees with no detonation, but the LS2 made no more power than it did at 29.5 degrees. It had given all it had, producing final numbers of 442/427.
As for the rest of the fuel system, careful observation of the Nasty Performance fuel-pressure gauge showed that the OEM pump was supplying plenty of volume to maintain 58 psi. The AFR confirmed this, hovering at 12.5-12.7 throughout the final pull.
This dyno sheet shows D6C's...
This dyno sheet shows D6C's output on gas (with the MSD injectors and Nasty fuel rails) vs. final power after the E85 conversion. Check out the massive 20hp gain through the meat of the power band.
In the end, D6C rolled out of HiTech with 22 rwhp more than it had on arrival. What's impossible to quantify is the snappy throttle response the car now has, no doubt attributable to the more aggressive timing curve. It also had a much cleaner idle, thanks to the MSD Jammer injectors and the fresh tune. Is it possible that it would now show something in the neighborhood of 473 rwhp on the LG dyno? Sure, it is. And if such an opportunity were to present itself, you can be sure I'd be all over it.
In the Real World
A few weeks prior to the E85 conversion, I competed with D6C in a unique autocross put on by the Minnesota Austin Healey Club. The course culminated with a flat-out, 3/10-mile straightaway on a rural airport taxiway. Stationed at the end of the taxiway was a course marshal with a radar gun. On 92-octane gasoline, D6C knocked out 131 mph at the top end of the straight. Pretty good, but not enough to match the Ford GT or the built-LS6-powered Porsche 914 on hand, both of which managed 132 mph. Damn.
HiTech Motorsport's new facility...
HiTech Motorsport's new facility in Elk River, Minnesota, features a state-of-the-art dyno cell with a Dynojet 248 and a massive ventilation system capable of changing the air every 9 seconds. The rest of the shop is just as impressive, with an engine dyno in the adjoining room and full machine-shop and assembly facilities. HiTech also has more than 5,000 square feet of hoist area, making it the largest and most comprehensive shop in the Twin Cities.
Two weeks after completing the E85 conversion, I again competed at this event. Much to my chagrin, the straightaway had been shortened approximately 200 feet, meaning it was essentially a quarter-mile drag strip. While this was a bummer initially, that frown quickly turned upside down when D6C posted a new corn-powered top speed of 133 mph. Yes, I picked up two mph in 200 fewer feet of real estate. That is an impressive gain. The GT was back, though, and with more power as well. This time it threw down a 136. Double damn.
Conclusion
So, is E85 right for everyone? Probably not. Is it worth considering? Absolutely, with a few qualifiers. One, you need to make sure it's available in your area. Two, you need to have access to a knowledgeable tuner or the expertise to do the work yourself. Three, you should have the ability to take advantage of E85's higher octane by running more boost, timing, or compression. And four, you should be prepared to find yourself at the center of many arguments among your gearhead friends.
In the end, there is no question that more power can be made with E85 than with unleaded pump gas. The deal gets even sweeter when you consider that you are doing something positive for the environment and the economy. Alternative fuels do not mean the end of high-performance as we know it. In fact, they can open many doors to even higher performance. That alone should make them worth the price of admission.