Nobody wants to be limited on horsepower, and as racers we do everything we can to avoid this issue. Since we’re making the switch to boost as a power adder with our Project Red Dragon we wanted to unlock our turbo’s full potential, so the decision was made to move to E85 fuel. To make this happen, we teamed up with DeatschWerks to build a killer E85 fuel system.
The gold standard in horsepower production is good old high octane race gas, which is fine for a full-on track car, but since Project Red Dragon is a street machine, we needed to look elsewhere. E85 is a popular option for performance vehicles with a power adder thanks its many wonderful properties — most notably its 105-110 octane rating. Today, we’ll cover making the transition from a gas fuel system to an E85 fuel system.
What You Need To Know Before You Buy
With so many cars carrying flex-fuel capabilities from the factory, finding E85 at the local gas station has become much easier. Now, you will still need to check the ethanol content of the pump E85 you get to be sure it is high enough to use. If you want to avoid that issue there are fuel companies that sell 85% ethanol. A good way to prevent any ethanol content issues is to add an ethanol sensor to your fuel system — we’re using one from Innovate that’s mounted before the surge tank.
E85 is different than regular gasoline, and older cars like Project Red Dragon don’t have an OEM fuel system that can deal with it. So, if you’re thinking about using E85 on a build, ever, you better make sure every fuel system part you use is rated for E85.
So, what’s so different about E85 versus regular gas? It’s the alcohol content that’s in E85…it’s going to be more corrosive than pump gas, so that means it will destroy a fuel system that wasn’t meant to use it.
Horsepower and fuel type determine the fuel load required by your engine. Using DeatschWerks fuel calculators you can determine the size of injectors and pump you will need to support your desired power output. – Kevin Cox, Deatschwerks
“In a fuel pump, where longevity and reliability are crucial, carbon commutators and encapsulated armatures are key to withstanding the corrosive nature of E85,” says Kevin Cox from DeatschWerks. “You also want to make sure the fuel injectors you’re using are designed to deal with E85.”
An average Bosch-based injector has a single stage filter, but the higher end Siemens injectors feature dual-stage magneto-mechanical fuel filters will catch ferrous contaminants during the magnetic filtration stage, and a stainless steel pleated mesh element that will catch non-ferrous contaminants from entering the engine.
Now, you need a way to move the E85 from your tank to the engine, and you can’t use just any type of hose. PTFE (Polytetrafluoroethylene, a synthetic fluoropolymer) hose is a special type of lined hose that is designed to deal with fluids like E85 that normal rubber hose can’t. The ethanol inside E85 breaks down rubber, so that’s why you need to use PTFE hose when plumbing your E85 fuel system. You’ll also need to buy PTFE fittings to go with the hose to prevent any leaks.
E85 In Boosted Applications
When we added nitrous oxide to Project Red Dragon, the fuel system needed an upgrade to keep the engine fed with plenty of fuel, so now adding another 200 horsepower, plus moving to E85 required even more changes. There is now an even larger volume requirement on the fuel system to keep enough E85 flowing to prevent any issues with the engine. This increase in volume is needed due to the makeup of E85, specifically, the chemical structure of the ethanol that’s in E85. As a fuel, E85 produces a lower amount of BTUs, so that’s why you need to use a larger amount of fuel: to make up for the lower amount of energy E85 produces. Now, what E85 can do is provide the octane we need to prevent timing issues, it also reduces the temperature inside the intake and cylinders, which lowers the overall load on the engine.
We previously mentioned that just going with straight race gas would be much easier for building a fuel system for a boosted car, but the cost of the fuel doesn’t make sense for a street car. That’s where E85 really shines for a street application — it costs significantly less than race gas while providing the same types of benefits.
“E85 has a much higher theoretical octane rating than pump gas and is available at many local gas stations. Typically, a 100-plus octane fuel will only be found at specific race fuel stations and other specialty racing stores. One hundred-plus octane racing fuel is also typically three to five times as expensive as pump E85, making it a lot less cost-effective for a street-driven application,” Cox says.
Now, you need to keep in mind that E85 isn’t a magic bullet for boost, as it does have some limitations. You really need to educate yourself about the fuel and how it works with boost so you don’t experience catastrophic engine failure.
Petroleum-based fuels have a certain amount of lubricant added to them, while ethanol does not, so you have to address this with your engine. The easiest ways to do this are to run a few tanks of high-quality gasoline through your engine…or you can use a top-end cylinder lubricant. By doing either one of these, you will ensure the engine is staying properly lubricated in all of its critical areas.
Besides supplementing your engine’s lubrication due to the lack of gasoline when using E85, there are some other items you need to keep in mind to prevent any issues.
“Ethanol is also hygroscopic, so it will absorb water out of the air and can cause corrosion or rusting of certain fuel system components. Cars should not be stored with E85 in the fuel system if possible. Also, because of the increased fuel demand with E85 over pump gas, fuel blow-by is increased in the cylinders, so when running E85 it is critical to change your oil more frequently,” Cox explains.
As well, it’s always important to be religious about your oil changes. The sheer volume of ethanol you’re dumping into the cylinders will, over tome, break down your oil. This is particuarlly important in a street car that with a lot of idle time.
Designing An E85 Fuel System For Boost
We live in a time where getting high-performance parts is easy…almost too easy, so that means you can buy the wrong items for a build before you even realize it. So you need to have a plan before you even fire up the computer and pull out the credit card to start making purchases.
“When you start looking at parts for an E85 fuel system that will be used in a boosted application, there are a few things to consider. For one, you need to have a realistic idea of what your horsepower goal is, how much boost you’re going to use, and how much fuel pressure you’re going to need. Each of these plays a part in determining the size and flow rate of each component in the fuel system,” Cox explains.
One hundred-plus octane racing fuel is typically three to five times more expensive as pump E85, that makes it a lot less cost-effective for a street-driven application. – Kevin Cox, Deatschwerks
A typical fuel system for an EFI vehicle is really simple when you think about it: you need something to pump the fuel, a filter to clean the fuel, something to regulate the fuel pressure, and injectors to introduce the fuel into the engine. Now, where things can get tricky is how you go about making sure all of these parts are sized correctly for your specific application.
“Horsepower and fuel type determine the fuel load required by your engine. Using DeatschWerks fuel calculators you can determine the size of injectors and pump you’ll need to support your desired power output. These tools make it easy to get it right the first time you order your parts,” Cox says.
When it came time to design the fuel system for Project Red Dragon we wanted to be sure it would be future-proof in case we introduce more horsepower down the road. This meant we needed to have plenty of fuel pump capacity and big injectors to keep the E85 flowing into our boosted LS engine. The goal of making around 750 horsepower to the tires might seem small by today’s standards, but we need plenty of fuel to do this right and have the ability to move even more when we decide to break the 1,000 horsepower mark.
Inside the stock tank of the Red Dragon we added a DW400 fuel pump to move the E85 from the tank to our DeatschWerks 5.5-liter staged surge tank. This pump can flow 415 LPH (at 58 psi) while pulling just 13.5 volts. This is the kind of pump that’s needed to ensure the surge tank never runs out of fuel.
A stock fourth-gen F-body fuel tank can be a real challenge to add fuel pumps to, so that’s why we decided to go a different route and use a surge tank from DeatschWerks. The 5.5-liter tank can support upwards of 2,000 horsepower with its triple-pump design. The three pumps are merged into a single -10AN outlet to make plumbing simple, plus you can wire the tank with a single-stage or dual stages for the pumps. We’re going to use two DW400 pumps inside to start that will work off a custom Racetronix wiring kit to trigger the second fuel pump when the car makes over 7-pounds of boost.
We’ll be using Deatschwerks PTFE braided lines and fittings for this fuel system; the lines have a 1,000 psi pressure rating and are capable of some fairly tight radius bends. DeatschWerks fittings are made from 6061 T-6 aluminum and are available in a variety of swivel options. We plan on using -6AN to feed the surge tank, -8AN as the main return line, and -10AN for the main feed line with this fuel system.
To keep the fuel pressure in check, we decided to use a DeatschWerks DWR2000 fuel pressure regulator. This particular regulator is rated up to 2,000 horsepower, can flow up to 1,000 LPH, and has a pressure range of 30-120 psi. After the regulator, we added a set of DeatschWerks CNC billet T6061 aluminum fuel rails for the LS6 intake (PN7-200). These come ready to be plumbed with -8AN ORB fittings on each end and will work perfectly with our return-style fuel system.
Besides the fuel pump, the fuel injectors are the most critical part of a fuel system and you need to make sure you have them sized correctly. Since we don’t want to tax the duty cycle of the injectors too much, we decided to use a set of DeatschWerks 2200CC/minute – 220 lb/hr injectors. These injectors come from DeatschWerks flow-matched within 2-percent, and have stainless steel internal parts. The injectors also use DeatschWerks EV14 Technology, which allows them to flow more, and have a faster response when under load. These injectors come with a card with information like the static flow data, pulsed flow data, and battery offset. This information will help a tuner create an accurate fuel map for your engine.
The E85 fuel system we’ve designed for Project Red Dragon will be more than enough to handle our current horsepower goals. This is one of the best ways to approach building an E85 fuel system for a boosted application: give yourself plenty of headroom to avoid fueling issues when you turn the wick up. A special thanks goes out to DeatschWerks in helping us come up with this monster-sized fuel system for Project Red Dragon. Follow along as we build Project Red Dragon into a boosted monster.