To support the power goals of our engine, we turned to Radium Engineering to upgrade the fuel rails, fuel pressure regulator, fuel pulsation damper, and install three pairs of Deatschwerks 1,500cc injectors.
Deatschwerks has built the most comprehensive injector offering in the industry with high impedance, low impedance, GDI, EFI, side feed and top feed injector options. With our power goals of over 600whp on E85, we will need over 7,800cc/min of fuel.
A common injector setup for this power level is the use of (2) 1,300cc primary injectors and (2) 2,600cc secondary injectors. The Billet Rotary Semi PPort Lower Intake Manifold that we are using has ports for (4) secondary injectors, giving us a lot more flexibility on injector sizing and staging. We decided to go with (6) Deatschwerks 1,500cc injectors; (2) for the primaries and (4) secondary injectors, totaling 9,000ccs/min of fuel. According to Turbosource, this should give us a little headroom to make over 600whp.
The FD RX-7 fuel injector kit from Deatschwerks feature 1,000cc primary and 2,400cc secondary injectors. We went with two pairs of 1,500cc injectors from Deatschwerks and ordered two additional 1,500cc injectors to end up with six 1,500cc injectors which totals 9,000cc of injector for our 13B REW engine.
We originally were going to use the Deatschwerks RX7 1993-1995 Fuel Rails prior to the engine fire and engine build in Part-10. With the new 4-injector Semi PPort lower intake manifold, we are not able to use this rail with (4) secondary injectors.
Taking a look at the stock FD RX-7 Lower Intake Manifold (LIM), we can see the two secondary fuel injector ports on the outer edges of the intake manifold. The smaller center two runners are for the primary ports where the factory injectors mount on the block itself. To the right is the Xcessive Manufacturing LIM that we were intending on using before building our engine with a Semi Peripheral-Port. While there are (4) injector ports on the manifold, we were going to plug off the two center ports since we did not need the additional fuel for a milder build.
Now that we built our engine with a Semi-Peripheral Port, we no longer could use the Xcessive LIM and bought the Billet Rotary LIM that has built in Semi-Peripheral ports that are fed by the secondary intake runners. Due to our greatly increased our power goals with this built motor, we now have the need to use all (4) injector ports on the lower intake manifold. The second set of secondary injectors (which could be a 3rd or -tertiary injector stage) are located on the center two smaller primary injector runners. When this 3rd stage of injectors turns on, it will add additional fuel to the primary injectors on the block, which isn’t the most ideal for creating a homogenous air:fuel mixture that enters the combustion chamber.
In the bottom-right is the new Turbosource Cast FD3S Lower Intake Manifold. This game-changing manifold can be ordered in the stock sideport configuration or the (pictured) Semi-Pport configuration with (6) injector ports and a custom fuel rail. The biggest advantage of this manifold other than having 2 more injector ports, is the significantly straighter runner design that feeds the Semi-Pport and gives the Pport its own fuel injector. This will greatly improve the fuel atomization and homogenization which should greatly improve efficiency and power. Needless to say, we will be testing this manifold in the future.
7 comments
I am still here, consuming every FD update. This thing gets more awesome with every post!
Thank you 🙂
Great series. What’s the story with aluminium fuel hardline and ethanol-based fuel? My (limited) understanding is that aluminium needs to be anodised at minimum to protect it from the jungle juice.
Yes, ethanol can corrode aluminum, particularly when it contains water or in high-concentration blends The alcohol reacts with the metal to form aluminum alcoholate, causing white, chalky corrosion, pitting, and potential, severe damage to fuel systems.
Thank you. E85 is hygroscopic and will absorb water which can lead to aluminum corrosion only if it sits for long periods of time. Raw ethanol is generally safe for aluminum. Since we will not store or let the car sit with E85, running the aluminum hard lines will not be a problem. We will also be running drums of Ignite ethanol, so that further reduces this concern.
Very cool updates.
As part of the testing you’re doing for the single pump setup, how does the cost of making the larger aluminum fuel feed line compare to adding a 2nd fuel pump and using the stock feed line?
There are many solutions to a given problem. We wanted to find the maximum power the 415 LPH DW400 fuel pump can support on a rotary without fuel line restrictions. Once we reach that point, we will turn to a brushless single pump solution based on the layout of our fuel starvation solution in the previous article.