FiTech Street EFI 400 HP Conversion - 1958 Corvette

I have converted my 1955 Belair to Edelbrock Pro-Flo EFI in 2003, and that is one of the best things i have done so far in terms of drive ability. Now having the 1958 Corvette with a non-original 1958 Rochester carburetor; i know that tuning, cold starting, summer temperatures in Texas and smell of gas in the garage will be always an issue for me.

I was aiming to buy a MSD Atomic set with Edelbrock Sump Pump; however lately noticed a new company Fitech with a new TBI and fuel pump solution at $1,200 total. They have reviews  from people who had driven them around 500 miles. It looks perfect and has more features than others such as self learning. Price is also close to half of competition.

There is no modification on the car hence no permanent damage to your originality besides the following fully and easily reversible tasks:
- heater hose insert for temp sensor
- add a return line to gas tank sending unit (i used the original steel line for fuel return, not cutting anything)
- remove the fuel pump and install a blocking plate

















So lets start with baseline:
- 283 cuin SBC with original 0890 points distributor, converted to Breakerless SE
- Stock intake manifold (smiley intake with carburetor heat up)
- 1958 Rochester 4GC 4 barrel carburetor
- Mechanical fuel pump Summit 250020, which gives 6.5-8 psi pressure compared to custom pump
- Original metal fuel line with stock glass filter

Shopping list:
- Fitech 30003 Go EFI Street 400 HP Fuel Injection at $795

 


- Fuel Pump Option 1 Fitech 40003 Fuel Command Center at $395: if you do not want to use a return line, and a buzzing fuel pump all the time, and if you have space under hood, you can use Command Center. It is powered from EFI system itself, collects the fuel from the stock pump in its sump body, and then pushes with 55 psi pressure to the EFI system. Driver side inside fender has a big room for such in my Corvette, however i do not want to install such a weight to fiber body. For this option, you would need 3/8" fuel line between mechanical and sump pump (in case the 5' hose from the 40003 set is not enough) and 1/4" fuel line for vent (Gates 27002) along with a tee (Dorman 47349) connection to existing vent line. You would also need a low pressure filter like Wix 33032 fuel filter (includes clamps)

- Fuel Pump Option 2 Fitech 40005 Frame Mount Fuel Delivery at $245. This is the in line external fuel pump solution to be used with a return line. I would not recommend running any returnless configuration with in line pump in Texas summers. This option requires that you build a return line to your tank if you don't have. The kit includes all fittings and hoses; however customization of your tank is your job. Some people remove the tank and make a complicated conversion, in that case make a 'in tank conversion'; i do not even want to empty the tank. Therefore, i ordered a new Fuel Sending Unit that i can modify while i still drive my car daily. I purchased Dorman 800-162 fuel repair line, i drilled the top of the sending unit and add this with JB weld for return. Another option is Moroso Return kit which connects to tank filling hose, however my Corvette neck does not have space for it. You will also need to block your fuel pump off, so Summit 401030 is a economical option. I am planning to use the original steel line for return, and lay the hoses for pressured fuel from tank.

- Intake Option 1: Keep the stock intake with Carter pattern. I bought Trans-Dapt 2064 adapter to convert my intake to square bolt pattern, fill the carburetor heat-up holes with 7/16" freeze plugs (Dorman 555-002, box of 10). I needed a hole for 3/8" water temperature sensor of EFI set. One idea is to use Four Seasons 84540 Tee Heater Fitting, which will enable to install 3/8 sensor on heater hose. Heater hose T will give a good reading as the water comes directly from block. Another option can be to use a thermostat housing riser with ports on it, however you should also make sure to raise the thermostat and place sensor below thermostat to measure accurately.

- Intake Option 2: Edelbrock Intake. A compatible intake with oil filler tube is Edelbrock Performer 2703, or 2701 without oil filler tube in case you want to modify your valve covers for ventilation. It says not compatible with Corvette hood, however the throttle body is shorter than carburetor itself, hence i measured and calculated that new setup Edelbrock+EFI will be 0.5" shorter than Stock Intake+Carter. Then i will need Edelbrock 7201 Intake gasket, 8008 carburetor stud kit, 8504 intake manifold bolt kit, 9300 gasket sealer and RTV silicone (Edelbrock says to use it instead of rubber front and rear gaskets). I would also bought Plastikote Engine Enamel 500F to paint the manifold for stock look. Total $300.

- ACDelco 508N 7mm spiral core Spark Plug Wire set as the EFI set cannot be used with Solid Core wires and i wanted to minimize the interference. The bad reviews i read about Fast EFI is all about interference. I did not want to cut and splice my self, and i was concerned about the length of other cables. I understand from forums that this is a good fit in length for stock route.

- Step Drill bit for 7/8" in case you will install the O2 sensor yourself instead of welding. I will replace by pipes and mufflers with aluminized ones from Corvette Central, welding breaks the Al+ coating therefore i prefer the clamp on installation. Drill needs to be short in order not to drill the other end of the pipe. I bought Ruko 101708 from Amazon for $9. You should keep a min of 10 degrees over the horizon to prevent condensation on the sensor so drilling without lowering the exhaust pipe by removing manifold connection is hardy possible, maybe with an angle drill. Also if you will clamp, clamps from the sets are very big. You will need two stainless clamps to clamp 2" or 2.5" exhaust pipe.

- 180F thermostat if you don't have any or lower F. Fitech suggested to use 180F as lower thermostats can make the EFI work in cold engine mode.

- Air Cleaner Assembly or base plate as your carburetor horn will be now 5" dia and stock will not fit. I bough a new cleaner set from Corvette Central Item # 151126 for $160

Conversion was almost flawless, and took half day for me to do everything except putting the push lock fittings into the hoses. It took another half day to do that, which was the only upsetting part for me.

So i first drained the radiator, cut the heater hose near the pump and inserted Four Seasons 84540 Tee Heater Fitting and installed the temperature sensor from the kit into it. I also replaced the thermostat at this stage to 180F

Next i used the drill but to drill a hole to exhaust pipe near the transmission and installed the O2 sensor with the kit provided and the clamps i purchased

Next, i installed the other fuel sending until i modified, used a rubber hose to connect steel line to return port and connect 8AN hose to sender port with a clamp. There is no pressure here so i think clamping would be fine.

Then i removed the fuel pump, fuel pump plate and rod; installed the blocking plate. I also removed the carburetor, steel line and glass filter between the pump and carburetor. I insterted the Dorman plugs to heating holes by hammering them down. After than i installed the Transdapt adapter. Use the gasket from the kit under the adapter, and screw the adapter to the intake by provided allen screws. Studs are also in the set for accommodating your injection kit.

Next step is to bolt down your injection system onto this adapter using the Fitech provided gaskets. At this stage, make up your mind about the cable routes for esthetic purposes. The cables are long enough so that you would not need to add any cable. However, i did not want to cut, so i bundled all the extra length and hid behind the coil. You need one connection to the fuel pump, one to the coil (-), one to the battery and one to the keyed power (if you have resistor, you can take from it, if not from + pole of the coil). Other cables run to O2 sensor and temperature sensor. One more cable is for the display/control panel, which i ran into the cockpit through the dashboard. That cable is also very long.

I then installed the filter before the pump, pump itself and micron filter after the pump by provided fittings and hoses. In my corvette your options are very limited so i connected them in series next to the frame. You need to connect a ground cable from frame to the pump.

Filters are directional, marked with arrows. Pump's connector should face the front of the car.

Here comes the problem. The push lock fittings are mission impossible. I have my both palms red and wounded trying that. I used WD40 for lubrication, but still it was very tedious to fit them fully. I used below setup for fitting the straight ones. It worked however when i came to two angled ones, i decided to heat the hose with hair dryer, which made it little easier (not much) to fit. At this point, i called Fitech twice for some questions, left voicemail  but no one called me back. 

So once these instalaltion, electric and hose connections are completed, i turned the ignition to on to feed the pump, checked for fuel leaks, setup the basic parameters on the control panel (engine displacement and cam) and then started the engine... Voilaaaa ! It started without any issues and ran very smoothly. I idled for 10 mins to make sure i reach 180F and no over temperature issues, checked for leaks or any cables/hoses near the exhaust and went for a test drive.

So everything ran fine for the moment. I will keep driving and experiencing the system.

*** Here is a late update. Do not connect the red wire directly to your battery, because then it affects the operation of your ammeter. Instead, connect the feeding red cable to the BATT (lowest) terminal of your voltage regulator. Then I have another problem. The generator and VR are rated at 30amp, and EFI draws 15amp. When I turn the headlights on, the generator cannot catch up and my battery starts helping, hence draining. I am still looking into this. New VRs are cheesy, go with NOS mechanical VRs. I will next step replace the generator with a rebuild one to seek a solution. If you are not concerned about the tach cable, then upgrade to an alternator (there are ones that look like generator)

Thank you for reading and comments !

Yavuz 

  

And here is the video of running !

FiTech Go EFI 4 600HP Self-Tuning Fuel Injection System