MSD Atomic EFI
I have had the MSD Atomic EFI installed on a 70 RR (Clone) with a mild 400B for around 6 months now. Here are a few comments about the install and performance:
1. The install was as easy as it sounds. The wiring could not be more simple. The most difficult part of the install is the weld-in bung for the oxygen sensor. If you have headers they have to come off which is no easy task in itself.
2. The system requires you to install the its own coolant temperature sensor. As far as i can tell there is no way to tap into this to keep your dash instrument functional. I used the smaller hole on the passenger side of the water pump housing to install an aftermarket electrical CTS.
3. I did not use the fan drive or timing control so I have no feedback on this.
4. I would not consider this a "return-less" system as they advertise. I live in a warm climate (Charlotte, NC). I installed the system as instructed mounting the fuel pump to the right rear inner frame rail. This location is near the limit of the 24" recommendation in the instructions as well as near the muffler. I did fabricate a heat shield to go between the muffler and pump. On an 85 degree day the system vapor locked and left me on the side of I-85 for an hour.
I spoke to the technician at MSD and he reluctantly admitted that the return-less system is more for a show car that will not be driven in heat. The problem is pump cooling. With a return type system the fuel flows constantly cooling the pump and preventing vapor lock.
However, it is not difficult to make a return type system. The system requires a sending unit with a 3/8" outlet (mine had a 5'/16") so had already purchased a Spectra Premium FG68B from Amazon (
http://www.amazon.com/Spectra-Premi...rId=004&n=15684181&s=automotive&vehicleType=5) and it came with an extra vent line. The MSD tech said this should work fine as a return since it is at low pressure. Also MSD sells a regulator for under $100 (
http://www.amazon.com/gp/product/B00062ZGN8/ref=oh_details_o05_s00_i00) that works well.
I had already run the new MSD EFI line to the throttle body since it can not use the factory steel line. The factory steel line CAN be used as a return. Also you will need an adapter for the outlet of the throttle body (
http://www.amazon.com/gp/product/B000CN5JLA/ref=oh_details_o03_s00_i00) to run the line to the regulator. Note the Earl's adaptor was too large and required a small amount of the aluminum throttle body housing to be filed away (MSD - this should be included with the system). This was not difficult with a Dremmel but I didn't like doing this to the expensive system. Finally I connected the output of the regulator to the factory steel fuel line and then the other end to the new vent in the sending unit.
I have been running the system this way for several months now thru the heat of the summer and it has performed flawlessly. I know this might sound complicated but it is actually very easy just keep in mind the extra couple of hundred dollars for a new sending unit and regulator.
As far as driving with the system I have been very happy with it. There are some adjustments that can be made with the handheld but once the first configuration is complete the system is ready to run. It starts easily when hot or cold, has a smooth idle, is very responsive at all RPMs and I got a ~10-15% economy improvement.
The only complaint is that the fuel pump is rather loud. I can't hear it when at speed but when stopped I can hear the whine. I am looking for a way to quiet this down. My entire floor is covered in Dynamat but it is still too loud.
Hope all this helps and I would be happy to answer any questions.
