Efi
Race Director
Joined: Nov 2006
Posts: 13,282
Likes: 7,863
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Well that kinda depends on who you talk to. Most on this forum like the Holley. Me, I'm running a Summit system made by Fi Tech. works really well.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,235
Likes: 9,376
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
The holley has a lot of support documentation. If you go with holley you may want to buy from efisystempro.com/ . You get free tech support and they have a great forum. The big thing is to make sure you have a good charging system and direct power from the battery. These things are touchy with RFi and low voltage. Once you get past that its pretty easy. All the information will probably translate from one system to the other, its just how you would use the controller to adjust the settings. If you are into full control of the tune you have to hook a computer to the Holley EFI whil the FiTech can do it through the handheld. I just read an article on the subtle differences. You will have to decide on your fuel plumbing. I went with the intank pump and regulator so you dont need a return line. used -6AN line up front and put the 100 micron filter up in the engine compartment. Eventually i will plumb in the return to the stock line just as a backup. If you have issues, You will learn alot about how your fuel system interacts with everything and come out with a better understanding of how a carburetor is self reliant. As an example the carb has a choke idle, then a throttle idle set screw plus the idle vacuum screw. THese relate to the throttle position sensor, the Idle air control and the throttle set screw of the EFI. All of which have to be adjusted in accordance with each other. Then once you get going there would be the power valve of the carb which is the same as the Accelerator enrich on the EFI.
Another thing they dont tell you is that the EFI, if you control the timing through it, doesnt see the base timing like a distributor so you have to add those things up. So maybe your engine likes a base timing of 15 degrees but your vacuum advance when connected bumps that up to 27 degrees, you have to tell the EFI that, then you have to set the cruise timing and the WOT timing. So if you have great timing curve with the distributor set on its own, have the EFI learn its tune with that setup. THen go in and lockout the distributor and let the EFI control the timing. Its less variables to throw at the EFI all at once.
But once you get it setup, no more pumping the throttle, no more cold engine hard starts, no more hot engine hard starts, just turn the key on to prime the fuel pump and EFI, then turn the engine over and it starts.......
Another thing they dont tell you is that the EFI, if you control the timing through it, doesnt see the base timing like a distributor so you have to add those things up. So maybe your engine likes a base timing of 15 degrees but your vacuum advance when connected bumps that up to 27 degrees, you have to tell the EFI that, then you have to set the cruise timing and the WOT timing. So if you have great timing curve with the distributor set on its own, have the EFI learn its tune with that setup. THen go in and lockout the distributor and let the EFI control the timing. Its less variables to throw at the EFI all at once.
But once you get it setup, no more pumping the throttle, no more cold engine hard starts, no more hot engine hard starts, just turn the key on to prime the fuel pump and EFI, then turn the engine over and it starts.......
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,235
Likes: 9,376
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
https://lateral-g.net/self-tune-show...%20hooked%20up.
this is one of many comparisons I found although the other story I read I cant find but the conclusions are about the same.
this is one of many comparisons I found although the other story I read I cant find but the conclusions are about the same.
Race Director
Joined: Jul 2007
Posts: 15,131
Likes: 283
From: Salt Lake City Utah
2020 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
I'm a Holley distributor so I went with a Sniper with an OE manifold kit for originality and a tank kit for the pump. Couldn't be happier.
Le Mans Master
Joined: May 2003
Posts: 8,877
Likes: 3,556
From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
As Rescue Rodgers pointed- electrical and fuel to the system.
Doing those things correctly will solve a lot of headaches with either/any system.
For the fuel system-I'm a fan of the Holley hydramat- however looking at the pricing of retrofits - it might make sense to replace the tank with one designed for EFI.
https://www.tanksinc.com/index.cfm/p...rod/prd443.htm
Doing those things correctly will solve a lot of headaches with either/any system.
For the fuel system-I'm a fan of the Holley hydramat- however looking at the pricing of retrofits - it might make sense to replace the tank with one designed for EFI.
https://www.tanksinc.com/index.cfm/p...rod/prd443.htm
Burning Brakes
Joined: May 2017
Posts: 774
Likes: 375
From: Seattle WA
The holley has a lot of support documentation. If you go with holley you may want to buy from efisystempro.com/ . You get free tech support and they have a great forum. The big thing is to make sure you have a good charging system and direct power from the battery. These things are touchy with RFi and low voltage. Once you get past that its pretty easy. All the information will probably translate from one system to the other, its just how you would use the controller to adjust the settings. If you are into full control of the tune you have to hook a computer to the Holley EFI whil the FiTech can do it through the handheld. I just read an article on the subtle differences. You will have to decide on your fuel plumbing. I went with the intank pump and regulator so you dont need a return line. used -6AN line up front and put the 100 micron filter up in the engine compartment. Eventually i will plumb in the return to the stock line just as a backup. If you have issues, You will learn alot about how your fuel system interacts with everything and come out with a better understanding of how a carburetor is self reliant. As an example the carb has a choke idle, then a throttle idle set screw plus the idle vacuum screw. THese relate to the throttle position sensor, the Idle air control and the throttle set screw of the EFI. All of which have to be adjusted in accordance with each other. Then once you get going there would be the power valve of the carb which is the same as the Accelerator enrich on the EFI.
Another thing they dont tell you is that the EFI, if you control the timing through it, doesnt see the base timing like a distributor so you have to add those things up. So maybe your engine likes a base timing of 15 degrees but your vacuum advance when connected bumps that up to 27 degrees, you have to tell the EFI that, then you have to set the cruise timing and the WOT timing. So if you have great timing curve with the distributor set on its own, have the EFI learn its tune with that setup. THen go in and lockout the distributor and let the EFI control the timing. Its less variables to throw at the EFI all at once.
But once you get it setup, no more pumping the throttle, no more cold engine hard starts, no more hot engine hard starts, just turn the key on to prime the fuel pump and EFI, then turn the engine over and it starts.......
Another thing they dont tell you is that the EFI, if you control the timing through it, doesnt see the base timing like a distributor so you have to add those things up. So maybe your engine likes a base timing of 15 degrees but your vacuum advance when connected bumps that up to 27 degrees, you have to tell the EFI that, then you have to set the cruise timing and the WOT timing. So if you have great timing curve with the distributor set on its own, have the EFI learn its tune with that setup. THen go in and lockout the distributor and let the EFI control the timing. Its less variables to throw at the EFI all at once.
But once you get it setup, no more pumping the throttle, no more cold engine hard starts, no more hot engine hard starts, just turn the key on to prime the fuel pump and EFI, then turn the engine over and it starts.......
I would also add as a plus is the much better throttle response.
But yeah, it isn't just bolting the throttle body on and going. You need 68(ish) psi of fuel pressure which means fuel pump and a regulator or return line.
I do love mine though! Sniper is the way I went.
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Melting Slicks
Joined: Aug 2016
Posts: 2,347
Likes: 1,181
From: CLEVELAND STUCK IN OHIO
2024 C3 of the Year Finalist- Modified
I’m running FiTech,,,, I have had good customer support when I needed it, but really reliable in my case. Again, as said by others, get your electrical system running perfectly, or no ones brand will ever work correctly.