Elec fuel injection

[B Neal]

Has anyone installed elec fuel injection on a 400 ci engine,  what injection did you use and what were the results.  I am kicking around the idea of changing from a 4 barrel to either tri power or ecec fuel injection. Like the looks of the tri power, but kind of like the idea of the fuel injection.   thanks in advance

[Frosty]

Ant went with the Holly HP system. He seemed to like it.

Someone else asked if anyone had tried the Fi-Tech system but the answer was no.

Stripes runs a Holley EFI on his 400

GTO68_455 says he has a "mega squirt 2" fuel injection  - not sure who makes that one.

SUMRCA said 2 years ago he had a  MSD fuel injection system.

 

I know they've gone out of business but at one time Barry Grant made a tri-power fuel injection system.

 

You might want to call Butler Performance - they sell Holley, F.A.S.T. and Edelbrock systems. They can probably answer most of your questions and talk price points too.

https://butlerperformance.com/c-1234728-air-fuel-efi-systems.html

 

[B Neal]

Thanks I will contact Butler, again Thanks

[Frosty]

Alway happy to help. Let us know what you decide to go with and why. We’d like to learn along with you.

[B Neal]

ok

[Stripes]

[Stripes]

The Holley X-flow 900 CFM works extremely well of a 468 Pontiac with a hyd roller cam. We made 500hp and over 550 ft lbs and have perfect cold starts, great fuel handling and better mileage than a factory carb.  We modified the stock iron intake to accept the X-flow, bolts right up with no spacer required. Factory air cleaner fits, no hood interference and much more HP than a RPM+ or Torker manifold.

Edited November 5, 2020 by Stripes

[64 kiwi boni]

hay stripes, tell us what you have done to that manifold???

it looks like you had a dual plane and have made it into a spread bore type configuration ??? but its different, your first picture is of a square bore type throttle body🙄

[Stripes]

Sure. The picture is of the same Pontiac iron spread bore intake manifold. The Holley Sniper X-flow has duel bolt holes to allow it to bolt to either a square bore manifold or a spread bore manifold. The issue with a Pontiac factory intake manifold is as shown in the photo, the restriction would have been huge if it had not been modified.  To resolve the issue, we took a sawsall and grinder and opened up the manifold to the point that the Sniper would see no restriction. This resulted in huge power increases and no need to run any power robbing spacers.

Sniper does make a 650cfm spread bore fuel injection unit. I felt since the original carb was 700cfm with the engine in stock form, a 650 cfm would restrict my HP. I realize they claim it supports 600hp, but we can discuss what that really means and doesn't mean at another time. On the dyno the 800 holley 4150 made 40 more hp than the factory carb. Lets talk about what works well.

Additionally, the factory manifold was up about 20hp over the E RPM+ and the torker, from our dyno tests when the engine was assembled. Both of these aftermarket manifolds  had hood and air cleaner clearance issues, in the car, which also caused the top of the carb to sit too close to the top of the air cleaner with drop base air cleaners. The drop base air cleaners were required to allow the top to clear the hood on a 69 firebird. Additionally, the hp loss was recorded on a dyno with no air cleaners at all!  So unless you are running over 500hp, and larger than a 468 turning up to 6000 rpm, an aftermarket intake manifold is a losing proposition.  I believe an aftermarket intake with a drop base air cleaner could be over 30hp down. To be fair, I port matched all intake ports to the D port E heads prior to dyno testing, and the iron factory intake was matched to RA4 port sizes the E heads use. Heck, even the Edelbrock intake manifolds ports sizes are way small on their manifolds when matching to their OWN out of the box D port Aluminum E heads.

Now, the engine with fuel injection appears totally stock with the air cleaner on, and the performance and drivability improvements are huge! I highly recommend the Sniper X-flow (900 CFM). Of course the best part is there is no VAPOR Lock anymore as the fuel line has 58lbs of pressure instead of a vapor lock inducing vacuum on the fuel line. Fuel pump in the tank can not be heard or seen! Wheel spin is instantaneous. Recently at a car show a bystander walked by and said, look a totally stock Pontiac 400. I found that highly complimentary since this was now a 455 bored 60, with  forged rods and pistons, a hyd roller Comp cam, RA3 exhaust manifolds, HEI, and a 900 CFM Sniper FI making over 500hp and nearly 600 ft lbs of tq.

Here are some more photos of the manifold as we modified it.

[64 kiwi boni]

Ah very nice work Stripes 👍

 now i understand what you did and i certainly see the advantages 

and good move sticking the high pressure pump in the tank, it allows it to stay cooler and quieter, i have done this my self along with allowing a surge tray to ensure the pump picks up fuel, even at wot or hard cornering 😋

 and yes it just looks stock under the hood 👍

well done mate

[Wrongway]

All I can add to that is, wow!!!

[Old guy44]

For whatever it might be worth to the discussion I have a 63 Catalina that came with the "high compression two barrel" engine. A 389 with 10:1 compression single exhaust and two barrel carb. In those years Pontiac was smoking some really foul stuff. We used to refer to them as being the only foreign car made in America. I spent months scouring the internet for a 4 bbl manifold with no success. I finally put on a 2 bbl Sniper and an HEI distributor. A vast improvement in every aspect of drivability. The biggest problem was the transmission. There is no way to make a roto hydro (slim jim) compatible with the Los Angeles freeway traffic so when the engine launched a rod I bit the bullet and installed an L83 and 6L80 trans. Best thing I ever did. Still have the sniper and HEI if any one wants one.

[Stripes]

FITECH makes a very cool 6 pack that is fuel injected. I have not personally used one but they look trick and have fuel injection! Check out https://fitechefi.com/product/go-efi-tri-power-600hp-system/

[Wrongway]

Yeahhhhh, thats cool Stripes! But pricey,,, ouch! 

[B Neal]

I have been looking at the FITECH Tri power You can get them cheaper at jegs and summit.  But according to Butler they need special offset studs to bolt to the stock Manifolds  and I can't find any aftermarket manifolds for pontiac.  Butler said theirs is going to cast about $ 5 grand.  Another thing I was wondering about is I dont think It works like the progressive linkage on a regular tripower. If it doesn't then what is the advantage of it other then looks. that is a lot of money just for looks

[Wrongway]

Ok Stripes, so they say the wiring, set up and tuning is easy. Just how easy is it? What do you have to hook up and how do you tune it?

[Stripes]

Regarding the tripower.  Thier advantage is they look cool. A single 4 barrel exceeded there performance when the rodchester was born. The fuel injection is even better.

[Stripes]

Wiring the Sniper was easy. The hardest part is removing all the wires you don't need, like nitrous, electric fan. Etc. You first take the car and have the exhaust bung placed in an exhaust pipe.  Wires to hook up: power, ground, temp sender, O2 sensor, fuel pump wire to pump. To tune. tell the system the engine size and desired idle and start it. If self tunes. I think driving it around it tuned itself 80% in about 30 minutes. The Xflow Sniper uses a external fuel regulator, I set at 60psi.

 

I bought a replacement battery that was the same size but had top and side post. I hooked the main power off the provided harness to the side terminals so I could continue to use the OE spring ring battery terminals.

[Stripes]

Running the single gas line to the front really simplified the installation. With the pump in the tank, the regulator returns everything over 60psi directly back to the tank.

Pressure line to the front covered in tape.

 

[64 kiwi boni]

2 hours ago, Stripes said:

Running the single gas line to the front really simplified the installation. With the pump in the tank, the regulator returns everything over 60psi directly back to the tank.

Pressure line to the front covered in tape.

 

That’s really interesting 

I would have thought the regulator went in line after the injection rail 

[Wrongway]

Interesting. So it does sound fairly straight forward. I thought I had read somewhere that you still had the option to plug a laptop in and make adjustments. Is that correct or is it strictly "auto tune"? I fried the ECU on my Harley a few years back. When replacing it I decided not to go back with a Harley ECU. In stead I went with a thunder max. I bought the unit that had "auto tune". But Iv since learned how to tune and write fuel maps. So I write my own maps and let the "auto tune" fine tune it. Then go in and see what the ECU has "fine tuned"  if anything and decide whether to keep or discard the changes. Does that set up allow you to tune or make changes manually?

Also, there's only one O2 sense? Does it matter which pipe you put it in? Can you add a second?

Edited January 2, 2021 by Wrongway

[Old guy44]

When I put the Sniper on my 63 I used the Holley frame mounted pump I never really heard the pump. I did however find another problem. When I had less than about 5 gal left in the tank it would slosh the fuel away from the pickup on a hard turn and the engine would instantly die. With regards to the O2 sensor either pipe is fine it just needs to read the exhaust so you want it within about 9-10 inches of the exhaust manifold. No welding is necessary it comes with a clamp on bung you just need to be able to drill the hole. Ideally you want it within about 25 degrees either side of the top line of the down pipe. I know of no way to add a second sensor. 

With regard to tuning, Yes you can interface with a laptop. There is a Holley approved shop within about 40 miles of my house and that is how they tune them. No I do not know the procedure, I never made it out there the 389 launched a rod before I ever set up an appointment.

What I do know about the Holley tune, you want to lean out the cold enrichment. If you are doing a lot of short trips particularly in cold weather you can watch the gas gauge drop. Stone cold with the air cleaner off there was a fuel fog about 6 inches above the unit. If you held a flashlight behind it it was clearly visible.

Driveabillity with the auto tune was a vast improvement over the 2bbl rochester but there were things that I believe could have been fine tuned out of it. 

I think for the driving I do I would have been  better off with a C series AFB but mine was an early 389 with the 6 bolt intake manifold and after a year of searching I never got close to finding a 4 bbl manifold. I am an old school guy and I understand tuning the Carter carb I don't know anything about tuning a fuel injection of any kind and that is a good part of the reason for my preference of a carburetur.

[Wrongway]

I get the old school part. I looked at the fuel injection off and on for the last couple of years and it just kind of scared me. I ended up buying a new 800 Edelbrock a few months ago, I just couldn't pull the trigger on the injection when looking at the cost of a system that I know nothing about and didn't know of anybody to talk to about it. Then this post came up and here we are, lol. Thanks for the info guys, Its something I'm really interested in and may look back into it again down the road after I get a few miles on her.

[Stripes]

Good luck! With the vapor lock issues we had, we didn't have a choice. While we are very happy with the Sniper, had we not had carb / vapor locking issues we would still be running a carb. As they add more alcohol each year to the gas, it gets more difficult to keep from boiling fuel in the lines, especially with increased hp which generates more heat.

[Wrongway]

Interesting. Thanks bro. I will let you know if I run into that issue.