Fuel Injection Conversion
Thread Starter
Racer
Joined: Feb 2009
Posts: 265
Likes: 0
Fuel Injection Conversion
My '71 has has a 427 small block with around 520 hp comparing it to dynoed combos I found on the internet. (My machine shop guys think closer to 550 hp) It now has a Performer RPM with an 850 Q-jet.
Is it true that adding fuel injection will increase hp by 10%? But that's not really why I'd want to do it anyway.
Looking at what's at Summit, seems I need something with at least a 1000 cfm throttle body to support over 500 hp?
Accel Ram DFI 77144 for $2700 looks good- other than that I don't see much that says it would be big enough.
I saw some throttle body only kits for around $1500 and multi-ports closer to $3000. Any big advantage to going multi-port? With throttle body injection, I'd probably have to change manifolds because of the spreadbore- don't think I have enough room for an adapter yet under the hood. So I'm thinking go all the way and get a multi-port- can sell the entire old setup for a few hundred.
What systems do you guys have and how do you like it? Thanks.
Is it true that adding fuel injection will increase hp by 10%? But that's not really why I'd want to do it anyway.
Looking at what's at Summit, seems I need something with at least a 1000 cfm throttle body to support over 500 hp?
Accel Ram DFI 77144 for $2700 looks good- other than that I don't see much that says it would be big enough.
I saw some throttle body only kits for around $1500 and multi-ports closer to $3000. Any big advantage to going multi-port? With throttle body injection, I'd probably have to change manifolds because of the spreadbore- don't think I have enough room for an adapter yet under the hood. So I'm thinking go all the way and get a multi-port- can sell the entire old setup for a few hundred.
What systems do you guys have and how do you like it? Thanks.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Unless your carb is not performing up to its fullest potential fuel injection will not add any HP at the top end. Now mid range and driveability will be increased a lot. I went to fuel injection last year and never looked back. I will not run a carb again. I have a pretty good combo that produces in the low 500HP range similar to yours. With the carb adjusted to peak performance it ran well at WOT. Cruising and cold starting and driving it would sometimes not agree with all circumstances. Now with a good fuel injection system it runs perfect no mateer if it is 20 degrees or 100 degrees. Always starts and runs great. Driving around the throttle response is much better. WOT is just like it was with the carb. I run a Mass Flo system on mine. Is it the best, I can't say but it is way better than any carb system I have driven.
Thread Starter
Racer
Joined: Feb 2009
Posts: 265
Likes: 0
Unless your carb is not performing up to its fullest potential fuel injection will not add any HP at the top end. Now mid range and driveability will be increased a lot.
Do you mean mid-range hp will increase? That'd be cool- it doesn't spend a lot of time at redline anyway for a street car.
I went to fuel injection last year and never looked back. I will not run a carb again. I have a pretty good combo that produces in the low 500HP range similar to yours. With the carb adjusted to peak performance it ran well at WOT. Cruising and cold starting and driving it would sometimes not agree with all circumstances.
Sounds like mine now- really can't complain much- it runs really well. Stumbles some when it's cold, and seems hard to modulate wider throttle openings- seems mostly like all or nothing making it too easy to spin the tires at higher rpm's in 1st and 2nd gear.
Now with a good fuel injection system it runs perfect no mateer if it is 20 degrees or 100 degrees. Always starts and runs great. Driving around the throttle response is much better.
That's the kind of stuff I'm looking for- must be running out of stuff to do the car!! Good problem to have.
WOT is just like it was with the carb. I run a Mass Flo system on mine. Is it the best, I can't say but it is way better than any carb system I have driven
What model #, price and where to find? Thanks.
Do you mean mid-range hp will increase? That'd be cool- it doesn't spend a lot of time at redline anyway for a street car.
I went to fuel injection last year and never looked back. I will not run a carb again. I have a pretty good combo that produces in the low 500HP range similar to yours. With the carb adjusted to peak performance it ran well at WOT. Cruising and cold starting and driving it would sometimes not agree with all circumstances.
Sounds like mine now- really can't complain much- it runs really well. Stumbles some when it's cold, and seems hard to modulate wider throttle openings- seems mostly like all or nothing making it too easy to spin the tires at higher rpm's in 1st and 2nd gear.
Now with a good fuel injection system it runs perfect no mateer if it is 20 degrees or 100 degrees. Always starts and runs great. Driving around the throttle response is much better.
That's the kind of stuff I'm looking for- must be running out of stuff to do the car!! Good problem to have.
WOT is just like it was with the carb. I run a Mass Flo system on mine. Is it the best, I can't say but it is way better than any carb system I have driven
What model #, price and where to find? Thanks.
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
Do a search on the theory behind carbs, throttle body FI, MPFI, and SPFI. Carbs meter best by hi flow, that;s why hp levels are usually similar. Sequetial port makes amazing differences with low rpm torque. My LS2 400hp motor gets 26mpg on the hiway, starts every time, never fowls plugs, etc.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
After driving some LS motors I decided I needed fuel injection. If I did not have so much money in my motor I would have put in a LS motor. I decided the next best thing was to fuel inject my motor. I looked around and thought why not try the Mass Flo. It is a multiport system and it is based on (bad word here) a Ford system. That does not bother me.
I too wanted to try something different and play with the fuel injection. It has been great. The mid range and throttle response was way improved. I have since put in a roller cam and bigger heads to make even more power. I need to get to the dyno or the strip now to see what it will do.
The cost is expensive but what isn't anymore. The system was around 2900 and with the fuel system upgrades and plumbing it was at about 3500 or so. Worth every penny to me. I was not worried about fuel economy or what the payback would be. I wanted to get in and fire it up and drive it hard. Mission accomplished.
Here is their site.
http://www.mass-floefi.com/
I too wanted to try something different and play with the fuel injection. It has been great. The mid range and throttle response was way improved. I have since put in a roller cam and bigger heads to make even more power. I need to get to the dyno or the strip now to see what it will do.
The cost is expensive but what isn't anymore. The system was around 2900 and with the fuel system upgrades and plumbing it was at about 3500 or so. Worth every penny to me. I was not worried about fuel economy or what the payback would be. I wanted to get in and fire it up and drive it hard. Mission accomplished.
Here is their site.
http://www.mass-floefi.com/
