What EFI route should I take?

[grizzlyoffroad]

OK guys....I KNOW that I want EFI on my new blazer build, but I'm not sure what route to take. I already have a built 350 in the truck, but it has a Holley carb that keeps flooding out. Should I really fool around with adapting a used TBI/TPI to my motor, or just buy one of the add on kits by Holley or Edelbrock? Which ones is better. Any thoughts? Pros/Cons??

 

[Russell]

Can you give us some specs on the engine?

Specifically about the cam if possible

 

[grizzlyoffroad]

No, sadly I can't give you details. I bought the whole truck (81 chevy 1 ton) from a guy as a parts donor for my 72 blazer. The guy just said he has about $6000 wrapped up in the motor. All I know is that it has a pretty aggresive cam(pretty good lope to it), Performer intake, Holley double pumper, small dia headers, and it sounds like it has a gear driven timing set and solid lifters. I might be able to get a hold of the guys and get more details...we will see. What are your thoughts? Thanks

 

[Hossbaby50]

The problem is most FI stock style FI systems don't respond well to large aggressive cams. Your best bet might be an aftermarket FI setup that is easily adjustable & tunable. The factory setups MAP (manifold absolute pressure) systems like all TBI & many TPI systems don't play well with non-stockish cams. Even then it requires burning of custom chips to get the motor to run right. If the cam is to aggressive it will never run right.

MAF (mass airflow) TPI is a little better since the MAF sensor allows the engine to adjust itself somewhat to different things on the motor but it is still limited to how much cam it can have & still run right.

The best setup might be a Holley or Edelbrock system that is widely adjustable for cam & motor setups.

Knowing the cam grind/specs would be the biggest help on deciding which system would best suit your needs.

Harley

 

[grizzlyoffroad]

Ya, I'm glad you brought that up. I remember talking extensively with the Crane Cam guys before picking a cam for my 95 TBI chevy(tow rig). I had to be careful how aggressive I went as to not screw up the computer. What are the differences between the Holley and Edel kits....who's got the edge?

 

[Russell]

Unfortunately, I can't really help you much with the aftermarket systems, don't know a whole lot about them. But, I do know that you will be wanting to go with one, no way a stock EFI system is going to satisfy your injection needs with an engine like that.

 

[grizzlyoffroad]

Anyone know the differences between the aftermarket kits? Who's the best?

 

[Thunder]

Edelbreock MPFI has its own programer so you are limited to the values in the programer to manage your engine. You tell them your engine specs. Edelbrock burns you a chip to plug into your ECM. Then you use the hand held tuner to fine tune it. if they get the chip wrong you have to wait til they get another chip burnt and send it to you to get things right.

Holley 950 Comander uses software and a cable to your laptop to program ECM. It is more user frendly and tuneable. between the 2 I think holley gives more bang for the buck. IMHO better parts too. To tune, you use windows based software. It has a bunch of base programs for many applications pre loaded to get your engine running. Or you can upload a program for your engine from Holly. Then you use your laptop to fine tune it. Easier than using pre burnt chips.


Another good system you should concider is :http://www.fuelairspark.com/
Their XFI system is becoming very popular. It is a highly tuneable system that can run as a batch fire or sequential fire giving almost infinite tuneability. The box can also control an electronic trans. IMO it is one of the best... Check it out!


Also i have heard accels new DFI 7 is a real good system. But i dont know much about it.

 

[Russell]

Oh, and I should mention that if you are fairly electrically sauvy, you might want to consider a megasquirt controller, I hear they are pretty amazing little ECMs too.

 

[Burt4x4]

I put Edelbrock's MPFI on my 454 and I love it. I did have alot of troubles understanding how to tune it...never ever done that before..so I took it to a Dyno shop and had then tune it on the Dyno...good thing too as my engine was running WAY too lean.

I bought the Performer not the RPM version....