Haxby,
Thanks for starting a interesting thread.

I am not finding "from Summit racing is $1449" on the website, I see one for 3K.
Can you post the link please for me and others to view.

http://www.jegs.com/p/Holley/Holley-...38370/10002/-1

Good link Rookie! Here's the specific one I was referring to BigJim.

http://www.summitracing.com/parts/HLY-550-604/

Haxby,
What would the benefits be going to 8 individual injectors in the intake manifold runners with a throttle body. Or just using the throttle body with the 4 injectors on top like this system.
http://www.jegs.com/i/Holley/510/550...70#moreDetails

I can add 8 the injector bungs into an existing manifold and choose any CFM throttle body and go from there. I am just above the 600HP range with existing carb setup now. This might not be an option.

Also do you need some fancy ignition or can I still run my HEI.

OK .... we just did a ton of work to my MPI intakes with new fuel delivery ...should I be able to use these ecm's? I was going from mefi 1 to mefi4 .......m

Yes

My experience was not too bad, especially for a virgin EFI individual such as myself. I spent probably 30-45 minutes of total engine run time with the engine on a stand in my garage and about 5 minutes of run time in the boat on the trailer prior to the first sea trial. After an hour or two on the water I was confident enough to take the boat on a family trip. Swapping props helped tap into the higher kPa/lower rpm cells. I enjoyed the process immensely. This was all with a N/A SBC MEFI 1, yes I said it..... MEFI 1 (Merc 350 Mag EFI/MP circa 1995) application that had been completely rebuilt, stroker, heads, cam etc. This project was extremely successful.

I called a lot of folks in the industry regarding my specific application/project, including Mark, and nobody could be of any significant assistance regarding SBC applications. Mark didn't have any information or experience with SBC tunes. As it turns out the ol' MEFI 1, in spite of its age was robust and handled the extensive motor/cam/head mods well enough it was able to light right off and idle on it's own with a bone stock tune. I was able to trim the fuel tables in short order with MEFI Burn.

I was able to tune on my time and at my pace and get intimately familiar with how my boat operated. It also saved me money as all I had to do was get MEFI Burn and some bigger injectors. All my existing wiring harnesses, fuel lines, throttle linkage, sensors, ignition required no modification or fabrication. An aftermarket system would have involved significant, albeit not insurmountable modifications.

Having said all that, I'm glad you brought this Holley system to light, as in the future I probably won't ever use a carb should I tackle another project like this, but rather the Holley EFI discussed here. It looks slick and would definitely streamline the tuning process.

I think that would take the ECU out of the zero throttle map,
which is nice for tuning idle with a higher overlap cam on speed/density based systems.


Jeff

You may be able to open the throttle plates and then reset TPS voltage, worked on the GN.

What about guys with no EFI(similar to rookie's question)?

I have 502's making 575hp a piece. Running billet MSD's with 6AL boxes. Outside of the TB kit that rookie listed what other items do you need?

Would love to upgrade to EFI but not sure it's really within grasp from a cost prespective for straight up carbureted setups???

Thanks
Jim