The Stickman

Ok I am offically fed up with my carb and I am going EFI. I have a billet 4 barrel style throttle body. Now the question is what is the best intake to put under it. Getting bungs welded on and drilled out for the injectors and fuel rails will be easy. But I am sure some intake would be better for this than others. Some will have better overall design than others. So the question is which would be best?

cutlassefi

I've had both, a single plane (Holley Street Dominator) and a dual plane (Performer RPM). I'll never do another single plane for the street. The Dual plane is head and shoulders over the single. Both were done my Wilson manifolds in Ft. Laud. Everything else remained constant. The Dual plane is the way to go in my book. One of the main reasons the industry started using single plane for EFI was because they are easier to machine, all the runners are the same height etc. Plus you can tune some of the inherent defficiencies out of a single plane with some EFI controllers. Other than that the machining issue there is no reason in my book to use a sinlge plane for the street, none.

I'm an Accel Tech and dealer. Let me know when you're ready. Mine is a 72 Supreme Conv. with the original 350. It runs so much better than when it was carbureted and I now have better performance and mileage on Mid-Grade than I ever had with the carb on Premium. I'll never go back to a carb. Plus this controls my cooling fans, and locks up the converter on my 200-4R. IMO it's the way to go, nostalgic looks and 21st century driveability while retaining the original engine. If anyone tells you their EFI'd Olds didn't run much better than when it was carbureted, then they had a crappy EFI system.

HARDLUCK88

got any pics of the motor? that sounds cool.

The Stickman

Well since this thread is revived and I have new intakes which would be best. I know Cutlassefi says no to the Holley Street Dominator but would love to hear more why. I have the regular performer, the high rise performer, and the Holley Street Dominator.

cutlassefi

I'll send some pix as soon as I can. Don't have a comm cable for my digital camera right now. My beautiful new puppy liked it more than I did.

It's all going to depend on what your application is. If it's totally mild street, then the regular Performer is the one. A little hotter than that, the RPM, and more street/strip, maybe the Holley. Too many other issues with that manifold.

When I started my project years ago, I had an RPM, sold it cuz "everyone" told me to use a single plane, WRONG!! Keith Wilson himself at Wilson manifolds recommended the RPM. He asked why I sold it as I handed him my newly purchased Dominator. The reasons for most EFI companies using single planes are simple, just as I stated above. But beyond that the bottom line is Wilson, and others, are doing more and getting more HP everyday from Dual planes and they're more street friendly partially because of the more even and longer runners, especially in smaller displacement motors. If you run a batch only and/or only partially adjustable system especially, the inherent single plane issues will still be there, fuel puddling and uneven fuel distribution at low speeds. As mentioned most systems don't allow you the luxury of tuning out most of those problems. To a great degree the Accel and others like it will, however I still recommend the RPM over the Holley. Plus remember, typically you will gain about 8-10% more flow thru the manifold when going EFI cuz the air isn't laden with fuel till the very end.

There's no question in my mind there was a significant difference in overall running quality when I switched to the RPM. And even if I went mostly strip, I'm not sure I'd even go with the Holley then, probably go with the new Victor instead.

IMO the RPM is a great manifold, well suited to a wide variety of applications.

11971four4two

I Do still have the offenhauser

offy
350

midnightleadfoot

How is a dual plane better with efi.. as it is only air, not feeding the carb a signal to pull fuel from..
This should be good.


Also show any oem dual plane multi port intakes for efi..
seems to me they all have a common plem.

Gary M

The person before you resurrected an eight year old thread. cutlassefi Has a reputation for being very knowledgable on efi and engine building from what I've read. I'm tagging along to see what you find out.

cutlassefi

You're right, they do have a common plenum, with nice loooong, equal length runners. Just like a dual plane would vs a single plane.
And why do Edelbrock and others offer dual plane intakes, some of which are EFI ready, for late model LS and other engines. Hmmmmm

I have a question for you please, how many EFI projects have you done?

midnightleadfoot

Enough.. ours sing at 8500-9200 for a few hours at a time tho..
So I might not be at your level of skill

1970greensupreme

LOL, you bring back some memories for me. I should send you a pic of a sticker on one of my old tool box's, Accel Emic. I got one back in like 91 or so. I worked for Echlin who used to own EFI when they bought out DFI which became Accel's fuel injection baby. I spent a lot of time with John and Perry, they were the original owners of DFIin the 90's. God I"m getting old

1970greensupreme

From the work I did back in the 90's, I know, it was a while ago, we found that yes, manifold design cross's over off idle, ie power, mid-range, torque curve between carb and efi so the benefits of a manifold design as it pertains to those numbers you'll get the same results. Success in getting an engine to run right with EFI depends on your engine design. Some of the more radical engines we did we had to run them alpha N at idle, meaning limited feed-back due to a poor vac signal or MAF signal at or just off idle. You guys have it easier now, a wide band AFR gauge was 15K then. There were no self tuning systems, data loggers were in the 20 to 50K range.

cutlassefi

Uh huh. How about some details etc., then I can form an opinion as to how experienced you might be. I run into people that talk a big game all the time. I'm sure you can relate.

midnightleadfoot

Sorry .. What details would you like.. Details at this motorsports are not just given out..
Guess you'll have to form your own opinion..
I'm fine with that.. I care about were we run and finish on any given week end, not if a forum member thinks one way or the other..

RandyS

Got me curious too, where do you run at? How do you usually finish?

cutlassefi

Yyyyyeah, is it some sort of secret? You can't tell us what class, what engine you use, EFI system, fuel used etc., anything?
Uh huh, sure.

midnightleadfoot

http://www.nascar.com/content/dam/na...chedule_v6.pdf

Olds64

I closed the thread. No need to bash each other and argue.