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I have been considering EFI for a couple of years but most of the systems I have seen can support only 500hp. Current 383 make 595HP and and might someday get a 100-150 shot. What are my options for a sytem that will support 600+HP? EFI is totally foreign to me so I have a lot to learn before taking the plunge. Drivability, tuneability, performance, mileage and cost are all factors. Maybe the economy will cooperate in 2010 and I will actually be able to do this!!

Well Tom with my first sbc 427 was dynoed at 617hp and i use the holley comander 950 with a wide band upgrade , Jim uses the throtle body and mine is a MPFI . Very drivable as jim know's...and at cruise if your not playing around i get 20 miles to the gallon. Talk you Doug F here and ask him . They are coming out with a new ECU i think i'm going to upgrade and try it in the spring.
Mark.

"HP Rating" limits with EFI would be due to any of the following:
- Injector Size (pure math, more HP you need bigger injectors)
- ECU programability - Any laptop tunable EFI should be able to be run on about any engine (that is a blanket statement but means you can't just drop a factory ECU on a high HP engine unless you have software to tune it)
- Fuel Pump Flow - same as injectors, get one to support your needs.
- These days you want one with a WB02 sensor.
- Intake/Throttle Body size - for example you can't make 600 HP with a factory TPI setup.

THat's a simple explanation.

THe new EFI Holley is releasing will have a self tuning fuel table which makes things a lot easier, along with a ton of other powerful features.

You don't have to get all the parts from the same company. You can get an ECU/Harness from one and an intake from another. That is not a problem to do.

I want to talk to you Doug about the new system your coming out with, i have the wide band right now...but i'm really interested in this new setup . Will it do much more than what i have allready with old ECU ?. I run big cylinder heads and cams with a bunch of overlap.
Mark.

Mark,
You can talk here, email me, or call me sometime after it is released. What benefits will it have for you? That is always hard. Does your car run the way you want it to right now? Does the C950 have the features you need? If the answer is yes, and you don't want to use the extras the new ECU such as a 5.7" touch screen, gauges, etc, and you're not one to have the "newest" thing, no need to change really. It will do anything you need to do with nitrous, has integrated water/meth, and more. The Dominator ECU can run drive by wire and an electronic (60/80E) transmission. As well as DIS ignition. I put twin drive by wire throttle bodies on my Nova this winter.

It will be a very nice system. The C950 was a pretty basic system, but for many it did the job. It did for me. Took me into mid 9's with dry nitrous on a 3750 lb street car and ran fine. The new stuff is just what happens when you do something new with the latest technology and a lot of improvements.

When is the anticipated release date for this new system Doug?

Isn't the holley commander 950 / 900 cfm rated for 600hp already?

The "horsepower rating" is on the complete kit as sold, and there are different versions with different injector sizes.

Mark's is the c950 / 900 cfm, but I think he has larger injectors in it.

This is all a 2 edged sword. My 900 cfm tbi was, when NIB, rated at 450 hp. With the 85 lb injectors that are on it, it will easily support 650 plus. But I gotta idle the damned thing. So I got the fuel pressure down at 16 psi from 22, and my pulse width at idle is still way way low.

Dougs Nova will be making what near a thousand HP? and with dry nitrous, he's got some big injectors on that thing. Wonder how he idles?

The idle characteristics have a lot to do with the specific injector opening curve at low pulsewidths. They vary a ton. At a certain opening time and system voltage, you get "non-linear" opening where a lower opening time might put in more fuel actually, and this makes tuning a real pain.

The 85 lb/hr TBI injectors don't have the best low pulse-width response. The 72/75 lb/hr TBI injectors that are sold can idle in a mild SBC no problem as they have a very good low pulse-width linearity.

I run 60 lb/hr injectors in my car. They have no problem at idle in my engine as it is a decently cammed big block The test would be using those in say a 350 inch turbo enigne wiht a small cam that idles at 700 RPM.

Lots of variables.

Stuff should start shipping around the end of this month (Feb). March for sure. Not all the accessories, but the ECU's and harnesses. Lots of new product to get in the pipeline.