Anyone ever used the holley projection 2d tbi system??? Seems you can pick them up pretty reasonable off e-bag. Fuel injection seems to be the way to go...... I would be bolting this up to an offy manifold. manifold heating shouldn't be much of an issue seeming as this is a summer vehicle only.

any input appreciated

Try doing a search on the TBI conversion. I have only been around this site for a little over a year and I have never heard anything good about it.
I think the problem is that you will still have the fuel distribution problems that are associated with a carb and limited tunability.

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Chris'
Autobody
Restoration
Service

The TBI and fuel system parts are fine, but the computers are mosly junk. At least the early analog systems are junk, and the digitals may be better?

I wrestled with, and barely got to work, an old analog system, with circuit mods - maybe 100 hours in it?? Upgraded to Megasquirt computer in 2003 and it's all good since then. Mine is the 670 CFM 2bbl. I would not recommend that for a mild Slant, though, only a pretty high HP one. You can also find 400 CFM TBIs, which would be a good match for a stock or somewhat built up motor.

Lou

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Home of Slant6-powered fun machines since 1988

My slant is far from mild (approx 220 hp.), so there should be no issues with the 670 cfm throttle body. Is the computer the holley kit comes with digital or analog? I am presuming digital.
Is it tuneable? I know multi port is the ideal way to go, but even TBI should be significantly better than my 390 Holley. I am mainly looking to pick up fuel mileage and throttle response. Also are there any issues with running nitrous and fuel injection that I should be aware of?

Analog and digital types both exist. DO NOT bother with the analog. I have no experience with the digital, but guess it is not much better. Driving the kit with www.msefi.com hardware is much more tunable.

I get about 1-2 mpg better than a well tuned carb. Should be no issues with nitrous except for possibly fuel distribution.

Lou

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Home of Slant6-powered fun machines since 1988

The Commander 950 seems to be a respectable ECU, but the Pro-Jection is not something I'd want to touch. There's two major problems with the Pro-Jection, both of which have only one remedy: Hook the throttle body to a different ECU.

1. It's an alpha-N system, using just throttle angle and RPM. I don't think it even corrects for air temperature.

2. The base map is for a Chevy V8. This would not be a problem if it was a fully tuneable ECU, but instead, the only way you can adjust the ECU is with five adjustable screws. There's no way you can make enough adjustment to go from a SBC to a slant six with five adjustments.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

Very well put, Matt.

Lou

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Home of Slant6-powered fun machines since 1988

The Commander 950 can set the modifiers in the ECU to use Either Alpha- N or Speed Density EFI. The base map is for a Checy V-8, but the website has basic maps that range from the 4.3L chevy to 'generic' maps based on original cam/carb and vacc. readings. I already have made a 'base map' (spark and fuel) based on current experience from the carbed Hpak build I have (and several maps based on OEM distributor maps, and the MP distributor mapping).

This ECU can drive the TBI system, but as always, unless you get the TBI cheap and just need to 'tune' the thing without pulling out a bunch of jets, springs, etc...the TBI is pretty close to a carb anyway...

On another note, I also saw a awhile back that Holley had released a single barrel TBI unit at one time to replace the OEM 1 barrel Holley Carbs, I have yet to see one, but they may pop up from time to time at swap meets as a bolt on to replace old carbs, and easy to use with the megasquirt system in the 'stockers' (I'm wondering how the old Holley 3739 300cfm units for 1982-1987 GM 4-6 cylinder cars were...).

FYI,

-D.Idiot

Like I said, the Commander's pretty decent. Both of my points were about the Pro-Jection - they may have sold a few of the early Commander systems under the Pro-Jection name, but now the Pro-Jection only comes with the alpha-N ECU with screwdriver adjustment.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

The old Pro-jection 4di and 2di systems, I agree are unworkable as TBI systems get compared to the new stuff, the 4di is now replaced by the Commander TBI system, the old 2di system still is sold, but can be retrofitted to use the Commander prom instead of the screwdriver (but would only be worth the money if the person could get the TB and other assorted parts cheap...better ways to spend quite a few hundred $$$).
Just trying to let the original poster/perusers know, so when they open up their Summit catalog they know that some things are not the same as the old days...


-D.Idiot

H'mm! Hadn't heard about that. Interesting. What do you see them going for at the meets? Seems to me a single-barrel TBI off a 2.5 Mopar could probably be made to work similarly, though the bolt pattern isn't SAE 1.5" like the old 1bbl carbs...

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Speaking of K-car TBIs, there's an interesting article in the latest Hot Rod where the guys at Spectre put a K-car TBI on a Maverick six with an adapter plate. It looks like it's around 1/2" thick aluminum plate that they used.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

I haven't seen an issue of "Hot Rod" in at least 15 years. Didn't even know it was still in print. Care to scan the article?

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I have several swapped TBI TBs in service around here...all are Rochester 220s. Thats the easy part.

It took me all day to wire my 73 Sub for TBI and all next day to plumb it.

I could have a 4.3 TB on my Ebeam manifold in a NY minute. The GM TBI wiring requires 5 wires to tap into the slant wiring(2 are ground) You get computer controlled HEI timing....O2 sensor...yada yada.

The work is in the intank pump and fuel lines.....

The mania comes from trying to get it to run right.

O2 sensors are our friend.......

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Yeah....Im the one who destroyed this rare, vintage automobile.....

I've only seen one and it had seen better days (was searching for something else to blow my funds on that day...). There used to be a 'kit' also for the 258 AMC BBD equipped engines Holley 501-2 ... The one barrel TBI was rated at 300cfm.... But these are ancient numbers.

-D.Idiot