Whos's running EFI and which brand. One better than another? Thinking of making the switch.

 

I'd like to read about this also. I know GM makes fuel injection for BB's sold in Suburbans and trucks. I think (would guess) that someone modifies them to run with high performance rectangular intake port BB heads.

Love those Big Block Head rectangular intake ports. Each one of the eight intake ports is larger than the exhaust pipe for normal car's entire engine!

 

Not worth the money on a weekend cruzer. A properly tuned carb works almost as well, and usually makes more power

 

http://www.ronsraceshop.com/products.asp?ID=620

 

I saw Zwede's Holley setup and liked the fact that he could still use his L-88 air chamber/cleaner. The air chamber wouldn't work with the above setup.

 

the edelbrock setup that summitracing is alot cheaper and you can still use the existing aircleaner setup. the part number is EDL-3550

 

Len,
I saw Zwede's car last year at the Cruise In and thought it was awesome. That sold me on his setup. I have wanted it ever since. That is surely one of my next mods that I am going to make. I love the individual injector idea.

 

for 3700 bucks id leave the carb on

 

Sorry, I couldn't bite my lip on this
Worth the money is relative, It's worth every dime if you have it to spend! I personally have not had luck with carburetors on weekend cruzers, especially Holleys. Power valves, gaskets, etc have a way of drying up when not used regularly.

A properly tuned carb does work almost as well, but only at a given condition. Change anything, like temp, altitude (O2) etc. and all bets are off

Usually makes more power? Sorry, got to raise the flag on that one

Bullshark

 

Len, I have the Holley Commander 950 (same as Zwede's) on the 69 BB. It did fit under the L88 air chamber but it was close, I had to do a little tayloring. The air chamber hood opening was about 1/2 inch to far forward so I had to do a little fiberglass work. Zwede choose to machine a little off the throttle body to gain clearance between the air chamber and the top of the drop base, I choose to modify the drop base slightly at the front to get it to fit. It's close though.

If you go with Holley, get the wideband O2 sensor setup

I love the Holley Commander ECU and its programming ability. I thought about throwing the MEFI 3 ECU on Project RamJet in the trash and upgrading to the Holley ECU, but that's a project for later.







Bullshark

 

I think the modern FI kits are very cool. It does seem like a lot of money, but when figured into the whole project cost for most of us, not so bad after all! And you get rock-solid startup reliability year-round. I haven't finished tweaking the carb on mine yet, so a decision on FI will wait awhile for me...

Also, am I the first to notice and give favorable comments on how cool those vintage finned aluminum valve covers look with all that new high-tech FI hardware? Shame to think lots of that is covered up by the air cleaner base - so nice! I see sets of M/T's on ebay and I think - $35 a pair and they look so good! Do these old covers have oil drippers in them as well?

 

Bullshark,
I must say that MEFI worked just fine on my small block, but there's nothing you can do to tweak it.
I'm running my RamJet 350 with a 730 ECM. I suppose it could also run a big block, but I don't know if GM used it on big blocks.
This switch is relatively inexpensive since you can find all the parts at recycling centers(junkyards). I did have to buy the following:
V-8 Prom ~$ 55
IAT sensor ~ 6 bucks
O2 sensor(already had)..bought 11 of them for ~15 bucks.
ECM ~30 bucks
Junkyard harness ~35 bucks...I used this to splice into my Ramjet harness. And now have a bunch of extra wire...shoulda done this ages ago.
I actually have the MEFI wired in parallel so I can switch over if my 730 ECM fails (I did this because I didn't know how well the whole experiment was gonna work out).
The expensive part was buying the Tunerpro programs and computer interface unit and blank chip(chip was only ~6 bucks)....about 330 bucks. BUT, it would have cost me this much to have the MEFI reprogrammed professionally and it would be a generic programming. And besides, I can now monitor text data, view graphs, and record data on my laptop.
And, I got to learn a little bit.

 

I agree if you have money to burn then everything is relative. I am not flaming you but there are a lot of guys here who have some pretty radical street motors (upwards of 1000 hp) and they runs carbs with no problem. Perhaps you just need to be a better carb tuner. As far as changing temp and altitude; it takes a pretty dramatic difference to put a carb much out of tune.

The reason a carb makes more power than a FI unit is due to the atomization of the fuel..tell you what rather than me rambling on here is an article from who is probably the top carb builder in the country. Take a read.

http://www.pro-system.com/scoop92102.html

 

after reading this i would have to agree and would say that the best way to go would be to just buy the metering kit from holly so you can tune your carb as best as possable. here is the part number from summit racing for the holly air fuel ratio meter HLY-534-51

 

My main concern is ease of starting if I weren't around. My wife & kids are accustomed to modern FI and just turning the key to start the car. If I'm not around, there's no way they'd know how to start the Vette, especially if it's been sitting a couple weeks. What I do now is pump the pedal 3 times and try to start. (no choke) I think you guys know the rest. It usually doesn't start right up and I have to play with the pedal to get it going. Plus it has no choke.

If they can't easily start the car, I think they'd just let it waste away or sell it, at a loss, feeling that it's a POS because it won't start.

That why I thought a move to FI would solve that concern and make the vette more "user friendly". They'd get in turn the key and start right up.

 

John, Yep, no doubt about me having to be a better carb tuner but that is part of what I like about FI. It takes one hell of alot of experience and know how to achieve the kind of performance you are talking about with all the mechanical control elements. With FI it is alot easier to play what if and change your configurations as you optimize. Reconfiguring a carb ain't easy and takes time Yes, I have heard the atomization argument, but IMHO that is far out weighed by the multiple sensors and computer control parameters that FI offers. I have read many articles that say this results in more performance across the varitety of environments our cars operated in.
A couple of quotes from your professional counterparts

Steve Johnson, BG Products: EFI makes more power, but our EFI system costs $2,400, compared to $400-450 for our Speed Demon carburetor. You only gain about 10 hp at the peak, so for a lot of guys it isn’t worth the money. Off-roaders will probably go to EFI before street machiners because it helps them overcome steep grades and vibrations that cause trouble with carbs.

Warren Johnson, Pro Stock racer: There’s no excuse for not moving to EFI. The traditional sanctioning bodies are 180 degrees reversed from reality. The "self-driving car that we can’t tech" excuse doesn’t hold up. The old guard has always used that excuse, but it’s time to bring the tech department into the 21st century. EFI is more user-friendly than carburetion and will help the more novice tuners. They can perfect the combo on the dyno, then the EFI will self-correct for atmospheric conditions. After a short learning curve, EFI actually levels the playing field. Anyone can learn to tune an EFI, but there are only about two to three legitimate carb experts that can really dial in carbs for Pro Stock.

Jim McFarland: If you boil everything down to combustion efficiency, ultimately full-sequential port-EFI systems will make the most power. Carbs are not good providers of mixture quality when tuning one cylinder at a time.


There is a good discussion of pros and cons at http://www.carcraft.com/techarticles/849/

Another one:
It's EFI Versus Carb in a Big-Block Dyno Showdown Holley vs Holley

The electrical engineer in me is most definitly biased but I respect your expertise. The article you reference was written by a carb house that has a bias also

Bullshark

 

I guess we will have to agree to disagree on the power potential between FI and carbs. A lot of the sensors you mentioned can be used with a carb as well. I do agree FI is a far superior set up and I would like it on my race motor as well. I just think it is too exspensive for the average weekend cruizer, but so is a set of 18* heads. There is no doubt FI is the wave of the future and letting it in Pro-stock would be really cool.

 

Nope. But it sure works good with a centrifugal blower!