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Traditional Carb Vs. EFI Systems

  
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Traditional Carb Vs. EFI Systems

 
chrisaustria chrisaustria
User | Posts: 187 | Joined: 01/13
Posted: 01/11/14
09:36 AM

Hi!

Is it worth spending that much money on an EFI instead of a carb?
I now use a Holley Ultra DP 750cfm with my 464 engine in the GTO.

I was already told about the benefits of an annular booster carb compared to my downleg style carb. But I'd like to know more about the EFI systems to make a decision.
For example a Holley Terminiator EFI: http://www.summitracing.com/parts/hly-550-405/overview/

Can I expect a big benefit compared to my Holley DP? And what about the cfm rating, is 950cfm too much with the EFI? There will be no choke as well, but it won't need one I guess to support the engine with the proper AFR?  

shyrgfuh3 shyrgfuh3
Enthusiast | Posts: 450 | Joined: 11/13
Posted: 01/11/14
09:40 AM

hi chris i'll transfer info over later.

when you hit the send button and it says in black print that there was an error etc, your post actually goes through. just go to new topics and it will be there. it is just a quirk of the site.  

shyrgfuh3 shyrgfuh3
Enthusiast | Posts: 450 | Joined: 11/13
Posted: 01/11/14
09:46 AM

Hi, Chris;


I'm not into that fancy stuff so I'm not much help to part of the question, but if you compare it to a non annular straight leg booster carb, the efi you are interested in is a big improvement if it is sized correctly. I suggest contacting holley directly for this type of info.

If you frequently change elevation by more than 1000 ft while driving, it will perform much better overall than a non efi.  

chrisaustria chrisaustria
User | Posts: 187 | Joined: 01/13
Posted: 01/11/14
09:55 AM

Thats a good point. I live at 1500ft.

The car could see a max of 6500ft but that won't happen often.
Most of the time the elevation is between 1500 and 4000ft if I start to drive the car longer distances with the new transmission.

There are very nice roads to drive that lead from 1500 to about 2600ft that I drive often, even with my current setup. On these roads I couldn't feel much of a difference.  

idrivejunk idrivejunk
Addict | Posts: 5139 | Joined: 12/09
Posted: 01/11/14
10:00 AM

Chris, a partner magazine to this one, "Car Craft" has MSD, FAST, Holley and Edelbrock self-learning systems compared side by side, installed on a Nova in the March 2014 issue. I don't know how long before that info will be up on the site, but it sure is a good comparison that would be useful to you now. The issue features a red Chevelle on the cover, and its also injected. The owner said there wasn't much difference from a carb but EFI just didn't slop fuel everywhere. There are a lot of folks out there unhappy with their EFI choices, so again you do well to ask lots of questions.

One observation I have made is that the Aeromotive name always seems to be mentioned in quality fuel plumbing jobs.

As far as chokes and EFI goes- I saw a straight six Landcruiser that has an extra fuel sprayer which worked like a choke, on 1980s fuel injection. I don't think theres anything like that on these new setups, they just sense conditions and adjust the fuel map to suit within established parameters. Personally I have a carb and don't use the choke (on my Pontiac 455, the daily driver is EFI).

I also have read up on annular boosters and its something I'd like to try out.  
idrivejunk

tuffnuff tuffnuff
Moderator | Posts: 2567 | Joined: 12/09
Posted: 01/11/14
10:07 AM

Throttle body EFI's are still wet flow systems and there will be no earth shattering difference between a well tuned "Annular Booster Venturi Carb" which outperforms your dogleg booster carb.,. However, a dry flow EFI system would mean direct port injection, which effectively eliminates fuel coagulation or puddling between intake cycles.,. this type would be the best.
Fuel, even atomized does not negotiate turns of any kind too well, air on the other hand is less effected.
Instead of a costly EFI, I would opt for an annular booster carb or send your old carb to Barry Grant for the upgrade.

http://www.carcraft.com/techarticles/116_0508_carburetor_showdown/

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

Poncho462 Poncho462
User | Posts: 103 | Joined: 01/12
Posted: 01/11/14
10:18 AM

Good timing on this topic Chris...

I agree with Tuff, as the cost per smile ratio of these kits is very high compared to a properly set up annular discharge carb.  I've used nothing but this type booster for years.  With a new tank(recommended), in tank FI pump kit, and the EFI kit, the cost is over $3000 US for any decent self-learning system.  But they do have modern driveability, but most show little performance increase if any.

The March 2014 issue of Car Craft, which I think is still the current issue, has an actual comparison on the same 496 cu in big block chevy in a Nova that tests 4 of the newest self tuning EFI systems, all costing right around $2000 US.  And they note that you need to spend at least around $700 more for a good fuel pump system, and that's assuming you do all the work yourself.  This article is a very comprehensive review of what's available, with a lot of background info on how and why.  They also go into a lot of info on comparisons regarding the relative merits of both carbs and EFI, though they did not run a baseline carb as part of the test.  They do describe the car in detail but not much about the carb used.  

I'd recommend reading the article completely right away if you subscribe to CC, or if not, try to find a news-stand copy(I know that might be hard for you Chris).  

I looked at their website, and they do not seem to have it posted online yet, though they do have a digital subscription, which would probably provide it instantly if you signed up.  Anyway, check it out to find a lot of info in one place on the EFI kits.

PS:  It is the main cover story, and the car on the cover is a red Chevelle.  
"Wherever you go, there you are."..Buckaroo Banzai, 1984

tuffnuff tuffnuff
Moderator | Posts: 2567 | Joined: 12/09
Posted: 01/11/14
10:53 AM

I founda few articles on CC that deals with Accel EFI installation.
A bud ran Accel EFI on a mud truck and it worked great, after a lot of hassle.,.
I'm not sure if Chris could get the support he needs, in Austria.

http://www.carcraft.com/techarticles/ccrp_0405_accel_dfi_efi_system/

http://www.carcraft.com/techarticles/116_0308_efi/


My bud Robin's rig with Accel 950 EFI

Robinsrig 1

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

shyrgfuh3 shyrgfuh3
Enthusiast | Posts: 450 | Joined: 11/13
Posted: 01/11/14
11:03 AM

I would say that if you don't notice a diff in perf during elevation changes now,  and there is no burbling or sputtering with elevation changes, it is unnecessary if using it for that purpose, however I think it would still give a reasonable improvement in hp and tq even if you do not notice it simply because it does use annular boosters. I can'tbimagine why it would work worse than a non efi annular PROVIDING it does what they claim it will with little set up effort.  

chrisaustria chrisaustria
User | Posts: 187 | Joined: 01/13
Posted: 01/11/14
11:49 AM

The problem is the relation between cost and result. But you have to know I have to adjust my carb(s) on my own and I'm not a professional. My tools are a jet assortment, 2 different power valves, a vacuum gauge and a air/fuel meter connected into my header collector.

The good thing about the EFI should be the computer controlled and self adjusting air/fuel management. If that works like it should I think I cannot set my carb as good as this would be. Result = the EFI will run better than any of my carbs I could use. Do you think this is true?

Tuff mentioned that his buddy needed a lot of support until the EFI ran great. That would be the same problem over here as to find someone who will set up a carb.

I'll ask Holley about the cfm ratings with the EFI.

Larry, thank you for the advice, I'll sign up and hope for an online article about the different EFI's. Would be really interesting to read.

The annular carb is still an option and I'm convinced it would make more power plus I can Keep my fuel lines and pump. The EFI will probably not be able to produce more hp, but my biggest concern is the setup like I mentioned. A System that always has the best possible setup (computer controlled) is likely to beat MY carb all the time. On the other hand, maybe my own setup is better than I would guess... I have no comparison.  

shyrgfuh3 shyrgfuh3
Enthusiast | Posts: 450 | Joined: 11/13
Posted: 01/11/14
12:25 PM

hi please read my previous post carefully again.

IF it does what it is suppose to, IF IF IF

Your fuel economy will increase which will eventually make it pay for itself.

IF IF IF, it works right it WILL out perform your carb and a non efi ANNULAR carb.

Your carb is very good, an annular will stomnp it. the efi is an annukar with no choke housing to impede air flow.

it is more like a race carb body.

it certainly looks good on paper.

it might give you SLOWER ets because the electronic fuel adjustment might not change fast enough. 68redbird had that exact prob with a fast efi chinese unit.  

chrisaustria chrisaustria
User | Posts: 187 | Joined: 01/13
Posted: 01/11/14
01:13 PM

I know, the IF is the problem, that's why the article would help a lot.

IF 1 = if my carb has a good setup (because I've done it by myself)
IF 2 = if I can adjust an annular as well as the downleg now by myself
IF 3 = if the EFI does what they promise (by itself)

The DP is good at pumping a lot of fuel into the engine at a sudden full throttle operation, maybe the EFI is too slow, but on the other hand modern cars are not too slow doing this, so a fast computer should be able to react very quickly. I always try to get things Made in USA not in China.

Better fuel milage isn't my main concern, but I'll get that for sure. If the tank is empty I need about $165 to fill it up at the moment. I wouldn't call that cheap.  

idrivejunk idrivejunk
Addict | Posts: 5139 | Joined: 12/09
Posted: 01/11/14
02:19 PM

Chris, my rough estimate going by your fuel cost indicates that you would need to drive your new EFI system well over thirty thousand kilometers to offset a $2,500 installation ...

IF you were able to gain an average of three miles per gallon by doing the swap. Thats a lot, your carb would have to be badly rich now to make that much difference.

Now you are finding out why so many of us keep the original hardware like carbs and transmissions- improved pieces aren't practical investments as much as they are luxuries. And the potential for expensive mistakes run high. Try this- plan a fuel system first, to supply an EFI unit. Then see where you're at with costs. That might help guide your direction.

As far as the article says, there is only three tenths of a mile per gallon difference between the four EFI systems tested. That doesn't help with carb comparison but there is plenty of that to be found on the web.

High points of the systems were Holley's upgrade potential, with ability to run trans controllers and nitrous on the Terminator setup. MSD's Atomic had versatility on it's side, as far as applications covered with simple requirements. Edelbrock's E-street virtue was the display and software, along with easy installation like most of their products. The FAST EZ-EFI 2.0 had more power potential than all, with the ability to run twice as many injectors. They were going to test another brand but discovered it required a laptop for installation so they did not. But that system was less expensive, too. They also sort of rated each system on cold starts (at California temperatures).  
idrivejunk

idrivejunk idrivejunk
Addict | Posts: 5139 | Joined: 12/09
Posted: 01/12/14
10:37 AM

Hope I didn't step out of line or on anybody's toes with that post, its only intent was to help the thought process along and my guesses may be way off ... Chris just say so if I did not make sense. Hopefully you will continue to research this topic further.

Matt  
idrivejunk

tuffnuff tuffnuff
Moderator | Posts: 2567 | Joined: 12/09
Posted: 01/12/14
10:39 AM

Check this thread out.

http://forums.hotrod.com/70/9534356/pit-stop/holley-750-ultra/#9530791



Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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