EFI experience

[(C)arlos]

Hi guys
Currently I am in the planing phase for my second Gt40. One thought that came up is the fuel delivery, should it be a carb again or a aftermarket EFI this time?
I have not really played with the stuff,yet and I struggle to separate marketing from reality here reading through all the different vendor webpages.
Do we have any experience here on the forum with EFI's from Edelbrock, Holly or even Hilbron ?
The goal here is not to build a race car rather then to find the right balance between fuel economy, power output and a nice running engine.

A few years ago hot road issued a great comperison test, EFi compared to carb which was very nice but I guess technology moved on and the test (two years or so old) might be a bit outdated. However the additional HP they gained wasn't big enough to convince me really. Overall the same engine carburated vs. EFI might had 20-40 HP more wich is quite a lot of money for little HP, compared it to other tuning parts I can buy for an average of 3000$.

So what are your recommendations here ?

Thx
Skeleton

 

[Graham]

Try this link:-

http://www.gt40s.com/forum/gt40-tec...ine-cooling/30922-efi-versus-carburettor.html

Cheers,

Graham.

 

[(C)arlos]

cool thx haven't seen it for what ever reason

 

[Jim Cowden]

Its not about the power it is about the drivability.
EFI is the only way in my eyes it has the ability to adjust specific points in the fuel and ignition maps,cold start,idle control ect ect.
There are good systems and poor. If it has 3-4 load cells you might as well buy a carby.

Jim

 

[gtpete]

Hi, if you can go for the mapped ing/fuel system, its like night and day. There are a large amount of systems on the market atm at really good prices. Not only do you get better drivabilty but a whole host of extra features like traction control, different maps for different fuel or performance levels, logging, fault finding etc etc. Hope that helps abit. Pete.

 

[Randy V]

On a Dyno* - there is precious little** difference between a properly tuned EFI system and a properly tuned carburetion setup.

* Dyno - Steady state - controlled environment - no G-Forces involved
** Little - An internal combustion engine is just a big pump. It really doesn't care how it gets its fuel-air mixture very much (note there are some efficiencies to be had in either camp)..

BIG EXCEPTION HERE
When it comes to the abosulte best means to distribute fuel to an ICE - It would be difficult to argue the obvious efficiencies of Direct Combustion Chamber Injection. This is something that a carb setup cannot do.

For simplicity - it's hard to argue the merits of a Carb system.

 

[(C)arlos]

Hi Guys, thx so far....is it legal to scan some pages from Hot Road Issue from 2008 and post it here, this shows clearly what I am looking after ?

 

[Chris Simpson]

Three advantages of EFI (which I have on my '40) are that the 8 throttle bodies look like the original Webers, you can see out of the back in the internal rear view mirror (the air cleaner gets in the way if it is a 4 barrel carb) and once set up, the EFI stays tuned. Also, it is said that a carb will supply the correct mixture for part of the rev range but EFI will supply the correct mixture throughout the rev range. The main disadvantage (including the cost!) of EFI is that it requires a lot of setting up initially using a rolling road.

 

[Mike Pass]

For Efi you have a choice of using a 4 barrell throttle body setup which fits Holley type inlet manifolds or a full 8 inlet setup. The throttle bodies can be either single or in pairs Weber IDA style. You can get a throttle body set up which looks almost exactly like the original weber setup. There are many different ecus which can be used but all will need rolling road or dyno time to set up properly. You will also need to have a system to pump fuel frpm the two tanks and a swirl pot to feed the high pressure pump and also the various returns.
Mike Huddart is a contrbutor to this forum a does a nice setup with original weber IDA style setup using the Accel ecu complete with loom etc. You can contact him at Huddart Engines
The setup looks good and works very well. A choice of cam will give you the driveability or power you want up to 500bhp+
Cheers
Mike

 

[Seymour Snerd]

is it legal to scan some pages from Hot Road Issue from 2008 and post it here

I-am-not-a-lawyer-but.... I have been around intellectual property issues enough to say with confidence that in the US the answer is "no."

However, here's is a relevant snippet of US copyright law (TITLE 17 > CHAPTER 1 > § 107):

"Notwithstanding the provisions of sections 106 and 106A, the fair use of a copyrighted work, including such use by reproduction in copies or phonorecords or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. ."

So, would you please write a review of that article and/or teach us about the subject? :idea:

Also, which 2008 issue was it?

 

[Ron Scarboro]

A couple of pics of the Inglese EFI solution. And what is on my dining room table waiting for a motor from a fuel system standpoint.

I went with a "surge tank" as opposed to a swirl pot.

 

[Eric]

Skeleton

Not to cause a thread drift here, but being a publishing professional I can tell you that it is illegal to scan pages from a magazine (book, whatever) and post it on the Internet for free or fee without permission of the copyright holder (under the copyright laws followed in the U. S. and majority of the world...Berne Convention, in case anybody cares). I am not a lawyer and this does not constitue legal advice.

Now, to get the thread back on topic. I think Randy has summed it up nicely. In theory, EFI and carburation both accurately meter fuel to produce power. The advantage of EFI is that it can be tuned over a wide range of conditions, including various engine speeds and environmental conditions. That's why an EFI-equipped vehicle is *generally* more drivable than a carburated vehicle...because it is more adaptable to changing conditions. Will you get more power from EFI? Perhaps, if you are very good at tuning the system.

As I've posted in other threads, the real advantage EFI has over carburation comes in the area of emissions control (for the same reason: adaptability over a wide range of conditions). But, also, with EFI you can jump in the car, turn the key, and drive down the road. No waiting for the car to warm up, no sluggish response on those chilly mornings, just drive.

For what it's worth, I'm doing an EFI system, but I'm starting with an engine that is already fuel injected ('96 351W from an E-350 van). Therefore, much of the cost of the EFI system is built into what I paid for the engine. If I was starting with a carburated engine, I really doubt I would add EFI. As you pointed out, it is very expensive compared to carburation.

Eric

 

[Blaine #1076]

I was posting my counter balance question and saw yours.

I have just spent the last few weeks getting my RedLine - Weber 8 stack system problem solved (after a major winter rebuild). It ran great before. Wayne at Weber their engineer is great helped me locate my problems.

The mechanical stacks and throttle plates are fairly common and do not dictate the type of control system you wish to use. so if you wish you can purchase this separately or as a kit.

Here is the fun part, the older say circa 2000 on systems use older processing so are a bit more fundamental to set up. If you are starting from scratch you will need to be fairly electronically minded as the various inputs and out puts are not connect and play. i.e. very complicated with no internet information immediately available.

The older systems are Red-line Weber
newer systems:
FAST (quick learn and basic) they now have a plug and play system.
Inglese'

Carbs are too easy and passe' - you need to show your peers that you are a serious gear head, it is a real accomplishment and feeing of success to get a beautiful set of stacks burping along.

 

[marc]

I think you are asking a loaded question.
1. Is this a driver or a racer
2. size of motor
3. where will it be driven (more of an elevation question)
4. what is your expectations for the 40?

I used to design competitive computers for industrial and commercial applications. If you don't know what you are going to use it for how can we give you a good answer.

Being in Germany, I would be more inclined as a Nuringburg (sp) toy.

My P4 is track only, while the LS7 is EFI (Management system still up in air) I haven't ruled out going a different way. depends on what I can get away with. Carbs can do just fine on a road racer, but I am a year away from that decision right now. I would just have to change the pumps and the regulator in the fuel system to go to carbs.

 

[Jon Briggs]

Being in Germany, I would say the only way you can go is with EFI. The EU will make sure of that with ever increasing restrictions on cars that can not meet emissions requirements. And to stand any chance of meeting those requirements the only way is EFI.
We already have proposed restrictions on entering some European cities in cars that don't meet these emissions requirements, and these restrictions will only get worse.

 

[(C)arlos]

Hi guys,
as my job is keeping me busy for this week like hell, just a quick response.
First of all thx for all the input.
- During the weekend I am going to write a summary from the Hot Road testing and share it with you ...
- All my cars are registered as vintage cares, so I have no issues with smoke regulations ( If BP can pollute the whole east coast with oil I give a shit about my CO and Noise level ).
- Major reason to go with an EFI next time is of course fuel consumption, today 30L are quite normal under pressure....and 20l during cruise speed is to much, too.
- drivability, fair point but I have to say, the Edelbrock performs quite nice on the GT...so I can't see a real value in this except cold winter days maybe.
- Apparel, he no brainer, a Hilborn or Weber Injection looks far better on a GT then a carb

So stay tuned for the summary

Cheers
skeleton

 

[Ian Anderson]

One other thing you may not have yet considered is Alternator capacity.

GT40 EFI will require at least 2 pumps run at the same time - low pressure to swirl pot and high pressure to injectors. and also power to the "brain"

In all it can run to about 20 amps constant current dependant on fuel pumps

So add this to lights, spot lights, fans etc and it can add up to more than the alternator can produce!


Ian

 

[Tom]

One other thing you may not have yet considered is Alternator capacity.

GT40 EFI will require at least 2 pumps run at the same time - low pressure to swirl pot and high pressure to injectors. and also power to the "brain"...

Ian

Ian, I'm curious why a swirl pot is required with EFI setup? I am still in the Fuel System pre-planning stage with my RCR, but living in CO at 6000' and taking weekend drives in the summer that range from 12,000' to 5000', EFI is really the only way to go out here. However, I believe in keeping it simple and at the moment, looking at going with two independant systems (switchable Left n Right) with in-tank pumps 255L pumps feeding the motor.

I may still sort the car out initially with a carb but it will be EFI prep'd by the time it hits the road.

 

[Bill Musarra]

My take on it is the dual pump setup is a throwback to the originals. With the fuel sloshing back and forth in the tanks they would draw a lot of air and the high pressure pumps had a short life as a result. The low pressure pumps on the other hand can handle the air without much problem, though they saw much less air than the long narrow tanks afford. So the way to get around it was to make a "swirl pot" that acted as a reserve for the high pressure pumps and kept them from sucking air. With the multiple carb and webber setups, I would think would cause problems from, air getting to some of the units, to vapor lock, and cause stumbling to outright coughs.
To solve the dual tank problem they used a changeover valve system that allowed the switching between tanks. Some I believe had equalizing lines between the tanks. With the changeovers, you just have to remember which one was switched last, so you didn't switch to an empty tank(solved with two fuel gauges).
Secondly the EFI system type pumps are not lift type pumps and the short distance they have to lift, I believe, puts a strain on them, shortening their life. Some have gotten around this issue by lowering the mounting of the pumps to the level of thier tanks by finding hidden places in their framework. This however seems to take away from the "proper look" of the cars.
These can be gotten around by using one or even one set of pumps and no changeover valve, using the proper hosing on the return and pickup line. If using one "set" of pumps you can still retain the "look". Several members are using them now including myself.

Bill

 

[Ian Anderson]

Ian, I'm curious why a swirl pot is required with EFI setup? I am still in the Fuel System pre-planning stage with my RCR, but living in CO at 6000' and taking weekend drives in the summer that range from 12,000' to 5000', EFI is really the only way to go out here. However, I believe in keeping it simple and at the moment, looking at going with two independant systems (switchable Left n Right) with in-tank pumps 255L pumps feeding the motor.

I may still sort the car out initially with a carb but it will be EFI prep'd by the time it hits the road.

As Bill says
Under braking the fuel sloshes forward and away from the pick up point.
This will cause air to be drawn into the pump. It's OK for a low pressure pump to pump a few gulps of air as you decelerate as the carb fuel bowls will keep the engine running.

But with EFI the pumps run continuously and the whole fuel rail is kept at about 40psi - with air not being acceptable - injectors will not work etc.
The pumps are also a different type an when they pump air the vanes wear quickly and overheat.

On my car (explosafe (wire wool type) tanks) less than 1/2 tank and under hard braking I can get the LP pump to pump air (the Facit I'm running changes it's note and hammers on air and ticks on petrol)

So this then is used to fill a swirl pot and the HP / EFI pump draws from and returns to the swirlpot hopefully meaning it never pumps air. The LP pump purely keeps the swirl pot full.

Ian