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MPEFI cars vs. carbureted
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Author:  argentina-slantsixer [ Mon Oct 09, 2006 6:42 am ]
Post subject:  MPEFI cars vs. carbureted
Hey crowd

Just wondering...

just got home from a short trip (4 hours drive) on my VW golf MPEFI. I didn't know why I was buying the car then and I still can't figure out what I did... :lol:

So called economy advantages are non existent (in terms of MPG) over a well tuned and kept engine. (MPEFI vs CARB)

Electronics are a pain in the ass.

Cleaning dirty injectors is much more worse than a carburetor

Power sucks

Driveability is erratic and tends to misbehave...

I really just dont get the "let's go EFI" phenomenon. Perhaps somebody running an EFI car would care to enlighten me?

BTW, car is safe and sound, all sensors are/were replaced in a timely maneer, oil changes frequently, I even clean the "step-by-step" valve (I don't know how you call it there, is the literall translation of how we call it down here... is the PCV thing I think) filters changed, etc... ain't a neglected czr.
Author:  dakight [ Mon Oct 09, 2006 8:07 am ]
Post subject: 
Plain and simply, it's the emissions. EFI is much more adaptable to computer control than is a carburetor. Given the ever increasing stringency of emissions standards and the requirement that the manufacturer provide a warranty of extended duration, computer controlled ignittion and fuel metering was the only viable system.

PS. I have an 8 year old Dakota with MPI; it is now over 140,000 miles on the original injectors and fuel system. It still runs great.
Author:  SlantSixDan [ Mon Oct 09, 2006 8:44 am ]
Post subject: 
Emissions regulations were indeed the prime mover behind the abandonment of carburetors and the adoption of EFI. The carburetor performs several important functions internally: it measures engine load, calculates the amount of fuel needed, and adds the required fuel to the airstream. With fuel injection, these functions are performed by separate subsystems and components. This means that each subsystem can be specialized and optimized for its particular role, which brings a number of important performance benefits compared to the compromise solution offered by carburetors. The carburetor modifications and complications needed to comply with increasingly-strict exhaust emission regulations of the 1970s and 1980s gradually eroded and then reversed the simplicity, cost and packaging advantages carburetors had traditionally offered.

Low emissions are just one of the benefits of EFI over carburetors, though. There is also much more consistent and overall better driveability across a wider range of conditions, and better performance potential (more precise fuel metering and timing, and can use a bigger cam without streetability problems, since you aren't handcuffed to manifold vacuum to draw fuel for idle and low-speed operation).

As for reliability, that is a "whole system" question. If the available gasoline is of consistently high quality and cleanliness, and the injectors are of good design, then the system is essentially maintenance free aside from occasional fuel filters. If the fuel injectors are poorly designed or the gasoline isn't carefully and consistently formulated for clean burning, then injectors will clog and require periodic cleaning, which can be difficult and expensive. This was a problem in North America when fuel injection was first introduced, up through the early 1980s when automakers got together with oil companies and devised a set of technical standards for cleanliness and detergency of gasoline. Those standards were put into place (and have been periodically updated), and since that time, injector clogging is no longer a significant problem, and the average car owner spends a LOT less time and money on fuel system repair and maintenance than he did in the carbureted days. Of course, if the fuel injection system as a whole is poorly designed or built, then reliability would be poor. My experience with VWs like yours was enough to make me swear off VWs forever.

I might also politely mention that comparing a 1.8-litre VW with fuel injection to a 3.7-litre carbureted Dodge is rather like comparing watermelons to, I don't know, sunglasses. :-) Far too much difference, far too many variables, not remotely comparable.
Author:  argentina-slantsixer [ Mon Oct 09, 2006 1:08 pm ]
Post subject: 
yeah. I miss my car! :D :roll:
Author:  sick6 [ Tue Oct 10, 2006 5:12 am ]
Post subject: 
I have been toying with the idea of converting my slant to EFI........but the price tag is holding me back. maybe I am just hearing outdated data, but I am hearing price tags around $1500 to switch, not even using new parts. not to mention probably needing to get a better computer.

currently I am running a holley 390 (with no problems so lets not start that up again) and a ton of head work, clifford headers and manifold (old style, no bungs :( ) 10.5 to 1 comp, clifford hi-po cam (280/290) full balance, need a new ignition anyway.........its hard to find a good place just to start reading from where to go from here.

I found the article on this site but I haven't found any cam specs yet.
Author:  slantzilla [ Tue Oct 10, 2006 7:51 am ]
Post subject: 
We talked to the owner of the 320 horse Slant that was dyno'd with EFI on it. The EFI kit was right around $8000. :shock:

I personally like EFI, given the right circumstances. I just plain don't drive a car on the street enough to justify the expense of a changeover.

I also wouldn't judge EFI by my experiences with a VW either. :P

An ex girlfriend had a GTI 1.8T. It ran great when it ran, but she finally traded it in because the dealer couldn't fix a fuel system problem. :roll:
Author:  Tom Drake [ Tue Oct 10, 2006 9:28 am ]
Post subject: 
Quote:
The EFI kit was right around $8000.
:shock: That has got to be wrong. I am having a hard time seeing where you spend 8K on EFI!

Electromotive's TEC III system with sensors is less than $2000. Where could you spend another $6000???? (That would include the ignition system and the datalog feature in the TEC III.)


Tom
Author:  Reed [ Tue Oct 10, 2006 9:30 am ]
Post subject: 
MPGMIKE- the guy with the 44 MPG turbo-ed Duster- is putting together an all in one turbo and EFI kit for the slant six. He says he will be selling them on e-bay soon. I haven't heard a price from him though.
Author:  slantzilla [ Tue Oct 10, 2006 11:09 am ]
Post subject: 
Quote:
Quote:
The EFI kit was right around $8000.
:shock: That has got to be wrong. I am having a hard time seeing where you spend 8K on EFI!

Electromotive's TEC III system with sensors is less than $2000. Where could you spend another $6000???? (That would include the ignition system and the datalog feature in the TEC III.)


Tom
Tom, I don't recall the brand name, but the price is why Romeo said he did not own it. I know when I heard it I had to spit out my Gatorade so I wouldn't choke. :shock:
Author:  Tom Drake [ Tue Oct 10, 2006 11:33 am ]
Post subject: 
Dennis that does sound quite high. (whew) I can understand why some people would run away from that price.

Hogans will build you a custom sheet metal intake with injector bosses( and I believe fuel rail) for $1800. That would still leave you with $4200 to spend on everything else including the motor! :shock:


Tom
Author:  sick6 [ Tue Oct 10, 2006 12:13 pm ]
Post subject: 
So, is the article on this board sound like a good place to start then? I went looking for hard numbers but I am getting the feeling its not something can have hard and fast rules.

can anyone point me to what they have done personally that worked out well?

I am starting from zero here.

I am interested 50% for performance gains, 25% for the "neat" factor, and 25% for drivability if that helps at all. Car is a weekend warrior.
Author:  Matt Cramer [ Wed Oct 18, 2006 5:12 pm ]
Post subject: 
Here's my own cost estimates for what I've spent on converting to EFI.
Many of the parts are new.

Manifold - used Clifford piece modified with fuel rail and junkyard throttle body: $650
Used throttle body off a Crown Vic: $20
Toyota Supra injectors - used, but rebuilt and blueprinted: $200
Megasquirt ECU and Stimulator (kits): $200
Innovate Motorsports LC-1 wideband oxygen sensor kit: $200
High pressure fuel pump: $80
Ignition changes (Lean Burn distributor, HEI module): $70
Fuel pressure regulator: $70
Miscellanious (mostly AN hoses): $250

Total: $1740

I could probably have cut the cost in half if I had been building a throttle body setup for a naturally aspirated car without caring about the NHRA regulations.
Author:  sandy in BC [ Wed Oct 18, 2006 6:03 pm ]
Post subject: 
It all depends on where you start and where you want to end up.

I could put a TBI setup on a Clifford manifold for under $600. That would be a 470 cfm unit with 305 injectors....$20....ECU and wiring and sensors $100....fuel pump $125...adapter TBI to 4 barrel $25....return line to tank $100....custom chip $75...lean burn dist $50....and $100 for "other".

Would that increase performance over a Holley 4 barrel?....no
would it start and run better than a BBD?....yes
Would it get better mileage than a holley 1920?..doubt it.
Would it look really cool?....no
Could it be done for less money?...yes
Would it take a month to get running right...prolly
Have I done this before?,,,,yes..on a SBC and put 10 years and 400,000 miles on with a %50 increase in power and %35 better fuel mileage.

Would I do that before I spent $8000....oh yeah!
Author:  sick6 [ Thu Oct 19, 2006 4:34 am ]
Post subject: 
*sigh*

(first I gotta say this new fuel injection forum is a great idea, FINALLY!)

it all still sounds like a boat load of cash. your lists were very helpful though. I have the "old style" clifford 4 barrel manifold with no bungs, so there would be some money spent there.....

matt, how much of a improvement did you see with that particular switch?

how much do cam size and compression play into your choices of materials?
Author:  Sam Powell [ Thu Oct 19, 2006 6:17 am ]
Post subject: 
You have to evaluate your purpose in keeping your old Mopar when you answer the question raised here. I drove this car as a daily driver for 10 years, and loved it's simplicity and economy. It basically allowed me to put 2 daughters through college since I didn;t have a car payment. After they were both out of college, and one was married, this car got a well deserved retirement, and I began restoring and hot rodding it. I went with EFI because I thought a turbo would be cool, and I thought a blow through system would be simpler than a draw through, and EFI is easier to do with he blow through. I dont; know if I am right about that, but it is water over the dam, so-to-speak.
This Dart has not been a cheap daily driver from that day forward. It is a hobby, and I feel like I can spend as little or as much money on it as my hobby budget allows. If I wanted to keep it simple, reliable, and cheap, I would probably not switch to EFI or turbo. If I were to try and do today, what I was looking to do with this Dart 15 years ago, that is, put two girls through college,(and pay for weddings), I would buy a 15 year old Corolla. Today those cars are the cheap, low maintenance, never die old cars. But of course they will never be as cool as old Mopars. :wink:

Oh yes, and this is a big one, I also decided it was time to learn something new. I could rebuild a carburetor in my sleep while blindfolded.
It has not been easy to make this switch, and it has taken the support of some much younger and computer savey friends. But I am not sorry I did this. I just hope my 'friends' can still say the same thing. One of my tuning buddies is an employee who is about 35 years old. He never worked on cars before in his life, but said tuning on the EFI was like playing a video game. He really enjoyed himself. It certainly is not like rebuilding and tuning a carb.
Sam
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