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chigger
January 16th 2003, 11:49
I will be searching the internet for information on many kinds of fuel injection and I needed a place to list my findings. So here is where it starts.
There are many fuel injection setups out there. Most of the custom ones are quite expensive ($2,000+). Finding a workable solution for around $500 is my goal. Custom fabrication not included.
The VW diesel engines have a nice set up with a fuel distributer, pump, and throttle all in one. At present I don't know how they manage air flow sensing. The problem is they may not work with gas as the tolerances may be too wide due to diesel being a thicker liquid.
The purely mechanical fuel injections systems are very nice. Some have distributed outputs and some are constant flow (CIS) the Bosch Jetronic K.
There are also hybrid mechanical and electronic most of which were early developments and didn't work so well or maybe people didn't know how to make them work? The Bosch Jetronic KE.
The next development is the mostly electronic fuel injection. These have various stages of programability from swapping preprogramed chips to full laptop programing capability on the fly. LN Engineering comes to mind.
Several areas for research have come to my attendsion. How to determine the injector size and type? How to determine the throttle body size? Throtttle position sensors vs mass airflow sensors, vs flapper air flow sensors. How do you determine the air flow needs of you engine at a specific rpm and hp output?
All kinds of things. Anyway I will be posting interesting sites with information. Hope this is going to help.

Pillow
January 16th 2003, 15:54
As for CIS this guy adapts it to ACVWs.
http://www.sandrail.com/millerfi/

But the CIS is impossible for a Beetle to fit as there is no room for the fuel distributor and airbox.


I am thinking of a Chevy FI system conversion on a Beetle, but that is just a thought and no research has been done.

CB Performance sells T1 DP intakes that are machined for those injectors which make it nice off the bat.

kdanie
January 16th 2003, 18:42
I doubt the diesel injection will not work. I have no experience with VW diesels but extensive experience with small/medium and large marine diesels, they regulate the throttle by regulating only the fuel. No air volume sensing is used.

I will be building a low buck EFI for my engine once it is up and running on carbs. I will be using a MegaSquirt to control it, a 944 2.5L throttle body and custom (homemade) plenum and runners. I hope to do it all for less than $400. The MegaSquirt does not control the ignition, but I have a vacume advance Mallory so that is tuneable enough for me.

For injector/fuel pump sizing try http://members.tccoa.com/jmiller/finject.htm . For throttle position and other sensors you need to know the ECU you will use and pick compatable sensors.

For throttle bodies, pick one from an engine that makes about the same HP you are shooting for.

ken

Jim Andritsakos
January 16th 2003, 18:56
How about the wasserboxer EFI ???

Superman
January 16th 2003, 19:08
There is a company called SDS that has exactly what you're looking for and at that price. They market their stuff for watercooled cars but I don't see why it wouldn't work on the airsuckers. I think it stands for Simple Direct System or something to that effect and they do have a website.

Email my buddy John, he knows the site and info as he's doing it to his '75 1303 H2OSB@superbeetlesonly.com

Superman
January 16th 2003, 19:14
Originally posted by Pillow
But the CIS is impossible for a Beetle to fit as there is no room for the fuel distributor and airbox.

The CIS fuel distributor and airbox can be placed outside the engine bay and work as long as the (custom made) pipe is air tight. One could place the box under the body above the tranny, for example. I put mine on the right side of the engine bay but I did trim the bottom on the box out to lower it down. My Dad, on a Vanagon, put his under the storage compartment and ran a l-o-n-g pipe to it.

lightning bug
January 16th 2003, 20:57
As far as TB size, its pretty much based on your HP. No set "rule of thumb". For more accuracy: I was also told not to exceed a flow of 300 ft./sec. Anything over this and your car will feel jumpy at low RPM's. I have the formula for this somewhere. Injectors are also figured by HP and should bye sized at around 85% of their duty cycle. I also have SDS for my bug. Most of my friends with VW's are using it also with no complaints. No goofy laptop needed. Just the included handheld controller. Base systems start at around $700 for FI only and you can upgrade to ignition control, DIS etc. Its more than you want to spend but your getting full programability. My friend is an SDS dealer if you're interested. Feel free to E-mail me.

SDS website: www.sdsefi.com

The page below should answer most of your questions. Any others e-mail or call Ross at SDS. He is very helpful and will answer all of your questions.

Tech/FAQ page: www.sdsefi.com/tech.html

chigger
January 19th 2003, 01:22
Thanks fellows. I have found most of the sites you are talking about and a few more. Right know I am trying to sort alot of things out. www.smokemup.com has alot of automotive formula calculators including: How to determine your engine CMF (this is so you can determine the throttle body size) and determining you injector sizing.
The actual injection system is fairly simple. It is the other parts you need too which complicates things. The fuel pump, the pressure regulator, the fuel distributor, the oxygen sensors, enrichment circuits, and I could go on and on.
There are custom parts all over the net, the problem is finding stock parts and what cars they came on to minimize cost.
One item which is fairly noticable is that all the injected cars run throttle bodies which are quite a bit larger than the same cars with carbs. It may be the the carbs need more velocity to develop a vaccum signal where as the FI doesn't need a vaccum signal.
There are a lot of sites which cater to the ricers. For only $400 they will overbore the throttle body and polish it and you can expect 1 to 2 more HP. Doesn't sound cost affective to me. Will be back soon with more info, I hope.

chigger
January 23rd 2003, 11:49
Looks like I am going to have to bow out for a while. In order to calculate my needs for my engine it will be necessary for me to go back to square one and actually design my engine. Every thing affects everything, however some things can be changed rather easily and others can't be changed at all. The big hangup is trying to figure out how to determine the CFM through the valve at different lifts. This is going to help define the engines volumetric efficiency or how much HP per cu inch the engine will make. I don't have the option of actually trying it with an operating engine. Thanks for you help.
You might want to read the article on the 400hp Honda on the www.sdefi.com site. Them boys can do anything in their dreams.

lightning bug
January 23rd 2003, 17:51
Good Luck Chigger! Let us know how you make out. FWIW.... Most N/A engines run with 75-85% VE.

Jeza
January 29th 2003, 23:11
I've been thinking about fitting early Subaru FI to my 1600 TP from a Leone Turbo that a mate was wrecking..... ie I got all the bit's easily and cheaply. I figure that if the ECU never see's a boost signal then it should run okay on a N/A engine...Any ideas?

I was trying to find out info about this system from the people at http://pub1.ezboard.com/bultimatesubarumessageboards and one of them suggested this system:
http://www.bgsoflex.com/megasquirt.html
Which is a basic FI homebuilt ECU. Looks really good.

I'm still collecting info about fitting the Suby stuff to the beetle... so it may be a visit to the library in the weekend to check out any manuals I can find:)

Cheers
Jeremy

wahdubi
March 25th 2005, 11:15
The Digifant efi used on mexican beetles is fully electronic including control of ignition timing and can be had for a very good price if you simply buy the two main parts ECU and Distributor and get somneone to give you a schematic so you can wire it up yourself
This digifant is not related in anyway to the horrible digifant 1 and two sold in the states on golfs, vanagons and foxes etc. this is a bosch system licenced by VW of brazil and mexico only. I own three mexican beetles and the only complaint I have is a very small lag in throttle responce from idle because it uses a pressure sensor not an airflow meter otherwise it pulls like a champ all the way to the red and will fit up to a 2 liter engine type 1 to 4 without modification. The other sensors used in the system can be bought in the states as they are golf parts eg temp sensor ignition coil bla bla bla. AS for the guy (miller) doing Bosch jetronic systems this is nothing new at all Ive done this so many times that the thought of paying him for something I dont really need almost puts me off my beer. Get charles probst book on bosch systems (bentley publishers or amazon.com) and youll see how easy it is to walk into a junk yard pick up some parts and make your own I also recomend you buy ben watsons bosch fuel injection also from amazon. MY best result has been in using digifant to control my ignition timing with everything else disconnected (ignition control only) and using bosch K- jetronic to supply the juice and it works like a charm. My jetronic airflow meter is rubber mounted where the 34 pict carb and manifold would be if it had one facing left and one intake tube comes down from along the fan shroud where it splits into left and right to feed 1 and two and 3 and four so it does fit Good luck and remember its supposed to be fun to try these things

4agedub
March 25th 2005, 15:31
You can also look at Gotech MFI systems, it is a fully stand alone management system running both fuelling and ignition needs.

www.gotech.co.za

I ran one on my previous bug and was very happy with it.

721302
March 26th 2005, 02:13
i have been talking to the guy at tbichips.com about building a GM based efi system for my 1641cc and he suggested a ecm and tbi from a pontiac feiro since the ecm's in them are a simple system. he can burn a chip to do away with knock sensor and egr so that would not need to be hooked up to the VW engine. I already have the throttle body, wiring and ecm from a 2.5 feiro and am trying to make an adapter to bolt it to my stock beetle intake. I have built a few stand alone tbi harnesses from factory harnesses from GM vehicles so i am certain i can make the wiring work in a beetle. i think the hardest part will be mounting the TB and converting the ditributor so the GM ecm will control the timing and of course getting the perfect chip burned to run the air cooled engine. i will have to install a return fuel line and a eletronic fuel pump also. Sorry for the book but this is my plan and i hope it inspires others or if anyone has any further info for me.

Mark the canuck
March 27th 2005, 14:50
Another SDS user here :agree: