fuel injection V.S. carburation

[bear]

What is everyones thoughts on fuel injection V.S. carboration? I am getting a 2.4 l motor from Opels Unlimited. It is a late model 2.4 that is already equipt with fuel injection. The motor in coming from Germany. That is about all I know about it.

[RallyBob]

The 2.4 FI intake manifold won't fit under the hood of any US Opels. Not without a big hood scoop. That said, a stock 2.4 is rated at 128 ps, or about 123 hp at the flywheel. If you were to put a 2.0 head, 1.9 intake, and a Weber 38 DGAS onto that shortblock, you would be lucky to have 110 hp. A case in point, recently at Carlisle a Manta with a 2.4 shortblock with a ported 2.4 head, performance solid lifter cam, twin 45 DCOE Webers, and 2.5" exhaust dynoed at 125 hp to the wheels. I assure you that car is quite fast too.

You've stated in the past that you want a decent amount of power from your engine, so you have a few options. Twin 48mm Webers and intakes will flow a bunch of air, but will set you back about $1600 for the setup.

A hood scoop and the stock EFI intake is certainly a cheaper option, and it appears the intake flows decently. The limitations are the stock ECU and the stock injectors. You could use a programmable ECU with that intake though....

Another option is a cut-down version of that stock intake, or a custom fabricated intake manifold, again with the programmable ECU.

HTH
Bob

[bear]

I was thinking of using the Lenk hood, or possibly farbicating my own hood mods. I am going to run a 2 1/2" stainless steel exhaust front to back. The header was recommended by Opels unlimited . it is some sort of over sized header that is also used on 2.2 or 2.0 engines. What type of programables are available?
Thanks

[RallyBob]

When you say a 'header', are you refering to the stock 2.2 exhaust manifold? If so, you will lose power. The 2.4's stock exhaust manifold is far bigger than any other CIH's, and bigger than any of the aftermarket tubular headers sold in the US. So you'll need the 2.4 manifold and a custom exhaust, or a full-custom header to let that head breathe.....

For programmables, there are probably a hundred options. Prices vary from $800 to about $5000. You can get something very nice for $1200 or so.

Bob

[GTJIM]

It may be possible to hybridise a set up using stock GM parts. The Gen II Chevy Cavalier motors use a Bosch Motronic based injection system controlled by Delco ECUs which are reprogammable. The one I have from an Australian 1987 Holden Camira has a "hot wire" air flow measuring thingie attached directly to the plenum with the same square bolt pattern as the LE Jetronic set up of the 1975 on Opel plenum. Food for thought....

[bear]

Great thanks guys.
I will have to find out what type of header or manifold I am getting. As for the programables and the fuel injection keep the info comeing, I am kinda new to efi. Are there better injectors to use, than what come stock? In you oppinions what is the best progamable unit to run. ( Under $3000 us dollars)

[kmon]

Megasquirt offers a much cheaper setup that is comparable to the higher end side of things (after enough tweaking). The basic controller is just under $200, you soider the bits yourself. I'm going to use this unit on my new engine. The megasquirt controls fuel only, but they have derivities that can handle spark curves as well. If you want a more commerical system, their are 3 units I have experiance with, TEC-3 is a fantasic setup that is very user friendly, motec is one of the best for the money, wolf3d is another 'budget' system but dosent lack on features. All the above units do very similar things, and are all pretty simple to use. One feature that I'd highly recommend is a wideband o2(Lambda) sensor, this makes tuning much easier as it will tell you exactly how rich or lean you are running. I would do as much reading as I could, EFI is pretty straightforward, but their is a learning curve.

[RallyBob]

There are truly tons of options for EFI. As mentioned, there's the Electromotive (TEC 3), Motec, Wolf3D, and the DIY Megasquirt system....

Also there's DTA Fast, Haltech, Accel, Stinger EMS, Simple Digital Systems, Autronic, Lumenition, Weber Alpha, Emerald M3D, Pectel, and many others I can't remember.

Luckily, since you will be getting the 2.4 fuel injection, that system uses a more modern fuel rail with o-ring style injectors. So there are lots of options there for higher hp figures. You will need to assess your true hp goals and size the injectors accordingly. Marren Motorsports or RC Injectors are probably two of the best know companies that specialize in injectors only, and they can tell you what you need.

Alternatively, if you figure what you need yourself, you can get lower cost injectors through Summit or Jegs (MSD or Accel typically) which are designed for newer Camaro or Mustang engines...you just need to know the fuel flow and the required impedence for use with whatever EFI you choose. These injectors will work with the 2.4's fuel rail, but not the 1.9, 2.0, or 2.2 fuel rails and injector plates. They often are sold in sets of 8 too, but you could sell off the other 4 to another person looking to go aftermarket ECU on their Opel.

Bob

[bear]

Thanks Bob
I was wondering since you seem to be the guru of opels, Were are located, and would you be interested in building my motor ?

[RallyBob]

I'm up here in the northeast in Connecticut. I'm not building engines anymore, at least not for another 5 years or so when I set up a new shop in Vermont.
But you can always post questions here on opelgt.com and there are plenty of people here who can help you out.

Bob

[bear]

Ya know I am getting my motor from Opels Unlimited, It may just be that long before i get it.
Thanks I will ask around
Keith