fuel injection

[Guest imported_Julian]

anyone have any ideas on how I can fuel inject a 455 rather than stick a chev engine in my car??

[Guest pfloro]

Hello Julian:

What are your objectives: better drivability, better fuel economy, more power?

What year is the vehicle & how is it presently fed fuel?

If just better drivability is your desire, consider a TBI (throttle body injection) aftermarket system from Affordable Fuel Injection. This conversion is not to be taken lightly but is 'doable' by someone who is comfortable around mechanical & electrical systems. AFI has may options if you want to build a more complex FI system.

I very briefly considered a TBI conversion for my '84 Toronado with the 'low power' Olds 307 V8 (computer controlled Rochester QJet & too many emission controls). I decided to resolve the issues with the Qjet & just keep it stock. It runs great now and I can live with the anomalies of carb technology.

Paul

[Guest imported_Julian]

just wanting to get some better fuel economy and driveability. am putting a 455 in my 42 street rod and now with the price of gas..just trying make it get some decent gas milage.. thanks..

[joe_padavano]

Do you really drive the car enough to recoup the cost of the EFI system? Your best bet is probably to find a used Accel throttle body unit. The throttle body bolts to a 4bbl manifold and is relatively universal.

[Guest imported_Julian]

Sounds as though I will leave well enough alone.. and stick with the carb...thanks..Julian

[carbking]

Julian - a properly tuned Quadrajet will provide (at least after the first 5 minutes) as good driveability, fuel economy, and probably more power than the efi; and is certainly more reliable!

The world did not need cell phones prior to efi; cell phones were invented so one could contact the operator of the tow truck!

The key is getting a quadrajet DESIGNED for the style of engine you will be using, and then fine-tuning.

Jon.

[joe_padavano]

First, let me say that I'm a big fan of the Qjet and have no problems getting them to run properly (even the electronic Qjet on my 86 307 Olds).

Having said that, I'm also a cynic and frankly I wouldn't walk into a butcher shop with the name "BeefKing" and expect an unbiased answer if I ask the guy behind the counter whether I should make steak or fish for dinner.

EFI properly set up will ALWAYS meter fuel more accurately than a carb. The problem is, for a homemade system for an application like an Olds where you don't have the benefit of factory development, can you get it properly set up? There are a lot of advantages to being able to change the fuel map without getting your hands dirty. I have a friend with an Evo and he has software on his laptop that lets him change the fuel and ignition advance maps by simply dragging points on a 3D plot. He can also do the same thing by editing the values of cells in a spreadsheet. Very cool stuff.

Back to my original point, however. Will you really drive the car enough to make back the investment in EFI?

[carbking]

Joe - I really like your comment about the butcher shop (and I really do like fish!!!)

I also would totally agree with you on whether the original poster would drive enough miles to justify any change.

I cannot agree with you on efi always metering fuel better than a carburetor; in fact our experiences are about 90 percent the other direction, but then we have never done a head-to-head against a custom efi calibrated by an efi guru. However, against factory efi, a properly selected carburetor normally wins.

But to get back to your excellent comment concerning costs:

For the sake of argument, lets say that the original poster is getting 10 MPG; and that a XYZ fuel system will get 20 MPG on his vehicle (double) and costs $1000. At $4.00 gas, the vehicle must be driven 10,000 miles just to break even.

When one starts talking about adding components to improve fuel economy, the addition normally will not pay back UNLESS THE ITEM BEING REPLACED IS DEFECTIVE AND MUST BE REPLACED ANYWAY. Do the math BEFORE making a switch.

Sometime ago, we placed the following on our website to help enthusiasts reduce their operating costs:

Better fuel economy

Jon.

[Guest TrofeoSC]

I stumbled on this following another link. I'm going to touch on several points made in this discussion. My points in this discussion are going to revolve around GM fuel management, both the digitally controlled and the glorified fuel leak. I'm going to stay away from the emissions benefits since the applications discussed are pre-emissions.

There are many ways to convert to fuel injection. First you need to determine your goals and your funding. You can buy an off-the-shelf system, though with an odd application like an Olds engine the calibration will probably not be that close. Another approach is to use salvage parts and design your own. TBI (throttle body injection) is the easiest installation, as it would just require an adapter on a carb manifold. Port injection will require a bit more effort to mount the fuel injectors. If the salvage method interests you, spend some time on www.diy-efi.org and DIY PROM at www.thirdgen.org

Carbking - While I agree that a properly working QJet is tough to beat, your accuracy leaves something to be desired. Call me when you want to stand behind your challenge.

Can you imagine trying to carry a cell phone with the same technology as a carburetor? Let's just say it wouldn't fit in your pocket!

Please provide some supporting proof that a carb is more reliable than fuel injection. If you allowed a carb equipped engine to run as long as the modern fuel injected engine does without maintenance it probably wouldn't even start.

The biggest advantage of fuel injection is driveability and fuel mileage. The resolution of control available in even the late 1980's ECM's put to shame anything that could be done with a carburetor. With the later ECM's or modified operating code, higher resolution tables improve this even more. This is, of course, dependent on the skill of the tuner just as with the carburetor.

I don't want to close this with everyone thinking I'm a 'carb hater'. I still work on carburetors and my daily driver still has one. They are our heritage and without them the automobile wouldn't be where it is today.

Scott Pearson

88 Trofeo Supercharged