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Stantank · 11-30-2005, 08:23 AM

Hello all
I have a problem that I hope you may be able to help me with. I am in the process of restoring a 1978 Argosy 28 on a p-30 chassis with a 454 chevy engine. I am about to convert to fuel injection. I have been looking at the Holley 950-22s 4-bbl system. My problem is that I don't know the horse power of my 454. Holley has four 950-22s systems that range in horse power, 150-300 hp, 250-440hp, 375-500 hp, 450-575 hp. Would anyone have any experience with this type of conversion? Or would you have any suggestions that may help me with this conversion? I would appreciate anything that you can do.

guy99 · 11-30-2005, 11:10 AM

Maybe if you google on 1978 P-30, you can find the specs somewhere. My MH is an 84 so I think it would be different than a 78.

Keep us posted on your progress, I have thought of adding FI to my rig so I would love to hear of the experience of someone who has actually done it

Pick · 11-30-2005, 02:10 PM

My 2000 GMC pickup had the last of the 454's in it. It was rated at 290 HP, if that helps you any.

TheGanzman · 11-30-2005, 03:17 PM

I believe it's ~190-200HP; not much. . .

jim8860 · 11-30-2005, 03:25 PM

I think your motor runs about 225 Hp or so not to much at all. My feelings on the holly stuff is to good. Try calling Howell http://www.howell-efi.com/ they have more of a "factory setup" . I had much better luck useing there stuff.Goodluck Jim

Stantank · 12-01-2005, 07:14 PM

Thanks for all of the feedback. Good information concerning this kind of conversion is not so easy to find. I have learned quite a lot just browsing these pages.

shelocta · 12-01-2005, 07:47 PM

I've have done the upgrade on my '83 310 MH and I used the Holley 950-23s. If flows 650 CFM and if you assume that 5000 rpms is your top limit, the 23s will do nicely. If you went larger setting up the idle would be harder to do. PM me if you want to hear about all my adventures with the conversion.
Bil

ALANSD · 12-02-2005, 05:47 AM

the Holley set up is a throttle body? Forgive my ignorance on the model#.
What other changes do you dso to go to that from a typical quadrajet set up?

Stantank · 12-02-2005, 07:57 AM

I know for my engine I will need to replace the distributor. The Holley kit needs a magnetic or hall effects crank trigger system with after market cd ignition system. That is if you don’t have a GM 7 pin distributor. Then you use Holley’s wiring harness adapter (P/N 534-47).

59toaster · 12-04-2005, 09:55 AM

Factory TBI form a 87-89 454 GM truck will bolt on in place of a Quadrajet. Just need a speed sensor for the ECM and put a FI cam in it. All the rest is factory parts availabe at any parts store.

59toaster · 12-05-2005, 01:12 PM

I want to point out to our new users that these forums are intended to be a resource. This resource is only as good as the info that is available when you use the search function.

While I will gladly help out anybody that sends me a PM I feel that I can better help the forums if you ask the question in the thread that you had the question from. That way it will become a resource for others that may have the same question.

I have taken the liberty to post a question that was posed to me in a PM in reference to the post I made above.

Quote:

Originally Posted by Stantank

Hi 59toaster

Quote:

Originally Posted by Stantank

Thanks for responding. If you have done this type of conversion could you relate to me how it went for you and if it is worth doing. I have no idea where to start.
Thanks
Stan

I have the parts but have not done the conversion. I sold the truck I intended to put the system on. Then I changed course on the 1970 Pontiac Lemans I am working on that I was thinking of using it on and decided not to use it on that…(Demon 750 on a high rise looks a little more imposing). It happens to be the exact same FI that is on my 88 454 Suburban so I am holding onto the parts as spares.

I know several people that have done the conversion. Most that went with a FI cam profile if the engine was the same displacement and made sure to add a speed sensor and knock sensor have had very good luck. The computer is what you are matching the cam profile to. You will have to do a little reseach on engine the computer came off. The throttle body that is pictured above has the same plugs that were used on a 350 motor with the FI intake. That TBI will let you bolt on in place of a Qudrajet and sve you from having to replace the intake.

If you have a damaged or missing harness http://www.affordable-fuel-injection.com/, http://www.howell-efi.com/, http://www.painlesswiring.com/ and www.customefis.com/ (site seems to be down so check back) can make you a custom replacement.

You can get a custom chip burned that will allow you to use the stock cam but I hear mixed reviews. The profile of a FI cam is different. A Non FI cam may play hell with the MAP sensor. I think some of thproblems I hear about comes from people also trying to bypass stuff like EGR and speed sensors. It becomes a real hit or miss when you request a chip burner to do that. KEEP THE EGR. EGR helps fuel economy. It does not hurt performance.

Customefis has some shareware that you can turn a laptop into a data logger for factory GM FI. With that information John can burn you a chip. I believe Affordable and Howell also offer those services.

If you hit http://www.jagsthatrun.com/ they have some good conversion info including info on a drive through speed sensor that will let you retain stock speedo but still get the signal the EFI needs. In the stock application the speed sensor was was a optical sensor in the back of the Speedometer till the round body trucks came out. http://www.thirdgen.org/ you will find some forums that have heavy GM EFI content.

Stantank · 12-06-2005, 05:23 PM

I want to be able to make changes in the chip myself. This is why I have been looking at the Holley 950 kit. Also I don’t think that I could figure out the appropriate combination of parts for my engine without using a kit. I think that the programing is fairly straight forward, at least it is with the Holley. Could I put the part together as you have and use the Holley software to program the chip?

axleman · 12-06-2005, 06:03 PM

Stantank,

Have you checked out the Edelbrock Pro-Flo system? Why not modify fuel and spark curves at random as desired on the pad (included with the system - no laptop required) instead of programing chips. This system would seem to have many advantages in your application. The kit is sort of pricey but very complete and very dependable - I run one on a 454 chevy in a 1978 Monte Carlo. I will share more if interested!

Just my two cents.

Regards,
Henry

Stantank · 12-06-2005, 06:52 PM

Axleman,
Thanks for your input. I looked at the no laptop Holley system but it only runs the two barrel throttle body. Will the Edelbrock work on a 454 in a 28’ Argosy G.V.W.R 12,500? Or will any two barrel throttle body give me enough power? I would be very interested in your feedback

axleman · 12-06-2005, 08:08 PM

Stantank,

The Edelbrock will work with your application.

I don’t care for the two-barrel type set up. It may provide the power but your moving quite an object (your motor home).

Here are several of my thoughts:
Please go to the Edelbrock website and investigate the Pro-Flo systems available. The Pro-Flo is self contained, calibration module included. The calibration module can store multiple programs (that you define) for example – one for towing, one for highway etc. You could set program “A” for towing (where torque is required) with specific fuel and spark modifications set to tow then switch to program “B” for highway driving (were fuel economy is required) and flip between the two. I would definitely recommend multi-port fuel injection for your application not the TBI type pictured in “59toaster’s” post.

MY OPINION ONLY!

Still interested? Want to know more? Lets talk!

Regards,
Henry

59toaster · 12-06-2005, 08:10 PM

Quote:

Originally Posted by Stantank

I want to be able to make changes in the chip myself. This is why I have been looking at the Holley 950 kit. Also I don’t think that I could figure out the appropriate combination of parts for my engine without using a kit. I think that the programing is fairly straight forward, at least it is with the Holley. Could I put the part together as you have and use the Holley software to program the chip?

I know a lot of people that have had issues with the Holly FI. Depending on the holly system you get depends on how its programed. The "Digital" programs off a laptop and the cheaper version is Analog and you tune it with knobs on the ECM.

There is not much to figure out on the stock GM stuff. You find a 87-89 GM truck in a junk yard with a 454 and pull all the FI and harness. Or you search on line for one fore sale. The one I have I bought for $200 off a guy that was parting a truck.

Only thing you have to get if you have the harness is the Speed sensor and cam or get a chip burned if you try to stick wit hthe stock cam. The harness off the Square body trucks was laid in on the existing harness. Its totally self supporting and very easy to remove. Once you get into the 90's that harness is miserably tied up in the rest of the vehicle harness.

If you want to get real fancy then pull a OBDII system and use that Throttle body. You can program them on a Lap top. Just a lot more complicated and you have to find one out of a Manual truck so the ECM won't miss the Transmission. From 90 on GM trannys are run off the computer. If the ECM doesn't see the tranny it will go into limp mode. That has to be programed out or use a Manual transmissions ECM.

ALANSD · 12-07-2005, 05:22 AM

So with all those changes how much real power would you gain? Wouldn't it make as much sense to improve the carb, the exhaust and the ignition set up and gain as much or more? I don't know.

axleman · 12-07-2005, 07:12 AM

Quote:

Originally Posted by ALANSD

So with all those changes how much real power would you gain? Wouldn't it make as much sense to improve the carb, the exhaust and the ignition set up and gain as much or more? I don't know.

ALANSD,

Fuel injection + exhaust + ignition is the route to go.

Carburetors are dinosaurs at best.

Show me a single new car/truck/bus that still uses one – they are few. Lawn mowers are even fuel injected these days. In a word – RELIABILITY. No pumping the gas pedal, choke, variations in climate – just turn the key and it starts on the first turn – that’s the reason to look at fuel injection. Additionally, you don’t use a screwdriver to make adjustments – you use the computer – that’s pretty cool. To directly answer your question Alan, you may not gain a lot of power from fuel injection alone, just reliability.

I have successfully used competition Holley carburetors for years. But I wouldn’t take the best Holley carburetor for free – I am sold on fuel injection. On my fuel injected test candidate, a 1978 Monte Carlo, I could list many advantages of fuel injection, most notably – no overheating (computer controls this), no failed starts (computer controls this), no knock (computer controls this), no elevation adjustment (computer controls this), no rough idle (computer controls this) – are you beginning to see a tie!

Old school folks are scared by fuel injection. If your not comfortable – keep your carburetor. Just remember it is state of the art 1985!

MY OPINION ONLY!

I hope this helps.

Respectfully,
Henry

ALANSD · 12-07-2005, 09:59 AM

interesting...just gathering info. Thanks for the opinions.

Beginner · 02-11-2006, 08:42 PM

Stantank
The first EFI I serviced was the 1968 Volkswagon Squareback. It was a multipoint EFI. It worked well as long as it was kept up.
I have been working carburators before that and still overhaul and setup the GM computer controlled Quadrajet on occaasion, I have a 1984 Camaro with the computor carb.
The two main reasons the big three finally went to EFI was the EPA requirements and the cost of making a carburator. GM put off going to multipoint EFI as long as they could, but finally did.
The ability to properly service a carburator is a dying art. Very, Very few mechanics are left that can do it properly.
Would I buy a vehicle with a carburator of any description on it new today, no.
EFI is far easier to properly troubleshoot in todays industry and parts are readilly avalible. Also they are far more reliable. It is nothing for an EFI system to last the life of a car without trouble. Carburators cannot do that.
I strongly recommend, however, that you do two things;
1. Get in touch with Airstream to find out what engine you have in your unit. They should be able to tell you.
2. For ease of spare parts acquition get a Chevy/GMC with the system you want (mulitpoint gives more horsepower) Get ont that runs barely and transplant the entire system to your unit and strive for it to be as new as posssible to put the parts availability as far in the future as possible.
Hope this helps.
Beginner