Corvettes White

I want to drop an LT5 engine into a 1989 convertible…

…so I am beginning to do my homework. My greatest ignorance surrounds the electronic controls that I will need to find for this project. The four main components that I can identify are:

1. The Ignition Module
2. The Electronic Control Module, ECM
3. The Digital Dash Cluster
4. A great deal of wires.

Questions:

Can I use any year Ignition Module? Should I limit myself to a ‘90 Module? Must I find one from an ’89? I understand that the ’89 units were destroyed separately from the engines in the spirit of GM security. Will a ’90 unit generate a tach signal and can I loop that signal through to drive the Atari Dash’s Tach?

What part number or model year ECM should I use? 1228331? Again could I use a ’90 unit or must I try to find one from an ’89. Where do I mount it? I believe that in ’89 the standard location was inside behind the breadbox. However, a photo I have from an ’89 ZR-1 shows a computer above and to the left of the master cylinder. Am I totally confused?

The key is to provide all the signals to the 1989 Dash and to the Driver’s Information Center that they will need to work properly.

Wires? Where do I start? Especially if I have to relocate the ECM to under the hood.

Are there any experts out there?

IF anyone has any IDEAS, ADVICE, or better yet any PARTS; please offer these. The hard parts for the project will come along much easer. In fact they are starting to pile-up in the garage already much to the dismay of my wife who thinks I need another Vette like another hole in the head and my daughter who will never get to park in the garage again for the rest of her life. I want to this so it looks “Right.” I also appreciate that this project will cost a great deal of both time and money. But so what? (I have posted these questions in both the ZR-1 and the Scan & Tune sections because I need the help that bad.)

Thanks in advance,

George

xlr8nflorida

Seems like alot of $, that is not recoverable. Although having a convertible ZR-1 would be cool. Personally, I'd buy an average ZR-1 and do i dare say chop it and then put a hard top on it. Prolly would be alot cheaper.
JMHO :D

USAZR1

No offense but you have absolutely no idea what you would be getting into with this attempted swap,George. Modify the C5 or buy a ZR-1.

SPEEDEMON

George

Are you sure that engine is going to fit into a C5? That's a pretty big engine here. Is it going to fit under the your hood where it’s going to clear the top of the plenum? I would say just buy a ZR-1. You’ll find it more enjoyable and less headaches

90 Corvette ZR-1

Doesn't sound like something I would try. Too much $$$$ for not lot or return.

A26B

George, you really don't want to even attempt this swap. It is NOT a bolt in job. If you just had to have a vert, it would be easier to have a ZR-1 converted into one from a coupe. At least then you would have all the rest of a ZR-1, big butt, big tires, big brakes, etc.

Corvettes White

Guys - Guys

This will be in a C4, not a C5. I do have a C5 because I do need something to get parts with. But this will strictly be a project car for the fun of it. Hopefully something neat.

Yes I know about the money thing, not recovering your investment, etc. Well I don’t smoke or horse, and I limit my drinking bill to the bare minimum necessary for medical purposes. I expect that I will be able to buy near to a new Corvette for what this project will cost.

Yes, it would be easer to chop a ’90. But I want a 1989. The ZR-1 was to have come out in 1989 so in the style of hot rodders I want to build a phantom.

A Convertible ZR-1? Very cool. I know a guy who has one out here in California. Nothing else like it on the road.

And if I don’t build it what should I do with the 1989 LT5 engine sitting in my garage? It is out of a narrow body convertible GM built. I am not sure it is the same car but there is a photo of such a car in “Heart of the Beast.” At least I do not have to worry about the high cost of cam cover emblems since this engine never had any.

Seriously guys. I intend to do this so any help would be appreciated.

George

Edit: I didn’t say “horse.” Troy’s computer changed the word I wrote. It is said there are places in Texas where you can pay to ride a horse.


[Modified by 999, 10:55 PM 11/22/2002]

kabnvtt

Sounds like a great project. I am new to the ZR1 so I dont have any tips yet. Good luck cant wait to see the end result. :cheers:


[Modified by kabnvtt, 8:01 AM 11/23/2002]

90 Corvette ZR-1

Droping a LT5 into an L98 car isn't as easy as droping a 4 valve into a 2 valve mustang. That is to say its not a bolt in and change the ECM and alternator job. You have to change the motor mounts I think, the ECM, wiring, cooling system, you have to make sure that the dash will accept the signals from the ECM, you have to change the clutch, the bell housing, transmission, the imput shaft, breaks, tires which don't fit under the stock fenders, I don't know if the stock L98 spindles can handle the extra power of the LT5, you also have to have a place on the dash for the power key. I just don't see this project being worth the money that you would have to invest

Vette Guy

From watching the '92 ZR-1 owner's video, the entire frot suspension appears to be completely different from the standard C4, and the LT5 and front suspension are installed as one unit at the factory. You may need to check this out as well. :eek:

Mark

Scoob

wow, this is an ambitious project. I often thought about this when I had my '89 coupe. The lack of funds and know how prevented me from pursuing it, though.

While certainly a lot of work I don't think it is impossible. Many people probably tried to talk the guy who put the LT4 and the complete '96 interior into the C2 out of it, too.

Some projects cannot (and should not) be explained rationally.

I applaud your ambition and hope this turns out good for you.

A26B

Since thre's no lack of ambition here, I have an idea you might want to consider. There's a 90 ZR-1 salvage on eBay, http://cgi.ebay.com/ebaymotors/ws/eB...tem=1873300110 , that has a "perfect front end, including radiator, etc, for $2,000. I think you might want to consider buying this car, and putting the entire front frame section on your 89, then you could put your 89 body panels on the front end, but would have all the correct mounts, members, susp, etc for the LT5. As it turns out, not so very far from you.

Just a thought :) Good Luck & hope this turns out to be of some help.

Jerry

Corvettes White

THANK YOU!!! Scoob – for the moral support.

Mark and Kevin, I figured that I would need to buy a donor ’90 ZR-1 to provide all the hard parts, cooling HVAC, brake, etc. Also, Kevin, I do have a lead on an ’89-power key. I should know soon if the guy will sell it.

Jerry, I was aware that the car you spotted on Ebay was coming up. But you beat me to seeing it. I had tried to buy the car directly last week from the owner but he wanted to auction it off. $1500 to $2000 is about what a Corvette salvage yard would pay. Too bad the shocks are gone and the windshield broken. But this car would fit my needs very well for the right price.

I figured that it will take some time to find all the parts for such a project. The computer thing is what is at the top of my head now, it will just take me some time to figure out.

George

vetterestorer

GO FOR IT!!! I've swapped em all.
84 to a tpi
84 to a lt1
85 to a lt5
85 to a big block
Zr1 to a efi big block 468 (in progress)
It's not that difficult if you are good with your hands, any questions just E-mail. Parts for c 4's pretty much fit each other.

threestar40

Me thinks it can be done, but I would rather put it some where I had more room like an old chevy truck or something. Talk about a sleeper. You could even get one of those ZR 1 wannabe roll pans for under the tailgate.

If you go for a short bed, regular cab, fleetside, gmc truck, you will have all the room you could ever ask for and with 4-6 drop these trucks look like kick As $ hot rods. I have seen one on the web, but it looked like crap because the guy had poor taste :jester I'll bet he thought it looked good though ;)

Keep it pretty stock appearing on the outside except a few tell-tale signs. Like some 335/40's. :smash:

I wouldn't do it, because when your done, It will be all hacked up and won't be very special at all...Its not a phantom, It's a vette for god's sake.

If you want a phantom put it something else besides a vette...then you would have something pretty special. Of course, MHO. :smash:

Corvettes White

Thanks for the offer, Mike. I will take you up on it.

George

-=Jeff=-

Now you are making me want to save my pennies and do this to my 89..

I already have a 1991 Dash and ZR1 engine harness.. I would just need the motor and such.. I think it can be done and since you have a LT5 already you have the big $$ Item

Z-Dreaming

Go for it.

You would have a unique vette that served the need for speed, and one that turned heads as well.

Falcon

I saw a '64 Vette that had a LT5 motor and runing gear in it. What an amazing looking car. There were many modifications, but it looked very professionally done when completed.

Good Luck, and damn the cost, full speed ahead!!!!

Corvettes White

Jeff,

I am very serous about this. About a year ago I started and as funds and time have allowed I have been going after this idea. Now I would not be worrying about the computers if I did not have even more esoteric parts of this puzzle already bought and stashed. I am asking at this time about the computers because I figure it will take me another year to figure out what, find, and then buy what I need. A donor vert. will be the easiest part.

So in the garage besides an Engineering Unit motor…

I have a complete set of 1989 ZR-1 wheels (the 11”wheels) that supposedly were used for tire testing by Goodyear. The casting dates, if I remember, are from 1988.

And a brand new 1989 8000-rpm dash. Which is why I am so worried about the computers in the first place. What would be the point of dropping in an LT5 if the tach. only read to 6k?

Maybe you and I can together buy a wrecked ’90? You can have the engine and trans. for your project and I will take the rest of the car the odds and ends that I know that I will need.

George

Z & Falcon, Thanks for the support.



[Modified by 999, 5:27 PM 11/24/2002]