'85 project...
Thread Starter
Instructor
Joined: Oct 2006
Posts: 241
Likes: 8
From: COLUMBIA STATION OHIO
'85 project...
I am about to purchase a project car....a 1985 black Corvette that has been sitting for 8 years. I have had 3 c5's, which I have spent many hours modding and repairing. I have never even changed plugs on a c4. My intentions are to go through this car from top to bottom, and transform it into a tire melting beast. Any advice other than "stick with the c5's"? I know this forum is an excellent source for info., so I'm sure I'll be here regularly as this project progresses.
Melting Slicks
Joined: Apr 2007
Posts: 2,616
Likes: 111
Either plan a rebuild of the entire engine with a new set of aluminum heads, or purchase a crate engine with a four bolt main block and one piece rear main seal. The 85 has a 2 piece rear main seal and 2 bolt main. If you expect any real horsepower at all, ditch the long runner intake system and opt for either a mini-ram (my personal favorite) or a shorter runner intake system. The tpi system simply chokes the motor at higher rpms if you do not; unless you enjoy a truck motor in a vette. The search function here will help on your build and good luck.
Burning Brakes
Joined: Sep 2006
Posts: 1,202
Likes: 3
From: MD
OR CARB IT 
Anyway, it's a fun car. If you actually want to be melting tires, however, you might wanna start reading the threads about beefing up the D44 or plan on a solid-rear swap. Motor is easy (it's a SBC after all) and trans isn't hard either (700R4 been around for years, ZF6 is pretty stout, and there's always the TKO swap) but the rear is gonna be your weakest point.
Anyway, it's a fun car. If you actually want to be melting tires, however, you might wanna start reading the threads about beefing up the D44 or plan on a solid-rear swap. Motor is easy (it's a SBC after all) and trans isn't hard either (700R4 been around for years, ZF6 is pretty stout, and there's always the TKO swap) but the rear is gonna be your weakest point.
Thread Starter
Instructor
Joined: Oct 2006
Posts: 241
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From: COLUMBIA STATION OHIO
I'm planning on maybe installing an LS6 W/6 speed and go from there. The original drive train will be discarded......I really don't want to go the 9" Ford rear end route. I guess I'll have to come up with a plan for the rear end. Thanks for the input.
Melting Slicks
Joined: May 2007
Posts: 2,171
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From: Warwick RI
Keep us posted on this one, it sounds like you have some nice plans.
Burning Brakes
Joined: Sep 2006
Posts: 1,202
Likes: 3
From: MD
A long as you aren't looking to run 10's all day you can build the D44 to withstand pretty hard use. It's just gonna take a lot of careful clearancing, some heat/cryo treating, and some money. Start searching for the drag-guys threads on the rear end work. Billet axle stubs and nitrous-ready half shafts, cryo'd case, etc. I've heard that if you brace the center section of the rear it holds up better. Some guys tie it in to their cages (not sure if you're caging this or not).
Ski-dwn-it has a nice 12-bolt bolt-in solid rear kit (search for "bolt in solid rear" and you'll likely find it. Looks stock once it's in there.
Ski-dwn-it has a nice 12-bolt bolt-in solid rear kit (search for "bolt in solid rear" and you'll likely find it. Looks stock once it's in there.
Le Mans Master
Joined: May 2003
Posts: 5,362
Likes: 3
From: Delray Beach FL
I am doing the same thing with an 86. Just finished restoring the interior and now it is ready for the shop. Plans on my 86 are:
434 Stroker (Carb'ed)
Race-ready 700R4
Solid Rear End with spooled 4.56 gears (I purchased one of ski_dwn_it's rear ends)
6 point roll bar
I am searching for extremely low 10's with my 86. I want it right on the cusp of needing safety equipment necessary for a 9 second car. I figure I will run it for a year or so in the 10's and then when I get bored, throw a 300 progressive shot on it and add the additional safety equipment and get certified so I can go into the 9's or 8's.
I had considered doing an LSx swap into my 86, but the fabrication costs were going to be too much. Who knows...maybe I'll do an LSx into my 86 Monte Carlo SS.
434 Stroker (Carb'ed)
Race-ready 700R4
Solid Rear End with spooled 4.56 gears (I purchased one of ski_dwn_it's rear ends)
6 point roll bar
I am searching for extremely low 10's with my 86. I want it right on the cusp of needing safety equipment necessary for a 9 second car. I figure I will run it for a year or so in the 10's and then when I get bored, throw a 300 progressive shot on it and add the additional safety equipment and get certified so I can go into the 9's or 8's.
I had considered doing an LSx swap into my 86, but the fabrication costs were going to be too much. Who knows...maybe I'll do an LSx into my 86 Monte Carlo SS.
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Thread Starter
Instructor
Joined: Oct 2006
Posts: 241
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From: COLUMBIA STATION OHIO
Qickzilver....sounds like you're doing what I'm about to start on. Spool rear end?....I recently replaced one with a Detroit locker, not in a Vette, but a '66 Nova.....I found the spool to be pretty much un manageable on the street. Then again, maybe your not planning on any street driving.
Burning Brakes
Joined: Sep 2006
Posts: 1,202
Likes: 3
From: MD
A detroit locker being more manageable than a spool? Yeah, as long as you make sure you let off the gas before entering ANY decent turn. I hated having a locker in a parking lot. On and off the gas 20 times to lurch it into a parking space. Never had a spooled car, though. Is it really worse than a locker?
Le Mans Master
Joined: May 2003
Posts: 5,362
Likes: 3
From: Delray Beach FL
My 86 will see some street driving. I have to drive it to and from the track, as I don't have a vehicle to tow the 86 up there. I also plan on taking it on local Corvette Cruises. I am sure it will take some getting used to, with the spool, but since most roads in Florida are straight, I don't have to worry about too many turns. When discussing the rear with Jesse (ski_dwn_it), we were both concerned that the amount of power I will be putting to the rear end, there would be a chance that I could break the rear with a Trac-Loc. I will be running 30" tall slicks (as well as street tires) on the car with a 4.56 gear ratio. Jesse's setup is very close to what I am planning for my motor. He is running a spool in the rear of his C4 as well. Jesse said it does take some getting used to, trying to park a car with a spool, but after a while, he doesn't notice a difference with his spool and parking his Vette. So, I'd rather have it built for durability. I don't want to try to have it towed from the track by breaking something that I could have gone stronger with. That is why I am also going with all forged internals in the motor and most likely an iron block. Might have a little more weight, but will be harder to blow up.
When discussing the rear with Jesse (ski_dwn_it), we were both concerned that the amount of power I will be putting to the rear end, there would be a chance that I could break the rear with a Trac-Loc. I will be running 30" tall slicks (as well as street tires) on the car with a 4.56 gear ratio. Jesse's setup is very close to what I am planning for my motor. He is running a spool in the rear of his C4 as well. Jesse said it does take some getting used to, trying to park a car with a spool, but after a while, he doesn't notice a difference with his spool and parking his Vette. So, I'd rather have it built for durability. I don't want to try to have it towed from the track by breaking something that I could have gone stronger with. That is why I am also going with all forged internals in the motor and most likely an iron block. Might have a little more weight, but will be harder to blow up.
Team Owner
Joined: Feb 2006
Posts: 24,460
Likes: 7
From: sw Ohio
I picked up my '85 as sort of a project/weekend driver and its a beast. I would recommend rebuilding the original engine depending on what your goal is for power that is. The TPI is a great intake if you plan on driving it on the street. Its got impressive low end power that will shred tires quick.
Le Mans Master
Joined: May 2003
Posts: 5,362
Likes: 3
From: Delray Beach FL
But the factory TPI runs out at 5000 rpms or so. For drag racing, it just doesn't cut it. I took my 86 to the track last weekend to see what it would do. Best time was a 14.18 in the quarter. I managed to cut a 1.89 60' time on street tires. But after that, I could not get it to hook up at all. My 86 has a Dana 44 with 3.73 gears that a previous owner had added. That helped with the times, but it was waiting till 6700rpms to shift when floored. I could feel the power drop off around 5200 rpms. All comes down to where you want to drive it. My 86 is fun on the street right now, but nowhere near where I want it to be.
Thread Starter
Instructor
Joined: Oct 2006
Posts: 241
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From: COLUMBIA STATION OHIO
Jleatherman...I find the Detroit locker to be much better than the spool for street driving. Before I went that route, I talked to a lot of people.....half of them said what you said....the Detroit locker was terrible. I don't know if maybe some are just not set up properly or what. Maybe the spool I had wasn't set up right. But I find a huge difference with this unit.....driving around a curve in the road is not nearly as scarey. I can actually stay in my own lane now.
Pro
Joined: Sep 2004
Posts: 505
Likes: 1
From: Guntersville Alabama
Thread Starter
Instructor
Joined: Oct 2006
Posts: 241
Likes: 8
From: COLUMBIA STATION OHIO
93cruiser...I am still investigating the possibilities of which trans. will make the most sense......I'm starting on it this weekend, so I have some time to consider this. I hope to be complete by July 1.