nacitar Posted August 15, 2012 Share Posted August 15, 2012 I've read about this swap before here: http://www.pape.ws/allan_and_rosanne/Z-Car_Stuff/Swapping%20a%20C4%20Corvette%20IRS%20Into%20a%20240Z_files-Scottie/Swapping%20a%20C4%20Corvette%20IRS%20Into%20a%20240Z.htm Anyhow, while browsing today I came across A rear cradle kit for the c4 IRS here: http://www.streetrodgarage.com/c4corvetteirsrearcradlekit.aspx Anyone know if this would be useful in putting the C4 IRS into a Z? Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted August 15, 2012 Share Posted August 15, 2012 Problem with a z is that the whole car is narrow and small-you would need some wide fender flares or cut the car down the middle to make it wider. Quote Link to comment Share on other sites More sharing options...
nacitar Posted August 15, 2012 Author Share Posted August 15, 2012 Problem with a z is that the whole car is narrow and small-you would need some wide fender flares or cut the car down the middle to make it wider. Well, in the link I provided the guy shortened the IRS a bit as well. That said, I suppose the product I linked would likely also be too wide to be of use (if it would even be of use in the first place). Quote Link to comment Share on other sites More sharing options...
roger280zx Posted August 20, 2012 Share Posted August 20, 2012 There is an s30 on CL here in GA with a complete C4 suspension underneath it, wheels, brakes, the whole 9. Fresh paint too, last time I saw it it was listed for $800. It does look like a jeep though, WAY up in the air, but if you had to have that suspension then I guess you have to have it. Quote Link to comment Share on other sites More sharing options...
v8dats Posted August 20, 2012 Share Posted August 20, 2012 ooo.. link? lol Quote Link to comment Share on other sites More sharing options...
King's Evil Posted November 16, 2012 Share Posted November 16, 2012 I am in the progress swapping a 1987 Corvette rearend on my 73" 240z, I'd tell ya it takes alot of cutting and welding on the IRS and the Z if you wanted to make it look "stock". Quote Link to comment Share on other sites More sharing options...
heavy85 Posted November 17, 2012 Share Posted November 17, 2012 Have to ask why change rear suspension? What are you hoping to accomplish and what's the purpose of the car? Quote Link to comment Share on other sites More sharing options...
King's Evil Posted November 17, 2012 Share Posted November 17, 2012 Have to ask why change rear suspension? What are you hoping to accomplish and what's the purpose of the car? To answer your question, I think "for me" the corvette IRS is alot cheaper than Arizona prices for brake set up, and LSD conversion, and misc parts. Plus the C4 aluminum rearend maybe alot lighter than the stock 1st gen Datsun rearend component., therefore it ease up the suspension weigh travel and rotating mass once narrowed. I wanna throw out that the corvette brakes maybe better/cheaer than most disc brakes that offered for the stock Datsun setup and even for the aftermarket Q45 setups.The Corvette c4 is much an heavier car than the 240Z, and its braking might be worthwile for the 240Z. I got the 1987 Corvette Dana 44 rear end for dirt cheap cheap, almost for free for me, it was in complete condition. I had to modify the corvette rear end into size to match up the 240Z suspension. I might run wheel adapter for the front to widen up the track of the 240z to gain its handing maybe would be better than stock with its wheel adapter.. I am using the 17x11 aluminum wheels with 335/35-17 tires which is heavier than the stock setup, with the c4 rearend, which is lighter, it may equalize to the stock 240z setup and remove the wheel hop and wheel spin for higher hp applications. The first gen suffer this alot even with upgraded suspension in the rear. I am still in the progress building the Z with this Corvette end, I see many benefits over any stock setup for a Z. It may preform better since the C4 provide the anti squat setup. "Note: Many Z out there suffer the rear squat under acceleration with higher hp/tq set up" It only take true guts to cut a Z up to fit this C4 rearend. I took this path because it was cheaper than anything else, and I believe I could I could cut a Z up and make it better. I spend over a thousand to get it to fit, maybe more. It also take real measurement to cut up a Corvette rearend to match the front to equalize track width to gain handling. I am just throwing random information out there about my little Z project, plus I am a bit drunk at the moment. Please accept for my spelling or grammar errors. Quote Link to comment Share on other sites More sharing options...
Snailed Posted November 17, 2012 Share Posted November 17, 2012 That cradle wouldn't be much help. As long as you don't change the geometry of the suspension for the worse when locating the trailing links you would be better off doing it like the guy in the first link, making individual mounts that are incorporated into the unibody. I would not copy his front diff mount though. Overall this is a pretty easy conversion if you don't have the money for all the billet, bolt on stuff. and can build stuff. Go for it! Quote Link to comment Share on other sites More sharing options...
ozzzzz Posted November 17, 2012 Share Posted November 17, 2012 (edited) How much HP are you making or plan on making? If memory serves the c4 has an aluminum differential housing and a dana44 doesn't it? Edited November 17, 2012 by ozzzzz Quote Link to comment Share on other sites More sharing options...
roger280zx Posted November 17, 2012 Share Posted November 17, 2012 The C4 rear end has been done several times and is pretty well documented. Not sure what you mean by this: "cut up a Corvette rearend to match the front to equalize track width to gain handling.". Most of the best handling Z's have more attention paid to the FRONT suspension. I'm not telling you not to do it, hell I think its a great idea. I just hope that you're doing it for the right reasons. Most of the C4 IRS Z's I've seen where built that way for drag racing... gears, lsd's, weight... while retaining the handling characteristics of an IRS car. I would never have considered this swap to be one engineered to enhance handling. Quote Link to comment Share on other sites More sharing options...
evildky Posted November 27, 2012 Share Posted November 27, 2012 ScottyGNZ did it years ago and documented it. Do a search and use a time machine. He narrowed allt he C4 bits to fit under the S30, the S30 still required major surgery to accept this type of IRS, Scotty's car was a purpose built drag car. Quote Link to comment Share on other sites More sharing options...
King's Evil Posted December 2, 2012 Share Posted December 2, 2012 (edited) Should the C4 track width be the same in the front of a Z for a auto cross? The stock c4 setup is about 7 inch wider track than in the front of a first gen Z. I think having the c4 wide is good for drag, but alot of understeer. Making it narrow enough the front track is .5 or 1 inch wider than in the track rear. Corvette Rearend is 80lb lighter than the Oem Datsun Rearend. I think it a great upgrade, less unsprung weight. Edited December 2, 2012 by King's Evil Quote Link to comment Share on other sites More sharing options...
v8dats Posted December 3, 2012 Share Posted December 3, 2012 Kings Evil.. Can you post pics of your c4 swap? I'm working on a c4 IFS and onto the IRS early next year. I'm not narrowing them because i am running wide flares and Corvette offset wheels. If you have pics or a link and wouldn't mind sharing; I would love to check them out. Thanks! Quote Link to comment Share on other sites More sharing options...
King's Evil Posted December 5, 2012 Share Posted December 5, 2012 Kings Evil.. Can you post pics of your c4 swap? I'm working on a c4 IFS and onto the IRS early next year. I'm not narrowing them because i am running wide flares and Corvette offset wheels. If you have pics or a link and wouldn't mind sharing; I would love to check them out. Thanks! I'll post a build tread f Quote Link to comment Share on other sites More sharing options...
King's Evil Posted December 5, 2012 Share Posted December 5, 2012 Kings Evil.. Can you post pics of your c4 swap? I'm working on a c4 IFS and onto the IRS early next year. I'm not narrowing them because i am running wide flares and Corvette offset wheels. If you have pics or a link and wouldn't mind sharing; I would love to check them out. Thanks! I'll post a build tread for my C4 swap and Z once everything is done. It's kinda my rule to do that. Ill help out with questions and all. Sooner it's done sooner the build tread would follow up. Just hope someone can chime in with my question about the track with differance setup. I almost was going to not narrow it and run wide flares, but I want my Z look little stockish for that sleeper effect, and it's alot easier to get around in a small z. Quote Link to comment Share on other sites More sharing options...
v8dats Posted December 5, 2012 Share Posted December 5, 2012 Ok... Quote Link to comment Share on other sites More sharing options...
Sean111 Posted December 17, 2012 Share Posted December 17, 2012 I was going to use a C4 diff, but they're a little scarce up here. Ended up buying 2 Thunderbird SC's for $500 to use for parts. They have a Ford 8.8" IRS, with 3.27 gearing and posi... Quote Link to comment Share on other sites More sharing options...
Sean111 Posted December 17, 2012 Share Posted December 17, 2012 Or if you can find one, I believe the Lincoln Mark VIIIs use the same thing, but with an aluminum housing. Quote Link to comment Share on other sites More sharing options...
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