Guest 280Aden Posted January 26, 2007 Share Posted January 26, 2007 I have an '83 280ZX 2+2 and an '83 Turbo- I'm gonna do the turbo swap into the 2+2 (it's in better condition) and have been told that the T5 will mate up with the NA diff (longer gearing) but that it would bog down off the line. I am setting up the 2+2 as a daily driver, and want to be able to get some good gas mileage out of it after the swap. Anybody whos done a "hybrid" swap like this let me know of any potential problems, and what kind of revs i can expect at highway speeds. Quote Link to comment Share on other sites More sharing options...
Paz8 Posted January 26, 2007 Share Posted January 26, 2007 According to the info I have 81 to 83 ZX's have the following rear gears, Auto trans 3.54 R180, turbo 3.54 R200 rear, manual trans non turbo 3.9 R200. You want the stronger R200 rear, from everything I have heard about turbos is that lower rear gearing does not allow the turbo to spool up properly because the engine revs up too quickly, the turbo can't reach it's peak rpm as fast as the engine (turbo lag). I'm sure someone else has a different slant on this topic. Quote Link to comment Share on other sites More sharing options...
naviathan Posted January 26, 2007 Share Posted January 26, 2007 Paz, you're backwards, the turbo has the 3.9 and the non turbo has 3.54. They lowered the gearing in the turbo because it took too long to get the turbo to spool with the higher 3.54 rear and it launched harder off the line with the 3.9 giving it more of the high end sports car feel. They lowered the compression ratio to account for the boost so a good jump off the line was almost impossible with 3.54. 280Aden - WASUP!!!!! We'll build that engine right before it goes in, don't worry. The only problem I can see us running into is the drivershaft. The 2+2 is longer and the turbo shaft is different from the standard shaft. Matter of fact I never looked at what the difference was between the T5 shaft and the standard tranny shaft. I'll get all the info before hand, but we'll probably have to either find a turbo 2+2 drive shaft (could be difficult) or just have the one we;ve got modified. Hopefully someone else can chime in and tell me what the difference is between the two other than the tapering on the turbo shaft. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted January 26, 2007 Share Posted January 26, 2007 It is for sure 3.54 in the Turbo, 3.9 In the MT, and 3.54 (R180) in the AT. I would go with a 3.54, but it really depends on your tire diameter and motor. PS. You might do like I did and get a 3.7.... They are very common http://forums.hybridz.org/showthread.php?t=103512&page=3 Post #52 of that thread specifies which cars came with what rear ends. Make sure to get an R200 if you plan to build your motor up. Quote Link to comment Share on other sites More sharing options...
Roostmonkey Posted January 26, 2007 Share Posted January 26, 2007 I think I gotta go with Paz on this one. 3.90's in a turbo suck,I made that mistake but have gone to 3.7 since and its much better. Quote Link to comment Share on other sites More sharing options...
madkaw Posted January 27, 2007 Share Posted January 27, 2007 Naviathan is wrong, the turbo came with the 3.54. If you check gear ratios of the trans of the bw t-5 you'll see that your first and second gear will be extremely low with the 3.90 rear. That's a good deal for my NA engine , not good for the turbo motor. Quote Link to comment Share on other sites More sharing options...
Paz8 Posted January 27, 2007 Share Posted January 27, 2007 280aden, back to your question, use the rear and half shafts from the turbo car, that way your going to have a stronger drive line. The extra weight of the four seater chassis probably won't make much of a difference with a well setup turbo L28 and manual trans. Your going to need all the electronics and wiring from the turbo car. PS Thank you for your service to our country. Quote Link to comment Share on other sites More sharing options...
Warren Posted January 27, 2007 Share Posted January 27, 2007 Just for the record, with the hopes of clarifying what came with what, consult the diagram below. Hope it helps, Warren Quote Link to comment Share on other sites More sharing options...
naviathan Posted February 1, 2007 Share Posted February 1, 2007 Wow...Ok I was completely wrong. I thought the turbo had the lower geared rear for a faster take off until the turbo kicked in. I didn't realize the BW T-5 was so low geared in first and second. Damn, now I want to get my hands on a 3.54 rear. Better gas mileage and since my aim is a daily driver that would be nice. No wonder my 81 winds out really quick in first. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted February 2, 2007 Share Posted February 2, 2007 Naviathon... I expect to have a 3.54 soon (open, I think). It's part of a package deal. I may sell it. I dunno yet. Open 3.54's are pretty easy to find and you can buy a brand new Power Brute CLSD for $450-500. Quote Link to comment Share on other sites More sharing options...
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