4znova1 Posted March 31, 2007 Share Posted March 31, 2007 I have a 3.90 diff on my 2+2 turbo, i have heard that i am better off using a 3.54 diff setup with a turbo car since the turbo produces more boost under load. Im looking for great low end pull and best possible 0-60 time. has anyone experimented with this?? it would be nice to also have better cruising speed on the highway Quote Link to comment Share on other sites More sharing options...
mc Posted March 31, 2007 Share Posted March 31, 2007 ..i've read similar info as well...i have a R200 3.90 rear in my 88 200sx SE that has been converted to a remote turbo set up...i have recently picked up a R200 rear with 3.54 gears ..it was from a early 80's 300zx turbo...the weather is starting to get nicer so hopefully in a month or so it will get installed. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted April 2, 2007 Share Posted April 2, 2007 Best bet is the 3.54. The turbo engine has way more torque, with a 3.90 you will go through the gears so fast you will end up spending more time shifting gears than winding through them. Also consider using a later model transmission as well. Quote Link to comment Share on other sites More sharing options...
4znova1 Posted April 3, 2007 Author Share Posted April 3, 2007 I do have a 5spd out of an n/a zx which is in the 2+2 turbo, i also have a transmission that i think came out of a nissan truck because it says l20 on it instead of z, but it is the same style trans, i have heard that the 5spd out of a 720 has great low end first gear and good cruising final drive. But anyway, so the 3.54 would be the best even with a 2+2? do you know anything about the l20 5 speeds?? Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted April 3, 2007 Share Posted April 3, 2007 I have a 3.54 R180 in my Z. original setup was an automatic in my 1978 280z. Pulled that out and installed a 5-speed, kept the stock rear end. I like it. Top end is awsome, my speedo read 145mph last night when goofn on the highway Quote Link to comment Share on other sites More sharing options...
nienberg.11 Posted April 3, 2007 Share Posted April 3, 2007 145... Impressive. I can't wait to get my suspension in shape so I can try that. Quote Link to comment Share on other sites More sharing options...
4znova1 Posted April 4, 2007 Author Share Posted April 4, 2007 yah i have a 78 that was originally auto with an r180, the rear end held for a few months after i installed the four speed but started to clunk, i just put as r200 3.54 out of a 78 and an l20 5speed in so im gonna see how it does. what are these r200's good up to horsepower wise? Quote Link to comment Share on other sites More sharing options...
Tony D Posted April 4, 2007 Share Posted April 4, 2007 Best bet is the 3.54. The turbo engine has way more torque, with a 3.90 you will go through the gears so fast you will end up spending more time shifting gears than winding through them. Well, that all depends on what kind of tire height you have, doesn't it? Start looking at some of the taller tires that will fit on a Z, and it becomes VERY easy to turn a 3.9 into a 3.54 gearset using a taller tire setup. Same goes for having a 3.36 in a car with wide, super-low-profile tires, in reality the effective gear ratio is more near 3.9 in some cases. I know my 3.9 in the Fairlady was far enough out of ratio with some 215's on the back that a Motorcycle cop pulled me out of the carpool lane to have a talk with me, and I only thought I was going 120kph... In fact, it was quite a bit more... Gear recomendations without asking about tire height is grasping at straws. If you use stock-height tires, then maybe yes. But generally people here are running something of a performance tire/wheel combination, and that can have a GREAT effect on the gearing. Personally, I really like the 3.7 gearset in the turbo cars running stock tire height. 3.54 always seemed sluggish out of the hole through first to me. Quote Link to comment Share on other sites More sharing options...
wheelman Posted April 4, 2007 Share Posted April 4, 2007 I rode in a 240 with a 280ZXT engine and a Subaru 3.70 R160 LSD in it this last weekend. It pulled like a train from about 2500RPM. First gear was a little low but it made for great launches and once into second things happened real fast. Not sure how a 3.54 gear set would compare but for a cheap LSD with a good gear ratio it's tough to beat that Subaru R160. To use the R160 you will need half-shafts with the older 240Z bolt in type flanges. Wheelman Quote Link to comment Share on other sites More sharing options...
steveosupremeo Posted April 5, 2007 Share Posted April 5, 2007 hey tony, what was the aspect ratio of the tire, the 215 width doesn't tell me much without at least knowing the wheel diameter and aspect ratio/sidewall height...60 series? Quote Link to comment Share on other sites More sharing options...
GrayZee Posted April 5, 2007 Share Posted April 5, 2007 Well, that all depends on what kind of tire height you have, doesn't it? Start looking at some of the taller tires that will fit on a Z, and it becomes VERY easy to turn a 3.9 into a 3.54 gearset using a taller tire setup. Same goes for having a 3.36 in a car with wide, super-low-profile tires, in reality the effective gear ratio is more near 3.9 in some cases. I know my 3.9 in the Fairlady was far enough out of ratio with some 215's on the back that a Motorcycle cop pulled me out of the carpool lane to have a talk with me, and I only thought I was going 120kph... In fact, it was quite a bit more... Gear recomendations without asking about tire height is grasping at straws. If you use stock-height tires, then maybe yes. But generally people here are running something of a performance tire/wheel combination, and that can have a GREAT effect on the gearing. Personally, I really like the 3.7 gearset in the turbo cars running stock tire height. 3.54 always seemed sluggish out of the hole through first to me. Yes you are right, tire size plays a role as well. I didn't get into that because some days you don't feel like posting a novel when most people just want a quick answer. Myself I always have tried to keep tire size somewhat near stock height so as NOT to throw out the speedometer, but that is just my preference. 4znova1, here are a couple of links you might find useful: http://www.geocities.com/z_design_studio/ http://www.miata.net/garage/tirecalcold.html I run the 3.54 diff along with the 83 Nissan 5spd. I like the combination rather than have a setup that causes me to have to shift constantly. I guess depending on your point of view you might say it is "sluggish" off the start. Turbo engines are kinda use two ends of the spectrum, they can be gutless with little off the hop go and need a big of a flogging to get them to really pick up hard. I personally would rather lose some zip off idle under light throttle and have the gearing I need for a full out, heavy throttled launch. In which case it is not sluggish at all.. In fact I have a serious traction problem. It's all in the preference, I hope those links help you out. Quote Link to comment Share on other sites More sharing options...
240zwannabe Posted April 6, 2007 Share Posted April 6, 2007 i don't mean to jack your thread but i have a pretty stupid question. i'm completely oblivious to gearing other than the obvious stuff, but i would like to know the advantages to having a 3.36 R200...i've got one and plan to use it on my turbo setup, i know it's rare and sought after but quite honestly i'm kinda lost as to why. thanks Quote Link to comment Share on other sites More sharing options...
BleachZee Posted April 6, 2007 Share Posted April 6, 2007 Its rare because it was only found in one year 280ZX with a rare 4-speed option. It is sought after only by very few. It is not what you call a high demand item. Its just the tallest gearing you can get in an R200 now except for maybe a few NISMO units that were sold a while back but are NLA. If you have a lot of torque and are going for a high top speed that is the diff you want. As for me, I've got the stock 3.54 and I'm going to a 3.7 Stock tire size and going for less than 300hp Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted April 6, 2007 Share Posted April 6, 2007 Actually, it's not that sought after. I'll trade you for a 3.54 . I sure miss the feeling of a 3.54 with 25" tall tires. Right now I'm running a 3.70 with 23.8" tall tires. Quote Link to comment Share on other sites More sharing options...
240zwannabe Posted April 6, 2007 Share Posted April 6, 2007 Actually, it's not that sought after. I'll trade you for a 3.54 . I sure miss the feeling of a 3.54 with 25" tall tires. Right now I'm running a 3.70 with 23.8" tall tires. thats why i always thought it to be sought after by many, all the local z guys find out i have one and immediately want to buy it or trade haha. thanks i appreciate the help. edit: i'll be shooting for the neighborhood of 375-425, so it sounds like thats the diff for me Quote Link to comment Share on other sites More sharing options...
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