datzenmike Posted April 9, 2014 Report Share Posted April 9, 2014 So,if I was looking for one of these h190 lsd's which 4 cyl,2wd trucks possibly have them? Also,doesn't a 510 wagon also use a h190 ? Would this differential be a possible swap into a wagon as well? I understand that the gears might need to be changed to make it a daily driveable car,or truck whichever it would be swapped into. The '88 through '93 D-21 Hardbody had them as an option BUT... only on the 4 cylinder 2wd trucks. That would be the Z24i and the KA24E motors. That should save you some time. The very back of the differential will have a small orange sticker on it saying... Or simply... Take a rag with you. The 29 spline truck side gears are specific to the LSD and are square with the clutch discs stacked onto them. The 510 wagon (23 spline) or any non LSD side gears are just round and won't work. Other ratio H-190 ring and pinion gears can be swapped into the LSD differential, for sure. Quote Link to comment
Loren O Posted April 9, 2014 Report Share Posted April 9, 2014 Thanks! That should help. Looks like my goom will have to continue to live without lsd,but maybe my 521 will get one,eventually. Quote Link to comment
EastBay521 Posted April 10, 2014 Author Report Share Posted April 10, 2014 I would not expect a radical change in the fuel economy with the different rear axle ratio. Yes, there will be some gains, but the biggest drag on a vehicle moving at freeway speeds is just shoving air out of the way. Air resistance does not change if the rear axle ratio changes. A higher (lower numerically) rear axle ratio will force you to be in the lower gears longer. Fourth gear is the most efficient, because it is one to one, no losses from running power through the cluster gear in the transmission. http://community.ratsun.net/topic/54128-post-your-521/page-20 it made sense when i read this but i didnt think it such an effect on the vehicle. it seems my truck is only efficient at freeway speeds in 4th gear or in 5th doing about 80mph. doing about 65-70 in 5th, the air resistance is very noticeable. maybe an LZ would make it easier to push through the air? I currently have an L18 with a dogleg. i also have this big ass obstruction on the roof i have yet to take it off and see if it makes a difference Quote Link to comment
ggzilla Posted April 12, 2014 Report Share Posted April 12, 2014 Yes, an LZ is easier to push through the air. Air resistance increases with speed. Takes more HP to go 80 than 75. But aerodynamics is only part of the problem. Mechanical friction also increases exponentially with speed. Thats why an L16 gets better fuel economy with a 5-speed (or with a higher final drive). Its not about how it feels. Measure it. A lot of vehicles feel smoother at some speed and that is alignment and vibration. Quote Link to comment
datzenmike Posted April 12, 2014 Report Share Posted April 12, 2014 Not sure why you are changing the rear end only that you are. The best one for the 521 would be the stock one. The L18 doesn't have a lot of power so it needs the gears to be able to speed along on the highway. Going to a 3.889 will lower your top speed because the motor won't be revved high enough to make power to push the air out of the way. It takes 4 times as much power to go 80 than to go 40 and that's just the air resistance. Double the speed, four times the effort. I assume the rear end gear change is to increase mileage then???? Well if this is the case going to an LZ goes completely against this. Yes it will make more power and push through the air better and go faster because it's a larger motor. Seems like you want better mileage and to go faster. This is not possible. Gasoline contains only so much energy and it will only move your truck X distance. You can juggle the motor, differential and transmission around but you can't change the energy available. The 3.889 will be a bit sluggish accelerating and cruise speeds on the highway may need more throttle to maintain. Hills, passing and driving into the wind will require more effort. If you maintain the posted speed limit you may gain a small mileage increase. 1 Quote Link to comment
EastBay521 Posted April 12, 2014 Author Report Share Posted April 12, 2014 the rear end swap was to get better gas mileage and top speed. Quote Link to comment
datzenmike Posted April 12, 2014 Report Share Posted April 12, 2014 I have a 710 sedan automatic L18 with 4.11s in it. It went 90 MPH up a long slight incline. I know that putting a 3.90 or a 3.70 in it wouldn't make it go that fast. I worked out the RPMs to 5,400 and that's how much power was needed to go 90. Changing to a 3.90 would drop the RPMs to (about) 5,100... it's not going to make as much power at that RPM to push the air out of the way. Quote Link to comment
banzai510(hainz) Posted April 12, 2014 Report Share Posted April 12, 2014 a 521 is a 60/ 65mph rig thats it . if you want any kind of gas milage. man that truck looks cool with the patina 1 Quote Link to comment
kelowg Posted August 25, 2014 Report Share Posted August 25, 2014 Well, goin to put 3.88 in my rig with a LZ21. have to see how she does. Anymore interest in 4.11 3rd member needing bearings,mayb keep as spare. Quote Link to comment
wayno Posted August 25, 2014 Report Share Posted August 25, 2014 I have to say that I got crummy mileage with my L16(4 spd.) going any speed, I want to be able to go the speed limit, and my L16 never got even 20mpg(hiway) because I was always floored(437s and stock carb). I put an L20b in it, and I averaged 17/19mpg(hiway), but at least it would do the speed limit, I once went on a trip and let someone else drive it, she got 23mpg, but I will admit that the truck was loaded down with hanggliders and camping equipment, so it likely would have got better mileage unloaded. Now it is a dually with an LZ23, on the trip when I broke it in I got 23mpg going several different speeds(averaging 70/80mph), one time fast enough to break the speedo needle off, and I still did not have my foot all the way into it, I would suggest that I could possibly get over 25+mpg if I could drive 55/60mph which I can't, but I got 23mpg on that trip, going that fast. I have found that since I now have power, I get better mileage because my foot is barely in the pedal anymore to do the speed limit. I cannot give you any recent estimates of mileage, as either I am towing a fully loaded trailer with a flatbed full of debris, or I am towing another vehicle with it as it tows the best of any rig I have because it has the power to do so. 1 Quote Link to comment
thisismatt Posted March 16, 2015 Report Share Posted March 16, 2015 So, who has found an H190 lsd they want to sell to me for my 521? :P Quote Link to comment
wayno Posted March 16, 2015 Report Share Posted March 16, 2015 So, who has found an H190 lsd they want to sell to me for my 521? :P WTF Quote Link to comment
thisismatt Posted March 16, 2015 Report Share Posted March 16, 2015 WTF Well wayno, you seem to have found one, and mike has found one/them... Who's sitting on one they need to unload? Quote Link to comment
wayno Posted March 16, 2015 Report Share Posted March 16, 2015 Isn't this supposed to be in the classifieds??? Well wayno, you seem to have found one, and mike has found one/them... Who's sitting on one they need to unload? Quote Link to comment
thisismatt Posted March 16, 2015 Report Share Posted March 16, 2015 Isn't this supposed to be in the classifieds??? Buddy, it was tongue in cheek. I was reading this thread for other information, but hey, if someone has one they want to sell I'm all ears...just not caring about buying one enough to post a wanted ad. Besides, I can hardly get anyone to ship a fan knob, nevermind a 3rd member. Where's the beef? Quote Link to comment
oldskoolvws Posted March 16, 2015 Report Share Posted March 16, 2015 This is an awesome thread. Does this have any effect on the speedo? I don't believe so but I need to know :) I believe its the gears in trans only yes? I need to find the right one. Its great. Cluster speed 80, truck speed 60 LOL. 1 Quote Link to comment
wayno Posted March 16, 2015 Report Share Posted March 16, 2015 You just need to find out what color you need. 1 Quote Link to comment
oldskoolvws Posted March 16, 2015 Report Share Posted March 16, 2015 You just need to find out what color you need. L20 & dogleg 5. Stock rear, any idea which? Quote Link to comment
wayno Posted March 16, 2015 Report Share Posted March 16, 2015 L20 & dogleg 5. Stock rear, any idea which? No I don't have any idea which one you need, I have the same issue, showing 80/90mph when I am going 60/70mph, but I just live with it, as I am to lazy to fix it/figure it out. :lol: Quote Link to comment
oldskoolvws Posted March 17, 2015 Report Share Posted March 17, 2015 Well are they still available? Maybe I'll buy them all hehehehe. Quote Link to comment
wayno Posted March 17, 2015 Report Share Posted March 17, 2015 If I was motivated I could look at each Datsun/Nissan 720 in every yard I go to, eventually I could find every one of them except for the 488 gears, it's on the tag in the engine compartment. Do you still have the stock gears in your 521, what engine did it come with? What color are the turn signal indicators in your instrument cluster? Quote Link to comment
ggzilla Posted March 17, 2015 Report Share Posted March 17, 2015 You can buy the gears new from Nissan. Which gear you need depends on: * final drive gear ratio * tire size * speedometer tolerance, which by spec varies up to 15% Quote Link to comment
datzenmike Posted March 17, 2015 Report Share Posted March 17, 2015 This is an awesome thread. Does this have any effect on the speedo? I don't believe so but I need to know :) I believe its the gears in trans only yes? I need to find the right one. Its great. Cluster speed 80, truck speed 60 LOL. The speedometer gear in the transmission has nothing to do with the transmission and everything to do with the differential gearing (and tire size if you go to a much larger diameter tire) If you ebver get a differential, get the speedo gear in it's transmission, they are mated. L20 & dogleg 5. Stock rear, any idea which? The 200sx dogleg had a 17 tooth pinion gear in it which is selected to work with a 3.70? diff and what ever the S10 had for tires. If swapped into a 4.375 diff ratio 521 the speedometer will be out by 18% and will be spinning 18% faster than it should. Thats reading 70 at 60 MPH. You would need a 20 tooth pinion gear to slow it down. (this assumes the tire size is close to the 200sx size) Quote Link to comment
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