How bad is the j30 lsd?

[mkory]

Since the gearing's taller in the j30 differential, I've read that swapping for one will make my car more sluggish, unless putting down SERIOUS power. My engine is completely stock, and I'm wondering how bad of an effect will the j30 differential have?

[SHIFTrl240]

j30 has same ratio, j30t has taller

i am testament that the j30 diff i have, out of a 93 j30, does not have taller gears.

[sactos13]

I don't think the difference is much more than barely noticable. Tire size I think would be more crucial, that is unless you already have 17's on your car or something.

For instance:at 100 mph, 24" tire (205x55x15), 3.916 ratio (j30), and 0%slip (manual) gives a trap rpm of 5485With a stock ratio of 4.083636 it's 5719 at 100 mph

I'd say the vlsd is more beneficial than the loss of ratio, which you can easily overcome with a smaller tire if acceleration from the line is your goal.

This was calculated off tci's websitehttp://www.tciauto.com/tech_in...tm#12

Here they say there are some different ratios. but I wouldn't let that hold you back. They even get a little foggy there....http://www.ka24development.com/vlsd.html
Modified by sactos13 at 4:25 PM 10/15/2004

[808DRFTR]

I heard it's better esp. if you have a turbo cause of the ratio. Only thing is if your car is ABS/Non-ABS. If Non-ABS you may have a problem with your driveline being too long, iirc it has to be shortened ".75 or get a driveline from a ABS 240

[Darius]

Since the stock ka isn't that torquey, it is noticeable. I'm not worried about power now because i am saving for the rb, but that's just me.

And sactos13 is right on with his numbers which equate to 4% taller gearing. I got a speeding ticket last night for going 75 in a 65 when I had the cruise set at 72. (4% difference) And what a little biatch for ticketing me for that, what a joke.

[kamikazestorm420]

ka is torquey.

[VA240]

If you're going to stay N/A you should also consider finding a JDM 180sx diff with 4.36 gearing. IMO much better overall gearing for street use and acceleration.

-VA240

[driftin8ez]

i too have a j30 vLsd and may engine is completely stock besides and exhaust and intake but like i said my power is completly stock. At worst case the vls will have a 3.9** ratio. I have noticed a little diferance in lower rpm when trying to take of. Such as a lane change at 50 in 5th gear. But when just going from a stop and launching you can really feel the differance and it is way faster of the line than my old 1 wheel drive. oh ya and that crock about the abs sensor being so much longer that you need a new driveshaft is bs. The driveline has about 1.5" of slack if you really forced it so the abs sensor making the vlsd .75" longer does not hurt anything. Just slide the driveshaft on it will work.

[mkory]

I wouldnt think a 4% taller ratio would be that big of a difference. Is it really that noticeable?

[574-240sx]

You will eventually run into rear main seals going out in the trans. When the driveshaft get shoved further into the trans it starts to eat the rear main seal. I had to replace mine after 3K. Thats also with alot of drifting, 3 drift practices and a 1 competition, not including all the playing. It takes about 20 minutes to a hour to replace a main seal depending on your mechanical skill level. Rear main seals run about five bucks at the local parts store.

[Darius]

Yes the extra .75" does hurt the transmission. You need play in your driveshaft and the ABS sensor takes up 95% of that play. I have an auto and the thing drops into and out of gear really hard, so if you're gonna do it right and care about the life of your transmission I'd suggest getting an ABS driveshaft.

[clearview]

i put a j30 in my 95. i does throw the speedo off enough to get a ticket. i dont have abs so i replaced my driveshaft. it was nice to have vlsd.i replaced the rear with another with Nismo lsd and 4.63 gears. that throws your speedo way off but your going slower than it reads. the 4.63s are fun with JWT cams.

[Nissan-S14]

ok.... I have a 95 240sx with a 95 J30VLSD, quicker 1/4 mile time, much better burnout, much better to drift, that is if you had an open diffy before. But im sure a KAAZ or any other LSD will be way better then the J30, but it does its job for me just fine. My 1/4 time droped from 15.7 to 15.3