Diff. Gearing

[jrad240sx]

ok i was wondering about the gearing in the differential. i have a build thread of my motor. i have a extra diff that im going to weld but i dont know if i want longer gears or leave the stock ones. i got my car up to 142 and wanted to know other peoples opinion. i use it for a daily driver i made a 152 hp on the dyno dynamics. i don't know that much about gearing but i do know quiet a bit about the motor itself. my build thread is Jrad240sx Build

[IBustV8s]

i wouldnt put a welded diff in a dd. to unsafe and handling goes to s*** also u will go through rear tires like a fat kid eating candy

[jrad240sx]

Well my buddy does his as a daily driver for about 2 3 years now. I go through tires like crazy anyways. And through town I can't stand one wheel racing I can just feel my power wheel not catching traction till end of second. I'm mainly wanting to know if there is other gear ratios I could put in? If not I'll just stick with stock

[compactfean]

Im running a welded right now and granted the traction is awesome its not worth the hastle. Around corners it will slow you down. My camber is at aboout -2 in the rear and my tires wear ridiculously on the inside which didn't before. If you want more top speed you could go with a j30 rear end (which is viscous LSD) and 3.916 gear ratio but wouldn't go with much taller until you start making more power. If you think welded is your preference stick with stock. Welded also puts alot of stress on the subframe and bushings. I've had to replace alot since I put the welded in. Also if it even rains you will under steer like crazy. The car only wants to go straight no matter what.

[jrad240sx]

Well I know about the j30 but I don't know if I want that one either. I don't like the idea of fluid makin it lock up but hell I didn't think about putting stress on it.... Hmmm Well i just hate j30 are so expensive and not really worth the price in a way cause I heard those don't last as long either. I REALLY appreciate ur opinion and experience in the matter! My car is mainly a fun daily but maybe just weekend driver in racing on the street and possibly some track days not many because I can't afford alot of drifting but I definitely love going fast and side ways pulling out of places. My buddy has a j30 and I might just need to ask him if I could drive it to see ya know

[compactfean]

Its too bad you don't live in Reno! There is an untouched 300zx and a 240sx and both have vlsd. At pick and pull. I feal ya on the fluid theory but i Ended up getting a j30 put one shim in it and got a one piece driveline because I can't take it anymore. I'm just waiting on my bolts for the j30 (which are hard to find). I will say I couldn't catch traction from 1st through third till I went welded, then I started eaten vett's. (They still pull on me at lower speeds) but you will definitely get sideways and have traction either way you go. Honestly the open end is garbage anyway so why not try welding it. Its way cheap and if you don't like it try something else. Fyi I've. Busted 2 axles and had to replace all subframe bushings.

[jrad240sx]

oh nice lol well i drive it hard for a daily and i just think that fluid would get to hot to quick to often lol ya know but how many horseys you got on yours cause i only got 152 to wheels hopefully going turbo in future. i have extra one to so if not i could put open back in or at least during winter weather....

[compactfean]

Its sad but. I've never dyno'd my car. I actually overbuilt my motor for the Turbo I'm running (hks sleeves...the whole nine) but I've got my gt3071r maxed at 25psi on pump gas. If I were to do it over again I would have went ka-t with a gt3082r with a t4 flange. Actually in the winter it was easier for me to get around on the welded, just really scary to turn. If you weld it make sure after your done welding the spider gears, make sure there isn't any slag on the ring gear and it moves freely. I learned that from the Guy who welded mine. He said d if its not clean it can cause issues.

[jrad240sx]

you got sr? i have yet to learn all the turbo stuff and how the little stuff works and what not but i got the motor down easy. is yours a daily at 25 psi? yea ill ask my buddy all about it when i weld since he has had his for daily for long time. and i bet i almost got caught on the flat spot on top of a hill cause i had one wheel spinning....ill clean it up best i can and what kind of oil should i run with just the stock gearing welded? figured it might need thicker oil? possibly synthetic?

[compactfean]

Yeah its a SR and I have a avcr to control boost so I go from mode a and hit the scramble boost button (I know 2 fast to ferious but its tight) mode a is 10psi mode b 15psi and scramble. At 25 and all daily. Driven. You. Wont need any special gear oil and if your n/a I personally would go with 4.36 gears found in Nissan frontiers I think.. it will kill your top speed but will definately help your acceleration. You would need ring and pinion. Gear.

[jrad240sx]

lol nice thats funny! well i like top speed i would just want a little longer would i go boost but i guess for now it will be fine i really just want more traction and to kick it sides easy breezy lemon squeezy lol. but not a bad idea for a track car! cause i planned on way down the road turning into track car if everything is not wore down by then....and i might run synthetic cause makes me feel all warm inside knowing i have syn. hahaha factory weight gear oil is fine?

[compactfean]

Yep. I've been running oe gear oil with it over a year now. Yeah that's kinda like me...for the welded I used the cheapo gear oil. For my viscious I got some synthetic. It sounds like your going this route so my best suggestion is get some ruca's and get it aligned and have them set your camber to 0 (you could even do like +.5° so when the rear is under a load the tires are perfectly flat) this will give you even more traction and make your tires wear less severe.

[jrad240sx]

well the only thing i will have is a full gas tank and and i only have some 1inch drop springs i dont know got them off another car i bought so didnt know exactly how much of a drop. i have 17s on them right now but i was thinking sometime when i use all my tires up for these rims im going to like 15s but i want a little wider i think mine now are like 205mm whats too big for the front turning without getting spacers or something else?

[compactfean]

Any kind of drop your stock camber will not go out far enough. As far as rims. I've seen. 8.5" up front and 10" in the back....its all about offset when it comes to not using spacers. Rims get expensive in those sizes though. I'm running 300zx wheels which are the tt so 8.5" rear 7.5 front with five lug conversion. And for s13's I had to use 10mm spacers in the front. I also got achiba studs and truck. Lug nuts. If I went with a smaller tire I wouldn't have had to use spacers but it really all depends on the rim tire combo.

[jrad240sx]

i dont know it in inches but i want to get some negative offset dont know how much but i am going to get 15s eventually with some like 55 series tires and i would like some like 245mm at the most....but i appreciate the help ill get back to you eventually when i talk to my friend thanks