I have a roadster rear end and a 200sx rear end. i would have to modify the 200sx because it uses a spring and lader setup i believe but i know it would be worth it .. see the older 200sx axel is not as wide as the new ones i think .. i will figure it out i wana stay away from a huge drag project.. with biggger slicks and stronger rear end i wont need to tub or even mini tub yet. this ka24de is maybee pushing 190 to the fly. my build one is pushing 300 to the flywheel. Built similar to the nissan offroad truck ka24de project with weber induction. I also forgot to mention i do have traction bars under this 1200 .. when i jack up car from pumpkin , right when rear end is lifted the body lifts as well .. really stiff in back. i think i need to make it sink a bit on the launch .. i dont know .. thank for all your guys input. i will keep u posted on the project and i will submit some photos.. and btw the axles were out of the vehicle when i welded the spider gears.. and i have broke 7 axels in 2 years.

Nice Pun Pro!

You hit the nail on the head..... something is wrong with the weight transfer. And when he gets the weight transfer right, and the rear end hooks up, it will put even more stress on the axles.....

There has to be a balance though.....and the balance is simple (to me anyway) - make it as light as possible, but still reliable. Sometimes it can take some trial and error to find this balance.

yeah lightweight is cheap horsepower. but horsepower is useless if you can't get it to the ground!

the thing is, it's wheelspinning with slicks - so something is wrong with the weight transfer. a set of 90/10 shocks might do the trick up front, but they're plain horrible to drive with.

i mean, ANY diff will prob be heavier than the one you have in there - so it's just a matter of how much heavier. the 9in will be about 55-60kg more than a hilux / BW rear end - depending if you run gearsets or a full spool.

if it were my car, i'd choose the commodore / skyline BW and fit up a 4.5ish detroit locker. i'd keep the std leaves and just run a 2link / trampbar rear end instead.

but that's just my o-pinion....pardon the pun

I would stay away from a Ford 9 inch. Strong, yes, but it will also cost you 3% more power to turn than say, another unnamed rearend that uses 12 bolts to hold the ring gear on. The 9 inch meshes the pinion low on the ring gear, bad for friction.

It may not COST you power on a dyno, but in real life, in makes the car slower....wether it be cicuits or drag racing.

Also, the diff is unsprung weight.....which is even worse than body weight.....keeping unsprung weight down to a minimum is key. The extent that my mate has gone to, to reduce the weight of his diff in the sprinter is incredible, but it is significantly lighter than a standard sprinter diff.....and it also helped the car turn quick lap times. It also broke at the last race meeting , after 12 months of hard racing, and a fair amount of testing. He is now considering going to a full spool set-up - which is stronger, and also lighter I believe.

I wonder if the axles where removed before welding???
If not, could the heat from welding the spider gears have
anealed the axles????

I must strongly disagree that adding weight to the rear of the car is good.
Weight transfer..yes...but just weight no!!!!!!!
There are better ways of improving traction without adding large amounts of extra weight.

no denying that at all - less intertial resistance means the engine can use it's power elsewhere.

but a heavy gearset / tailshaft / whatever wont COST you power, it just moves it from the wheels to the heavy rotational items.

funnily enough, you'll still record the same power at the wheels with or without a lightweight drivetrain item(s).

You also have to consider how much power it takes to get the heavier diff assembly (gears and axles) spinning. The lighter the internals, the less effort it will take to get the whole lot turning.

As an example, a very good friend just had an experimental tailshaft made for his car. It's an all aluminium tailshaft, wrapped in carbon fibre, and weighs half of what the original tailshaft weighed - the difference in engine response and acceleration was quite noticable in the car - and the lap times were quicker.

i don't see how a diff can cost you power.

people go on about strong and heavy diffs adding weight and killing 1/4m times. but the trouble is, a strong and lightweight diff doesn't put enough weight over the back wheels to get traction - so the benefit of low weight is offset by no traction andyou're back to square one. at least with a strong and heavy diff (ala nine inch) you get the bonus of traction AND an unbreakable diff.

i'd go the diff you mentioned if you have it just "laying around".

The 510 wagon rear diff has 23 spline axle that are 24mm diameter. These are very small for the torque you are putting through them.
Try modifying the rear from an 80's 200SX V6 to fit, as these are more than adequate with 29 spline 30mm diameter axles. These axles are used behind 300 hp V6 VG30 engines regulary in rally trim.