I have started to get into a lot of road racing and some drifting(not much) on my friends FB who is too big for these sports. he has a GSL-SE with a T2 engine stock rebuilt and ported turbo and tranny rebuilt, motor is also rebuilt and kept at almost stock hp levels. the suspension is RB springs with tokico blue shocks and large RB sway bars. he is now installing a roll cage and some more suspension pieces of rmore adjustability. the last time i raced the car was 3 weeks ago at willow springs raceway. i noticed the rear end was getting harder to get to slide out( in the drifting side of the track) and a bit more difficult to oversteer in the road course( i dont like understeer too much push). i went to look at a few sites to upgrade the LSD and found this website.

http://www.gurumotorsports.com/

they have an upgrade for the FB rearend which is their LSD and also some axles and a 5 lug hub assembly. since we are also goin to go slightly bigger on tires we might as well do a T2 front brake conversion with this 5 lug hub assbly. of course we are going to talk to Comp. Mazda and see if they can make a stronger 3.90 gearset. we are also both hesitant to do so because this company charges quite a bit ( check it out for yourselves) for this upgrade including the fact that they are in austrailia. but we both are drooling for a setup like this. does anyone have this setup here in the states?

 

Your rear end isn't causing this, your suspension improvements are, try disconnecting the rear sway bar end links for a session and your rear tires should break free much easier.

An LSD will help but just find a GSL rear which will also give you disc brakes, but wont chnage your stud pattern.

 

i see... but we are going bigger rims because the tires we use on the stockers flex too much and are looking into a set of 16"s. the reason why i asked this is because the car was so easy to oversteer with the suspension setup and was a dream to handle when drifting before i started to experience this. we will try this in a few weeks once he gets his friend to finish making a brand new harness. the one in the car now is nearly cooked to death. and the dealer is asking too damn much

 

What about just Welding the Rear.

 

i dont want to do that cause not only is it unreliable it won't hold up long once we start to turn up the wick

 

cptpain,
Question, I couldn't seem to find the 5 lug hub assembly on their site. Where did you find it? Thanks!

-Bern

 

its always good to give advise but its bad to give the wrong advise.
disconnecting the rear swaybar will help the car not oversteer. the stiffer the suspension is the easier it is to oversteer.when you disconnect your sway bar you are actually softning the rear suspension by letting the back of the vehicle roll and have less contact on one of the tires. if this helps ovrsteer then open diffs would have done it just fine.
i have a 13brew in my 84 gsl and after a while the same thing happened to me i found that the clutches where going out in the rear.
i got another rear and shimmed the clutches and its been like 4 years now of flawless perfomance even with almost double to hp.

 

How is it unreliable?

A Racer I know does this with out any problems.

 

works and works well are two different things dude, w

elded diffs tend to crack in strange ways, the stock ring and pinion gears are often made of cast steel, this makes it very difficult to weld without inducing stress cracks in the metal hence the often time inopertune cracking, think, you weld the gears in one spot, they eventually let loose, and the diff rotates 270 degrees, or however much it can until it hits the welded spot again, then it suddenly locks up when it hits the welded portion. the amount of driveline shock it introduces is unbelievable, much higher that the 50,000~80,000 lbs of strength of the original cast steel, or the mild tubular steel of the driveshaft, now this is fine and dandy in a 1/4 mile car, but in a circuit track, or road course the sudden failure of the rear axel will likely throw you in a spin or worse.

kenn

 

This guy runs road racing and only brakes one every now and then. plus the Open diffs are very cheap.

But whatever is best for you.

 

Years ago I broke a spyder gear in my 65 Barracuda, so I welded them up. This was basicaly a stock engine and drive train. After breaking the gears and rewelding them 3 times in one summer, ( I was a certified welder at the time), I gave up and bought a used posi rearend. Normal driving around town and cornering just put too much stress on the gears and the welds. It may work fine on a road course with wider turns and full throttle to break the inside tire loose, but it just doesn't last with in town, sedate driving, and 90* corners.

 

you're right, but you're really wrong too. with the rear sway bar disconnected it will allow more movement and allow the rear suspension to reach the bind point and, boon snap over steer! I've run with and without the bar on and i highly recomend keeping it on the car! unless you like what everyone is trying to enginieer out of our suspensions snap over steer and bind.

 

i did autocross for several years and i tried leaving the sway bar on the back but the car was just too stiff i guess spring rate also did not help, but taking it out helped alot . see there is alot of factors tht come into play too , drivng style and the hp you are running.
for example i driver that jerks the steering with sharp movement will have oversteer no matter what , also a 1st gen with 400 rwhp will oversteer going in a straight line

 

it should be right below the LSD..oh nevermind i miss-counted the studs on the hub, it just changes the hub to a floating hub design that comes with new hubs and axles

 

its in my experience that welded diffs dont appeal to me ( i like them for other people, not me) a friend of his used to drag his car and would run a high14 on his NA FC until one fateful day the ring broke and cracked the casing. it wasnt a pretty sight.