Tasmin Diff

[NTEL]

Hi, I'm currently running a 4.09:1 ratio open diff in the Taz racer. Its OK with sticky tyres on but when driving in cold conditions with cold tyres I'm getting too much wheel spin. Its crap from a standing start as only one wheel spins up and I can't get the power down.

I'd like to convert this to a POWR-LOK LSD. Does anybody know where I can get the necessary bits from or has anybody got a spare one sitting in the shed?

[Graham]

what engine are you running and what sort of power.. The powerlockers dont work well with the 2.8. Its not got enough torque to get it to work properly and it screws the handling completelty, as it locks and unlocks... totally unsettling the back of the car in big fast corners (i.e. gerrards at mallory) It does help you off the line though.
You either need to get a powerlocker specially built or a much better option is to find a quaife unit..

you can compensate a bit for lifting and spinning the inside rear on corners by making and fitting a rear anti-roll bar

Cheers

G

Edited by Graham on Tuesday 6th May 11:33

[NTEL]

Graham said:

what engine are you running and what sort of power.. The powerlockers dont work well with the 2.8. Its not got enough torque to get it to work properly and it screws the handling completelty, as it locks and unlocks... totally unsettling the back of the car in big fast corners (i.e. gerrards at mallory) It does help you off the line though.
You either need to get a powerlocker specially built or a much better option is to find a quaife unit..

you can compensate a bit for lifting and spinning the inside rear on corners by making and fitting a rear anti-roll bar

Cheers

G

Edited by Graham on Tuesday 6th May 11:33

Hi Graham, Its got a John Toovey built, V6 2.9L Cologne (carbs)running at about 200bhp. I've priced up a quaife unit but I can't afford one. Have looked into the rear anti roll bar but have been put off that because of alledged handling problems.

I believe a couple of Tasmin racers have had the diff "welded" up in the past. Any idea what effect that would have?

Edited by NTEL on Tuesday 6th May 11:52

[broadside]

Locked diff will push the back end out into a slide as the inside wheel that would normally run at a different speed to the outer wheel with a normal diff is turning at the same speed with a locked diff causing the back end to skip or slide depending on the amount of grip through a corner. The other thing you can do with a locked diff is drive the car on two wheels, thereby driving between the narrow gap of the two cars in front and taking the chequered flag in a spectacular stylee.

I hope that helps, sort of......

[Graham]

I'd be very surprised if any of the racers had run with a locked (welded diff) on the circuit it would give you some interesting handling, and tear the tyres apart quite quickly...
Maybe on short sprints, without big corners you get away with it but you'd be very sideways.

As your sprinting you might get away with a powerlocker, but I'd Try supension settings at rear arb first.

when we took the powerlocker out of my taz ( run it since it was built) and put in an open diff with a ratio that was too high ( bit of a pita the ratio, broke diff so had to bung one in quickly then regs said you had to stay with that ratio all season). We went from mid field to taking the class overall and several lap records with no other mods to the car and a season old motor...

Starting with the locker in the car I didnt have enough experience to spot the handling issues, took it out and it was like night and day on the handling, yes you could spin up the inside wheel ( we did some very odd things with the rear end setup at mallory to get round this) but much much easier to settle the car in big corners rather than having to fight it all the way round...

we put it back in for the birkett as the high ratio would have been a bugger in traffic. I only got a few laps before the motor dropped a valve, but I quickly realised how undrivable the car was with the locker in there...

The locker I used was a brand new unit, so maybe a 2nd hand well worn unit might work a bit better. You can get them fiddled with to work with the weight of the car and the power of the engine but need a specialist to set it up. remember the Jag probably has twice the weight and twice the torque.

cheers

G