Aron9000

I generally don't like to abuse my baby. So I've never really experimented with launching her HARD for that best e.t . . . .


BTW, car is a stock 1992 SC300, 5 speed, still original clutch with 71k miles. Only mods are some 18" Lexus dealer accesory "spider" wheels, with new Pirelli Pzero all season tires. 255/35/R18 in the rears. I know for one thing these tires are a lot stickier than the worn 15" goodyear eagles the car came with.

I know that a 3000rpm clutch dump results in a little wheelspin and some NASTY wheel hop, which I want to avoid. Slipping the clutch at lesser RPM just kind of bogs it.

So how do you launch your 5 speed???

I've had a couple of seriously fast automatic cars in the past, but that was easy. Brake torque it till the rear wheels spin just a tad, lift off the brake and ease into the throttle and feather it a bit till your foot is on the floor, slam into 2nd, more wheelspin. Main rule of thumb was to have it pointed in a straight line before you put the hammer down. Just slamming the loud pedal from a dead stop would produce a nice smoke show, you weren't going anywhere quick though.

At least with this Lexus I feel confident using all the power coming out of a corner, ie it won't try to turn ends with me like my old automatic LS1 Camaro. IE put your foot down coming our of a corner going 20-30mph, it slams into 1st, sends you sideways. Do the same thing coming out of a corner at 45-60mph, it slams from 4th to 2nd, your arms better move damn quick if you want to catch the slide. Do this nonsense when its raining or on a washed out/gravely road, you kill yourself.

uras300

iTrader: (2)

The answer is you don't.

Launching a car from a dead stop puts tremendous amount of stress on drive train. Majority of our much beloved SC's are nearing 20 years of age and considering you have no upgrades on your SC, it is likely that you'll break deteriorated parts in the process.

However, since you mentioned your experiences with 3000rpm clutch dump and other unsuccessful launch attempts, I'm assuming you'll try again anyway. So, here's a step by step for you.

1. Purchase a W58/R154, clutch, differential, and all stock drive train associated parts for the likely event you'll break them.
2. Evaluate the pros and cons of said repair cost versus having fun a few times from a dead stop.
3. Launch the poor SC anyway and ruin a perfectly good SC.

On a serious note, you should enjoy your stock SC in the winding road, just as the grand tourer Lexus intended it to be.

bmxkeeler

To launch it your best bet is to preload it with your e-brake. Then come out hard with your clutch soaking up most of the launch. You want to slip your clutch easily and slowly that way the drive train doesn't absorb the energy from the launch. This will cause the least wear and tear on your car and the smoothest launch. You'll eat through clutches doing it this way but shouldn't break anything.

mikef

iTrader: (3)

what about a v160, are they any better from a dead stop launching?

ArodDaLob

iTrader: (14)

get worn/thin tires in back and rpm drop that bish. the lack of traction helps lessen the strain on the drivetrain. the resulting smoke will attract those of the opposite sex as well. win/win situation.


disclaimer: don't take me seriously. please.

SCstone

haha I agree with uras300 and I want to agree with arod. but usually tire smoke attracts the same sex.

IMO you shouldn't be treating your stock 71k 5spd SC like a LSx camaro. this isnt a redneck drag car or a Honda this is a luxury version of Toyota's flagship highway king built for the downhill and you should treat it as such. trying to figue out a good launch for your GE is like playing football without a cup.

RicoLSX

I guess I'm the only one trying to do standstills and trying to kick my non-LSD SC3 sideways around here, LOL. Well that stopped now that the 18s went on.

While on the subject, how well do the driveshaft/rear diff/half shafts do with power? I see the turbo guys making pretty big HP figures, not sure on TQ though. I'll be putting down 500rwhp give or take and 450-470rwtq but at a lot lower RPM (LSx motor) probably than the turbo folks.

Ali SC3

iTrader: (10)

step 1. add rpms
step 2. try again
step 3 (optional). fix wheel hop

and for the differential, the unit itselves are strong, but the open diff's will self destruct at higher torque levels if you get into a situation where you slide and end up pumping all the power through one wheel. The lsd unit is a must for reliability but you may be able to get away with that level for a while.

KahnBB6

iTrader: (5)

I sort of launch mine but not really. There isn't enough NA power to warrant doing a crazy launch and reap any benefits considering how hard it is on the clutch if you tend to drive your car every day.

If I'm trying to go fast I'll engage the clutch normally but from there on I floor it and go through the gears. Easier on the drivetrain as most have mentioned. Even built R154's are much happier if they aren't launched within an inch of their lives.

The diffs are strong. LSD's do help but the Torsens can catch you off guard in the rain if you aren't used to them or you haven't modified your alignment to Lance spec. Or it you are running BFGoodrich KDW tires in the rain (cliffs: NOT a rain-friendly tire!). The right tire, however, is extremely safe in the rain with a stiff suspension, LSD, TT rear sway and Lance alignment. I currently use BFG Comp2's.

A stock SC300 5-speed behaves VERY differently (more docile) in the rain than an SC that is set up like that, however I think the independent rear suspension versus a solid rear axle has a lot to do with that.

stockhatch

iTrader: (12)

I've said it before and I'll say it again...trebuchet.

KahnBB6

iTrader: (5)

^^ LOL. Yes. They can be tamed a bit but... fundamentally yes

lookEVO

iTrader: (1)

Just dont.

Its a heavy car that isnt meant for drag racing and you havent modded anything anyways.

aragundicm

the resulting smoke will attract those of the opposite sex as well.

Aron9000

Well thanks for the honest replies, although I could have done without the sarcasm and bull****.

I really haven't ****ed around with it much after inducing some serious wheel hop a couple of times. I was mainly looking for ways around the wheel-hop, but it seems its kind of inevitable if you launch the car aggressively with the stock suspension setup. Which I really don't want to modify.

This is the first car I've owned with an independent rear suspension and less than 350hp. Past cars have included that LS1 Camaro, a 1995 Cadillac Fleetwood with a bunch of mods, and a 1979 3/4 ton GMC truck, 2wd, 4 speed, and a hot 383 SBC under the hood. That truck was just damn silly, no traction AT ALL with the stock sized tires.

2o7SC3

Without mods you really just don't, not to say im not guilty but a regular roll and banging a few gears seems to be the best way to not feel as if you're wishing death on your 5 speed.