gwu128

It was at Saturday afternoon, road was wet. I was at an intersaction waiting for the light to turn green. when the light turns green, I slowly took off, the car was rolling about 10~15mph, than I step on the gas a little bit more, suddenly my car just got loose control and the rear end start skid to the right, my car start to spin and hit the center divider, luckily the car stop.
My question was, does anybody has this exprience with their car, I am afraid to let my wife drive this car now, what can I add or change to prevent this happen again. (maybe install a LSD?)

I did install Precision Torque Converter on my car, I also have 19" wheel 245/f & 275/r, the tire still have about 80% tread on them.

I need to solve this problem fast, thanks in advance.

GW

willard west

If your traction control wasn't turned OFF then it has FAILED!

LexusRules

LSD will help a lot... also look into different tires that are better in the wet. If you are really serious consider wider rim and wider tire

mayandoom

Even without the TC upgrade, your car will skid to the right as the rear right tire is the first to go unless you upgrade to a LSD. The Lexus Traction Control system is great in that it allows a certain amount of wheelspin before kicking in. It allows for better launches from the line. This is not so great if your next to a guard rail and your car gets a little sidways. LSD upgrade is in order. Hope the damage was not bad.

gwu128

I have Bridgestone Potenza S-03 on my rear wheel, It there anything better than this?

I guess I need to call Steve and order the LSD for my toy.

willard west

I would go out of my way, go the EXTRA mile, to find someone who has tried this already. The Lexus ABS/TRAC system is four channel and so it should be able to do a better job of allocating torque than an actual "mechanical" LSD.

You could also find the two systems "fighting" each other, mechanical LSD actions slower and thus completely out of sync with the much faster acting TRAC.

You might even find yourself with broken rear axles as happened to many high powered cars in the early sixties with the early versions of LSD.

If you can't find anyone who has already tried this out do you really want to be number ONE?


The LEADING edge is more often than not the BLEEDING edge!

LexusRules

dude... many people already have LSD... it works good and ur talking about early 60s american garbage..

the trac cant do anything except take away poewr and apply brakes, the LSD puts power down evenly to the tire with most grip... TRAC or VSC cant do that.. thats a mechanical part.. subarus can do it because they already have the right mechanical parts.. either that or they lie in the commertials

enginyr

I have the same problem with 245's all around. I figured the 275 would solve this problem. I don't understand how you can post something like this with all the mods you've done?

willard west

I didn't say LSD didn't work great, it clearly does.

But my questioning of LSD was its use in conjunction with TRAC.

And the early sixties axle breaking problem was caused by the "LSD" (wasn't called that but at the moment I can't remember what it was called) sometimes "swapping" ALL of the torque from a 300HP erngine too quickly left, right, left, and right again with so much suddeness that it snapped the axles.

And that's what I fear might happen with BOTH systems installed and simultaneosuly active.

Now let's assume he's WOT and one wheel breaks loose and begins to spin. The LSD will start winding up its clutch pack so that more of the torque is allocated to the other wheel. If the spinning wheel happens to be setting on a patch of ice or an icy roadbed side, or just simply does not have enough "tire patch", traction, with the roadbed to "absorb 50% of the engine drive torque, then eventually half of the torque ("limited" slip, remember!) will end up on the wheel with traction. If it starts spinning too then of course all is lost and the only thing left to do is lift your right foot.

But let's assume that the left wheel has enough traction that it doesn't break loose but the right wheel continues to spin freely.

Now, wouldn't anybody, recognizing what is happening, and being of sound mind and body, get his foot out of the throttle?

And now that's all the TRAC system is, an LSD implemention with a little human "thinking" logic build into the program, if the TRAC system cannot act to prevent wheelspin then after a few milliseconds it starts to dethrottle the engine, just exactly what you would/should do except not quite as quickly.

Oh, what you really wanted to do was "burn-out and create a low of black rbber smoke"! Then turn off the TRAC and go for it.

Oh, should I point out that had he had the TRAC turned on there would have been no threat of hitting that guard rail.


Go to teamseattle.com and post a question for one of the drivers, ask if TRAC doesn't force more torque to the roadbed than does an LSD?

LexusRules

thing is.. it doesn't happen.. at least not with any cars under 500HP so far.. besides when u launch a car over 500HP and the wheels start spinning.. they aren't gonna re-grip the road they are gonna keep spinning.. one slip two slip boom burnout...

LSD is the answer for the wet road problem

bitkahuna

iTrader: (20)

LSD only helps in turns, not going straight.

bitkahuna

iTrader: (20)

A car with 300+HP, high performance torque converter, very low profile performance tires on 19s, wet conditions... HELLO?

LexusRules

when going straight i thought the LSD will only put power down to the tire with most traction.. or a certain % of the power...

stock if one tire starts spinning most of the power will go to that tire

wwest

You buy them books, you send them to school...

LSD, Limited Slip Differential. Operates ANYTIME one wheel turns faster, sustained, than the other, going straight, sideways, turning, upside down, etc.

Those little gears have no idea how or where the car is pointed, they just know, "hey, that other guy is moving faster than me, I gotta catch up".

The LSD's clutch application rate is designed such that it will not come into play in an ordinary, moderate, slow and easy, turn.

"Aren't gonna re-grip..."

You just pointed out the very tremendous advantage of TRAC over LSD!

Even with WOT TRAC will brake, slow, the spinning wheel/tire and possibly give it a chance to regain its adhesion with the roadbed.

As long is WOT is maintained LSD will allow the wheel (or wheels) once spinning, to continue spinning virtually tractionless.

There is a new type of LSD now available in the racing venue. The rear driveshaft feeds two completely independent viscous clutches, one for the left and one for the right. If either rear wheel does turn at the speed of the input driveshaft then that VC tightens.

gwu128: was the TRAC off?

///MDex

A wider tire? He's running 275s.