What Type Of Rearend Does The Sc 430 Have? Is It A Limited Slip Or What? I Have An O6. Just Curios.

 

Wishful thinking buddy. We have 'el cheapo' open differentials on our $60K+ cars with V8s.
Sorry to be the bearer of bad news. Take care.

 

yup, all lexus 430 drivetrain has open differential, including 06. but from what i read on the ls430 (04+), it's gear ratio is changed from 3.26 to 3.76

forgot where i read that

 

Really? Simple way to find out. My '04 car shows 61 mph in top gear (5th, obvioulsy) at 2K rpm (92 mph at 3K rpm).
Can somebody with an '02/'03 post your results? How about you Henry? You have an '05, right?

I sincerely doubt this change, but could be wrong. I always thought the rpms in top gear were kind of high on this car. My much heavier (6-cyl) Acura shows 70 mph at 2K rpms. Good day.

 

06 went to 3.76 rear end, compensated by the new 6 speed trans. not sure if the available LSD units out there will fit in that pumpkin. Would be a nice and easy fix as 3.76 Supra units are rare.

 

yeah jc, its hard to compare the rpm coz' they went with 6 speed for 06 as well. i bet that's why they go with 3.76 gear go compensate the 6 speed. for my 05 (old gearing), at 80mph it's about 2800rpm. my gs400 (same tranny setup) with 3.76 gearing it's 3000rpm at 80mph.

and actually personally, i don't really care about the lsd that much. when i got the supra 3.76 unit for my gs400, i actually cared more about the 3.76 gearing more than lsd. lsd is useful when you really push teh car hard through corners and such. otherwise normal differential would be ok

 

I would assume it would help with the 1/4 mile time also if you happen to peeling out?

 

well like i said before, if the road condition is pretty much the same left and right, when you drag, both wheel will get the same traction. keep in mind, the design of open differential is that when both sides are equal, they get 50/50 traction. but only when one side is losing traction, that side (losing traction) is starting to spin instead of the other.

so that means lsd is most useful when you are on hard corners when your inner wheels are kinda "lift off" and losing traction, that's when lsd is useful and put traction on the other side.

that's why i said unless you push the car so hard on daily driving where you take corners very hard, otherwise, you just make the turns and then gun it, you are not really losing that much traction.

and if you talk about race on the freeways, even if you are talking about in and out traffic, you are not going to "lift off" one wheel. racing on the streets where there are hard corners? you will have to go pretty fast, i am talking about 30+mph on corners. might as well re-think on those race or driving style

 

oh and for example, my gs400, when stock, had open differential. one thing i was out doing drag myself on local street to test the g-pro, and i left nice tire marks on both sides

 

i dont have alot of experience with rear wheel drive cars but in my fwd car the tranny was close to one side thus causing more wheel spin on one side when launching.

 

A LSD is also good for helping the car rotate (over-steer) under power and will help stablize the car when not under power (engine braking).

I think the biggest reason why there was no LSD on these cars is because of the maintence of the LSD. The one in my Mcoupe always had me worried, its not cheap to have them rebuilt.

Ken 02 SC430
99 R6

 

Many many posts in these forums of the pros and cons of LSD. A LSD can be very dangerous in corners as once both tires start to slip the car will flip around faster than anyone can control. That fast. it is great for dry controlled corners and also for drag racing in the dry where traction from both tires will get you out of the dig but wet conditions=scary. But then the factory electronic traction control is also dangerous in how it zaps your power when leaving an intersection in the rain at even moderate speeds.

 

Two things.
FIrst, yes Henry, I was talking about pre-'06 cars, of course. Well, if your car turns 2800 rpm at just 80 mph, there were changes for sure. Mine turns 92 mph at exactly 3000 rpm. And I think that's already high. My Acura turns over 100 mph at the same 3000 rpms, and it's only a 6-banger (and 5-sp auto as well).
Second, the most compelling reason to have LSD is for a quick getaway when turning 90º into a fast intersection. But as previously said, the stupid traction control is my biggest complaint about this car by far. Sometimes I forget to turn it off when I hit a 'T' intersection near my house where I need to accelerate quickly into the 50 mph (a lot higher sometimes) traffic, only to have that darn system shut my power down for what seems like eternity. And even when I remember to turn it off, it's extremely easy to break it loose. I bought a V8 to be able to take off quickly if needed, but in this case, a Civic can take off quicker than me . Oh well. I still love my car .

 

lol, jc, well if the car break lose, that's loss of traction right? that's why the vsc was trying to save you with lsd, it might hold better for a while, but if that's lose too (and believe me, with 3.76 and lsd, it's EASY), like lee said, you are gone

 

The surface is asphalt, and no sand or anything slippery. The traction control is just ridiculously sensitive. I can take off much quicker without it, and even though the car is peeling off a bit, I don't have to make any corrections, so don't think I'm going full throttle or anything aggressive. The LSD would help to take off much quicker due to 2 tires getting traction, not one.

I know traction control is a desirable feature, but Lexus needs to do a MUCH better job, and let it step in like on BMWs, when it's really going to save you... not cause an accident. There're actually TWO problems: it kicks in WAAAY to soon, and it takes forever to let the power back on. And the latter is what makes it particularly dangerous IMO. This is not a deal breaker on this car at all, but it's a fair criticism. Hope you're not one of those crazy hard liners who can't stand anything negative said about their cars; it's just a car man, and I have one too. Take care.