feejap

Hello all,
I just acquired a 1998 UCF21, and after having driven 30miles I put on coilovers and 19s (staggered)..
As I drove home, I noticed that the VSC light comes on (brakes applied, loss of power) especially when I am turning left at over ~40mph..
The 19s I put on are from my friend's ex-UCF21. They fit perfectly but I believe the front tires would need to be replaced soon..

Anyone know what this problem is? It's not only annoying but dangerous because it actually grabbed the brakes once while I was in a corner..

Any input would be grately appreciated..

Cheers
Jeff

JBrady

If the system senses unusual (not stock) rates of tire rotation it will assume that loss of traction is occuring which is one of the parameters that the VSC is designed to monitor and control. This could be that the front tires are worn and actually are slipping relative to the rears during a turn OR possibly more likely the tires have a different total diameter resulting in a variance of speed between the front and rears again causing the above.

PureDrifter

iTrader: (10)

to be honest, the LS' VSC system is actually pretty tolerant of different wheel diameters on the front and back provided they are the same ACROSS the axle.

if the wheel/tire size across the axles are the same, more than likely you have the coilovers adjusted so the rear left is unloading a little too much when ur turning. Though, you could have just damaged an ABS Speed sensor wire.....

feejap

Thanks for the replies..
As for the wheels being different in diameter, I am running the following set up.
F: 235/35-19
R: 265/30-19

My friend assures me this is the correct setup for the UCF21. However he is not a particularly gifted guy when it comes to cars, so I stand to be corrected

I'm not sure if the ABS sensor wires have been damaged, but this VSC problem only happens when I am going at speed (~40mph) and turning left. Could this indicate a wire problem?

How do I know if the rear left is unloading too much? How should I adjust it?

Cheers,
Jeff

PureDrifter

iTrader: (10)

make sure the car is at least level across the axles and that should be enough.

both of those tires are way too small for the car, and i would worry about load rating as well if they arent XL rated. you'll want the same widths but in a 40/35 aspect ratio, front/rear.

feejap

Thx PureDrifter. I have asked my mechanic to find me some 235/40 and 265/35s, but that will have to wait..
Hope the VSC problem is solved after the tie-rods!!

JBrady

That is interesting info and good to know.

I based my reply on my car prior to getting a new set of Michelins. I had been trying to decide what to try (tire wise) and had mismatched tires following a flat that was replaced with a used tire. Going quickly through a double s on a road I traveled frequently I began setting off the VSC without sliding or skidding. Since I had taken this corner combination many times before at speeds higher than were now causing the VSC my conclusion was the VSC sensing different speeds due to different wear/tread depth and different traction between tire types. This using the stock 225/60-16 size all around.

PureDrifter

iTrader: (10)

what you are saying makes sense. If one corner has a noticeably different OD than the other wheel on that axle (specifically) then the system will freak out a little bit. Lexus seems to have made the car sensitive to wheel sizing across the axle more than per-side or by all 4 wheels, allowing the tires to be changed in pairs and rotated.

feejap

VSC problem solved!! Alignment redone and now perfect!!

dbltakegs3

what was the fix?

skperformance

iTrader: (6)

I think you have a wheel hub issue and the alignment made it stay in spec but it will go again.