DSC/VSC issues?

[NocturnalEmber]

So I was driving my car in sport mode (6MT), not very aggressively, mind you, around a freeway on ramp. I was maybe doing 45-50 with moderate steering input and I felt two small lurches like the front wheels lost traction momentarily then regained it.

I felt this was odd, as the car was not anywhere near its limits (I've autocrossed multiple times before in other cars, so I'm fairly familiar with when a car is approaching its chassis limits and/or the limits of the tires.) Turns out the traction control light flashed both times this happened (the one in the top right of the cluster.)

This seemed *really* odd to me, almost like it was intervening way before it should. This wasn't a WOT or 50% throttle on curved on ramp acceleration pulling high G's. This was maybe 45-50 with the wheel maybe turned to 10:00~ from center. I tried it on different on and off ramps, going different directions, and it just seems to be kicking on relatively early, way earlier than I'd expect it to.

Anyone have any idea why this would be? I hate to just jump straight to "thats normal" because this wasn't approaching the limits of the tires or chassis whatsoever, the tires were pretty quiet at this point, nowhere hear the edge of grip. Yaw didn't seem to extreme to me, either.

Sure, I turned off VSC and I don't think it did it that time around, but it just seems like the system was overly sensitive, and I don't particularly want the VSC off light on the top left of the cluster staring at me all day.


Any thoughts?

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[razorlab]

Is the car lowered? That will make TC more sensitive. You can also use one click off and that should take away most of that intervention without going full VSC off.

 

[NocturnalEmber]

Is the car lowered? That will make TC more sensitive. You can also use one click off and that should take away most of that intervention without going full VSC off.

Ride height is stock, as is the whole car.

disabling vsc with the one click off is a solution, but I guess my concern is it just seems like its activating way too early even with VSC on.

If i was going in with 50%+ throttle and a crazy sharp steering angle/yaw I could understand...but this is maybe 45-50mph around a very generous on ramp. The tires are well within their limits and so is the car but it will just randomly actuate the VSC and pull the car out of...nothing..because nothing is happening.

It's very bizarre.

 

[razorlab]

Ride height is stock, as is the whole car.

disabling vsc with the one click off is a solution, but I guess my concern is it just seems like its activating way too early even with VSC on.

If i was going in with 50%+ throttle and a crazy sharp steering angle/yaw I could understand...but this is maybe 45-50mph around a very generous on ramp. The tires are well within their limits and so is the car but it will just randomly actuate the VSC and pull the car out of...nothing..because nothing is happening.

It's very bizarre.

You mentioned you have two different tires front/rear in another thread. What tires are you using?

 

[NocturnalEmber]

You mentioned you have two different tires front/rear in another thread. What tires are you using?

The fronts are the factory pilot super sports. Rears are what the past toyota dealer put on, Firestone Firehawk Indy 500's. Which based on what I can see on tire rack, isn't a garbage tire, but I'd certainly have matched all four with a better but same brand if it were me.

tread depth between the fronts varies by about 1/32 , same with the rears, the tires were replaced at different times

Edit: I know this is anecdotal, but I did disable VSC with the one touch and took the same off ramp doing about 75 with way more throttle input and steering angle, Still not at the limits of the tires or chassis (tires were quiet.) Had VSC been on, it would definitely have kicked in at its usual potentially overly conservative time (50mph and half throttle) But the car had no issue with the turn otherwise.

 

[swrdply400mrelay]

Was this a one off or it happens regularly?

If it’s a one off it’s probably nothing.

After having my springs installed, I was cruising on the highway on the drive home around 65 mph, changed lanes, and the light flashed. Hasn’t happened since.

 

[Optimusprimerib]

To OP, the tires may need to be specified in idrive. Also, mismatched tires have been an issue for others who experienced similar issues as you. Similar to when you change the battery, you have to specify it so the “car knows how to behave”. Sorry for the poor explanation.

 

[razorlab]

To OP, the tires may need to be specified in idrive. Also, mismatched tires have been an issue for others who experienced similar issues as you. Similar to when you change the battery, you have to specify it so the “car knows how to behave”. Sorry for the poor explanation.

lol, the car doesn't know what tire compound you have. The idrive selection (summer/winter) is for inflation pressure information only.

 

[Traxion]

The fronts are the factory pilot super sports. Rears are what the past toyota dealer put on, Firestone Firehawk Indy 500's. Which based on what I can see on tire rack, isn't a garbage tire, but I'd certainly have matched all four with a better but same brand if it were me.

You still didn't say if the tire sizes are proper. Are the rears within the 275-295/35/19 range?

Razorlab already mentioned ride height, but you may want to measure anyway and make sure it's near 14.5 inches from center of the wheel to the bottom of the fender. My fronts are .5 inch lower and I get the early VSC kicking in on easy sweeping 70mph on ramps. Ride height and weird tire sizes are the culprit 90% of the time.

 

[NocturnalEmber]

You still didn't say if the tire sizes are proper. Are the rears within the 275-295/35/19 range?

Razorlab already mentioned ride height, but you may want to measure anyway and make sure it's near 14.5 inches from center of the wheel to the bottom of the fender. My fronts are .5 inch lower and I get the early VSC kicking in on easy sweeping 70mph on ramps. Ride height and weird tire sizes are the culprit 90% of the time.

I mentioned the whole car was stock, but I guess I should have been more clear, the tires are factory sizes.

I'll get to measuring tomorrow for sure. Center of the wheel as in the center cap?

 

[NocturnalEmber]

Was this a one off or it happens regularly?

If it’s a one off it’s probably nothing.

After having my springs installed, I was cruising on the highway on the drive home around 65 mph, changed lanes, and the light flashed. Hasn’t happened since.

I would say its about as repeatable as it can get, happens every time.

I've tried a few on/off ramps and its consistent whether its a left or right curved on ramp. The car is nowhere near losing traction or anywhere near its limits but the VSC will activate regardless.

 

[Traxion]

I'll get to measuring tomorrow for sure. Center of the wheel as in the center cap?

Yeah center of the center cap.

 

[NocturnalEmber]

For anyone finding this at a later point in time:

I ended up returning the car for essentially a same spec supra that came in afterwards. While I can't say for sure what caused the other car to activate VSC, This second one does not do that (and neither did my first Supra.)

The only variable in this situation that I can think of is that this new one has the factory oem Pilot Super Sports all around, while the one I returned had the factory ones up front and two Firehawk Indy Pro 500's on the rear. Also worth mentioning was that all four tires were slightly different with tread depth. The car didn't pull or behave weird, sans the VSC activating on curved on ramps, so I'm going to chalk that one up to the tire differences.

 

[swrdply400mrelay]

For anyone finding this at a later point in time:

I ended up returning the car for essentially a same spec supra that came in afterwards. While I can't say for sure what caused the other car to activate VSC, This second one does not do that (and neither did my first Supra.)

The only variable in this situation that I can think of is that this new one has the factory oem Pilot Super Sports all around, while the one I returned had the factory ones up front and two Firehawk Indy Pro 500's on the rear. Also worth mentioning was that all four tires were slightly different with tread depth. The car didn't pull or behave weird, sans the VSC activating on curved on ramps, so I'm going to chalk that one up to the tire differences.

What spec did u end up getting?

 

[NocturnalEmber]

What spec did u end up getting?

3.0, same as before, got kinda lucky that another one came in just like it with better conditions.

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