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TCS and Throttle Response

Joined
30 July 2001
Messages
294
Location
Sunnyvale, CA, USA
I recall reading a number of posts from people claiming that disabling TCS improves throttle response. Is there a technical reason that this may be true, or are people imagining things?
 
It does improve throttle response down low but the point of the TCS is to reduce wheelspin upon hard acceleration.

Disable it when you are more comfortable with your NSX. I would also be weary about having it disabled in the rain.
 
Originally posted by Dan H:
It does improve throttle response down low

Hmmm…how exactly (mechanically) does disabling the TCS improve throttle response “down low”? I’ve played around with TCS over the years and know the mechanical design a bit and am slightly confused by the statement above.

As far as I understand the system, TCS has absolutely no effect on throttle response until the TCS computer decides to control the throttle; when this happens, the TCS dash light flashes and it is quite apparent that TCS is controlling the throttle and upsetting “throttle response”. That is, enabling/disabling the TCS under non TCS conditions doesn’t and cannot do anything to change throttle response.

The TCS computer controls a motor attached to the throttle at the throttle body. This motor is as physically attached to the throttle when the TCS is enabled as it is when it is disabled (the TCS dash button does not mechanically engage/disengage the motor or do anything mechanical). Only when the TCS computer decides to do its thing is any power applied to this motor and the throttle response altered.

Originally posted by Dan H:
…but the point of the TCS is to reduce wheelspin upon hard acceleration. Disable it when you are more comfortable with your NSX. I would also be weary about having it disabled in the rain.

Good points. Unless you have a GOOD reason to disable the TCS, it’s best to keep it on. As far as I know, TCS does not affect throttle response (unless the TCS is engaged (flashing TCS dash light)). So improved throttle response is not a GOOD reason to disable TCS. There *may* be other GOOD reasons to disable TCS but unless you know what they are and those reasons come from YOUR OWN experiences then I’d keep the damn button on all the time.

I would never think of disabling a safety feature on my car because someone else says it improves their car’s performance in some abstract way. People say lots of things, but they’ll not be the one in your car when it’s going sideways down the road headed for a tree. Seatbelts, SRS, ABS, and TCS are all safety features of our vehicles and to voluntarily disable any of these devices should come from you own logical deduction of vehicle dynamics based on hard facts.

.02
DanO
 
My mistake DanO, I guess for me, it "felt" faster down low when driving my friend's Saab but really wasn't helping much since it didn't allow the tires to hook up well. I haven't driven an NSX yet so I retract my statements above.

Good idea also about disabling TCS. I would imagine that someone can get in trouble after selling his NSX with it disabled and if something were to happen.
 
Good points but here is a twist.

On the drive by wire throttle (I have a 98-T), the TCS seems to be more sensitive. This was especially hightened at the track (Sears Point front straight where the asphalt is somewhat slippery)..... while I was tracking out from turn 11 and accelerating I was being chastized ok crtiqued by no other than Jim Grinstead for playing with the throttle and not being smooth! Huh? We finally figured out it was the TCS .... when we turned it off the symptom was gone .... I don't recall seeing the light come on (perhaps I was too busy to see the light) .....

I have driven the tracks with TCS on and off just to see what the handling will look like. With the TCS on, and if you are driving at about 8/10 or more, the car takes over your inputs when you really want to be able to feather the throttle to control a 4 wheel drift or a slight oversteer .... worst time to have the TCS come on ..... turn the TCS off to get better feedback from your car. And, get those Comptech non-compliance toe links .....

Under normal driving it's a safety margin that you want to have; keep it on.
 
Originally posted by Hrant:
I don't recall seeing the light come on...

I’m not sure about the later models but I know that on my car (a ’92) the TCS dash light turns on whenever the TCS is messing around with the throttle…always. My bet is that it always turns the dash light on when it’s doing its stuff…always.

Like you say, TCS at the track is a different story and at some point along the track learning curve a driver will encounter firsthand experience with TCS doing things that he/she may or may not like. If a driver is learning incrementally then they will be able to logically decide whether this TCS thing is something they really want on at the track. I expect that very few NSX drivers have the luxury to encounter this situation in a controlled, instructed incremental way. To get to the point where TCS is doing more harm than good means that the driver is near (or over) the traction limits of his/her car when accelerating out of a turn and is approaching a drifting condition where sensitive and predictable throttle and steering response is necessary to master this form of art. Most good drivers can get around racetrack driving school events quite well (and quite fast) without getting to this point.

Anyway, if one finds themselves at a point where TCS is screwing them up on the street (going around corners anyway) then they are going WAY too fast for the conditions and putting themselves and the public at risk by not leaving enough traction in the bank to maneuver around obstacles. TCS disabled for a good burnout is another story <g>.

DanO
 
Hrant,

That is odd, becauase my experience is the opposite!

On my '91, TCS would often kick in when I didn't really want it to. It was somewhat unpredictable which was the worst part. I'm sure if you know what set of inputs it was looking for you could figure it out, but I never really did. Sometimes it would let me put the car into a 4-wheel drift and other times it would not. In the rain it would activate more often than I wanted. It also clamped down really hard if I tried to launch the car from a stop. This was with OEM tire sizes or comparable.

But on my '98 I can always throttle steer or 4-wheel drift the car (within reason) with TCS active. You mentioned the pavement is a little slick at the track where you experienced problems, but at MSR during NSXPO the track was quite slick and I still wasn't having problems with TCS. I ran with it both on and off.

It will not allow the kind of drifting you see in "drifting" videos, but it's always been forgiving up to the optimal slip angle at the track. It also does better in the rain (I haven't driven the car in the rain since I bought it until the drive to and from NSXPO this year but I did play with it then). It's also a little more forgiving for launches from a stop than my '91, but for an optimal launch I still need to turn it off.

That's not to say it doesn't kick in... I can certainly MAKE it kick in on the street or on the track (even at low speeds). It's just that I've never had it kick in unexpectedly, and that's with the added power of the supercharger on the '98, wherease on my '91 it would sometimes come on unexpectedly or with less provocation than I thought it should, particularly at low speeds.

Also importantly, it is generally much smoother when it does kick in than on my '91 where it was rather abrupt.

I wonder why two '98s behave differently?? What serial number is your car? Mine is 183.

[This message has been edited by Lud (edited 05 December 2002).]
 
Originally posted by Lud:
Hrant,

That is odd, becauase my experience is the opposite!

........ well, I don't think so; I think we are saying the same thing in differnt ways ....

On my '91, TCS would often kick in when I didn't really want it to. It was somewhat unpredictable which was the worst part. I'm sure if you know what set of inputs it was looking for you could figure it out, but I never really did. Sometimes it would let me put the car into a 4-wheel drift and other times it would not. In the rain it would activate more often than I wanted. It also clamped down really hard if I tried to launch the car from a stop. This was with OEM tire sizes or comparable.

But on my '98 I can always throttle steer or 4-wheel drift the car (within reason) with TCS active.

......... Exactly, the operative word is within reason
wink.gif


You mentioned the pavement is a little slick at the track where you experienced problems, but at MSR during NSXPO the track was quite slick and I still wasn't having problems with TCS. I ran with it both on and off.

......... That is why I thought I did not see the light on the dash and I often do look for such things (remember oil gauge ... ).... but Jim was on my case that I was playing with the throttle on/off and here I was arguing with the coach ..... so I opted to turn it off and he stopped complaining ..... LOL!

It will not allow the kind of drifting you see in "drifting" videos, but it's always been forgiving up to the optimal slip angle at the track.

........ Agreed. I notice the TCS start when taking off camber turns and trying to throttle through them - the unbalance creates it to kick it thus gives you a weird sensation that you are losing the back ....., or when taking sharp S turns with body lean backand forth and throttling through there as well .... I have not had problems with 4 wheel drifing when tracking out on full throttle - and I really do not want to find out either .... and never on straights through the gears thus my reference to the slippery surface at Sears as the possible culprit. Others who have run at Sears more may have a better sense.

It also does better in the rain (I haven't driven the car in the rain since I bought it until the drive to and from NSXPO this year but I did play with it then).


.......... I agree, especially if you are not on new tires
biggrin.gif


It's also a little more forgiving for launches from a stop than my '91, but for an optimal launch I still need to turn it off.

........ I tried launching once at 3000-3500 RPM, and after smelling the aroma of a clutch, I have resigned to rolling starts with or without TCS .....
frown.gif


That's not to say it doesn't kick in... I can certainly MAKE it kick in on the street or on the track (even at low speeds). It's just that I've never had it kick in unexpectedly,


........... I think this is a definitional issue. What you may expect or anticipate is what others may not expect given their lower driving skills or comfort level ....
wink.gif


and that's with the added power of the supercharger on the '98, wherease on my '91 it would sometimes come on unexpectedly or with less provocation than I thought it should, particularly at low speeds.

Also importantly, it is generally much smoother when it does kick in than on my '91 where it was rather abrupt.

........ have not and do not push/drive other's cars that far so I trust you on this one.

I wonder why two '98s behave differently?? What serial number is your car? Mine is 183.

.... as I said, I don't think they are behaving that differently. 092.


[This message has been edited by Lud (edited 05 December 2002).]



[This message has been edited by Hrant (edited 05 December 2002).]
 
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