Im sorry but im gonna have to raise the bull**** flag on this one. Having the O/D switch off DOES NOT INCREASE TOURQE!!! ALL IT DOES IS NOT ALLOW 4TH GEAR SHIFTING!!!!

 

OK dude, I followed your flippant suggestion to "do a search", and had to laugh when I could see that you have contradicted yourself on this very point.

In another post back in 2001, you said "Gate shifting is shifting an automatic transmission MANUALLY via running through the low gears on the shift stick. 1st -> 2nd -> Drive. People have experimented with it on the track, and none that I've seen improve the track times over leaving the gear in drive (auto).

So... which is it bud?

 

REALLY flooring it is REALLY bad for your transmission.

TQ, I meant to type TC, as in "torque convertor". I guess I was expecting too much of you to assume that you'd figure out torque convertors can "tighten" and torque itself cannot. Ever coast along at 40mph and hit the OD off button? What do you suppose that jerking sensation is under your car?

1st to 2nd gate shifting in my experience does nothing but increase acceleration lag. In my car at least, 2nd to 3rd shifting is slow with the automatic, thus 2nd to Drive gate shifting, as I endorsed, DOES make a difference. Didn't it cross your mind that from 2001 to 2003, I could have possibly learned a bit more about my car's abilities between the two year span of driving it?

 

Somehow I get this feeling Ive never actually floored it all the way.... I put the pedal down as much as I can comfortably, but what is this "pop" and pedal depressing down even furthur I hear about? Ever actually read that oart of the owners manual? It sounds like a broken record "press the pedal down for full acceleration. When more acceleration is needed, press the pwr switch. When even more acceleration is needed, push the pedal down all the way...." its like jeez, this car has like 3 different levels of "flooring it" And I dont see how maxing out a car will hurt it.... shifts that are tighter I hear are actually better for your transmission. Lexus V8s are built and can handle a rough and tough sprint once or twice a day.

 

Drilling your transmission like that is a great way to burn ATF fluid.

 

Floor your paddle to maximize your fuel supply but what if you already maximize your fuel supply. Another way is to unplug couple hoses from your intake robber hose and test drive, guarantee you will feel the different when you floor that gas paddle. NO MONEY TO SPEND ON THIS KIND OF TESTING.

 

I can't take much more of this.

 

Lex, you're pretty educated in these matters... What's your take on this?

 

Ok,... i forgot who said O/D didn't change anything,... where did you see me type that it added horsepower?? With O/D off, it changes the shift points of all the gears lower than 4th, thus stayin' in each gear longer,.... meaning you can get more hp / tq out of each gear if it is allowed to rev higher. Wow, what a theory.... If you're drivin' an automatic at say,... 60 mph and simply hit the switch if it's on to turn it off, your rpm's jump up about 2000 rpm or a lil less,...and it's far more responsive.

ECT/PWR mode doesn't create some imaginary hp,... it controls the shifting to maximize power in each gear, or you could do normal to maximize fuel efficiency, hence shifting at lower rpms, consuming less fuel.

I guess some of ya'll didn't watch my video clips in the racing section of me launchin' manually from 0 -120mph,... the only time it shifts at redline is if you manually do it, otherwise it always shifts around 5400 or somewhere in that area. I can't say from a stand still it makes much difference being I tried it both ways at the track ( HRP with jbrady and AgGS400 ), but when already rollin', it makes a hell of a difference because the ECU doesn't know to kick down a gear and leave it there so you can whoop somebody on a rollin' take off. I gate shift ONLY when I KNOW someone is rollin' next to me tryin' to bait me into a race and I know I'm goin' to need the torque from the higher rpm's.

I guess somebody didn't bother lookin' at the closeness in weight of these cars,... this ain't comparing a 3000lb car vs a 4000lb car, nor is this a comparision of only a 10hp / 10 ft-lb difference either. Everybody keeps alluding the the SC400 as if it were ONLY available in one motor trim,.... 250, 260, 290,... I know two of those you're not goin' to beat,... I've raced a couple of 300's on the hwy and it didn't happen. Now as for a 250hp model,... maybe,... I can see that as a possiblility,... but nothin' I'd bet a paycheck on.

 

SC400-V8,
You are probably right, you haven't floored your car yet. The "pop" lexus_sc400_n20 alludes to the the tranny kick-down switch. Most japanese automatics have this.

ECT - power will change the fuel and ignition timing curve to a more powerful less economical map, more reponse/power however at WOT the ECU is already using the power map so if you are floored, there's no difference with the ECT setting.

You are going to heat your AFT ANYTIME you get on the gas, completely floored or 95% throttle is still going to heat your ATF pretty much the same amount. If your car is stock, the engineers have built in a safety margin so it shouldn't wear your tranny anymore if you go 95% or 100% throttle. If your car is NOT stock, the extra torque/power the engine is making has closed that safety margin and the more likely you will burn your clutches.

A manual tranny will be faster when it's power limited. An auto tranny will be faster when it's traction limited. If you have more power then traction , you don't care if you're losing 15 or 20 percent power. You just want the fastest hardest shift possible ... hence auto

 

All that the ECT switch does in PWR mode is change the speed @ which the unit will downshift and raise the shift points, just like on the newer ones where the SNOW mode does the opposite, the threshold speed @ which the unit will kick down is lowered (it won't shift down above a certain rpm), as well as starting the vehicle off in 2nd gear so as not to break the tyres loose upon initial acceleration. The software seems to be different on the later models (Lexus' Ai shift control), and there's a noticeable difference in shift quality between SC3 and SC4, and between early and late years. The Supra uses essentially the same A340/A341e box, but again the software is different, but the valve body is the same. Hitting the OD button (or clicking the gate to the left on later models) will do absolutely nothing if you are below the speed at which the unit would have gone into fourth gear, above that speed the only difference is that you are higher up in the rev range in third instead of lower in the rev range in fourth, therefore the engine will tend to have more torque since it's in the 'meat' of it's powerband, but the engine is never producing more peak torque than it was in OD.

 

I respect the members involved in this discussion too much to be calling anyone's Bull****
Everything below is just my opinion on the way I see it due to my experiences, no harm no foul .

NAZTY97, first of all, if you are reading my messages correctly, you'd notice I'm actually agreeing with you on the exact point. I said the 250hp of the SC400 is CAN be beatable but not the 260hp and certainly not the 290hp. Please go back earlier in the post to see where I said this. Given that you have a 260hp version, I'm sure you are fully confident about beating the SC3.
Also, I'm fully aware of the weight difference. It's not a 1000 lbs, but it's still a factor. the HP difference is also not a 100hp difference but 25hp. Do you know how much hp the automatic transmission zaps as opposed to a manual? Give me an estimate. Factor that in with 100lbs weight difference as well as ability to launch a manual from standstill and I do not see why anyone would be shocked that a 5spd sc3 CAN beat a pre95 sc4...

lex400sc, if I'm not mistakening, that jerking sensation is your car downshifting to 3rd. Much like an manual downshifting, alot of times a harsh downshift (say 5th->3rd) will feel like as if you hit a wall (if you've driven manual b4) and get a jerk.

Sure, flooring your SC is bad for your car, but so is alot of things (like drag racing, dropping the clutch..etc). In terms of manually shifting, I think that's "bad" for your car too. I've heard and seen countless Legend's who's got transmission problems because their owners
constantly manual shift their auto gear box. Of course most of us here will say those transmissions are a POS so I wont go there.
My other point regarding turning OD off - I guess I'll go with anything Lex Luthor had to say.
My opinion is,,, if you car does not shift at redline when in D, then so be it. However, I just can't imagine Toyota designed this car so that it will not shift at redline unless OD is off. That is still just a bit too hard to believe. Maybe alot of the SC's tend to have this problem, but it's because it's still a problem (however common), and not neccessary came like it off the factory line as a design/engineering decision.
Driving at a lower gear in auto 'seems' fast, but #'s tend to prove otherwise on the track. Even the newer gate shifters like the Acura TL-S drivers will tell you that shifting manually does not produce better performance than if you just leave it in drive. Again, the above apply for the SC only if your car redlines in D every gear.
Also, I don't know about you guys but I doubt C&D and R&T folks got their best SC400 times by shifting their own gears.

 

Legends, my car does shift at redline with OD on, matter of fact if it's cold out and I leave the house, if I floor it, on the very first 1-2 shift the car makes, it's actually bounced off the rev limiter a few times. Sounds just like my 2-step did on my GN

 

I was sitting in my car... thinking about the post abotu flooring it in an SC.... soemone said if you floor it ALL the way... you'll feel a pop and the pedal will go down even more... I had no idea what they were talking about. I read the vehicle manual... it said that if yet even more acceleration is needed, apply more pressure to the pedal beyond full throttle. This will activate the kick-down switch. I immediately jumped into the drivers seat and floored the pedal... then applied some more pressure and surely enough, it popped and went down even furthur. This would explain alot. This is the case, Ive never actually floored it and would explain why i've been getting 8 second 0-60 times instead of 7-7.2 the magazines gave it. I find out new stuff everyday.

 

That was me that said that