ROK

Let's please not get up in arms being the already obnoxiously litigious society that is the USA. Next thing you'll complain about to add to the pile is split hot mick d's coffee as a result of this lag. 4th degree burns. imminent death.

You guys are barking up the wrong tree imho. Learn to pick your battles. If we have an equally obnoxious thread about a much more salient issue like the fuel pump that makes noise, that has allegedly stranded a couple of folks, and Lexus is still slow to act, what makes you think they're going to "fix" this?

I too had an isf. not an old tired one. a brand new one '13. it's downshifting was dog slow to respond when driven with alacrity. it lagged at times just like the rcf. i still loved the thing because all these "issues" were non-factors.

F1nALMSfan

Haha, yea all about complaining over here. I should start getting that daily coffee for the anticipated lawsuit too....

I'm not picking any battles, not sure who we're fighting, and you're right, I don't think Lexus will ever fix this. We are just discussing an issue that a few owners are having. I don't see why you seem to take such offense to that. If you aren't experiencing it, no need to even chime in here.

The ISF did not have the same type of lag as what I am describing. It was slow to respond on down shifts, but never was there a lack of throttle response from the engine.

Props for using alacrity though, a much underutilized word

CoolCanuck

I agree F1, I never had this issue happen to my ISF. It is not a downshifting issue but a throttle response. It's funny because the issue reminds me of the Fast & Furious movie where they use nitrous and they show the animated flow of the nitrous from the time he pounds the gas to the car actually taking off.

I haven't mentioned it to the dealer yet as it is not a critical issue but it's an annoyance to say the least. I might pop by at some point in the Spring just to see what they say.

Hope those guys why are experiencing the issue will continue to post helpful updates or experience here so that maybe one day we can eliminate the lag issue.

For those who don't think it's an issue or just have nothing constructive to add, please move along.

JT2MA71

iTrader: (7)

I have yet to experience this "lag." But definitely did not experience it on my 2013 IS-F. One thing that was annoying to me though, on the IS-f is the popping of the driveline and slight jerking of the car when coming to a stop. The RC-F is smooth as silk when going to a stop.

LexusRCF15

I brought my car into the dealer for the lag which you guys speak about and he let me drive another RCF on the lot. It too exhibited the lag which occurs in Normal mode while cruising at around 30-40mph and giving it heavy throttle (not necessarily WOT). He spoke to his "engineer" that also drives an RCF and he told me that they're aware of the issue but suggested driving it in manual mode. Since then I drive in Sport S+ (bc it only shifts from 1-6) and the problem goes away in auto - though u have to wait like 20 minutes till it gets up to temperature. Until then, it shifts from 1-8 and exhibits the same lag. The Apexi throttle controller is an excellent addition, but the lag is still there. I wonder if the GS-F exhibits the same problem???

asinow

I also have experienced the lag. I find it to be annoying. With that said, I'll try the sport+ mode in auto. I dont like always shifting.

I mentioned it to my SR and he had a tech go out with me. After informing him it was a "F" and not a 350, he told me it was the nature of "drive by wire." He already lost me on the 350 comment... so drive by wire did not sit well. It was the first F he'd seen. Go figure.

Anyway, If Lexus is aware of this and anyone has info on the fix or update, please share it with us.

Thanks...

ISF001

That's because you are most likely in sixth, seventh, or even eighth gear.

The car is built for abuse and high revving. Lock the torque converter and enjoy the F for what It is meant to deliver.

F1nALMSfan

Not a chance, it is in 2nd gear. We are talking low speeds here, about 15 mph perhaps. The lag is engine response, not transmission in this case.

I definitely do enjoy the car, high revving engine and all. Eagerly counting down the days until I can remove my snows and bring back the summers!

FR500GT

iTrader: (7)

While the Apexi throttle controller won't "fix" the issue, it will certainly help your car feel more responsive and for $200 I think you will be thoroughly impressed.

mjeds

can you please enlighten me as to how you know you are in 2nd gear.

I ask because for the past 4 days I have tried very hard to replicate your description of the issue and I cannot.
watching the gear position screen on my dash, in ECO or Normal mode @ 20mph my car is in 4th, 30 it is in 5th and 40 it is in 6th and sometimes 7th.

now I can reproduce the lag you describe, where in I come down a freeway off ramp, am in normal or eco mode, I coast down, from 65mph to about 40mph, the car drops from 8th to 7th and sometimes 6th but that depend on if I get below 40mph 37mph seems to be the point where it drops to 6th, but I saw it happen once at 39mph..

about 50 ft. from the end of the ramp I brake, bring the car down to 25mph and I am solidly in 5th. I release the brake, coast into the turn wherein the speed drops to about 20-21 and I accelerate out of the turn.


at the acceleration out of the turn:

if I roll the throttle slowly the car drops from 5th to 3rd and there is no lag

if I mash the throttle the car hesitates before dumping 5th into 2nd then kind of lurches and it grabs the gear.

the difference I notice.

LAG experienced:

In the coasting down the car has the ECO light on the dash so it is definitely in Atkinson cycle, mashing the gas causes a hesitation as the car tries to come out of Atkinson cycle AND drop from 5th to 2nd.

This lag is very familiar to me as I stated previously from dealing with cars that have multi-cylinder shut down when cruising, it is the same type of hesitation where-in the car is trying to bring up the deactivated cylinders and safely downshift.
---
No LAG Experience. when rolling the throttle the ECO light goes off but I am not trying to get the car to take off, just maintain speed, and slowly accelerate. As a result the car has time to first switch out of Atkinson cycle then drop gears one at a time vs. the above where it is trying to slam from 5th to 2nd.

I can reproduce the exact some LAG and non LAG situation in a straight line, coasting down from 65mph braking to about 25 then trying to accelerate, I get lag if I go WOT or semi-WOT, I do not get lag if I roll the throttle slowly.

but at 20mph the car is in at least 4th gear, at 40 it is in 6th/7th if you are driving in ECO or Normal mode.
in Sport mode @ 20mph the car is in 3nd, at 40mph it is 4th.
in Sport+ mode @ 20mph the car is in 2nd, at 40mph it can be in 2nd or 3rd depending on what the computer is anticipating you are going to do, that is it will hold 2nd gear longer if you are giving it load.


Now I realize your post says 15mph, but I never dropped below 20mph in my testing. but I was able to reproduce the lag, and it is pretty much what I figured, the computer trying to get the motor and the transmission in sync coming out of ECO mode and going into semi-hard to hard acceleration mode.