I noticed when I'm in Sport+ and have manual shift on, when you start to drive normal from a stop, it will start in first gear and quickly shift to second gear and then the car will stay in that gear until it red lines or you paddle shift.

How do you get it to stay in first until I tell it to shift. It seems it will stay in first if I floor the car, but not in normal take off.

Any thoughts as to what I'm missing here?

 

The transmission pretty much has a life of its own. Even under full throttle it can randomly upshift well before redline. Also first gear is more like a "granny" gear. More just to get the car moving and my experience is it doesn't load the engine enough to build full boost with the turbo. Peak I've seen in any gear is about 19 psi and usually in 1st I've seen about 12 psi.

I would assume the reason they shift so quickly is from a fuel economy perspective. It seems to do it all modes. I really hate the transmission programming the more I drive it. They could have used some sort of IMU to prevent the car from upshifting when in Sport + mode while in the middle of a tight turn while driving somewhat aggressively.

There is no real "manual" mode to this transmission. It decides when it wants to shift usually, not you. Sure you can do some minor up and downshifting with the paddles but after a second or 2 it goes back to full auto mode.

 

In Sport + / Sequential, it's very much like a manual. If it does shift on its own, it must be close to redline. I've never let it go that far without pulling the up paddle, so I don't know.

 

How often does yours actually go to redline? I've never seen a shift yet at redline. Highest I've seen is 6300-6400. I have seen it shift as early as 5900 even under wide open going from 1st to 2nd or 2nd to 3rd even when in Sport + and S (for trans).

 

I've never let the RPM get near redline. Why would I?

I guess I'm not understanding the problem. Why does anyone want the RPM to run higher than it's supposed to or needs to? The gears are there for a reason.

 

He wants to spin it higher to see if his quarter mile time improves.

 

I am not going to continuously run at redline but for maximum acceleration, it needs to shift at or near redline. It significantly impacts even the 0-60 time by a few tenths from what I can tell so far for those that it might matter.

To look at it another way, Hondacura put in a pretty good motor in the new RDX, then then put in a transmission that significantly handicaps its performance. It's like they put stiletto heels on it instead of running shoes for the 100m dash.

 

I'd be willing to bet the slightly early upshift from 1st gear is to protect some component of the driveline from excessive torque, possibly the rear differential.

I'm not convinced it has anything to do with fuel economy in Sport+ mode. Maybe more so in other modes.

Just $0.02

 

My car often does the early upshift regardless of mode it is in. The rear diff would have to be pretty crappy if considering it doesn't ever get all 100% of the torque. There is a lot of torque multiplication with the low first gear but I find it odd the front is the only one that can handle all the load.

 

Okay, hold on here...

When in manual shift mode in Sport+ the RPM's go to about 2500 and she will shift right into 2nd gear. I'm not trying to go beyond the red line at all. Yes, I too have see the car shift before even getting close to the red line as others have stated. My guess is the tach is not fast enough to track actual engine rpm.

I'm just trying to understand what's taking place, that's all. For a really nice car, I'm trying to figure out what makes it tick.

 

You should be able to tell by ear whether the engine speed is 2500 rpm or 6000 rpm. Easily. 6000 rpm is screaming like a banshee.

Anyway, the tach may be a bit superfluous in an exclusively AT driven vehicle, but I would be surprised if it is significantly laggy and/or inaccurate.

My comment on torque management isn't without support. Search threads on "tuning" chip options and you will find discussion of this. I'm sure the companies that produce the tuning chips could provide much more definitive data.

OTOH whether it's the clutches of the rear diff that motivate the torque management is pure conjecture on my part, and I'm not very committed to it. Since I see OP is from Florida, it's quite possible his vehicle is FWD.

 

Yes, FWD. I didn't feel the need for AWD wasn't easy finding my car without AWD.

 

There really isn’t much point going beyond ~6500 RPM as Hp begins to drop, with a 10 speed the shifts are so small that you can keep it in the power band much easier, also all the torque for this car comes on at 1500rpms, maybe you could raise the rev limiter with a flash, but I think Acura tuned it this way to protect the engine/transmission, and power drop off is at this point anyways, as far as first gear, it gets the car moving, it’s not meant to rev to redline, the car is faster in second gear, first gear is crazy small

 

that’s in 4th gear from the video, roughly 6600-6700rpms in 4th gear



here is a nice 0-60mph test

i think people forget, you can obviously always squeeze some more performance out of a car, but they have to balance the tune between reliability and performance, especially with these longer warranties acura gives them Honda, hell I have Acuracare for 120k miles and 8 years, they have to build a product that can handle performing regularly for that length of time, if you tuned for 100% performance, the car would drive like crap for daily driving, although it can be done with drive modes, and you would either cause failures earlier or raise the cost for having to over engineer things more then they already are. I love my RDX, and I think it performs great, I’m 27, but do realize, every time I’ve seen someone driving an Acura, 70% of the time it’s an older person in their 50s+, it’s a balance between luxury and performance, when I went to the dealer to buy mine I thought I was stopping at a nursing home, everyone buying Acura’s were older folks, I do see some younger people don’t get me wrong, but that’s what I’ve seen at my dealer, and yes I wanna be hip, cool and I style when I get older, and still want performance.

to add to my post before, 1st gear delivers max amount of torque but at the sacrifice of fuel economy, so as far as accelerations it’s great, but for fuel economy it needs to get out of that gear as fast as possible, that’s why when driving normal it shifts out of it very fast, when flooring it, it goes to redline

 

Stupid question, does the Turbo only work in Sports+ mode?

 

The turbo is always working in all modes, whether you are in boost depends on how much throttle you give it

 

I think he meant the boost indicator thing.

 

And that's an adjustable parameter. Look in settings if you want it displayed in more modes than just Sport+

Whether it's useful is a whole different issue.

 

The only thing the turbo boost gauge is good for is showing that you are actually under boost. According to my OBD2 software programs it is at least good for that and when it is fully lit up so to speak you are at max boost or at least 19 psi on my car. Pretty much a worthless gauge.

The 10 spd transmission sort of negates the benefit of a wide torque band in some ways. It spends more time shifting that it needs to. Maybe it could upshift 2 gears and save a shift. The ultra low does NOT make it quicker in any of the testing I've done 0-60. At least not by enough I'd worry. My variations from run to run are greater than the difference in running in any of the modes. My best run so far was in Comfort, next best in Snow and Sport & Sport + are about the same. The variation though between all of those 4 modes, if I take the best run 0-60, under similar temps and humidity is less than .1 seconds.

 

I find your hard work very interesting! 20 years ago I was tuning F-bodies and Vettes. Haven't gotten into these newer cars yet. So the tuner your using, has it really made a difference to the point of buying? Are they canned tunes or can you make your own adjustments to fuel, timing, turbo etc.?

 

Glad it is interesting. While my car isn't tuned, I have access to someone who is running the Ktuner in his RDX. I spent years modding cars and bikes, probably close to 40 years now. I am a big fan of forced induction in all its forms.

Basically with the tune for the RDX tune from Ktuner is you get 2 tunes as basemaps. There is a Stg 1 and Stg 2 tunes. Neither of these are producing a ton more top end HP from what I see but the midrange pull is pretty satisfying. Imagine someone dropping a 4 or 5 liter motor under the hood of the RDX which sadly transforms into maybe a 3.5 liter above 5k.

I am sure this is done for longevity as well as some limitation of other parts to support the airflow the motor will need at higher RPMs. Having said that they seem to be great tunes for the vast majority of people. Basically I would call them almost a set it and forget it tune. Just keep at least 91 octane in it and the motor likely would last almost as long as stock.

After driving the other RDX I think the $440 or whatever they get for the Ktuner v1.2 is a screaming deal. You can use their basemaps and if you go to a dyno or to the strip tweak it more if you know what you are doing. There is a good software program (Ktuner) that you can run on your laptop that can connect to the tuner to collect and log real time data. You can use this info to tweak the tune later. I am not sure if the RDX has a wideband 02 sensor which is usually essential to really dial in the tune. There is also an Android app that has most of the functionality. Once the tune is loaded into the ECU, it overwrite the stock info there. You can download the stock info again whenever you want. I think it takes about 5 minutes or so to do.

It is all I can do after driving that other RDX to whip out my credit card and order it. It really makes the RDX more like what I thought it should be in the first place. Only thing holding me back is the reaction I'd get when the credit card bill comes in and my SO sees it. It is clearly the best bang for the buck performance mod you can make for the RDX. I had another chance to drive it to night. It was a bit cooler here. The other owner let me take off the traction control and hard on the throttle in second gear through a tight left hand turn it was actually drifting the car and you as you felt the tires break loose. It was like driving a little rally car. The RDX could be such a blast with about another 100 HP or so.

 

wavshrdr thanks for posting back. Great info. I'll look into the Ktuner. Are they the only tuner for the RDX right now. I have a 2020. Was it you or someone else that said nothing is available for 2020 as of yet.

 

I think I need to look into this Ktuner...

 

Ktuner definitely has a tune out for the 2020. They can send it to you if you buy the Ktuner. Honestly I think this is how the RDX should have came from the factory as its base tune. it shows you why going with a 2 liter turbo motor can be a lot of fun vs a high revving 6 cylinder. Not to mention if you are altitude the turbo motor is going to maintain a lot more of its power once you starting getting as high as Denver or higher.