I bought the Apexi smart accel controller and installed it in about 15 minutes.

First I want to be VERY clear:

This does not claim to make the car faster. I know that already. I did not buy it to make the car faster. This is not a real performance "mod" in that all it does is change the character/response/curve of the accelerator pedal. I understand there is a lot of controversy about these devices, so there is no need to argue about whether these are "snake oil" or not. It's been covered many many times in other threads.

I am just posting here to share my impressions of what it does and does not do, for the benefit of others who may want something like this.

A throttle controller, on paper, does nothing more than "lie" to the car's computer about what you are doing with your right foot. In my opinion, there's some benefit to tricking the G37 which I'll do my best to describe. I have no commercial interest nor affiliation with the company. I will also add that I think this is a rather silly modification for the money (in MY opinion), HOWEVER it does what it claims, and I think it's helpful to understand what exactly it does. It is able to change the character of the car's accelerator pedal behavior quite significantly, and I believe that the gas pedal response in this car can benefit from some changes.


So why did I buy this?

I bought this just to see how it could change the character of my accelerator pedal. I find the G37 to be way too touchy when starting from a stop. It's "tricky" to pull away smoothly without a jerk.


There are 8 modes of operation which I will cover/group separately. You can change the mode on the fly, while driving or while stopped. It can remember the mode it is in when you turn the car off, so when you start the car again, you are in the same mode. OR you can set it to revert to "stock" every time you restart the car. The mode is indicated on the selector by the color of the light. It was pretty easy for me to memorize what each color means as the colors used are somewhat intuitive.

"Normal": Stock

"Low throttle mode": This changes the throttle curve so it is more linear and more gentle through the part throttle range. It does not introduce any delays in throttle application. It just makes it much more natural in my opinion. I can start from a stop much smoother now. This mode alone makes it worth it (to me), and that is good, because this is why I bought it.

"Eco modes 1 through 3": These modes introduce a delayed smooth ramp-up of the throttle when you step on the gas. It is to smooth out throttle increases, with the idea that you can get better fuel mileage this way. Makes for a nice smooth takeoff too. It acts a lot like the BMW I drove in ECO mode. I would say that this probably does work to improve the MPG for the average driver (who may not be so good at finessing the gas pedal). I can get good MPG on my own without this, but it's a nice feature. On the most economical setting, it adds a sense of smoothness and mass to the way the car pulls away which is kind of interesting too. Very classy if you're being a a chauffeur. On the least-economical of the ECO settings it is only a little bit apparent that it is doing something. It's a refreshing change from the head-jerk.

"Boost modes 1 and 2": I'm going to try to describe it as best as I can. When you give the car more gas, this mode briefly exaggerates that effect. It is not just increasing the throttle position. It is increasing the "punch" that occurs when you give the car more gas. For the automatic transmission, this does wonders for responsiveness. Because the car sees you "stab" at the gas some any time you give it more gas while cruising, the transmission is much more willing to downshift. It behaves like some of the more responsive transmissions I've driven, responding to small throttle inputs with a quick downshift. The boost modes on the Apexi are the most interesting given what they do for the 7AT, but I have to say it is just too touchy from a stop (for MY taste) when in the boost modes. Still, very very cool. The car takes on a faster more responsive character. Note that the car is not in fact faster, but it will feel like it is. One could certainly argue that persuading the 7AT to downshift quick may in fact make the car faster if you are driving it spiritedly while in fully automatic mode.

"High throttle mode": This just does the opposite of "low throttle mode", more effective throttle movement. I did not play with this mode much, but it may serve as a much less touchy "boost" mode while still giving the benefits of making the transmission more responsive. I'll report back on this mode some more if someone is interested.

As an engineer and a reluctant fan of what I call "perception engineering" I enjoyed playing with the Apexi. By perception engineering, I mean designing something to make the user think it is better than it really is on paper. This device can make the car feel faster even though it isn't any faster. You could do the same thing by just being more aggressive with your foot. It can make the takeoff smoother for you, by making the throttle on this car more linear, even though you could do that yourself with your foot if you concentrate. I don't want to concentrate on pedal application when I'm pulling away, I just want it to feel more natural and refined and linear, like other sports/sporty cars I've driven.

So what does this smart accel controller do that you can not already do with your foot? Technically, absolutely nothing. However, I can not train my foot to do what this controller does with its trickery, and I've had this car for a year. It changes the character of the car. It did what I want, which is to take the necessary mental concentration out of modulating the overly sensitive gas pedal on this car when I pull away from a stop. And I have to say that the boost modes are pretty darn amusing when you factor in what it does to the transmission.

************So, the benefits, as I see them:*************

1) It can make the accelerator less sensitive. This makes pulling away from a stop smoother and more refined feeling. This can also improve your MPG.

2) It can make the accelerator more sensitive and "punchy". Makes the 7AT transmission much more responsive in the process, but beware the acceleration from a stop is touchy in "Boost 2".

My only concern is about fail-safes... I now have a black box between what I command with my right foot and what the car does. Can this device malfunction in a way to cause unintended acceleration?

Cost was $225 plus shipping.

 

If you don't mind my asking, what does something like this actually cost? Retail is around $270 correct?

 

I just edited my post. It was $225 plus shipping.

 

Pics by any chance?

 

These graphs do a very good job of explaining what I tried to put in 1000 words.... The relationship between time and throttle output (for the boost and eco modes)... and for pedal position and throttle output (for the other modes). I can pretty much feel the car responding the way it shows in each graph.

This is not my own photo - I found this online with google search:



And a pic of the button, again not my own photo, from google image search:

 

Thanks for the pic, and it does better than 1000 words, lol. What part of VA you're from?

 

Your pretty safe. Solid state electronics are extremely reliable within its given operation ranges. Unless your car's electrical system somehow craps out and have huge voltage spike your safe, and if somehow that does happen it much more likely that a component will just burn out and not output anything (0% throttle). If you do have a unexpected acceleration just bump the stick to neutral.

 

Great write up.. i was looking into this to help smooth out my take off as well as help with the MPG for my basic commute ( i know, i know its a sports car and its suppose to get 5 mpg..., but a little more wouldn't hurt right?)..

but i'll be looking into this mod possibly in the future too..

--quick question was it just a accelerator pedal wire tap? unplug the pedal--> plug into the module--> and plug the module to the accelerator pedal?

good stuff though!! i'm glad that it helped You in some way.

-1scG37s

 

Yep, for anyone curious, install goes like this:

Remove the rectangular plastic cover over the two bolts holding down the bottom of the gas pedal and remove bolts. It was a PITA to get that cover off.

Now you can lift up the gas pedal and see the connector. Unplug connector. Plug the two ends of the cable from the accel module into the pedal and harness respectively. You don't have to cut any wires.

Next the tricky part is hooking up the reverse gear sensing wire. This goes to the reverse lights. I did not hook up this wire. The purpose is to disable the accel controller when you are in reverse. That's a good idea if you are using it in "boost" mode. Since I am only planning to use the modes that reduce throttle sensitivity, I didn't connect this wire.

Route the wire and tuck away the small box and that's about it.

"Teaching" the accel module the full throttle and closed throttle positions is next. It's a few step process that's explained in the instructions. They caution you in the instructions that this step must be completed correctly or you could get a check engine light. The indicator light on the device made it clear enough to me that I completed the steps and was good to go.

 

Any updates on how this has performed over time? Any issues? Still working? I'm considering installing to fix the same "touchy from start" issue on my 2013 g37. Before doing so though, was hoping to hear from you about feedback after extended use with the product.

 

Yes, still working perfectly. I've had it installed for almost 3 years already! Never have to touch it. I turned it off recently just to remember the difference. I can't believe how touchy this car is stock. 100% recommend this. Have never had a hiccup or problem of any kind.

I leave it on LOW-THROTTLE mode (dark green LED) all the time. It fixes this car's overly sensitive gas pedal on takeoff.

 

Excellent, great to hear. Thanks for the tip, mikeb2004! I've placed an order and will install it soon.

 

Bringing this post from the grave, what model number on the harness. I bought one ,but it was the wrong harness..

 

I'm glad I didn't know about this when I got the RJM clutch pedal. I probably would have spent 6 months trying to decide which to get. As it is, I set the clutch engagement pretty darn low tryin to balance it with the accelerator response.