This is the number one biggest annoyance I have with my 2016 C7 M7 and you described it perfectly. I have the Soler Throttle Controller which I really like, but have held off on the throttle body because of costs and I've heard pros and cons that the car's system can essentially "relearn" a throttle body's operation and over time deem the update negligible from stock. I can't ever see myself using my throttle controller in ECO mode as it's not the pedal response I'm looking for which is why I chose a throttle controller to begin with

 

I have both and, IMO, there are no cons to either, aside from cost. I didn't experience any TB relearn difficulty. Nor, do I deem either upgrade negligible even after running them for years. They function very nicely in tandem. My TC sweet spot Sport 5, which I believe to provide the most linear throttle response. The other setting I like/use most is Lock, which provides theft deterrence.

 

I shared all of your concerns. I’ve played with the throttle controller (Vitesse) in the more aggressive sport modes and it’s kind of fun but the more aggressive positions required a great deal of finesse when driving in Southern California traffic.

So here is my timeline, first I did the throttle controller and was not thrilled, then I got the throttle body and I was still not thrilled. No matter what I tried, the results were a compromise at best. There seems to be an off idle transition that happens awkwardly in the OEM environment. The sport settings and the throttle controller didn’t seem to do the trick. It was only when I adjusted the settings into the eco (negative 3) range that things began to improve. It seems that slowing (rather than speeding) the throttle action through this transition delivered the drivability that I was after. Interestingly, the throttle response and power beyond idle are excellent, the power isn’t reduced, it just comes in later. One final thought, I’m not sure if the car learned over time or if I adapted but it’s really quite nice these days. I located the throttle controller in the center console so rowdiness is just a twist of the dial located at my elbow. I’d get the controller first then go for the throttle body second. Make sure that the controller that you select has several eco modes. JMO.

 

I have both the Soler Throttle Controller and the Soler Throttle Body installed on my GS M7. Very easy install, not experienced any issues whatsoever. The learning steps were very simple. My sweet-spot is Sports 6. I’m very happy with it. The car drives great, feels very responsive.

 

You might be able to get what your after with just a throttle controller, you’ll just have to see how you like it.

 

Hi, I think what you describe as the “choking sound” is what I have been experiencing since I owned my 2019 stingray. Only 10k miles on it. After the cold start out is most noticeable IMO. Like when it’s idling and I slightly blip the throttle it’s like it hesitates and the motor actually sounds weak. I was thinking it just because of the factory cam and and aftermarket cam would fix that but after reading what you posted I now think it may be just the factory throttle body? I am going to consider ordering the solar throttle body and hope that improves the situation with the hesitation.

 

I can’t , definitively, tell you what is going on but here’s what I think is going on. As the OEM throttle begins to open there is some point at which there is a minor but abrupt change in airflow through the throttle body. It’s my supposition that the engine control module doesn’t respond rapidly enough to adjust fuel flow during this transition. Do I know this for a fact? No but that’s my supposition based on considerable experience working with mechanically actuated secondaries on single-pumper 4 barrel carburetors. These carbs exhibit a similar gasp if the secondaries are opened too abruptly at low rpm, fuel delivery can’t keep up with the rapid change in air flow and they go lean for a fraction of a second. Having no actual data to confirm my supposition but having some time on my hands I tried the only two readily available options available to me, the Vitesse throttle controller and the Solar ported throttle body.

With the throttle controller you can change the rate at which the throttle plate moves through the “choke” zone.

With the throttle body, the alterations to the throttle body itself can potentially diminish and/or eliminate the choke zone.

I tried the Vitesse throttle controller first. Speeding up the controller changed the character of the choke but didn’t eliminate it. It also made slow speed driving in traffic difficult at times because the throttle opened more abruptly. I never tried putting the controller in the eco mode which would have SLOWED the throttle action down as it passed through the choke zone because all the on line solutions suggested that speeding up throttle response was the answer.

I then purchased a Ported Solar Throttle Body. It is a nice quality piece by all appearances but it didn’t seem to have much effect on the choking issue.

At that point I kind of gave up and just lived with it. I really was really wasn’t enjoying the car that much. I love the low effort of the hydraulic clutch but, I struggle to feel the “friction point” of clutch engagement and when you combine that with the problematic tip-in cough it really wasn’t much fun to drive in heavy traffic. At some point, tiring of the abrupt throttle response in Sport 3 and just playing around, I put the controller in Eco 3. It was a busy day and I didn’t give it any more thought. The car is not a daily driver and sees only sees occasional use, so it was only some time later that I realized the choking problem seemed to have gone away. I have made no further investigations such as trying different combinations of parts or settings. My recommendation is to start with a throttle controller that offers an Eco or slow down function so you can try speeding up or slowing down throttle response. And review your results, if the problem persists try the throttle body. Eco 3 mode didn’t seem to reduce power, only how abruptly it arrives.

Good luck.

 

Cam replacement is an involved and expensive process. Throttle Body and/or Throttle Controller replacements are simple DIY projects that should take minutes to complete with a total parts cost of "only" between $230 and $670, depending on whether you do one or both and whether you go completely new TB or have them rework your stock one. If you're not satisfied with Soler solutions, they hold great resale value and you could still invest in the cam swap.

It's your car and your decision but, if I were you, I'd try the less expensive and simple solution(s) before jumping into a more expensive and complicated one.

 

A little insight into what's being addressed. The below screenshot (first one) shows two things from the stock (2019 in this case) programming. Other years are nearly identical with the occasional minor nips & tucks.

The throttle table shows how much the throttle blade opens....regardless of how far the gas pedal is pushed down...throughout the rpm range. There are also torque based tables (2nd screenshot) that are for Driver Demand. You can see how it's a smooth ramp. Make it steeper and you have faster throttle response and vice versa. These tables also account for what gear the transmission is in so there's more to it than I'm showing. Mike can offer up the real answer but I'll presume that the throttle controller fibs the throttle position to affect the driver demand tables.

As an aside, I think GM limited throttle opening in an attempt to reduce the cases of "too much car / not enough driver". Just a guess.

The flat spot people often cite is likely due to the VE coefficients. On the left side of the first screenshot is the 3D view of the factory Virtual VE table. The area I circled in red is roughly where the flat spot happens. Why GM didn't smooth this table, I have no idea. They have pretty smart folks so I can only surmise the juice wasn't worth the squeeze.

There are many other things going on so the below is a very simplistic display of a little of what's behind the curtain. It's pretty amazing what the Engineers accomplished and to think that much of this was started 12+ years ago makes it even more impressive.



Driver Demand




Anyway.....

 

I’ve seen a side by side tabletop demonstration of two throttle bodies, one with a stock accelerator pedal and one with a stock pedal and an aftermarket throttle controller. The OEM set up has a distinct lag in response whereas the controller equipped throttle can be adjusted to a wide range of responses.

Went on a drive today, she was a real sweetheart. I checked my setting, it was on Eco 5 yet she still responds aggressively when you give the pedal a stout wack.

 

I got a Soler throttle controller (controller only, not throttle body) for X-mass; by request... I installed it in my 2019 Grand Sport yesterday. Oh, wow, holly cow, Sport 6 is it for me!! I feel like my car has been holding out on me.
Took less than 10 minutes and no tools. Nice!

 

Is there an actual (verified) performance increase by adding the Modified, Ported, and Calibrated Throttle Body?

 

I’m unaware of a confirmed power increase, however the Solar ported throttle body clearly flows more air than the OEM unit. The off idle area is cleaned up and the shaft is cut down so it clearly flows more air but I have know idea if the stock LT1 actually can benefit from the modest increase in airflow. Additionally these changes do create a bit more airflow at smaller throttle settings so throttle action is more aggressive.

A throttle controller adds no additional power, it just operates the throttle more aggressively. The LT1 has buckets of low speed torque so snapping the throttle open delivers big results no matter if the throttle is snapped open with your foot alone or with the aid of a throttle controller.

 

Thank you.