Ragtop

Having tuned way to many electronic TB cars to count, and constantly testing the limits of what we can do without inducing reduced engine power, i can say that when an error is detected it is mere milliseconds after the fault is detected that reduced engine is set. That is if all the diagnostic parameters for that system had not been "tampered with" by a previous tuner.

I am not saying what you described did not happen, and i understand how you would be concerned to run it again. If you truly do want to go forward with this swap it will require some creative computer tuning to make it work, but i am certain we can do it

 

Iam not a tuner genious, nor do I know how every system relating to the corvette works. I certainly only know a little about how the PCM talks to every sensor, but I do know this:

Common sense logic. Right or wrong I believe what you say happened and to be true. Now to provide a solution to the problem so it won't happen again and set your mind at ease....hmm why would you go so drastic to do this whole cable to throttle body issue and mess with all the computer programming etc etc. You said it yourself that it was the cheesy crappy throttle motor that failed. Actually I believe you said it a few times. Why not repair the broken motor and replace it out with something much better? I am sure to repair this by yourself or a professional will be extremely cheaper then going the route you are thinking of going. This keeps your car with today's technology and repairs the problem to your liking...the way as you put it "GM should of done" in the first place. In addition, you won't be opening a whole new can of worms to deal with by introducing all the new cables and tuning into the scenario. I really REALLY would suggest you to first calm down and really think the problem. I know from experience that anger and frustration can fuel your mind for making decisions too quickly. I truly think if you go down the path your going...your in for a bunch of headaches, your tuner is going to get frustrated, and your going to spend a lot more money and end up with at best, no better results in the safety department, then if you just repaired the failed tb motor.

Iam surprised nobody has not said this yet, really surprised. I mean you wouldn't try to fix a new cordless telephone by using 2 cups and a piece of string? Then try to tune it over and over again to make it sound as good as your phone once did.

 

XtremmeVette, great insight, I did actually consider just replacing the motor with a higher quality unit. I would have to be careful to get a motor with very similar Kv and Kt or I'm sure the TAC module would have a hard time controlling the position of the throttle blade. I'm still weighing these two options, I justed posted to try and gage how difficult the tuning would be if I went that route.

 

Well, I have nothing to add other than to say I learned a few things by reading this thread. (The sensors, and computer communication- Not the arguments)
Thanks

But, Id like to think the computer would put the engine in reduced power mode MUCH faster than it takes for the traction control to kick in, as that takes probably close to a second.

 

Traction Control (and Active Handling) are good examples of where a computer gives YOU some control before stepping in .... yet .... that same computer instantly intervenes in other situations (ABS, RSC and DRP).

The Electronic Brake Control Module (EBCM) is the computer that manages functions such as TC, ABS, and AH. It is intentionally programmed to allow the driver some leeway in managing wheel spin during acceleration, for example. If you check your Owner's Manual regarding TC it says something to the effect that it limits wheel spin when they are spinning "too much". Chevy realized that if you couldn't at least "chirp" the tires on a Corvette .... how many would they sell ??? So while the EBCM realizes "instantly" that you are spinning the rear tires, it is programmed to allow it within certain limits .... as soon as you hit those limits .... it intervenes.

On the other side of the coin, that same computer (EBCM) does not allow the driver ANY leeway with the ABS system. If, under braking, a wheel speed sensor shows one wheel slowing faster than the other three the EBCM "instantly" intervenes and reduces brake fluid pressure to that wheel's caliper until that wheel's speed comes close to matching the other wheels again .... then the EBCM allows brake fluid pressure to be re-applied to that wheel.

As programmed on a Corvette the ABS allows the driver to control the brake line pressure up until pressure causes wheel lock. The EBCM can reduce pressure to a caliper, and it can return pressure up to the level commanded by the driver ... but no higher. There are systems that go further ..... Mercedes has "played with" a system that senses "panic braking" and then takes complete control of the brake system applying possibly a higher pressure than the driver has commanded to stop the vehicle as soon as possible.

That's where the real "debate" is in fly by wire systems ....who is in control .... the pilot/driver or the computer .... is the pilot/driver "commanding" the system .... or making a "request" that the computer then decides if it wants to execute or not?? This is, in fact, a basic difference in design between Boeing and Airbus aircraft .... Boeing believes the pilot commands the plane and Airbus believes the pilot is making requests.

In the case of a "stuck throttle" it is easy ..... reduce engine power or even shut it off instantly ..... that's an easy choice ..... what do you do if you sensed panic braking from the driver and the brake system is at maximum brake effort and that "idiot" driver just lifted his foot off the brake pedal with the car still moving.... do you keep braking to a stop or do you return brake system control to the driver ????

Make no mistake .... the EBCM is not "slow" to intervene with Traction Control ..... it is simply allowing you to have "fun" within certain limits .... and as soon as it sees you exceed those programmed limits ... it steps in. It ain't slow ... it's smart.

 

And TC does not "allow" me to have "fun within certain limits" when I turn it off. The decision by GM to not go "big brother" with TC is fine with me. Rather "Boeing-esque" don't you think?

Regarding your comparison to Boeing/Airbus design philosophy, put me in the camp of: "If it ain't Boeing, I ain't going".

 

I agree with all you said .... and the part in red .... Amen brother ... that is EXACTLY my belief also ..... no old MD aircraft ... no Airbus .... and no Soviet junk either. I would fly an L-1011 but they have pretty much all been retired/scrapped.