I was on a Mustang forum reading a post from a guy with a Mach 1, manual tranny. His complaint was that when shifting at low to mid engine speeds, it would take a while fo the engine rpms to come down after taking his foot off the accelerator pedal. This makes shifting difficult since you then need to wait for the rpms to drop before letting out the clutch to avoid any jerking.

Apparently, this delay in the closing of the throttle is on purpose, an emissions thing. Ford doesn't want the throttle closing too quickly.

The final answer for the guy was "get used to it". In my book, that really sucks. Someone suggested that it might be corrected with a chip upgrade, but...

My question... do any C6 owners observe any level of "throttle closing delay" as described above?

So far, the C6 has drive by wire (causing a certain amount of pedal delay that owner's have noticed), then it also apparently has an issue with the clutch (clutch delay valve maybe?) causing more weirdness... so now I am wondering what other potentially undesireable issues may exist that could make shifting a headahce.

I will say this... when I test drove a manual C5 last year, I thought it was one of the best manual tranny experiences I ever had. I was very happy with the clutch on that car, it was a breeze to shift. I hadn't driven a manual car in over a year prior to that test drive, and I jumped right in and drove it perfectly, not one buck or jerk, etc. If the C6 is as good or better overall (in terms of clutch operation and throttle operation), I'll be happy.

 

I've never noticed anything like this.

 

Yes,
My C6 with the Z51 package definately has a delay on throttle closing....I noticed it the first day I drove the car. I haven't experienced any issues with it but I haven't really driven the car hard yet....
I can't believe it helps it helps my mileage either..which still doen't equal what my 04 Z06 delivered at 2k Miles.

Pat

 

It isn't a mileage thing. It is an emissions and driveability thing. Since the 1970s dashpots that delayed closing of carb butterflies on deceleration, automakers have slowed throttle closing. If they didn't, there's a possiblity of backfire or engine stumbling. This is because of the emissions tuning of the engine.

 

It's something I've noticed on almost all cars and IMO it actually helps rather than hurts when shifting. Definitely not something I'd find myself wanting to change in any way.

Mike

 

I have noticed it and wondered if I am having a problem with it. Especially in reverse I see, not just holding the rpms, but increasing them! (Without touching the gas pedal)

 

If you are talking about what I think you are, it's normal. If you are in first or reverse (might be any gear) and you leave your foot off the gas, the car will apply more and more throttle as you go uphill and the grade of the incline increases. I have a long increasing grade hill that I have to back up and I can just take my foot off the gas and as the hill gets steeper and steeper, the throttle gets pressed more and more to keep the car above idle. As the hill gets steeper, I notice that it chooses a slightly higher RPM just to keep it from lugging. I believe it simply has a throttle table that tells it what throttle position to choose for pulling hills and the RPM it picks might be higher based on how much gas it is having to deliver.

Could that be what you are noticing? Increasing throttle/RPM is common for manual transmission cars to keep them from stalling.

Mike

 

I have definately noticed it at low speeds at lower RPMs on my Z51. I have since become use to it and really don't notice it during normal driving. It is definately 'computer controlled' and prevents a little accelerator stab and quick down shift in performance driving. I will try putting it in 'Performance Driving Mode' on the way home tonight to see if it changes anything. I dowbt it will since that only affects rear wheel spin as far as I can tell.
Bill