[james jefferson]

do any of you smart guys know of any merit to using a computer decode or setup device (as the hot-rodders do) to setup the C for better performance? k&n filters only do so much.

 

[05Hemi]

Ken Bell is building a huffer for the Hemi (Whipple gave up on it) because of the sophisticated electronics...ALL of which Daimler would not help them with. He says it is all new technology (MDS), so it is taking their engineers a lot of time to reverse engineer. If you hear of a breakthrough, please let us ALL know! Good luck.

 

[DrDeville]

On a similar topic, how about modifying the Hemi's transmission
mapping, to hold the engine at higher rpm in general driving,
and improve at-speed throttle response and acceleration?

Is the idea promising, do-able, and is anyone working on it?

Best,

George Ferguson

 

[300c Owner]

Any update on chip upgrades?

 

[300c Owner]

Any updates yet ... almost another month.

 

[AndyK]

Nope, but SEMA is next week so... knock on wood.

 

[CottyGee]

Yeah, the trans is a bit anemic on downshifts, really. I've been hoping it would "wake up" a bit as the adaptive thing gets seated in.

But so far, it's holding the higher gear with a good second of hesitation before a downshift, behaving just like a big car trans... Heck, it's behaving just like a friggin' hydrolic tranny!!! Them electronics are supposed to DO something!

A more aggressive trans map would make this car soooo much more fun to drive!

 

[joey]

I often notice the RPM's actually drop when I begin to accelerate.
I notice it a lot when I am cruising at a constant 40mph and my RPMs are around 1500, and when I push the gas peddle to accelerate the car actually seems to hesitate and slow down, and the RPMs drop down to around 1,100 for a second or two before the car actually starts to accelerate.
I have never noticed this strange momentary drop in RPM's in my other cars when I give the car more gas. Anyone else notice this slight hesitation and RPM drop? If anything it should be downshifting, creating higher RPMs, when I hit the gas pedal.

 

[arnoldw]

I often notice the RPM's actually drop when I begin to accelerate.
I notice it a lot when I am cruising at a constant 40mph and my RPMs are around 2400 (if I recall correctly), and when I push the gas peddle to accelerate the car actually seems to hesitate and slow down, and the RPMs drop down to around 2100 for a second or two before the car actually starts to accelerate.
I have never noticed this strange momentary drop in RPM's in my other cars when I give the car more gas. Anyone else notice this slight hesitation and RPM drop? If anything it should be downshifting, creating higher RPMs, when I hit the gas pedal.

Sounds like what you're describing is the torque convertor locking up, which is normal. If you let off the gas the convertor disengages so the car can coast further thereby getting better gas mileage. As you lightly press on the gas the car stays in a higher gear and the convertor gradually slides back into lockup causing the rpm's to drop. If you give it more gas, say 1/3-1/2 throttle it would downshift to a lower gear. I've noticed this on my '93 concorde, '99 300m as well as my 300C.

 

[CottyGee]

I'd dearly love to be able to control the trans with a button... During most driving situations, the trans is fine the way it is. But sometimes, I want to get quick response.

The Supra I had had a trans mode button. In "sport" mode, I could generate a downshift with a feathering of the throttle, hold that gear for a second or two, then accelerate. It made driving in heavy traffic at freeway speeds really nice. As preparing for a lane change that would involve acceleration, feather the throttle lightly, check mirrors, and go. It was really, really nice. And that car was vastly underpowered compared to this one!

 

[joey]

Sounds like what you're describing is the torque converter locking up, which is normal. If you let off the gas the converter disengages so the car can coast further thereby getting better gas mileage. As you lightly press on the gas the car stays in a higher gear and the converter gradually slides back into lockup causing the rpm's to drop. If you give it more gas, say 1/3-1/2 throttle it would downshift to a lower gear. I've noticed this on my '93 concorde, '99 300m as well as my 300C.

I think you hit the nail on the head with the torque converter diagnosis.

It would be nice to be able to disable this torque converter hesitation.
The hesitation is similar to turbo lag.
I would give up the gas mileage savings for better throttle/acceleration response, but I doubt there is a way to tweak the converter without replacing the torque converter with a different model/brand.
I plan on asking the dealer to check my torque converter to make sure it is working correctly. I also notice a lot of little hesitations/power surges when cruising on the freeway.

I did some google searching on lockup torque converter and found these informative.
http://www.leeric.lsu.edu/bgbb/7/ecep/auto/f/f.htm
http://www.fordmuscle.com/archives/2000/09/converter/index2.shtml
http://www.popularmechanics.com/automotive/auto_technology/2004/7/hemi_build/print.phtml

 

[Hemi_Hombre]

I'd dearly love to be able to control the trans with a button... During most driving situations, the trans is fine the way it is. But sometimes, I want to get quick response.

May I recommend down-shifting with the Auto-Stick? Works great for throwing the ass-end into a power-drift.

 

[300c Owner]

Any word on the CHIP from SEMA?