With all the recent talk regarding the upgrading of the rear diff, durability, etc...I thought I'd pose the question:

Whether doing a burnout at the strip, launching on the street, or just mashing the car from a stop to see how long I can carry it sideways - I always end up with two black marks.

If the car is 'one tire fire' like everyone says, why are both wheels spinning?

Or am I missing something?

YES, I did a search for this - and the only other thing I found was Steve Hellums saying his car laid two solid black marks as well.

SQ

 

I two have no problem laying rubber at will from both tires!

 

i also get 2 Black Stains ... lol.

 

I think he was referring to a LSD type setup as opposed to a posi setup... I could be wrong though.

 

I would think these cars had LSD if I didn't know better...

SQ

 

in a '06 parts book it looks looks like an open sided rear not a lsd maybe a srt rear is different.

 

It's an electronic differential. As opposed to the internals of the differential locking to divert torque, each wheel can be braked independently by the onboard computers to do the same thing. Mercedes Benz has been doing this for a while now.

 

this must be the traction control you are talking about.

 

hey Old Man how ya doin,
yes that would be the Traction Control issue - button or what ever it is called.
It's an electronic differential....each wheel can be braked independently by the onboard computer TC.

 

poor mans Posi traction, lol you can get the same effect by slight pulling the e-brake on some cars, but your making more drive-line drag.

 

not like the old days when you had a true locker like the detroit.

 

why don't you just buy the phantom grip LSD, it's only $500 your cornering ability will be outta sight!

 

I do believe LSD and Posi are one in the same.

 

both use friction plates.

 

the only thing being offered to us is... something like this... a posi unit and not a full LSD, but a unit that attempts to mimic the characteristics of an lsd.

http://www.modernperformance.com/dcx...antom_grip.jpg

and this...
is an lsd that we should be offered.
http://www.roadraceengineering.com/p...uaife-bare.jpg

 

I think the main difference between Posi, LSD & Mopar's "Sure grip or Sure lock is the auto maker. Ford = posi, GM = limited slip or locking & Mopar = Sure grip. Mine spin's posi till you try to bring it on around for a doughnut, when most of the weight of the car is on the outside rear tire it quits spinning. As long as I going in a fairly straight line it leave's about $20 worth on rubber on the road in two line's.

 

The ESP/Traction Control system does indeed use the application of one-wheel brakes to limit wheel spin. The advantage of this system is it does not make the car loose directional stability in low traction conditions (rain, dust, gravel or snow/ice) when power is applied in a corner. In those circumstances a "tight" or highly biased/loaded posi/sure grip rear end can make a car dangerously "tail-happy" and prone to wild over steer. The Crossfire has a very short wheelbase in proportion to it's track. DCX didn't want these cars going *** first into ditches whenever it rained...

Here's my hard-learned experience. I had a '97 Cougar with a 4.6 SOHC "mod motor". I had adapted various Mustang hop up parts and got the engine running pretty strong. I had a 3,200 rpm stall torque converter and a TransGo shift kit which hit the gears pretty hard at full throttle.

But the factory open rear end limited the car. I could have installed a FoMoCo Eaton clutch type limited slip like used in the T-bird Super Coupe or Cobra Mustang. (both used the same IRS).

But I'm an old Mopar guy and am used to the "cone-type Sure Grip" limited slip unit like Auburn makes. I got greedy and installed their "Posi-Pro" unit; a very highly loaded/biased unit which is very resistant to differential wheel speed. On dry pavement it was great ! The car hooked and launched like crazy !

But the first rainy night...I tried accelerating on a uphill curving on-ramp onto a bridge on Northbound I-75. I kicked it down and all hell broke loose. The hard shift shocked the tires. The Posi locked-up and BOTH TIRES LOST TRACTION. With both rear wheels spinning the car fishtailed wildly. I attempted to correct and lifted but it was too late. I entered the expressway totally out of shape, skidded sideways across three lanes of traffic, the rear end smacked the guardrail...HARD !

Fortunately, since it was late at night and traffic was very light, there were no other cars involved. The impact actually got the car pointed in the right direction and I nursed my crumpled Cougar home. It was a very scary and expensive lesson for me!

That's my story, and I'm sticking to it !

Cincinnati Slim

 

I would like to know what the difference is in qtr mile time if the car was relying on only a mechanical limited slip rear vs. the electronic brake activated traction control-with the ESP turned 'off' on my car, both tires will start to spin out of the hole, but will switch from side to side as the computer tries to keep clamping on one brake/side, then the other...marks end up looking like ===---___----__---___ (and that is only if the computer doesn't over-ride the throttle and shut down power). My other car is a '72 Demon 340 with a 4 speed, and it is a lot more predictable to launch, and more consistent on a bad day than my SRT is on it's best-I guess the pure mechanical nature of it I find more predictable than the electronic 'Nannies' that oversee any exuberant driving that occours in the Crossfire!

 

In my 3 years of drag racing experience in a car of nearly identical size, weight, weight distribution, wheel base, and H.P. as the Crossfire, I can say a posi unit with no traction control would easily walk away from a car with ESP on a drag strip. Anytime a system regulates power, or applies a brake to correct wheel spin, it uses up precious seconds of acceleration.
In the real world, day in day out driving, on wet streets, or snow, the ESP would really shine most of the time.
As Cincy Slim pointed out, a posi unit will make your car "fish tail" since the differential is hunting for the wheel with the most traction, and that situation can come back and bite you under the right circumstances.
But I can guarantee, if our cars had posi, and we could completely disable the traction control, the Crossfire would be known as the "donut king" of most any parking lot competition.

 

can't you pull fuses 17 and 18 and turn of the ESP.


also their was a post and a video, to take fuse 17 and 18 out to prevent this from coming on.

http://www.youtube.com/watch?v=RwRK97G2lFM

https://www.crossfireforum.org/forum/...ad.php?t=19708

https://www.crossfireforum.org/forum/...ighlight=fuses

https://www.crossfireforum.org/forum/...&highlight=esp