SRT Engineers Chat Session - 7/23/08 6pm - 8pm EST

[ekool]

This Chat Session is OPEN FOR PRE QUESTIONS - This thread will be opened 2 hours prior to the event at 4pm EST on 7/23/08 (Wednesday).

Participant Guidelines:

• Keep all questions on topic and related to the SRT lineup of vehicles - off-topic posts will be removed
• Direct ALL questions to the SRT Team AND allow the SRT Team to answer ALL questions (no member discussions here)
• Review existing posts to avoid repeats of a same question
• Limit each post to 1 or 2 questions and be as brief and clear as possible
• Allow time for a response - questions are not answered in order of post. If it appears you were missed, AND the same question was not previously answered for someone else, you may re-post before the session ends
• The SRT Team cannot answer questions about future product

[ekool]

The thread is open! You may now post your questions. The Engineering team should be available after 6pm EST to begin answering them.

[skeletonizer]

I am an extremely proud owner of a 2006 300c SRT8, built 04/06.

Let me start by thanking you guys for an awesome machine! It is worth every penny. It has operated nearly flawlessly as a daily driver/occasional bracket racer rain, snow, and shine.

Early in July I attempted to change my brake pads. The pad change was initiated due to the fact that the rear pads were nearing the "squeeler" pad wear indicator. They still stopped the car like always but it was time for a swap. I did all four as I didn't want to do half a brake job.

Upon removing the right front pads I noted the plating had come off the face of the caliper pistons. (pic below taken much later after calipers were removed)


The car is a year round daily driver in Northern Michigan and has approximately 36,000 miles on it. The pads are original and the rotors were replaced per TSB# 05-006-06. The below pics shows the wear on the front pads at the time of the discovery.


It was noted that the pistons on the inboard side of the caliper would not return to the bottomed out position. The dust boots were rolled back and it was noted that the plating on the pistons had been compromised all the way down to the pressure seal. One of the pistons was removed for further inspection. (pictured below: The top pic is of the piston upon removal, the bottom is after brushing the loose plating away to show the extent of the plating failure.)



The plating on the outboard pistons did not appear to be as bad. The driver side showed signs of the plating on the face failing (see pic below) but it did not fall off during dis-assembly. Uneven resistance was noted on the inboard pistons of the driver side when placing them into the bottomed out position.


The dealer had no caliper parts available other than dust boots. They were more than willing to sell me calipers to the tune of $400 each. I have since fixed the problem for considerably less than the cost of just one new caliper.

On a side note the rear pads showed a bevel or taper to the wear. (see pic below)


What is the purpose of the shim on the rear pad and it's unusual shape? (pic below) Would not the fact that the piston is bisected by the edge of the square holes cause binding of the piston in the bores? Just curious?


Here are other threads about this same issue:
http://www.chargerforums.com/forums/...ad.php?t=81218

http://www.300cforums.com/forums/srt...corrosion.html

http://www.lxforums.com/board/showthread.php?t=120799

http://www.***********/forums/showthread.php?t=19635

http://www.***************/showthread.php?t=41689

http://www.******************/forums...ead.php?t=7608

No doubt you are impressed with my brevity.

I can not be here for follow up questions so I am breaking the rules a bit and asking multiple questions. Be gentle with me admin.

Have you noted other failures of this nature?
Is the caliper still an "unserviceable" part as the 2006 Service manual indicates?
Are their plans to offer caliper parts in the future?
Have materials or design changes to the SRT8 calipers been made since the production cycle began?
I have seen that some of the earlier builds had a cup piston disign on the fronts similar to the rears, when (VIN break point) was the change made?
If another experienced this problem and was willing to let a dealer tech work on the car would it be a warranty item?
Would custom stainless steel pistons work in the caliper without other alterations? (I know, but I have to try. )

[T-Time]

First Off, I Love this 07 Jeep SRT8. I live Downtown Chicago, It's Crazy how many heads it turns. And if They take more than a second look, I give them there moneys worth. Put it in Nuetral and Goose it a little.

I recently took the Jeep on a Road course (April). Not racing, but hard driving. I thought it handled it great. I tried to take it easy on the brakes. I did have a little coolant spray It looked like it was coming from the water pump. But minimal and has been fine since.

I'm considering doing it again in Sept. (4 to 5, 20 min. sessions).

Qu. Can I feel confident that the Jeep can handle this? Do You feel this has been taken into consideration when designing the SRT models? I'd just like your opinion.

Thanks,
Jeff

[oneliterlandspeed]

My hats off to a Spectacular group of engineers, You have given us a great machine.

Topic: Stock connecting rods.

With all the modifications and quest to squeeze out even more Horsepower discussed on this site I have not seen any information on the stock connecting rods. At what Horsepower/torque would it be appropriate to up grade the connecting rods.

Thank you for taking the time to interface with us, it is greatly appreciated.

Terry

[Daddy Kool]

You guys rock.
I have a '09 SRT Challenger on order in Canada. Is the Sirius Sat. standard? If yes, Do the '09s have the bee stinger antenna on the roof ?

[SRT800]

I just wanted to extend my kudos to Ed, Craig, David and the entire SRT Team. I have three technical questions:

- will the SRT8 6-speed manual (I'm assuming the Trak Pak 3.92 gears if that helps) be without a top speed limiter or fuel cut?

- what is the maximum RPM that the driveshaft is "safe" to for first or second mode harmonics?

- are the fuel injectors and fuel strategy for the 6-speed 6.1L Hemi as installed in the Challenger SRT8 the same as prior auto-stick SRT8's?

Good luck on the Mopar supercharger!

BTW, I ordered two 6-speed Challengers SRT8 for SEMA (hope they come in time....) and I have a few parts under design via a borrowed '08.

[06infernocdn]

I have owned my 2006 SRT8 Jeep since brand new and it currently has 47000 km on it....the rear end/exhaust/differentials have been making an odd whirling noise upon medium acceleration (between 40 - 70 mph ) since the differentials underwent the dealer recommended service at 30,000km.. is this sound normal?
I have had many problems since Aug 2006, SRT door sill plate was not on the driver side, bright pedals were not given, the express window up pushes into the metal on the door, the door hinge is rusting, I have had to replace the front tires (an inner sidewall blowout, and uneven wear), I have had to replace all 4 rotors and pads at 39,000 km.
Also a question about the rims, they are chipping away I have noticed deep pits, to my knowledge these rims should not be reacting so poorly to stone chips, dealer offered to just refinish but I am sure that they will just be even worse after, is this a normal quality issue?
Last question when I shut the vehicle off it makes a sound from the area under the driver door side that I can only describe as a sputter or whirle, the dealer said that it was the transfercase acctuators resetting and that it is a normal sound..my answer is that it didnt do it when I bought the vehicle, is this a normal sound?

[California-Peter]

I recently bought my GC 2008. Sad, that I don't live in Germany anymore w/o any speed limits.
The current semi-metal brakes of this GC 2008 produce lots of brake dust and mess up the nice polished rims. On the search for ceramic brake pads I found the "GS6" product of Satisfied Brakes http://www.satisfiedbrakes.com/brakes/index.html). Do you recommend them or do you have a better source?

[RapidTransit]

On one of these chat sessions a year and a half to two years ago, one of you mentioned that CNC'd heads and camshafts were being developed by Mopar Performance for the 6.1--something similar to the performance package for the 5.7. Are there still plans to release those camshafts (and presumably tuning) for the 6.1?

As always, thanks for participating!