SRT Engineers Roundtable: 07/21/10

[Hemi31]

Sorry, I'm going to give you the same answer that Paul gave you. Your stock exhaust basically is a straight through and will support 650-700hp.

Good enough for me.

[SRTEngineers]

A lot of folks on the forum have had a problem with engine stalling. For me on three separate occasions the car (2009 Challenger SRT8) has stalled when slowing down and preparing to make a turn. It happened twice with my 6.1L engine and once with the 426. Given it has happened with the stock and stroker engines I don't think it is the engine. Is it a potential problem with how the fuel system/tank is designed ? Would like any insight on where to look for the problem and how to solve the issue?

There is a software fix coming to correct this issue. Stay tuned.

[SRTEngineers]

Can you shed any light on the theory that line locs may be causing Getrag clucth pack failures, and why?

Thanks,

Ken

Still digging into that on. We've got a plan to get one of the axles back to take a look at it. I see some long smokey burnouts in my future. Darn

[SRTEngineers]

Thanks SRT engineers, I like what you did so much, I bought two.


What recommendations do you have to improve the life of the ball joints in the upper control arms up front?

Best thing to do is keep the stock ride height and alignment settings.

[ydahsmils2001]

Did you guys test the Magnum, or LX for that matter beyond 200mph? Say in a wind tunnel?

[Hemi31]

There is a software fix coming to correct this issue. Stay tuned.

now thats funny

[SRTEngineers]

Why is the TCM programming still such a mystery to aftermarket companies. Seems like the PCM tuning has either been released or at least decoded allowing us to reap some good performance gains. Why not release the TCM tuning codes to allow us to keep up with the competition (which is getting very stiff).

Lots of these cars with aftermarket parts are making power past 6400 rpms and my buddy with an '06 300 SRT8 (without the TCM flash) is able to paddle hold the shift at times to 7000 rpms without a problem. Some of us here are big boys and are willing risk popping a motor (on our dime).

Sorry, for right now there are no plans to open up the cals for modification. Altough we know many of you are capable ofmaking the right kinds of mods remember the trans is not rated for anything above the production performance output.

[HOTHEMI1]

When the porfessionals took us around the track they turned the esp off what are the gaines from having it off? 2009 srt8 6.1 challenger

[SRTEngineers]

The 6.1L oil pump is a 5.7L Hemi pump with a higher relief spring (the new Eagle 5.7L pump is a different animal with larger rotors). As such the pressure when the relief valve starts supercharging the pump inlet is higher to help with the additional demand of the piston squirters. The only time the lifters will see this pressure is when activated and it should not cause lifter problems.

[SRTEngineers]

Hello & Thank you for your time

I own a 2009 300C AWD, I'm trying to build an AWD SRT8. The new Borg Warner front axle disconect system is both AWD & or RWD!! I would like to drop in a new 6.4 392 VVT MDS when it comes out. Will the Borg Warner transfer case handle the power, can I change the 3.07 ratio to 3.55 or 3.73 LSD with a transfer case performance upgrade & what else would I have to consider to make my 2009 300C AWD, a 300C AWD SRT8?

Thank you very much

Mods List to Date:

Mopar Cold Air Intake, Billet Aluminum Fuel Rails w/ Fuel Pressure Gauge for the 392 Crate Motor, 6.1 SRT8 Injectors & Spark Plugs, Engine Strut Brace & Rear Sway Bar
Custom Borla Cat Back #140112, KW Varient 2 Coilovers, Jet 180 Thermostat, MSD Hemi Blaster Coils, StopTech Cross Drilled Rotors fr/rr, Hawk Performance Pads Ceramic up front & HP Plus rear, SLP Line Lock, Functional Fiberglass Ram Air Hood, Vossen VVS 075 Wheels 20x9 fr/rr, Nitto Invo 245/45/ZR20 Ultra High Performance Summer Tires ft/rr,
Mopar SRT8 Illuminated Door Sills (Scuff Plates), SRT8 Trunk Lip Spoiler, & SRT8 Badges
SRT8 Pedals & Custom SRT8 Cluster Gauges


Future mods List:

Kooks Long Tube Headers with High Flow Cats, or Borla XR-1 Long Tube Headers, CNC Aluminum Heads & Cam for the Eagle Engine, 90mm Throtle Body, 5.7 Eagle 392 Stroker Kit, or a New 6.4L 392ci VVT MDS Hemi, STS Rear Mount Twin Turbo or SMS Super Charger, 1000 Hp Half Shafts front & rear, 1000 Hp Drive Shaft, 1000 HP Nag1 Transmission, 1000 HP Borg Warner Front Transfer Case Upgrade & 3:55 or 3:73 rear end gears to match the Transfer Case, Brembo GT Drilled Rotors w/8 Piston fr & 6 piston rr Aluminium Calipers w/ High Performance Pads & w/ High Performance Metal Braided Tubes, Vossen VVS 075 20x10.5 in. w/ Nitto NT05R 285/40/ZR20 rears, 4000 Stall Converter, Police Transmission & Engine Oil Cooler, B5 Blue Pearl SRT8 Challenger front Seats, AWD Custom Tune, Predator.

The BW T-case is normally RWD but engages the front when needed. So yes it is kinda both AWD and RWD.

[SRTEngineers]

Hey guys and gals..thanks for having these disscussions...I have posted this before and wondering if this is going to take place per earlier chats..
Quote:
Quote:
http://www.chargerforums.com/forums/...&postcount=173
Originally Posted by Joeyclutch
I've been having a problem with a front end noise. Its been to the dealership several times and nothing has been resolved. They have replaced the steering rack, control arms, the bushings, struts and bracketts. I only drive this car abhout 4000 miles a year so I feel that this should not ben happening. The regional service rep said that this "noise" is a characteristic of the SRT vehicles from 2006-2007. I have driven in other SRT vehicles and did not notice this noise at all. Obviously they thought there was a problem with my car or they would not have switched out all of those parts. I even went so far as to look into the Lemon Law but unfortunately I was passed the alloted time. I dont think this is fair and need advice. Thank you.


For 2008, there was a check valve change to the shocks which helps this noise. They are retuned for better ride as well, so we suggest replacing all 4 if you want to go this route. The source of the remaining noise is the front upper strut mount in rebound events. We are working on a design change to help the issue, but it will be some time before we will have something out. Thanks to these webchats, we are able to convince management we need to keep working on it.
Is there a replacement strut mount available yet? If so, is there a way to differentiate the new design vs. old to make sure I am getting the new one?

Is there a way to differentiate (visually) the revised dampers from the old ones?

Thank you

I was just wanting a time line that I could possibly get the redesigned dampers..The dealership has replaced both struts and several other parts, but when showing them the chat answer from before..they are also waiting the redesigned part.....Any thoughts on this

And thanks in advance..
Ralph

Best way to check the parts is the part numbers.
2008FrontFront RT04854577AC Front LT 04854576ACRearRear LT05039344ADRear RT05039344AD
The new upper strut mounts are now tooled and should be available soon.

[SRTEngineers]

It continues to be bandied about that the 6.1 (and to a lesser degree the 5.7) has an excessive PCV oil vapor ingestion issue that is the root-cause for pulling timing (by-way of the knock sensors - supposedly reacting to octane level degradation because of significant oil consumption/oxidation under normal operating conditions. The cure recommnded by the vendors for this ailment is purchasing/installing a catchcan.

During (factory) engine assembly, are the knock sensors raw voltage O/P tested, or even monitored from engine-to-engine? It appears the amount of timing being pulled due to knock sensor activation (real or perceived) varies from platform to platform. Is this normal (it's understood that fuel quality, engine load, atmospheric conditions, etc play a part)?

Both the 5.7L and 6.1L engines meet all corporate requirements for PCV performance. However, as we have mentioned in previous chats, installing a catch can shouldn't harm anything.

During end of line testing, output from the knock sensor is verified to be present. Comparing the amount of knock retard between vehicles can be deceiving. As you mentioned there are many factors that affect knock limit. Unless the conditions of your test subjects are identical (highly unlikely), the amount of knock retard can vary.

[SRTEngineers]

Given the popularity of the Drag Pack cars,

Why is there not a way to order a factory racer like the ARC Neons ? That are street legal and would make a nice weekend racer for someone.

Off a SRT that got all the fun go fast bits, but none of the extra weight ?

Nothing like that right now but there is a Challenger BIW coing very shortly. That with all the bits and pieces out there might make a great road racing project .....

[hemituner]

Has it been documented how much rear toe changes at measurements above and below design height??
Thanks
A.J.

[Black08Chally]

The 6 speed cars can get a 3.73 or a 3.91 ratio in the diff. On the auto cars there is no option for a 'performance gear'. The magic ratio to gain a little bit of an edge with the auto cars is the 3.23, I'd love to see the Getrag available with this gear set.