Cuda340

Here are the responses of the SRT Engineers to tonight's Chat Session:

Originally Posted by toofart Posting on behalf of Challenger lovers at CT:1. (toofart) I have a catch can/oil separator, and at every oil change I empty an ounce or two of black oil. If I did not have this device, do you agree this oil would coat my intake manifold, valves, and enter the combustion chamber thus effectively lowering my fuel octane?
We have run full validation across all the different vehicle lines with the 6.1L engine and not see any issues. That being the case, we don't feel they are necessary.

We do not see it as a issue. But if you wish to use one make sure it is of quality.

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Originally Posted by toofart Posting on behalf of Challenger lovers at CT:4. (rodderrick) Why do the brakes dust up so bad with stock pads, and what is the best substitute without losing braking capability?
One of the 5-pillars of an SRT is outstanding brake performance. With all high performance brake systems, one trade off is a bit more brake dust. In order to maintain the same braking performance we develop these cars to, we recommend using OEM parts only. If you use other brake pads , you may get less brake dust, but you will give up performance.



Originally Posted by toofart Posting on behalf of Challenger lovers at CT:2. (toofart) For 6-speed cars, is the differential able to support hard launches and shifts at the drag strip using slicks, or very high traction radials?
We did some testing on Nitto and BFG Drag radials, although we did not run them to failure. You will significantly reduce the life of the differential and other driveline components with stickier than stock F1s, but it won't break the first time you do.

Originally Posted by toofart Posting on behalf of Challenger lovers at CT:7. (spencer60) You mentioned previously the cats are major exhaust restrictions. Whats' the airflow rating (cfm) for the RT and SRT factory parts?
Production cats are not rated in this way. We measure it in inches of backpressure. The cats are not a major restriction at all. They are just more than the cat back exhaust which is very little. You may get about 15 hp out of ditching the cats.

Originally Posted by toofart Posting on behalf of Challenger lovers at CT (we did our homework, guys!)13. (rumpass) If I plan on buying a used SRT8, can a Chrysler dealership tell me if the computer (tune) has been altered at some point in time?
Yes.

Originally Posted by toofart Posting on behalf of Challenger lovers at CT:8. (randycat) Can the ecm provide any other engine/transmission operation parameters through the obd-II port other than the industry standard mode 1's? Are there any Dodge/Chrysler specific mode-22's pid's that can be monitored? Are these pid codes documented anywhere?
It does, but they are propriatary to Chrysler. The Diablo has some cracked capabilities...

Originally Posted by toofart Posting on behalf of Challenger lovers at CT (we appreciate your time investment in coming here and answering what you can!!)10. (rodderrick) I've heard of many people mention throttle hesitation / lag under varying conditions. What could be the cause? Is there any drivetrain preservation program in the ECM?

Electronic throttles unfortunately have some delay compared to cable throttles that everyone is used to. The engine is also cammy with a torque hole in the 3000 rpm range which gives the impression of a bog.

Originally Posted by toofart Posting on behalf of Challenger lovers at CT:14. (Speedy!) When designing an engine, where do you set the bar in terms of longevity? 100,000 miles? 150,000 miles, etc?
150000+ for the 6.1.

riginally Posted by toofart Posting on behalf of Challenger lovers at CT:12. (randycat) While it is well accepted that using higher-than-recommended octane gasoline should yield no benefits on the hemi 5.7 under normal operation, is it possible that such octane could mitigate performance losses when the engine gets into one of its "heat-soak fits" during operation in hot weather?
Not neccessarily. The engine will derate due to high coolant temp, or air charge temp. The derate due to high coolant/air charge temp won't be affected by a higher octane. But, if the engine senses knock, and reduces spark, high octane fuel would reduce the spark retard.

Originally Posted by toofart Posting on behalf of Challenger lovers at CT:16. (13 sec fix) If you owned a Challenger and it exhibited wheelhop under hard acceleration, which components what would you do?
The most effective means of mitigating wheel hop on the Challenger is to change the motor mounts. SRT uses stiffer ones than than the R/T manual. Going stiffer than stock will significantly degrade NVH but will help.

If you launch it properly for the best times, it hops very little. If you dump the clutch at high rpm they spin clean. If you get it just a little too aggressive, you will get into a hop.

Originally Posted by toofart Posting on behalf of Challenger lovers at CT:17. (mokeman3) I've had the Getrag 226 differential replaced in my SRT auto at 5K miles because of a "whine" at 46 Mph when floating between power and coast. The new differential also does this, but now this new differential also has a very distinct whine under power between 59 and 60 Mph (and goes away at 58 Mph or 61 Mph). What can engineering tell us about this insofar as what is causing this with the Getrag 226, what can be done to eliminate/reduce this whine, and is it normal, or detrimental to continue to drive the car like this ?
Normal. The 226 will not be completely silent. The noise will not decrease the life of the diff.

Originally Posted by toofart Posting on behalf of Challenger lovers at CT:18. (randycat99) Is there a distinct and intentionally-designed difference in the responsiveness of the electronic throttle in the automatic between when you are in regular automatic mode and when you are in autostick mode? This is not so much when you hit the pedal from a standstill, but rather, if you are already moving along with your foot making small/med, but distinct, motions on the pedal. If you are bound from answering candidly, use the code, "You are better off not knowing".
No, there is no difference in the ETC calibration between the automatic or autostick mode.


riginally Posted by toofart Posting on behalf of Challenger lovers at CT:19. (can't remember who) Will running a lower temp than stock thermostat on a stock engine setup cause any sort of residue buildup or premature wear?
Sorry, that's something we've never tested and so we can't give you any feedback on this.


Originally Posted by toofart 3. (toofart) If your task was to shed 300 lbs of weight from a Challenger SRT8 to make the car more, uh, competitive, while retaining all the security features, what would you do?

The easiest way to drop weight is for the driver to go on a diet. The AL hood isn't too heavy, but the trunk weighs 40 lbs. Are you willing to give up Nav, Sunroof, power seats, etc...? Unfortunately, she comes from a hefty bloodline.

riginally Posted by toofart Posting on behalf of Challenger lovers at CT:20. (alpine zang) What EXACTLY does it do when you do the "key trick" (ie., key to START position while driving >10mph) and the ESP/BAS light and ESP light come on? I know it disables the ESP, but the car drove completely differently. The throttle was much snappier and I had to be careful not to jerk when barely changing throttle positions
The "key trick" actually sets a fault in and shuts down the ABS, traction control and ESC system. That is why the lights come on. The only change in throttle would be because the traction control is gone.
Originally Posted by toofart Posting on behalf of Challenger lovers at CT:21. (alpine zang) Is the EVIC actually different in the SRT-8 or is it just a different firmware? Can an R/T get the 1/8 & 1/4 mile as well as the Gs info with a change in firmware?That's it for the CT questions. Thanks guys!
Sorry, the performance pages are configured to only operate on the SRTs.

Originally Posted by SRT8Andre Question regarding breakin procedure for the 6.1... I have read on various forums that the SRT engines already have breakin miles on them prior to be delivered to the customer... is this true?
Not true. The emissions test rolls in the plant and some random quality checks can put on a minor amount of miles on the car. Other than that, there should be no miles on a new SRT.

Originally Posted by ricksinva Hello,09 Challenger SRT8.1. My car came with the Performance, staggered tire option. If I change to 245's all around, will that affect anything such as the traction control system or the speedometer? If so, can the dealer reprogram the car for that?2. The Service Manual (CD) for this car has not been available from Tech Authority for at least 2 months. It must be either a legal issue, or maybe some paperwork is simply sitting in someone's end basket, because it surely doesn't take this long to copy a CD. Can you look into this and maybe help push them along?3. I have a spare set of OEM, SRT wheels. Can I store them (real long term) in a hot attic (in Virginia)?Thanks for a great car!!!Rick

1) The cals are the same. Feel free to put the same size front and rear.
2) A number of things were held up during bankruptcy. We'll see if that is what is going on.
3) The wheels will be fine. Tires will not like the heat and age. It is a good idea to get new tires every 5-6 years regardless of tread depth. Brand new unscuffed tires may go 10 years if hermetically (sp?) sealed...

Originally Posted by Stylz One other question for us 5.7L owners. With the aftermarket so full of engine performance products (with many of them not, or even negatively affecting performance), do you guys know of any mods which could be made to a 5.7 motor to increase the horsepower without adversely affecting the reliability/drivability?

We do have a kit out here for your car but it's "off road use only". However, we cried when the test car left us with ~50 k. miles......

Originally Posted by charger08srt what is the best 0-60 and 1/4 times you guys achieved on a stock SRT charger?
1.52 for 0-60! See proof below. Won't tell you how I did it.

We run 12.90's in good air
Originally Posted by toofart From this question: 2. (toofart) For 6-speed cars, is the differential able to support hard launches and shifts at the drag strip using slicks, or very high traction radials?If you did run them to failure, which component(s) do you think would fail first?

Probably the diff or halfshafts. with stock cars just like you guys.

Originally Posted by 2nd SRT-4 Hello Engineers! 1. My C-SRT4 is consuming about 1 qt of oil per 3k mile with Mobil 1 0-40. Is this normal? I do drive hard, but mostly, city stop and go type traffic.2. Any numbers on the final production of the Caliber SRT-4?

1. What you are experiencing is normal.

2. Cannot respond to your question at this time.

Originally Posted by kevbo10 For your consideration:SRT8 Challenger:I have installed a Kenne Bell Super Charger on a stone cold stock 6.1L Challenger with a six speed. I’m running ten pounds of intercooled boost and using unleaded 108 octane racing fuel, putting out 600+ rwhp. The car is used for mild club racing; 50 – 170 mph (I don’t drag race). What are the chances of the motor living a nice life and retiring to Arizona? Seems to just fly now, w/o any problems.Thank you,Kevin

Your pistons are not happy.

Originally Posted by charger08srt is the 6.1 underrated hp wise... is it possible it's really making 440-450 hp stock at the crank... could this be the reason the engine hasn't had a power increase like the 5.7 thank you for your time
The 5.7L power upgrades are from the new version of the motor with variable cam timing.

Originally Posted by Viperam2 Question for the SRT10forumCan additives such as Lucasoil or Zmax be used with the Viper motor?
Additives are NOT recommended please reference your owners manual. (Full synthetic only)

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Originally Posted by charger08srt if I put high-flow cats on my srt wouldn't that throw an engine code
Yep. "off road use only"