Cuda340

There was a great chat session last night with the SRT engineers. Here are the questions and their answers:

Originally Posted by DonK
Great to have you guys back:

Is the reason there is not an AUTO-UP feature on the Challenger door windows because of the window drop of approximately 1/2 inch when you pull the door handle and full window up when you close the door?

Is the EVIC display in the speedometer any brighter or readable on sunny days than my current 2006 Magnum?

DonK

We couldn't implement auto-up on the Challenger windows because of the steep angle of the b-pillar glass edge. We have finger pinch protection on other products but due to the leverage of that steep edge we can't control pinch force there.

The EVIC display hasn't changed since your '06. It does get brighter with the cluster dimmer knob, though.

Originally Posted by Nixx
Hi engineers.

I purchased my '08 Challenger back in August. I followed the break in period suggested in the manual. However, I've been experiencing what I would call excessive wheel spin.

It happens easiest on rainy days, but even in dry weather, if I accelerate hard (like from a stop light), the wheels will break loose. There have been multiple occasions that it's been bad enough to cause the car to slide sideways. (stop light, turned left, broke loose mid turn)

This isn't the first SRT I've driven, especially in these conditions (I've been to the track experience twice) and it seems that the traction control isn't working properly.

I've taken it into the dealer several times for them to look at and every time they tell me that there's nothing wrong with it.

My question is, after all that... was the Challenger's traction control system designed to allow for more wheel spin, or is this a bigger issue that has yet to be corrected. I know a few other Challenger owners from the challengertalk.com forum that have experienced this same issue.

Thanks in advance!

The Challenger SRT8 traction control is designed to allow for some wheelspin to allow a good launch. A decent amount of yaw is allowed to make sure the car is fun to drive as well. As a practice, at SRT we design these systems to not be the fun police. They are just there to save your butt when really need it. Be assured that the stability control system fully meets 2012 FMVSS 126 requirements.

Originally Posted by LongDriving
Thanks for hosting this again! Is there any chance of having a catch can installed in SRT vehicles? Many members install them and are very happy with the results?

Thanks!

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.

Originally Posted by capt.albator
This forum is LX focused but I have a small question about the challenger go-wing if you dont mind. My car will mainly see highway speeds and go on a race track only once a year for fun. I doubt it will ever see 170mph. How did the go-wing do in wind-testing and is it much detrimental compared to the SRT triangle spoiler ?

Thanks

Both wings were tested at the Chrysler Wind Tunnel. The Go-Wing added more downforce to the rear with a slight impact to drag.

Originally Posted by Cuda340
Is it true that both key fobs on the Challenger have to be rotated in use or the computer thinks one has been lost and disables the code?

Is there any significant increase in horsepower using a cold air return (without a tuner) over the existing SRT air box? How about just adding a low restriction panel filter? k

FOB question - absolutely not. The two keys are tracked independently and should never be lost.

CAI - the SRT intake with the snorkel to the clean air in the wheel well work really really well. CAI kits that suck hot underhood air... suck hot underhood air.

Originally Posted by budoboy
Regarding the Challenger drag package cars:

There are about a 1000 lbs lighter right? Could you give us an idea of what was removed and how much those components weighed? Just curious where the most weight came off.

The weight loss comes from component removal, a modified BIW and several lightweight components. The BIW is based off the production Challenger - no door beams, no body sealer, etc. Components removed include the power steering system and HVAC. No component weights are available off-hand. Lightweight components are polycarbonate door glass, carbon fiber liftoff hood, performance front brakes, Viper-style front seats.

Originally Posted by NasaRacer
So looking at the EPA Gas Mileage website I noticed that 2009 LX SRT8s now only require 87 octane Regular gasoline and have also seen a bump up 1mpg in EPA highway mileage. So what kind of changes were made to the 6.1 V8 to achive this? Seems like there must be at least a slight reduction in power and performance?

We recommend 91 octane, but you can run 87 octane with a noticable degradation in performance. As for the EPA milage, there was a new EPA cycle established, which changed the rated milages for all vehicles.

Originally Posted by rubbel
With the use of synthetic oil such as Mobil 1 is there any advantage as far as reduced engine component wear, less emmissions, better performance, ect. by changing oil and oil filters more frequently than 6000 miles? Is changing oil every 3000 miles a waste of money and oil compared to any benefits?


Mobil 1 is good stuff and that's why we use in all SRT products. Changing it more often won't provide much benefit unless the oil change indicator comes up on your speedo display.

Originally Posted by Nixx
OK... just so I'm clear... I understand from your reply that the wheelspin is intentional. So, does that mean that the Challenger's system is "tuned" differently than the Chargers or 300s? I just want to be sure... I was side by side with my friend's Charger SRT8... I spun while he took off. Later he pulled along side and yelled out his window... "my traction control kicks your traction control's a**."

Don't get me wrong... I'm ok with the spin as long as I know when I should expect it.

Thanks again!

The ESP/Traction Control tuning is unique between the Charger, 300 and Challenger products, but it seems likely that your friend just used a bit less throttle.

Originally Posted by SRTDogg
Can you please shed any light on the largest tires which may fit in the wheel wells (without modifications) on the stock SRT wheels. I imagine when you spec'd out and built the wheels and chose tires, you did a lot of research on this.

Reason I ask is because like other owners, this car has a lot of torque and my tires slip/spin quite a bit when I go from a stop or going around corners and it isn't even wet out and I'm not on the throttle hardly. Rather than go buy new tires after only 1 year of us, if I could get larger tires in the back, I would be less likely to slip given the same amount of wear, because of the larger surface friction.

BTW, thanks for doing this - you guys are great and one of the very few organizations that continues to do this!





The biggest tires that offically fit are the 255/45R20 rear and 245/45r20 front. Anything bigger on the stock wheels will hit something at the extremes of travel and/or steering with loading from the road. We simply can't allow tire rubs from the factory. If you are willing to risk rubbing the body, fender wells, and suspension components, bigger tires will definitely fit.

Anything bigger than a 275 is too wide for the stock 9" wide rim. Remember that the non SRT 20" wheels are only 8" wide, so 245 is pretty much the max on them.

Originally Posted by jimh
Do the manual trans Challengers have stronger half shafts than we have now? Since it's pretty much a shortened LX will the Challenger half shafts fit on a Charger, or does the new rear change too much?

Thanks guys

The whole rear end got an upgrade for 2009 to handle the increased torque requirements of the manual trans. The halfshafts went from 28 to 32 splines. The axle got bigger (and got a real LSD). The driveshaft coupling got beefed up too. These upgrades are on all Challengers, 300s and Chargers starting in 2009 model year.

Quote:
Originally Posted by bespoke
Hi SRT guys/gals. Why is it so easy for the aftermarket tuners (Diablo, Superchips, etc.) to increase the output of any of your products with just a few simple calibration changes? Are all the smart engineers working in the aftermarket? Are you feeding them the secret +20 hp cals on the DL?

We know where you're going with this, however the aftermarket guys don't have to worry about all the downstream ramifications of increasing power to other vehicle systems, passing federal regs, meeting emissions, etc.

Or maybe we get a percentage of all their sales, who knows?

Originally Posted by Deuuuce
Ha! I'm sneaking in at work! Thanks guys! But I've got 3....

1. What is the weight of car with zero options vs. fully loaded.

2. Is oil analysis okay for extending oil change intervals?

3. Any timing or throttle response differences between automatic mode and manual mode in 1st - 3rd gears. (let's get their official take).


REQUEST: A Charger SRT-8 on F1s at VIR to get a few seconds better than the 3:18 posted by the (softer, worse weight distribution) Challenger in Car & Driver?

1. SRT's are pretty well optioned without options (we would prefer if they weren't, because heavier = worse no matter what). That said, fully optioning a car will probably be about a 200 lb delta or less, depending on what vehicle it is.

2. Change your oil when the automated indicator tells you to. That algorithm is based on our oil analysis in the dyno.

3. The engine controller does not change the timing surface or the throttle map depending on trans gear in the automatic cars. In the 2009 Challenger manual, we alter the throttle map per gear. In the Caliber SRT4, we alter the torque available per gear (torque steer mitigation).

We don't ever run the Grand Course that C&D runs. How fast a car goes around a track depends on a lot of things, especially the driver. We don't know if Tony Swan was having a good day that day. All other things held equal, the Challenger isn't faster or slower than the Charger.

Originally Posted by ascii77
Why does Chrysler choose 3K and 6K oil changes with Mobil 1 Synthetic Oil? Other manufactuers go 12K and 15K between Oil changes.

This is a corporate decision and we, as SRT, assume our customers are driving to the full potential of our vehicle on a more frequent basis than our competitor's drivers. Well worth the piece of mind.

Originally Posted by garyholl
I drive an 07 JGCSRT8 and have a question about headers. Are long tube headers going to make much difference versus the shortys already on it? What about cat and resonator deletes? Do they provide much of a boost?

The LX and WK SRT8 exhaust system as delivered have one of the lowest backpressures of any OE system out there. The resonators are basically straight-thru perf pipes, so removing them will only change your sound quality. We don't test vehicles without cats, but several of our race vehicles (OneLap, Targa, etc) have been successful with cat-deletes and long headers. We don't have the numbers handy, but can look into it for you.

Originally Posted by jfayardiii
Do you guys plan on producing any otyher Mopar parts for the SRT8? All that is available to keep the warranty is the CAI and exhaust.

Stay tuned. We're getting the stuff out as fast as we can.

Also, would my car still be covered under warranty if I get a predatorfast tuner?

NO!!!!!

Sorry, I have had mine for 4 weeks and I have a need to go faster.

Have you seen the SRT10?

Originally Posted by trublu69
Hi and Thanks for your time.

Regarding the "upgraded half shafts", is this for SRT specifically, or was this an across the board change for these cars regardless of powerplant?

It's been rumored that the 09 Challengers (SRT's) have been held up due to faulty half shafts, or possibly the installation of the wrong half shaft from the other cars ( 300, Charger, non SRT ), is this something you know about?

Thanks again.

Future Challenger SRT owner (09 6spd, ordered June 23)

SRT rear end, including half shafts, are unique. There is no problem with these and we were in full production when I was at the plant in early Sept.

Originally Posted by RCPilot
BP is adding up to 10% ethanol to it's premium gasoline as the norm now. I would assume others are going to be doing the same. Once that is all we can buy, there will be issues that were not calibrated into our SRTs. What is the possibility of a flash that will address the problems. Thanks.

Dan


What kind of issues? The car will handle it fine. The 10% ethanol compared to pure gasoline just has lower specific heat (BTU's/lb). It should only manifest itself with lower fuel economy.

Originally Posted by hd1ley
Any truth behind the rumor of the vortec supercharger being offered for our cars?
Does dodge feel the presure from shelby gt, camaro etc...


no truth to the rumors.

Does Shelby GT and Camaro feel the pressure of the 600hp Viper SRT10?

Originally Posted by DrZoom
Any opinion on pros/cons of running 180 degree thermostat?

We've answered this in the past, but we don't recommend changing the thermostat.... Our engine is calibrated to run at certain temperatures and has been tested under some of the worst conditions with no issues.

Originally Posted by Cuda340
Challenger SRTs.

See the image below. Hope this helps!
Attached Thumbnails


Quote:
Originally Posted by jimh
Do the manual trans Challengers have stronger half shafts than we have now? Since it's pretty much a shortened LX will the Challenger half shafts fit on a Charger, or does the new rear change too much?

Thanks guys

The whole rear end got an upgrade for 2009 to handle the increased torque requirements of the manual trans. The halfshafts went from 28 to 32 splines. The axle got bigger (and got a real LSD). The driveshaft coupling got beefed up too. These upgrades are on all Challengers, 300s and Chargers starting in 2009 model year.

Quote:
Originally Posted by ascii77
Why does Chrysler choose 3K and 6K oil changes with Mobil 1 Synthetic Oil? Other manufactuers go 12K and 15K between Oil changes.

This is a corporate decision and we, as SRT, assume our customers are driving to the full potential of our vehicle on a more frequent basis than our competitor's drivers. Well worth the piece of mind.


Quote:
Originally Posted by fargo59
hi guys, and thanks for doing this. my question is this:
the 226 rear end used in the challenger, and 09 charger, is this of any relation to the 226mm RIA used in the viper? also, what is the estimated torque capacity of the rear end and shafts (226mm LX/LC).

No relation to Viper.
The rear-end is engineered for 3100 N-m from the drive-shaft.


Quote:
Originally Posted by Cuda340
Is there any preset electronic control designed into the PCM to hold back engine performance until after the "break-in" period?

Why does the 5.7 have slightly higher compression than the 6.1 (10.5 v, 10.2)?

Yes. It fades in over the first 1000 miles. Be sure you follow the procedure.

The new 2009 5.7L has a higher compression ratio than the 2005 - 2009 6.1L, which was fundamentally based on the previous-generation 5.7L

mopar2ya

What exactly is "The Procedure"..??

The concensus of the forum was Drive It Like You Stole It as I recall...

Anbody actually read the manual..?? [8D]

BLK 6050

Thanks for sharing....very enlightening......

Andre@Edge

Thanks for the great post Cuda340. I had intened to tune in and was bummed when I couldnt. Now I know what I missed.

toofart

Thanks for that!! It's still not obvious to me (I may be dumb here) if the whole 'rear end got an upgrade for 2009 to handle the increased torque requirements' applies to 2009 SRTs only, or to R/T too.

RUBBERBNDMAN

I think it was on the drivers visor....

Paladin06

The procedure is in your owners manual. Interesting about the 180 thermo and CAI.

Thanks for sharing.

2007HemiCuda

Great read, I'd like to make one live.

Thor77

I had to kind of laugh at the guys sitting complaining about too much wheelspin.

"My 425hp Muscle-beast-car spins its wheels pretty easily, especially when it's wet."
"No Freakin Way!! Something must be seriously wrong with your car."

bwahahahahaha

vynle

i learned absolutly nothing from that!!! lame. they seemed so vague. difference between 09 and 08 rear end was established because of added torque !!! its the same motor right? i dont know, i must be cranky and need more coffee this morning!!!! vynle