SRT Chat HERE on May 14th!

[Y2K5SRT]

Once again the folks from SRT have generously offered to host a chat here for Viper owners (and prospective owners) on Wednesday, May 14th, 2008. It will take place here from 6:00 - 8:00 PM Eastern Daylight Time (that's 5:00 Central, 4:00 Mountain and 3:00 Pacific).

Now this is your chance to chat directly with SRT employees about the Viper platform - be it old or new. Just understand that ALL questions about future product (anything beyond the 2008 model) will be ignored if not deleted by our moderating staff first. Chrysler/SRT personnel are strictly forbidden from commenting about future product, so don't waste your typewriting. Our moderators will be standing by and will delete without warning - other than this one.

Given the short notice, we would encourage you to start posting questions here immediately. Our web staff will consolidate those questions into one reply before the actual chat starts and SRT will review them beforehand as well. As stated above, we reserve the right to edit or delete those questions that SRT cannot answer due to company policy.

We look forward to your questions and seeing you here on the 14th!

[musicncars]

When will cars with the aero package start being built? When can we expect to see some?
Thank You,
Benjamin

[STL RT/10]

Perhaps they can shed some light on my situation...

I recently pulled my fuel tank to replace the sending unit, as my fuel gauge was INOP. After re-installing it, everything was fine. After 50 miles or so, the SES light came on. It was an EVAP purge valve fault. I cleared it with a cheap scanner, but it came back after 10 miles or so. I then used a Snap-On scanner that actually had software for the Viper on it and did a complete clearing / test cycle. I also pulled the rear access panel again and checked for any poor connections, leaks, fuel vapor smell, etc. None existed. I drove 100 miles or so then (with several starts and stops), and the light is back on. Any thoughts? I can only assume that a small amount of air is somewhere from my removing the tank. Is there a reset procedure that should be performed when doing this? I may also note that putting gas in it can sometimes be a &*#$!. I have to hold the vapor recovery hose back to keep the pump running. It is almost like the tank isn't venting properly. Maybe this is common on RT/10s, as you have to hold the handle alomost vertically. It is an '02 RT/10 with 6k miles. Thanks!

Matt

[rcl4668]

1. Can you provide weights for the various 2008 rims (just rims without tires, lugs or TPMS sensors): standard 5-spoke rim, razor and H-spoke?

2. Can you confirm that the new lug nut torque per the 2008 service manual is 100 ft-lbs versus 90 ft lbs for the 2003-2006 cars? If this is accurate, why the increase for the 2008 model year?

3. I recently dynoed my 2008 Viper on a Mustang dynonometer to get a baseline figure on the stock powertrain before doing some modifications. The average of the three runs was 529 rear wheel hp and 505 rear wheel torque. What correction factor would you recommend to get an estimate of flywheel hp and torque?

Thanks for your help and for a great car. I am enjoying it immensely.

/Rich

[black08]

Hi. Congratulations on the great 2008 model you put together and the ACR which is wiping the floor with the competition on the road courses of the One Lap of America.

Can you please tell us, once and for all, whether there will be a Mopar horsepower upgrade for the 2008 model or not. There has been much speculation that such an upgrade to the 675 hp. range is forthcoming sometime in the future. Recently, however, one source advised that this is not going to happen.

I am seriously considering adding the Belanger exhaust system to my ACR when it arrives, however, wanted to know if something was coming from Mopar that I should wait for. Thank you.

[Malu59RT]

Regarding the 2008 Viper

Is there any way to increase the throttle response in the DBW? If you have ever driven a E46 M3, there is a "sport" button that makes throttle tip-in very sensitive, and I'm hoping there is a way to do that in the 2008 (optional flash).

Also, regarding the recent RRT that was released to take care of the CEL: What effect have you experienced on vehicles that did not have this problem, and had the RRT performed? The dealer performed this against my wishes, and the car feels LESS responsive afterwards. My car performed great and felt strong before, not so much now.

SRT, thanks so much for this car! I've been wanting one for 16 years, and finally have one to enjoy.

Jason

[rcl4668]

Originally Posted by Malu59RT

Regarding the 2008 Viper

Is there any way to increase the throttle response in the DBW? If you have ever driven a E46 M3, there is a "sport" button that makes throttle tip-in very sensitive, and I'm hoping there is a way to do that in the 2008 (optional flash).

Also, regarding the recent RRT that was released to take care of the CEL: What effect have you experienced on vehicles that did not have this problem, and had the RRT performed? The dealer performed this against my wishes, and the car feels LESS responsive afterwards. My car performed great and felt strong before, not so much now.

SRT, thanks so much for this car! I've been wanting one for 16 years, and finally have one to enjoy.

Jason

Jason --

I don't mean to hijack this thread but just as an FYI to you: I just received my 2008 from my dealer today after install of the Belanger headers/exhaust. They also performed the ECU reflash eben though my car was not having any problems previously. My tech informed me that the ECU reflash was designed solely to make the computer less sensitive to sending CEL codes for cylinder misfires. On the drive home my car did not seem less responsive, quite the opposite. It felt scary fast. The problem of course, is I cannot say for sure whether the Belanger components are masking any issue with throttle responsiveness.

So I guess my question for the SRT engineers is what specifically does the ECU reflash do for the computer? Does it in fact affect throttle or is it unrelated?

/Rich

[Malu59RT]

Thanks for the info Rich! I had heard people say they had better throttle response, but mine was the opposite It may just be in my head.

[Stealth]

Originally Posted by black08

Hi. Congratulations on the great 2008 model you put together and the ACR which is wiping the floor with the competition on the road courses of the One Lap of America.

Can you please tell us, once and for all, whether there will be a Mopar horsepower upgrade for the 2008 model or not. There has been much speculation that such an upgrade to the 675 hp. range is forthcoming sometime in the future. Recently, however, one source advised that this is not going to happen.

I am seriously considering adding the Belanger exhaust system to my ACR when it arrives, however, wanted to know if something was coming from Mopar that I should wait for. Thank you.

I second this!

[Bobpantax]

1. What changes, if any, are being made for the 2009 Viper? Since orders for the 2008 closed quite some time ago, I assume that there is no problem answering this question.

2. Will there be a fix for the fly by wire gas pedal delay? This is where the gas pedal is blipped and the delay causes the response to be out of phase with the input.

3. Will there be an official conversion kit for Gen III Vipers to be able to use the new tranny and differential? ( I know it's possible because Woodhouse already did it to my 2006 Coupe back in January and it works flawlessly. We replaced the tranny, yolk, driveshaft and differential.)

4. Have you given any consideration to using a better shifter? For instance, although it is very new, I have the shifter created in a collaberation between MGW and Woodhouse. It is superior to the stock piece. If you have not tried one, you should take the opportunity to do so.

5. I understand that the pistons for the '08 engine were not intended for use beyond the stock application and that if someone wants to mod the engine a piston change out is adviseable. Is this true? If so do you have any specs on the preferred pistons to use?

6. Have you given any consideration to offering an optional race traction control unit like the RaceLogic unit offered by Woodhouse? It's not a unit for everybody but it is great for its intended use.

7. Since the pistons in the Viper are the same pistons as those used in the SRT 8 engines and the six speed offered in the '09 SRT 8 Challenger is the same six speed used in the Viper, will there be any cost savings that will be passed through in Viper pricing?

8. Is the fly by wire gas pedal unit in the Jeep SRT 8 the same as the one used in the Viper?

9. Where are Vipers going to be made after the plant closes in 2010? How about Florida?

[Nader]

What brake pads are you running on the ACR?

I recently purchased stoptechs and there was a recommended procedure to seat the pads. The procedure was 10 - 60mph braking runs down to 5 mph at 80% plus braking force. Do you perform this prior to delivering ACRs? And if so I would like to apply for that position.

[Smog Dog]

Originally Posted by Bobpantax

2. Will there be a fix for the fly by wire gas pedal delay? This is where the gas pedal is blipped and the delay causes the response to be out of phase with the input.

Bob--I don't even notice the delay in my 08. Definitely not an issue to me when down shifting.

[SRT Engineers]

3. I recently dynoed my 2008 Viper on a Mustang dynonometer to get a baseline figure on the stock powertrain before doing some modifications. The average of the three runs was 529 rear wheel hp and 505 rear wheel torque. What correction factor would you recommend to get an estimate of flywheel hp and torque?

Thanks for your help and for a great car. I am enjoying it immensely.

/Rich[/quote]

RICH - I always tell people to use caution when trying to get and compare chassis dyno numbers. Many things can (and do) effect the numbers – how well are fluid temperatures (inlet air, charge air, exhaust gas, water and oil) controlled? If these variables aren’t controlled precisely from run to run and dyno to dyno valid numbers and comparison are not possible. How often are the dyno sensors (load cell, tach, pressure and temperature transducers) checked and calibrated (we do it every day in engineering)? All of these variables will effect how the engine is fueled and sparked so there is a potential for big variations. I hope you get my point…anyway, I would suggest correcting to SAE J1349 (29.77 in-hg dry barometer, 77 F inlet air, thermostat coolant temp and road oil temp) conditions since that is what is the current industry standard (and what we use). SAE J606 will give higher numbers (29.92 dry baro, 60 F inlet air) will give higher numbers and is often what the tuners use.

[SRT Engineers]

Originally Posted by Malu59RT

Regarding the 2008 Viper

Is there any way to increase the throttle response in the DBW? If you have ever driven a E46 M3, there is a "sport" button that makes throttle tip-in very sensitive, and I'm hoping there is a way to do that in the 2008 (optional flash).

Also, regarding the recent RRT that was released to take care of the CEL: What effect have you experienced on vehicles that did not have this problem, and had the RRT performed? The dealer performed this against my wishes, and the car feels LESS responsive afterwards. My car performed great and felt strong before, not so much now.

SRT, thanks so much for this car! I've been wanting one for 16 years, and finally have one to enjoy.

Jason

Jason -

The recent RRT was necessary to address an issue that came up after we were well into production relative to misfire detection. We started seeing cranks in production that fell outside of the “normal” range we had used for testing and development, specifically the crank position target wheel. These targets were not bad or out of specification, they just had a much different characteristic for these notches than we had calibrated for. As a result a false misfire code (P0300) was set and limited the engine speed to 2500 rpm and shut down the cylinders that the system interpreted as misfiring. The misfire calibration was adjusted to compensate for this variation and that cal was released in the RRT reflash. There we also a few other minor calibration changes made at this time but nothing that would change the drivability or the throttle response of the engine (regardless of the crankshaft) – this cal change would be transparent to the operator. If the car feels less (or more for that matter) responsive it would not be due to the reflash, period.

On a side note, there have been some problems at the dealers with the reflash and on occasion the flash can fail rendering the module inoperative. The dealer does not have the tools necessary to resurrect the module and we have been working with the dealers to get the modules back to engineering in these rare cases where we reflash and return them. Again, no damage actually occurs to the module and they will work as good as ever once returned.

[SRT Engineers]

Originally Posted by Bobpantax

5. I understand that the pistons for the '08 engine were not intended for use beyond the stock application and that if someone wants to mod the engine a piston change out is adviseable. Is this true? If so do you have any specs on the preferred pistons to use?

Bob,

The 2008 engine is a highly tuned and highly stressed engine. We left few stones unturned in the development or calibration process. Achieving 600 HP required that many of the parts be stressed to their limits and the pistons are one of the most highly stressed components in the engine. If the customer modifies the engine to increase the output by any significant amount (more than just say headers, i.e. supercharger, turbo, NOS), a quality forged piston would be a good idea. We don’t currently offer a replacement piston but many of the aftermarket suppliers could probably offer a good replacement part. Follow their recommendations for fit. Also be careful to make any adjustments for balance if the weight is much different than the stock piston. Don't forget to use a good engine builder and make sure the calibration matches the modifications!