SRT Chat HERE on May 14th!

[tbsviper]

First, thanks for building a great car! Background for question. We have seen that several new 08 Vipers have been crashed at the dealer, by new owners, etc. On this forum, someone suggested that perhaps it was possible to have a key/program that would cut performance for first, say 1,000 miles (break-in) or for use by new drivers. I have a supercharged jet ski and it has two keys, a "learner" and an "unlimited". While I fully appreciate Dodge can't make the Viper "idiot" proof, does the idea of two keys make sense? Is it feasible or too complicated in view of sophistication of engine management systems and emissions requirements?
Again, thanks for building a great car that I truly enjoy!

 

[black08]

Understand that you're looking for something to get a bit more performance however while we have some experience with the Belanger system we can't endorese it.

Thank you for your response. Do you feel that the addition of an aftermarket exhaust system with headers is too much stress on an already stressed engine?

 

[SRT Engineers]

Although the ACR is a bit lighter than the standard Viper, can you tell me why Chrysler was unable to address the weight issue, particularly when compared to the Z06?
I also notice on my SRT that, if the air conditioning is not on, it blows hot air on the vent position. What is the cause and can this be fixed?

The Z06 is lighter in large part because its motor is smaller. The Z06 aluminum chassis is also a weight benefit but it is only intended for a coupe. The Viper has a chassis built for both a coupe and convertible version. This adds a bit of weight. Also, the new Corvette ZR1 (which is based on the Z06 chassis) is about the same weight as the ACR. Horsepower, durability and stiffness all require weight. That said, we're not content with the current weight of the Viper.

Concerning the hot air, the 2008 Viper has made a big improvement versus the 03 to 06, particularly in reducing heat picked up in the plenum. We recommend that you take a test drive in an 08 to check it out.

 

[Paul Hawker]

Current feedback from 08 owners is that the new car is a significant improvement over the previous years cars.

Other than the engine/drive train. Which improvement are the engineers most proud of in the 08?

 

[SRT Engineers]

Thank you for your response. Do you feel that the addition of an aftermarket exhaust system with headers is too much stress on an already stressed engine?

The problem is we really don't know what the long term effects are since we haven't had an opportunity to do that kind of testing. It may be ok ...........

 

[Nader]

In first and third gear I get a decent amount of tranny noise through the shifter. Doesnt happen in any other gears. Is this normal? It does seem excessive. I do have the Mopar shifter which was installed by a quality dealership two years ago.

I have an 04 with 16,000 miles. Tranny fluid has been changed recently.

 

[SRT Engineers]

First, thanks for building a great car! Background for question. We have seen that several new 08 Vipers have been crashed at the dealer, by new owners, etc. On this forum, someone suggested that perhaps it was possible to have a key/program that would cut performance for first, say 1,000 miles (break-in) or for use by new drivers. I have a supercharged jet ski and it has two keys, a "learner" and an "unlimited". While I fully appreciate Dodge can't make the Viper "idiot" proof, does the idea of two keys make sense? Is it feasible or too complicated in view of sophistication of engine management systems and emissions requirements?
Again, thanks for building a great car that I truly enjoy!

The old ZR1 (1994) had a valet key... but later dropped it. Some of the concerns we would have in implementing one were likely shared.

The Segway has two speed cards as well...

 

[Alexarz]

The Z06 is lighter in large part because its motor is smaller. The Z06 aluminum chassis is also a weight benefit but it is only intended for a coupe. The Viper has a chassis built for both a coupe and convertible version. This adds a bit of weight. Also, the new Corvette ZR1 (which is based on the Z06 chassis) is about the same weight as the ACR. Horsepower, durability and stiffness all require weight. That said, we're not content with the current weight of the Viper.

Concerning the hot air, the 2008 Viper has made a big improvement versus the 03 to 06, particularly in reducing heat picked up in the plenum. We recommend that you take a test drive in an 08 to check it out.

I have noticed how rigid the Viper frame is and I am sure that a rigid frame adds weight. Do you know if the Viper frame is more rigid than the Z06 frame? Thanks for answering my questions but I intend to keep my '06. I commend you on improving the situation on the '08 but is there anything I can do to diminish the hot air coming in the vents on my '06?

 

[SRT Engineers]

I know that the air is heated. My question is why? I have never been in any other car that does this. The vent is supposed to circulate air from outside or close to it. Can it be remedied? What about the question I asked concerning weight?

The fresh air intake on this car is actually located in the engine box - this is different from most other cars and was done this way for packaging. On other cars it's usually on the other side of the firewall. Because of this air entering the HVAC tends to get more heated and will blow hot some air at you even if you don't have the fan on - especially if you don't have the AC on. We remedied this in the 08 car by moving hood louvers away from the plenum lowering the overlall intake temp.

 

[SRT Engineers]

What kind of performance can be gained with the aero package on the roadster? Is the wing on the roadster as effective as the ACR? Which is lighter the Vert or the coupe? What is the top speed of the roadster? Do you think the Viper can out perform the new ZR1? Also why not think about turbos or some kind of forced induction?

Thank you SRT and Dodge I LOVE my Viper and the new Gen 4!! You guys ROCK!

The ACR makes significantly more downforce than either aero package. The aero package wings are based on the ACR form but they are twelve inches narrower (cross/car) and do not have the Gurney kick up at the trailing edge.

The roadster aero package makes about the same downforce as a base coupe (roughly 170 lbs at 150 mph). The coupe aero package makes about 600 lbs of down force at 150 mph. The ACR makes 1000 lbs of DF at 150mph.

The ZR1 team has made some lofty claims about it's track performance. We'll have to wait and see what the production car does.

 

[SRT Engineers]

What kind of performance can be gained with the aero package on the roadster? Is the wing on the roadster as effective as the ACR? Which is lighter the Vert or the coupe? What is the top speed of the roadster? Do you think the Viper can out perform the new ZR1? Also why not think about turbos or some kind of forced induction?

Thank you SRT and Dodge I LOVE my Viper and the new Gen 4!! You guys ROCK!

The ACR makes significantly more downforce than either aero package. The aero package wings are based on the ACR form but they are twelve inches narrower (cross/car) and do not have the Gurney kick up at the trailing edge.

The roadster aero package makes about the same downforce as a base coupe (roughly 170 lbs at 150 mph). The coupe aero package makes about 600 lbs of down force at 150 mph. The ACR makes 1000 lbs of DF at 150mph.

The ZR1 team has made some lofty claims about it's track performance. We'll have to wait and see what the production car does.

 

[SRT Engineers]

I commend you on improving the situation on the '08 but is there anything I can do to diminish the hot air coming in the vents on my '06?

If you don't want to change your hood the best advice I can give you is just to run the AC. ....

 

[Nader]

The ACR makes significantly more downforce than either aero package. The aero package wings are based on the ACR form but they are twelve inches narrower (cross/car) and do not have the Gurney kick up at the trailing edge.

The roadster aero package makes about the same downforce as a base coupe (roughly 170 lbs at 150 mph). The coupe aero package makes about 600 lbs of down force at 150 mph. The ACR makes 1000 lbs of DF at 150mph.

The ZR1 team has made some lofty claims about it's track performance. We'll have to wait and see what the production car does.

The Roadster areo package makes only 170lbs of downforce? Why bother even offering it then? What on the coupe is creating more downforce then the roadster?

 

[SRT Engineers]

Reply for Nader on 1st and 3rd gear transmission noise...

I can't say why specifically 1st and 3rd would be worse. The Mopar shifter and many other aftermarket shifters do not have the rubber isolator that the production shifter has... therefore it is common that these shifters may allow a little more noise, vibration, or 'feedback' thru the shift knob in exchange for a precision feel. Make sure use are using the correct Mopar manual trans fluid P/N 04874459 (Castrol 75W-85) for the T56. Special note... the new '08 TR6060 uses onlyATF+4 fluid.

 

[SRT Engineers]

The Roadster areo package makes only 170lbs of downforce? Why bother even offering it then? What on the coupe is creating more downforce then the roadster?

170 lbs of downforce is actually very good considering we did it without adding any drag. The goal roadster aero package was to add moderate downforce without increasing drag. Most sports cars actually make about 100 to 200 lbs of lift at speed. The base roadster is neutral (roughly zero DF).

If you are going to the track, we recommend the ACR. If you've got to have a roadster and still plan on going to the track you'll notice a good improvement in high speed stability and grip with the aero package.

The wing on the coupe aero package is higher in the clean air stream. This makes the wing pick up more downforce.

 

[musicncars]

Thanks for the answer to my first question. I look forward to getting my car, hopefully soon.
Is the aero group wing on the Coupe the same as the ACR?

 

[Nader]

Thanks for the info. I thought the roadster was making SOME downforce at that speed.

170 lbs of downforce is actually very good considering we did it without adding any drag. The goal of the roadster aero package was to add moderate downforce without increasing drag. Most sports cars actually make about 100 to 200 lbs of lift at speed. The base roadster is neutral (roughly zero DF).

If you are going to the track, we recommend the ACR. If you've got to have a roadster and still plan on going to the track you'll notice a good improvement in high speed stability and grip with the aero package.

The wing on the coupe aero package is higher in the clean air stream. This makes the wing pick up more downforce.

 

[EZ 2B Green]

I am a first time Viper owner (2008 Roadster). I read much about the improvements to the 08 car which caused me to part with my C5 Z06. One of the improvements was the rear diff. Visco-loc (sp?) is the term I believe. I have read that a lot of Viper owners are switching to an aftermarket unit made by Quaife. Some have even gone so far as blaming accidents on the action of the rear diff. Could you tell us about the perfomance characteristics of the new diff and how it compares to aftermarket units? Thank you for your efforts to bring the Gen4 Viper to life!

 

[SRT Engineers]

Thanks for the answer to my first question. I look forward to getting my car, hopefully soon.
Is the aero group wing on the Coupe the same as the ACR?

The aero group coupe wing is the same general form as the ACR wing. It is twelve inches narrower and does not have the lip on the rear edge. The end plates are a little smaller but the position of the wing is the same.

 

[JonB]

Some Few, Early 2008s experienced a 'limp home' which was corrected with a PCM re-flash.
What kind of item (coil?) seemed to be the culprit. Have you killed this bug for good. (ACR in D-1)

JonB

 

[SRT Engineers]

Thanks for the answer to my first question. I look forward to getting my car, hopefully soon.
Is the aero group wing on the Coupe the same as the ACR?

We've attached a photo of the aero package coupe...

 

[SRT Engineers]

Some Few, Early 2008s experienced a 'limp home' which was corrected with a PCM re-flash.
What kind of item (coil?) seemed to be the culprit. Have you killed this bug for good. (ACR in D-1)

JonB

JonB - See our response in post #14 of this thread, that should answer your question.

 

[JonB]

DANG, I arrived late and scanned tooo fast. THANKS

I look forward to some meaty TECH SESSIONS at VOI-10, with youse guys, please!
I actually have skipped other activities to attend SRT-Team Viper TECH SESSIONS both days.
Remind the marketing side WE dont need no stinking commercials! We are already SOLD!

The bigger the SRT table at front the better, THANKS, and see you there.... Jon

 

[musicncars]

We've attached a photo of the aero package coupe...

Very Nice!!! You would'nt happen to have a pic of a aero group vert, would you? (hint, hint)lol
Thanks, have a great night!
Benjamin

 

[wallbanger]

Thanks for building the 08 ... it is a very rewarding american car...Earlier you state that you are not happy with the current weight of the car... what about the riding height... the 08 seems to sit about an inch to high all around... any improvement coming in this area

 

[SRT Engineers]

Could you tell us about the perfomance characteristics of the new diff and how it compares to aftermarket units?

The all new GKN ViscoLok differential is a 4 pinion, speed sensing limited slip differential. All previous Viper differentials were a 2 pinion design. The 4 pinions in the diff housing give the new diff improved torque capacity compared to previous diffs. The limited slip mechanism is a self contained viscous shear pump... when wheel speed differential occurs, the pump feeds pressure to a clutch pack to provide the necessary rear grip. The beauty of the self contained internal pump is that there is no delay for engagement, and it performs very well throughout a wide temperature range due to the stability of the viscous fluid.

Contrary to rumors about 'electronic diffs', traction control, etc., on the recent One Lap of America, the ACR Viper that dominated the road course events had a completely STOCK ViscoLok differential and it performed flawlessly.

 

[SRT Engineers]

Very Nice!!! You would'nt happen to have a pic of a aero group vert, would you? (hint, hint)lol
Thanks, have a great night!
Benjamin

This was a teaser car we built for SEMA. The ACR wheels are not available on the roadster but the wing is the same as the roadster aero group.

 

[doctorbob]

What benefit is the aero option on a coupe versus an ACR? In other words does the aero group on a coupe just help in track driving?

 

[SRT Engineers]

Thanks for building the 08 ... it is a very rewarding american car...Earlier you state that you are not happy with the current weight of the car... what about the riding height... the 08 seems to sit about an inch to high all around... any improvement coming in this area

Ride height is determined by minimum approach angle and suspension geometry (jounce/rebound) that is designed to provide an optimal performance package. Youre not going to find too many cars coming out of the factory that are lower then the Viper.

We never said we weren't happy with the weight.... but we all know that weight is the enemy of performance

Have a good one.

 

[SRT Engineers]

What benefit is the aero option on a coupe versus an ACR

See Post #41. The Coupe aero group is about 600 pounds of downforce and the ACR is 1000 pounds at 150 mph.