ACR vs. SRT aero pkg.

[Jeff Monheim]

Does anyone know the difference in top speed between the 08 ACR and the 08 SRT coupe with the new SRT not ACR aero pkg on it. I think the 08 ACR top speed is 177mph with 1000lbs of down force at 150mph. What is the down force of the SRT aero pkg at 150mph and the top speed of the SRT with the SRT areo pkg installed. Anybody have the FACTS and NUMBERS and from what SOURCE??

 

[Boxer12]

My guess is that the SRT wing has little to no downforce or effect on top speed, unless it creates drag and slows you down a bit, but I have no FACTS to base it on, just the fact that it doesn't look like anything but a polisher piece.

 

[wallbanger]

Do a search the facts are on this board .... the srt wing has some downforce on the coupe .... if i remember somewhere around 4-500lbs maybe and very little on the vert

 

[rcl4668]

Do a search the facts are on this board .... the srt wing has some downforce on the coupe .... if i remember somewhere around 4-500lbs maybe and very little on the vert

Ditto; my recollection of a post -- perhaps from an SRT engineering chat -- was that the "regular" SRT-10 aero group on both the coupe and roadster do in fact generate a decent amount of downforce but nowhere near what the ACR aero components generate.

/Rich

 

[SilveRT8]

I remember from the SRT Engineer's chat that downforce at 150 mph is as follow :
Vert= 0
Vert Aero = 170
Coupe = 150
Coupe aero = 600
ACR = 1000

Claude

 

[wallbanger]

great memory claude

 

[SilveRT8]

great memory claude

THANKS,
They also mentionned that the wing on the aero pkg was 6" narrower than the ACR and was not adjustable,installed low on the Vert and higher in the wind on the Coupe
Claude

 

[Newport Viper]

I remember from the SRT Engineer's chat that downforce at 150 mph is as follow :
Vert= 0
Vert Aero = 170
Coupe = 150
Coupe aero = 600
ACR = 1000

Claude

So the Vert is the fastest car top end then?

 

[mjorgensen Woodhouse]

Yes that is true but it is also the most likely to take off too!

So the Vert is the fastest car top end then?

 

[Jeff Monheim]

Thanks everyone! Thank you Claude! I could not find the info in the SRT Engineers chat forum. I read it some time ago but could not find anything on "TOP SPEED" or SPEED LOSS for the SRT aero pkg. Is there another SRT engineer chat coming soon??? I guess I could use the down force to drag ratio with known loss of speed for the ACR and just convert to the down force of the SRT aero package assuming the down force to drag ratio is linear and I have it!!! Well at least I would have something!
Something like 187 MPH???

 

[SSGViper]

Anyone have a pic of the Aero on a coupe?

 

[wallbanger]

lol... do i have pictures....

 

[wallbanger]

DAD! DAD! i told u to get the ssg

 

[Jeff Monheim]

Wallbanger, nice pic! I will have this by spring! It looks better than I expected, and you have it in my color. Minus the strips of course!
Great job!

 

[Boxer12]

Those are better pics of SRT wing than I have seen before, and I can see that it should the claimed amount of downforce. I would think the fastest car is the Cpe without any aero.

 

[Jeff Monheim]

Yes any aero pkg on the coupe will lower top end speed because of the drag it creates.
Coupe No Aero 202MPH
Roadster/Vert no aero 198MPH
ACR 177MPH
Coupe with SRT aero ???MPH

 

[rcl4668]

Yes any aero pkg on the coupe will lower top end speed because of the drag it creates.
Coupe No Aero 202MPH
Roadster/Vert no aero 198MPH
ACR 177MPH
Coupe with SRT aero ???MPH

I seem to recall seeing somewhere (SRT engineering chat perhaps?) that the roadster actually will match the coupe's 202 mph top speed with the top up but with it lowered it will do 197 mph.

 

[Jeff Monheim]

What I read was thevert would top out at 198MPH EVEN with its top down. So I thought top up or down 198 was the limit. But I could be wro.. ok I cant say that word, but you may be right!

 

[2002_Viper_GTS_ACR]

I seem to recall seeing somewhere (SRT engineering chat perhaps?) that the roadster actually will match the coupe's 202 mph top speed with the top up but with it lowered it will do 197 mph.

Very hard to believe that to be the case (not that your lieing). Can you get us the data/post verifying on that one?

 

[rcl4668]

Very hard to believe that to be the case (not that your lieing). Can you get us the data/post verifying on that one?

Sometimes I scare myself: I actually managed to find the quote from the SRT engineering chat in question:

"Unfortunately, I can not find the wheel weights right now. We can post them next time. However, I can tell you that the 5 spoke, H spoke, and razor wheels are very similar in weight. The only production Vipers wheels that are significantly different in weight are the Sidewinders (approx 30 lbs per vehicle).

The non-ACR Coupe and Convertible went 202 mph, average in both directions to cancel out wind. The '08 Convertible went 197 with the top down. We had to go to TRC to go that fast. The Chelsea and Arizona proving grounds ovals are too small."

/Rich

 

[Jeff Monheim]

Great job finding the post! I am loosing hair fast enough! 197 MPH with the top down Telly Savalis, here I come. I do love these cars!
Any word on the TOP SPEED with SRT aero pkg installed on the coupe???????

 

[CitySnake]

The '08 Convertible went 197 with the top down.

That would be painful!
And I'm a bit saddened to learn that I won't be able to reach 200 with the top down.

 

[2002_Viper_GTS_ACR]

Sometimes I scare myself: I actually managed to find the quote from the SRT engineering chat in question:

"Unfortunately, I can not find the wheel weights right now. We can post them next time. However, I can tell you that the 5 spoke, H spoke, and razor wheels are very similar in weight. The only production Vipers wheels that are significantly different in weight are the Sidewinders (approx 30 lbs per vehicle).

The non-ACR Coupe and Convertible went 202 mph, average in both directions to cancel out wind. The '08 Convertible went 197 with the top down. We had to go to TRC to go that fast. The Chelsea and Arizona proving grounds ovals are too small."

/Rich

Good find, and Wow. I don't quite get the physics behind it, since top down usually increase turbulence and resistance significantly... but only by 5 mph off of the top speed, thats incredible.

Thanks for finding it.

Jon

 

[Jeff Monheim]

Hey City your Vert looks Great! I did like the Green Stripe! and the aero pkg. You dont have any photos of how the wing and splitter are attached to the car do you??? I would truely like to see the attaching points and hardware.
If you find somewhere to drive over 165mph and up to 202MPH. I will meet you there and we can test these numbers out in the real world and let everyone know first hand.

 

[CitySnake]

Hey City your Vert looks Great! I did like the Green Stripe! and the aero pkg. You dont have any photos of how the wing and splitter are attached to the car do you??? I would truely like to see the attaching points and hardware.

Thanks Jeff. I didn't take any photos of the wing attachment, but it's quite simple. there are 4 bolts (2 on each side) that are screwed through the trunk deck with washers and nuts underneath. Not particularly high tech.

If you find somewhere to drive over 165mph and up to 202MPH. I will meet you there and we can test these numbers out in the real world and let everyone know first hand.

Yeah...LOL Like THAT"S going to happen!

 

[rcl4668]

One other word of advice in terms of aerodynamics: For you convertible owners, I did a high performance driving school at our local track (PIR) a few weeks ago and noticed while my instructor was driving my car at higher speeds (130+ mph) that the convertible boot cover/tonneau cover was literally being sucked off of the car. I decided to take it off for the rest of the day but you might also be able to tape down the leading edge of the tonneau cover with something paint friendly like blue painters tape.

/Rich

 

[Nader]

Yeah I noticed that also even at highway speeds. I dont use mine much for that reason.

One other word of advice in terms of aerodynamics: For you convertible owners, I did a high performance driving school at our local track (PIR) a few weeks ago and noticed while my instructor was driving my car at higher speeds (130+ mph) that the convertible boot cover/tonneau cover was literally being sucked off of the car. I decided to take it off for the rest of the day but you might also be able to tape down the leading edge of the tonneau cover with something paint friendly like blue painters tape.

/Rich

 

[vipernut]

Since you guys are talking about these components....my driveway/ garage will not allow for the protrusion of the front splitter...so I'm wanting to remove it ..but keep the wing on my 2008 AERO packaged SRT COUPE.....

Do you guys see any problems with this? (mechanically or technically?!)...

THANKS!

 

[rcl4668]

Since you guys are talking about these components....my driveway/ garage will not allow for the protrusion of the front splitter...so I'm wanting to remove it ..but keep the wing on my 2008 AERO packaged SRT COUPE.....

Do you guys see any problems with this? (mechanically or technically?!)...

THANKS!

Given that the non-ACR aero components don't generate as much downforce as the ACR parts, this is less of a concern but on any car that is capable of the speeds/performance of a 2008 Viper I would be reluctant to remove one part of the aero package while retaining the other. The wing will generate downforce but with the front splitter removed the car will lose aerodynamic balance. If you are just cruising around town at speeds below 60-70 mph, I imagine that's fine. If you will be driving faster, you could have some nasty unintended consequences (increased understeer, etc.)

/Rich

 

[Jeff Monheim]

Hey Vipernut check your ***!
Great color by the way!!