200 mph. How much HP do I need?

[J DAWG]

What will get me over 200 mph?

RT. With the stock 3.07's.

 

[Snake Bitten]

More than you can afford...just get new wheels, so you "look" like 200 mph!!!

 

[Chuck 98 RT/10]

I've heard to reach those speeds the need for better aerodynamics increases exponentially.

 

[Anthony - 98 GTS]

My understanding is around 600rwhp. I'll let you know in a couple of months.

 

[J DAWG]

More than you can afford...just get new wheels, so you "look" like 200 mph!!!

I hear ya Gerald, but my gf said I don't need the wheels.

I do however NEED to go 200 mph. Just a dream of mine. Definetly with the top off.

600 rwhp sounds resonable. Let me know how it goes Anthony.

 

[slaughterj]

More than you can afford...just get new wheels, so you "look" like 200 mph!!!

I hear ya Gerald, but my gf said I don't need the wheels.

I do however NEED to go 200 mph. Just a dream of mine. Definetly with the top off.

600 rwhp sounds resonable. Let me know how it goes Anthony.

600 rwhp worked for at least 1 gts I know of, and he had some more to go I believe, so I wouldn't be surprised if something around there would work for an rt/10 as well.

 

[Russ M]

TOP OFF!!!!!

That would be insane, the fastest I have been is about 170 with top off and windows down. And it felt like I was going to get sucked out of the car.

 

[Roadkill]

More than you can afford...just get new wheels, so you "look" like 200 mph!!!

I hear ya Gerald, but my gf said I don't need the wheels.

I do however NEED to go 200 mph. Just a dream of mine. Definetly with the top off.

600 rwhp sounds resonable. Let me know how it goes Anthony.

I agree with SnakeBitten.. you need new wheels.. yes.. that's it.. new wheels.. and then you can sell me your "old" wheels

 

[MadMaxx]

In the R&T speed shootout, a stock GTS did 197 MPH before having a waterpup spring a leak. Very cool

So, 600hp, tall-deck F40/Superbird style spoiler and a front spliter... should do 200+

MM

 

[Vip-RT10]

You need a Ferrari F50.....I hit 200 mph/325 kph in it and felt secure. It only has 600 hp (modified) but it could also can stop. Tires that can take those speeds and precisely balanced. Suspension that is race-like is needed as well and with aerodynamics, Chuck is dead on.

 

[Roger Morgan]

If you really want to go 200 see www.silverstateclassic.com and get ready, we will have several Vipers at this event but I assume you want to do it safely and legally. This is the deal but you need a lot of equipment at anything over the 165 tech (125-150 average) so read the rules and start packing. If you sign up tell them you want to be on the Viper Team and you get a small discount. Trust me when you are at speed for 90 miles its a lot different than high speed for a very short time.

 

[monnieh]

On a long enough time line, all Viper owners survivablity statics could drop to zero.

You know, I have no desire to go 200mph in a street car. Give me CART or INDY car crash technology and I'm there in a heartbeat.

 

[Torquemonster]

Roger's post is important.

Also, as speed increases so does the nervousness of the car.

155mph is a walk in the park cruise speed for many good cars and requires little concentration other than watching for hazards ahead in any car I've done it in. Above that I imagine things get a lot more critical.

If your Viper tramlines and requires constant steering adjustments at 150mph - it'd be extremely hairy at 200mph. Do you want to drive with white knuckles?

I'd expect that some alignment adjustments may be required to make the car better in a straight line - this may reduce turn in a bit, but the last thing you want is an unplanned lane change at 200mph.... narrower tires up front may also help stability. The guys who have run Vipers in Silverstate will tell you what they drove like and what they're doing to improve safety.

Making the power is the easy part.

 

[Flyviper]

Call and ask your local mortuary.

 

[RaceDeck]

I'll let you know in August...I am running at bonneville saltf-lats ....but not in my viper ( you need a cage over 165 mph) so I am running my 32' roadster that is now powered by a blown 2.4 liter mopar engine- being built by Daryl Cox of mopar racing- should put out around 550 -600 hp. We are going for a world record in this class (street roadster blown gas)

 

[Paolo Castellano]

I do however NEED to go 200 mph. Just a dream of mine. Definetly with the top off.

600 rwhp sounds resonable. Let me know how it goes Anthony.

[/QUOTE]


John, I just put the #'s in my spread sheet and came up with two figures: With the hard top I remember RT/10's have a CD of about .45 and with top off a CD of .50.

For a CD of .45 you will need approximately 624 RWHP to go 200 MPH.(Hard top on)
For a CD of .50 you will need approximately 684 RWHP to go 200 MPH. Top off

Compare this to a GTS needing "Only" 514 RWHP to do the same 200 MPH.

I would agree you would need some aerodynamic modifications to be stable. I remember being in an RT/10 once going 170+ and it felt nothing like the stability the GTS has at 190+. You would also have to check your wheel bearings, have brand new tires that are Y-Rated, have a high speed alignment and maybe add some rake to your car to add to the downforce proportionally. Heffner and myself are planning to do some closed track high speed testing. If you wanted to attend, I am sure I could give you a 200+ MPH ride if you filled out all the necessary waivers.........LOL!

 

[Paolo Castellano]

Roger's post is important.

Also, as speed increases so does the nervousness of the car.

155mph is a walk in the park cruise speed for many good cars and requires little concentration other than watching for hazards ahead in any car I've done it in. Above that I imagine things get a lot more critical.

If your Viper tramlines and requires constant steering adjustments at 150mph - it'd be extremely hairy at 200mph. Do you want to drive with white knuckles?

I'd expect that some alignment adjustments may be required to make the car better in a straight line - this may reduce turn in a bit, but the last thing you want is an unplanned lane change at 200mph.... narrower tires up front may also help stability. The guys who have run Vipers in Silverstate will tell you what they drove like and what they're doing to improve safety.

Making the power is the easy part.

Torquemonster, I would agree with everything you are saying. I would like to add that if the lanes are smooth(no ruts), The car does not require any steering input at all up to 193MPH. It goes straight as an arrow, no problem. Myself and Jason Heffner will do some closed track high speed testing with the extra power and measure any lift that could be occurring at all four suspension corners with potentiometers. I am designing some very functional aero pieces that will allow us to adjust the front and rear downforce on the move.

 

[Skyhawk]

J Smith - Found the password and can now post. If you had time to look at the Excel spreadsheet I sent to you earlier today, you will notice that there are two equations incorporated into calculating the HP required to go 200 mph. The first addresses the HP required to overcome rolling resistance and the second is the HP required to overcome aerodynamic drag. Combined, the two equations are HP = (Cr)(m)(g)+(1/2)(rho)(Cd)(A)(V). You will see each of these variables listed within the spreadsheet, along with an explanation of what they are. Most of these variables are unique to the vehicle and driver. The air density is a function of humidity, altitude, and temperature and is in there as well. Keep in mind that these equations are only theoretical. Also, this calculates the HP required to maintain a given velocity. It may take forever to get there, but this HP should keep you there, once there. This is why the second portion of the spreadsheet looks at the HP required to get you there in a given amount of time. It will take more HP to get you there in a shorter amount of time. I don't remember specifically what numbers were plugged into the calculator when I sent it to you, but they may have been the ones for my motorcycle. The real life dynamometer numbers and the numbers from the second part of the calculator tend to agree pretty well. As I mentioned in the e-mail, in my particular case, it takes my bike just under 10 seconds to break through the 200 mph mark and this corresponds nicely to having 363 RWHP with my weight. To merely get to 200 mph, without a time constraint, requires much less HP. Hope this supplements what was sent to you via e-mail. If I can help any further, just e-mail me.

 

[Fast Freddy]

i haver gone 180 mph in 5th gear (gps verified). i will attempt 200 mph in 6th gear with 600 rwhp. i use the stock 3.07 gears

 

[Paolo Castellano]

i haver gone 180 mph in 5th gear (gps verified). i will attempt 200 mph in 6th gear with 600 rwhp. i use the stock 3.07 gears

Freddy, you'll never do it in 6th gear! Here's why:

600 RWHP X .5 X 3.07 = 921 RWHP multiple
405 RWHP X .74 X 3.07 = 920 RWHP multiple

So you see, you have the exact same HP multiple as a stock car in 5th. Definitely not enough.

You can, however, hit between 210 and 212 MPH in 5th gear @ 6150 RPM. Let me know how it goes.

 

[J DAWG]

Paolo, Skyhawk. Thanbks for the graphs and info. It is amazing the increase in power needed to achieve those extra miles over a stock cars performance. Especially the affect of CD and the necessary power needed to overcome it in an RT.

John

 

[CitySnake]

This is an interesting subject. I would venture that by removing the outside rear view mirrors you could decrease enough drag to lower the necessary horsepower significantly...maybe 25-50 HP.

 

[SapphireGTS]

Assuming that drag forces are proportional to velocity squared, Drag is governed by the ricotti equation,

-m d/dt (v) = CA v^2

where m is the mass of the car, v is the speed and
CA is the drag coefficient

The drag coefficient is then

CA = (V2 - V1) * m / (V2 * V1 * t)

Say the mass is 3000 pounds giving
CA not CD = 0.56 (well say you have an RT with the top off and a fat girl in the passenger seat)

The power (HP) required to overcome drag is given by
HP = CA v^3.

to go 200 you will need a good 650+ HP, a big set of nuts and some good tires.

Although all of this does not take in mind Grade. HP is not the issue. It is simply overcoming the issue. If your drag was zero it take about 1 HP.

 

[garolittle]

What will get me over 200 mph?

RT. With the stock 3.07's.

Do not forget to check your brakes before you try it.

 

[Fast Freddy]

hey paolo. i assumed that 602 rwhp venom 650 car that went 203 mph years ago in motor trends speed freak issue was in 6th gear. as it turns out he was in 5th gear. he was radared on a closed course. out here in arizona we do out testing on open tracks. lol! anyway i found a link to a fancy viper gear & speed calculator over on one our other forums and it says that with my 3.07 gears at 6000 rpm's i will go 200 mph. so when i get the juice i will spray it at 5,500 (180mph) and stay on the bottle until i get to 200 mph. shouldn't take more than 15 seconds. its not good 2 use the juice for more than that amount of time. the nos dry kit comes with a 15 lb bottle.