Texas Mile: PICS, VIDS, and a Science Experiment

[345s-bspinnin]

I attended the Texas Mile this last weekend. Needless to say, it was a thrilling ride filled with fast speeds and a host of very scandalous cars (and trucks). I was quite pleased with my Viper. It was running strong and exceeded my expectations by a significant margin.

For the event, my car would be a test subject for my little nephew’s school experiment. I have listed the experiment assumptions, results, and findings using 5th grade scientific method as written by my little nephew (with a little help from uncle). As a side note, I did add a few extra VCA notes for inquiring minds. Hopefully most of you are smarter than a 5th grader

1.Define the question

What impacts does tire height/weight have on the top speed of a Dodge Viper SRT10 during a standing mile (drag mile) event?

VCA Note: For his experiment, no details on respective gearing change are provided, but I added those for you folks.

2. Gather information and resources (observe)

Vehicle:
- ’03 Dodge Viper SRT Convertible
- 500 horsepower

Variable Parameters Specifications:

Description Height Weight Size
Street Front 25.6 52 275/35-18
Street Rear 27.1 69 345/30-19
Race Front 25.2 50 305/30-18
Race Rear 25.9 54 335/30-18

VCA Notes:

Street Wheels:
- HRE 545 R Front, 275/35-18 with Nitto Invo
- HRE 545 R Front, 345/30-19 with Nitto Invo
Race Wheels:
- SSR Front, 305/30-18, Kumho V700
- SSR Front, 335/30-18, Kumho V700

Power Mods:
- ARH 1 3/4” long tube headers, no cats, stock mufflers with crossover
- A/C Performance Tuned
- 492whp/525wtq SAE, before final “fine tune” to A/F (guessing 500whp/525wtq SAE)

Suspension:
- Vipair Height Adjustable Suspension
- Eibach springs (500 lb Front/ 800 lb Rear)

Aerodynamic enhancements:
- Car was lowered ~2.75” Front and ~2.5” Rear
Note: Changing wheels altered vehicle height
- No tape used on car seams, didn’t want to be slowed down…lol

Weight Reduction: (aside from the battery, I wasn't really trying, but all the mods are lighter than OEM and probably worth mentioning)
- Vipair OEM Reproduction Hood (-15 lbs)
- Vipair Suspension (-14 lbs)
- Deka Lightweight Battery (-19 lbs)
- ARH Headers with test pipe (-4 lbs)
- Wheels (Variable from 0 lbs to -40 lbs)
TOTAL: (-52 to -92)

Side note on header weights:
- OEM Header with stocks cats = 22.6 lbs (per side)
- ARH 1 3/4” and test pipe: 20.4 lbs (per side)


3. Form hypothesis:

The lighter and shorter wheels will allow the car to accelerate quickest and achieve a higher top speed. Three experiments with different combination of wheels will be conducted. Each version of the experiment will be conducted with a different driver for repeatability. The average of the two runs will be used to analyze results.

4. Perform experiment and collect data:

Experiment 1:
Wheel Setup: Street Wheels Front/Rear
Results:
- Run1, Driver 1: 172.9 mph
- Run2, Driver 2: 171.4 mph
- Average: 172.2 mph

Experiment 2:
Wheel Setup: Race Wheels Front/ Rear
Results:
Saturday Afternoon:
- Run3, Driver 1: 174.6 mph
- Run4, Driver 2: 174.2 mph
Sunday Morning:
- Run5, Driver 1: 174.8 mph
- Run6, Driver 2: 174.1 mph
Total Average: 174.4

Experiment 3:
Wheel Setup: Street Wheel Front, Race Wheel Front used on Rear
Sunday Afternoon:
- Run7, Driver 1: 175.5 mph
- Run8, Driver 2: 176.7 mph
- Average: 176.1 mph

VCA Notes:
In addition to weight reduction, mechanical gearing will be affected by shorter diameter tires.

Computed Gear Change:
Experiment 1: Street tires (3.07)
Experiment 2: Race Tires (3.20) 4.2% shorter (using 335s)
Experiment 3: Combination (3.28) 7.0% shorter (using 305s)

Approximate engine speed at 1 mile mark (5th gear):
Experiment 1: 4850 rpm
Experiment 2: 5150 rpm
Ex3: 5400 rpm

For E3, the 4/5 shift (150 mph) happened a few hundred feet before the 1/2 mile mark!!!!!


5.Analyze data

- Experiment 2 yielded an average of 1.4% increase in top speed over Street Tires.
- Experiment 3 yielded an average of 2.4% increase in top Speed over Street Tires


Other VCA findings of interest.
- Started with fuel at approx 3/8 Tank, and ended at approx 1/8 Day 1 (4 runs)
- Added 4 gallons on Sunday morning
- Started with fuel at approx 3/8 Tank, and ended at approx 1/8
Day 2 (4 runs)
- Approx 8 gallon consumed for 8 runs; approx 1 mpg

6. Interpret data and draw conclusions that serve as a starting point for new hypothesis

Results indicate that changes to wheels size/height does impact final speed for a Dodge Viper SRT-10. The shorter and lighter wheels resulted in the highest average speeds.

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END OF EXPERIMENT
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Those are the experiment results. There were other vipers at the event. Debbie in a bone stock Gen III ran a 162mph and a Gen IV ran a 176.8 (Gary Weeks I think). I didn’t introduce myself, sorry.

VIDEO
Short video from the GoPro and HD Camera.
[media]http://www.youtube.com/watch?v=NsEEiVnHv64[/media]

PICS:
At the starting grid, on HRE Wheels

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Pics of Time Slip and GPS Speedo App on my phone that was surprisingly accurate.

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Pics with SSR and V700s.

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Down the track pics.

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My friend Flaco’s LSX turbo powered truck did a couple of 199s, even a 199.6, but didn’t manage to break the 200mph mark. That is truly a sick truck.

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Where the rubber met the road:

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Others from the event, including ARTs monster.

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Debbie's Stock SRT than ran a 162mph

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The Vette that rolled. Driver was okay.

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[Synergy]

Looks like an awesome experience! Drive safe

 

[viper GTS-R]

I was just watching Flaco's build on Youtube the other night, sick truck indeed! I love that helmet shot, new retrospectives are always cool!

--RS

 

[TrackAire]

Very nice write up and pics, congrats on your runs.

You car sounds like it has a cam, wicked sound at idle

Keep the cool scientific writeups coming, very informative.

Cheers,
George

 

[Ghoust]

wow. What an amazing experience it must be to actually do those speeds in a car you usually drive on the streets! Good times!!

 

[Tiago]

the car looked bad ass at the track!

forgot to include the effects of DA and wind conditions, could have easily been responsible for the speeds changing

 

[345s-bspinnin]

the car looked bad ass at the track!

forgot to include the effects of DA and wind conditions, could have easily been responsible for the speeds changing

Effects of DA and wind conditions are probably a bit beyond the scope of a 5th graders science experiment....lol.

On a more serious note, I really should reference conditions. Saturday's runs had a cross wind while Sunday's had a bit of head wind. Temperature may also matter and worth mentioning, especially since the fastest run was achieved during the hottest part of the day!

Time to go do a bit more homework.

 

[Sabera]

Quick question, this may be logical to most of you but what's with the tape?

I know they tape headlights to hold the glass together for crashes. But is this for aerodynamic purposes?

 

[Viperless]

Quick question, this may be logical to most of you but what's with the tape?

I know they tape headlights to hold the glass together for crashes. But is this for aerodynamic purposes?

Taping gaps reduces drag. As does large openings on the front like the foglight holes. Some also partially block the grill area off.

 

[Viperless]

Experiment #3 is interesting. Narrower tires on the front and rear....less drag and less rolling resistance. Ever notice how skinny the tires are on Bonneville cars?

Very cool experiment and a lot of work. Nice job Andres!

 

[happy56]

the skinny tires at Bonneville is because you want as much weight per sq.in pushing down on a very loose surface that we run on. I have crewed on a world record setting crew there so I know where I speak from. It is not like asphalt because it ''peels''away.

 

[Bobpantax]

Thank you for the post. One of our members ran at this event last year and hit 190 in a mildly modded Gen IV ( If I recall correctly, it only had headers and the Mopar controller). The thread includes a video of the run. The thread also includes an analysis of the effect of the following: the car was lowered a bit; ran smaller wheels and tires ;and, a tail wind which I believe was 23 MPH. I posted a mathematical formula that may be used to determine the "gearing affect" caused by the use of the smaller wheels and tires. If you use the search function, I am sure that you will find the thread.

Standing mile events are great fun. I wish there were more.

 

[Sabera]

Taping gaps reduces drag. As does large openings on the front like the foglight holes. Some also partially block the grill area off.

Thanks !

 

[Twister]

Wow!

Thanks for the data. Very nice of you to take the time to post all this info.

Very interesting is the stocker that went 162 while you managed 176 mph. I have to wonder if the driver had somthing to do with the 162 as I would have imagined 165-167 being more normal from other runs Ive read about.

How in the heck are some of you getting 490-500 rwhp SAE with just headers/exhaust/tune?????

Ive got eveything minus headers and throttle body and I cant get anywere near that yet. Im thinking that I need to stop playing with these mail order SCT tunes and just spend the $400 at roe raceing for the pro racer software and have it tuned on the dyno..


Equally impressive is at only 500 rwhp your car ran dead even with a 520 (PLUS???) rwhp gen4.

I guess the more gunt down low showed its face in this case as well as the gen3 verts weighing in at 3380 vs the gen4's 3450 pounds.


If I were you Id be smileing from ear to ear. What an amazing starting point and you havent even hardly started the modding yet.

Love to see your bolt on Gen3 in the 180's next year after a few more minor mods

 

[345s-bspinnin]

Thank you for the post. One of our members ran at this event last year and hit 190 in a mildly modded Gen IV ( If I recall correctly, it only had headers and the Mopar controller). The thread includes a video of the run. The thread also includes an analysis of the effect of the following: the car was lowered a bit; ran smaller wheels and tires ;and, a tail wind which I believe was 23 MPH. I posted a mathematical formula that may be used to determine the "gearing affect" caused by the use of the smaller wheels and tires. If you use the search function, I am sure that you will find the thread.

Standing mile events are great fun. I wish there were more.

I was present at the Texas Mile last year and actually met Viperless when he ran the 190mph. At the time, I was already certain that his shorter and lightweight wheel setup was a significant influence to his Vmax (my engineering background assured me of it). He also has lightweight rotors, which weren't mentioned, but am certain also play a critical role (-40 lbs just right there). The wind that Sunday was nowhere near 23mph. It wasn't a tail wind, but more a crosswind. Again, I do understand that a crosswind sometime helps more than a tail wind. I would say it was 10mph at most.

I did the math on the gearing (equivalent gear value and percentages are listed above) before I went to the mile. I followed the wheel setups n that sequence with the expectation that the last setup would be the quickest. Sunday did have a head wind, but still blew my previous times out of the water. The final speeds worked as expected/modeled, and I could not be more elated with my top speeds. There was a modded ZR1 (pulley and exhaust) that was running identical times to mine! That was a shocker.

These event sure are fun with an excess of wheel swapping, but let's just say that I took it for the team. Now the rest of you folks have objective proof to what works best in these standing mile events.

 

[Bobpantax]

We had a wonderful venue for standing mile events here at the Dade Collier Training and Transition Airport in the Everglades. The runway is 10,499 feet long and 150 feet wide. Unfortunately, Collier County decided to change its mind and determined that standing mile events would not be allowed. The last one was on 4/25/2010. It would be great if there was a series of VCA national Standing Mile Events limited to just Vipers. Perhaps some of the fighter pilot VCA members can convince their respective base commanders to allow the event. ( Preferably former SAC bases with the longer runways) The VCA has a significant event insurance policy and releases and waivers could be signed. Of course it would make the most sense to have at least one of the events in Florida. ( Isn't the base in Tampa an old SAC base with long runways?) There could also be an entry fee for the event that would go to a charity selected by the Base Commander.

 

[Nine Ball]

I was there in my 2009 Cadillac CTS-V. The gray one with HRE wheels, "BMW WHO" license plates. It went 167.1 mph. Surprised quite a few people, who didn't know what a CTS-V was. LOL. The car has a crank pulley and airbox, custom tune. 551 rwhp.

I saw your Viper, didn't realize it was the same car on different wheels. I thought it was two different cars, haha.

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[345s-bspinnin]

I was there in my 2009 Cadillac CTS-V. The gray one with HRE wheels, "BMW WHO" license plates. It went 167.1 mph. Surprised quite a few people, who didn't know what a CTS-V was. LOL. The car has a crank pulley and airbox, custom tune. 551 rwhp.

I saw your Viper, didn't realize it was the same car on different wheels. I thought it was two different cars, haha.

When I arrived in Beeville late Friday night, I looked outside the hotel window and saw a CTS-V with the BMW WHO plates. I did see it at the starting grid, but didn't realize that was you. I think Flatout or someone mentioned that you would be out there in your blown Z06, but I didn't see it either.

Your 167.1 mph is very healthy speed for that car. It am sure its blast to drive, especially without any of the drama or ruckus that plagues/pleases the rest of us. Congrats

 

[345s-bspinnin]

the car looked bad ass at the track!

forgot to include the effects of DA and wind conditions, could have easily been responsible for the speeds changing

I did a bit of searching for the conditions throughout Texas Mile weekend. The DA was about 2600 +/- 50 throughout the weekend.

Saturday's wind conditions were 5-13mph from S/SE (mostly crosswind), and Sunday's were 7-10 mph from E/ESE (crosswind with some headwind).

 

[345s-bspinnin]

Results are out. The TexasMile isn't updated yet, but results were emailed to the participants.

I listed my speed against some of the other participants' whose speed was relatively close to mine. Needless to say, mods aren't listed, but at least we can see a big picture of vehicles comparable in speed.

Best speeds shown below for each:

176.7 mph - '03 ARH Headers, A&C Tune (345s-bspinnin)

168.0 mph - '08 SRT Coupe
174.8 mph - '09 CTS-V
166.7 mph - '06 Z06
168.1 mph - '08 Z06
176.8 mph - '05 GSX R Hayabusa
161.1 mph - '06 Viper Convertible
159.5 mph - '06 Gallardo (stock, I spoke to owner)
185.4 mph - '99 RT/10 - Nitrous
162.3 mph - '09 ZR1
182.3 mph - '98 GTS Supercharged
173.5 mph - '09 GTR
172.8 mph - '11 ZR1
184.5 mph - '89 Honda CRX Hatch
177.7 mph - '10 ZR1
185.6 mph - '10 C6 SC
176.8 mph - '08 SRT Coupe
158.4 mph - '96 Viper
176.5 mph - '08 R8 - TT

 

[Nine Ball]

When I arrived in Beeville late Friday night, I looked outside the hotel window and saw a CTS-V with the BMW WHO plates. I did see it at the starting grid, but didn't realize that was you. I think Flatout or someone mentioned that you would be out there in your blown Z06, but I didn't see it either.

Your 167.1 mph is very healthy speed for that car. It am sure its blast to drive, especially without any of the drama or ruckus that plagues/pleases the rest of us. Congrats

Yes, I was supposed to run my supercharged Z06, was hoping for 190 in that car. I roasted the factory clutch the weekend before, thrashed all week to try and replace it... but the replacement clutch showed up a day too late. So, I ran the Cadillac instead. Here is how the Corvette was, and still is. I've been working out of town lately.

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[TrackAire]

Results are out. The TexasMile isn't updated yet, but results were emailed to the participants.

I listed my speed against some of the other participants' whose speed was relatively close to mine. Needless to say, mods aren't listed, but at least we can see a big picture of vehicles comparable in speed.

Best speeds shown below for each:

176.7 mph - '03 ARH Headers, A&C Tune (345s-bspinnin)

168.0 mph - '08 SRT Coupe
174.8 mph - '09 CTS-V
166.7 mph - '06 Z06
168.1 mph - '08 Z06
176.8 mph - '05 GSX R Hayabusa
161.1 mph - '06 Viper Convertible
159.5 mph - '06 Gallardo (stock, I spoke to owner)
185.4 mph - '99 RT/10 - Nitrous
162.3 mph - '09 ZR1
182.3 mph - '98 GTS Supercharged
173.5 mph - '09 GTR
172.8 mph - '11 ZR1
184.5 mph - '89 Honda CRX Hatch
177.7 mph - '10 ZR1
185.6 mph - '10 C6 SC
176.8 mph - '08 SRT Coupe
158.4 mph - '96 Viper
176.5 mph - '08 R8 - TT

I can't speak for the driving ability of the ZR1 owners, but you beat most of them or were right there, very well done.

So whether they were stock or not, you've got a very stong car.

Cheers,
George