Texas Mile: 191.5mph - All motor

345s-bspinnin

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No boost, no N2O, no new 5th gear, no excuses. Car had a few minor issues (discussed below), but I was able to do enough runs to exceed my 190mph naturally aspirated goal.


Here are some details and lessons learned for my fellow viper friends:

So I attended the Texas Mile this last weekend in search of a 190+ run with my newly modded Heads/Cam Car. Viper is a Gen III vert with a Greg Good Heads Cam Package and an A&C Tune laying down 614whp/590wtq on a moderate 12.8:1 AF tune. More details of my build can be found in my Heads/Cam Thread (CLICK ME). Car is now making 643whp/606 with throttle body and air filters, but I was not running with the throttle body or cold air filter setup at the TX Mile.

That 191.5mph did not come easy. TX Mile has imposed a new licensing process. You must meet safety requirements and move up classes before they let you run wild. I spent all Saturday simply doing “class runs” as wait time was 3-4 hrs between runs. On Sunday I set off to attempt my first 190+ run and noticed that my AF meter went into the red (lean) once I hit 4th gear. Needless to say, I let off. It was very peculiar since none of my dyno sessions, street logs, or previous runs showed such a thing. We racked our brains and concluded that the imperfect Texas Mile runway (rolling bumps) combined with a 1/4 tank of fuel were causing the fuel basket to be depleted by a thirsty engine as the fuel sloshed around (OEM Fuel system). I drove the car out of the airfield grounds and topped it off (93 oct pump fuel). I came back in and the mystery leaning was solved.

My first actual successful full WOT run yielded a 187.8 mph, but I came back to the pit with a light haze of white smoke from under the hood :(. We took a peek and noticed the passenger heat shield sprinkled with oil. It turns out that s ome oil was seeping from under my roller rocker spacer. The root of the issue was a few loose valve cover bolts that hold those aftermarket pesky wire separators (bolt through design). For some reason (heat softening plastic?) they had come loose. We tightened those wire separator bolts, cleaned up the sprinkled oil, and lined it up again. By this point, it was already a warm Sunday mid-afternoon. I drove it aggressively and hit the rev limiter on the 3/4 shift, but still managed to pull a 191.5 mph. I hot lapped it, and backed it up with a 190.5 mph pass before packing up and going home. By the way, did you guys know that the top start getting really windy after 190mph? I actually saw sunlight between the soft top and the windshield gasket area. I guess I should tape it down next time.

My fastest pass at mid-afternoon on Sunday had a DA of 1900 ft with a 7-9mph head wind. Morning conditions were much more favorable with DA at 600ft, and a 5 mph tail wind, but I unfortunately was staying off the TX Mile grounds and didn’t have anyone to come and save me a spot at 5 am :|

I spent a lot of time in the pits, and unfortunately don’t have too many general TX Mile ’12 pics. ARTs 1800 Viper ran on Friday and Saturday, and did achieve some respectable speeds. There were a few Vipers at the event. I spoke with Kyle “FrogMsr” who I believed ran a few 170.x on his modded Gen IV. There was a Gen III that ran 164mph with a K&N only. A black Gen II was running low 160s. I also witnessed the Fort GTs 257.7mph record run, followed by LMRs Camaro doing 253.XX.

I have so some data for the bench racers. The GPS (10Hz rate) seemed to lag, but this is the data I collected. You can see the big picture in the charts below. Here is the tabulated data:

Speed | Time (sec.)
0-60 | 3.8
0-100 | 6.7
0-130 | 10.5
0-150 | 15.1
60-130 | 6.7 (2 shifts)

Dist. E.T. MPH
1/8 6.7 98.2
1/4 11.3 134.6
1/2 17.8 159.5
3/4 23.1 178.6
1 27.8 191.5


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Short video:

http://youtu.be/0fsIRiScANQ
 

Bobpantax

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Great result. How much is the car lowered? What wheels and tires? What differential?
 

Nixon's SRT

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Wow thats Awesome. what else do you have done to the car? What rear end, t-56?
 
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345s-bspinnin

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Damn, that runway is pretty bumpy. Nice runs!!

Texas Mile's previous airstrip was significantly better than this new location. I swear I spun the the tires on the top of 4th. Look at my video closely and you will see my rpm jump almost 500rpm (34 sec. into the video).

Those bumps were also the reason I was leaning out.
 
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345s-bspinnin

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Wow thats Awesome. what else do you have done to the car? What rear end, t-56?

Heads and cam info on this thread: http://forums.viperclub.org/threads/652307-643whp-606wtq-Greg-Good-Heads-Cam-with-A-amp-C-Tune


Great result. How much is the car lowered? What wheels and tires? What differential?

Stock T-56, stock clutch, and stock rear end. Car was lowered 2.5 front, 2.0 rear, but the bumps were way to bad so I brought it back up about an 1 inch all the way around. Ran the stock sized wheels for must runs. My fastest speed occurred while using a shorty tire (305/30-18) in the rear just like last year.
 
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FLATOUT

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Saw Greg post your speed on the other site and figured you were having fun. Man trapping 134 in the 1/4 at 1900 DA is flying for a gen 3 NA. That would be a great trap speed for a Paxton gen 3. Your results further my ideology that heads and cam is one of the best ways to mod a gen 3.

Congrats buddy!
 

FLATOUT

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I would love to see what you could do with the revised 5th ratio. Do you know if many 200 mph setups are close to your 1/8 mph?
 
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345s-bspinnin

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I would love to see what you could do with the revised 5th ratio. Do you know if many 200 mph setups are close to your 1/8 mph?

A revised 5th gear "could" help. I did the math, and am convinced that the change is simply not worth it (neither financially, nor performance wise). With my current setup, I was at redline in 5th gear by the end of the mile. My poor mans shorty tire setup provides almost an exact equivalent as the new 5th gear final ratio with stock sized tire. The drawback of course is that I am in 5th from 147mph, instead of 160mph. But, with my setup I have the reduced weight (25lbs per rear wheel/tire) and mechanical gearing advantage on the previous 4 gears. At the end of the day, my analysis shows virtually equivalent end results. As much I would like a smooth shifting 6060, I won't spend $5k for a transmission/clutch change unless my T56 dies.

Texas mile only measures at the 1/2 and at the full mile. My 1/8 data is off my log, and frankly is slow. I was pulling those 1/8 speeds with my headers/tune setup. This surface is not prepped. I had to feather both 1st and 2nd. Most, if not all cars with 600+whp struggle with traction.
 

Bobpantax

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Very well thought out. I think that the way your power is distributed per the dyno graph on your other thread also helped quite a bit. Thanks for sharing the data.

A revised 5th gear "could" help. I did the math, and am convinced that the change is simply not worth it (neither financially, nor performance wise). With my current setup, I was at redline in 5th gear by the end of the mile. My poor mans shorty tire setup provides almost an exact equivalent as the new 5th gear final ratio with stock sized tire. The drawback of course is that I am in 5th from 147mph, instead of 160mph. But, with my setup I have the reduced weight (25lbs per rear wheel/tire) and mechanical gearing advantage on the previous 4 gears. At the end of the day, my analysis shows virtually equivalent end results. As much I would like a smooth shifting 6060, I won't spend $5k for a transmission/clutch change unless my T56 dies.

Texas mile only measures at the 1/2 and at the full mile. My 1/8 data is off my log, and frankly is slow. I was pulling those 1/8 speeds with my headers/tune setup. This surface is not prepped. I had to feather both 1st and 2nd. Most, if not all cars with 600+whp struggle with traction.
 

swexlin

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What is the theoretical top speed on a stock Gen3? I guess you would need more room than 1 mile to achieve it, correct? Not that my fat-a** is ever gonna get near that top speed!

At any rate, that is one nice setup you have there!
 
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FrgMstr

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Great talking to ya 345s-bspinnin! Busting 190mph in a NA car is a big deal. Big kudos and congrats your way bro!

I did 170.9 in my 2008. Catbacks is about it. :) Not too shabby. Maybe shoot for 180MPH next year, but that will not be cheap. :D
 

DaDood

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What camera did you use for the external shot? How did you deal with the wind noise? It actually sounded pretty good considering how fast you were going.
 
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FrgMstr

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nice! man that track is bumpy.

It is not really "scary" till after the 1 mile point. But after you do it once and you know it is coming, not such a big deal. Of course I went across it 20mph slower. Made 6 runs though.

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345s-bspinnin

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What camera did you use for the external shot? How did you deal with the wind noise? It actually sounded pretty good considering how fast you were going.

That external shot was done using a GoPro Hero2 HD. It had the rear "non-waterproof" panel. The new Hero2 does a much better job of suppressing wind noise. The interior shot was done with a standard GoPro affixed to my helmet.
 
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345s-bspinnin

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Man, that was bumpy at the end. Crazy to have to go over bumps like that going 190MPH... Nice run!!!

I agree the FrgMstr. The bumps at the end are bad, but you expect them. It was suggested to me that I stay on the throttle until after that transition/bump which is about 200 ft. after the 1-Mile marker. On my first fast run, I hit that bump hard and my body got off the seat enough that I actually tapped the soft top with my helmet. Not only that, my rear right tire rubbed on the fender lining :omg:. For the next round, I tightened my six-point harness and raised the car about 1". Those adjustments worked well for me.

I still think that the rolling humps between the 1/4 and 1/2 are worse, especially since you are accelerating and rowing through the gears. When the event shutdown, I drove the track with my SUV and Viper-on- trailer just to show my friends (pit crew) how bad the bumps were. Of course, the bumps don't feel bad at all when you going 40mph on a Cadillac, but you could see rubber laid down that part of the track. Many high horsepower cars were spinning their tires right in that area.
 

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