PBIR today with Viper

[Bobpantax]

I decided to test the Viper at a private track rental today. It has never been on a drag strip. Weather: Humidity greater than 60%. Temperature 80 but felt hotter. The track is about 110 miles from my house. I drove there. I did not let the car cool down. I hot lapped it. I failed to reduce the pressure in my rear tires. When I left the house they were at 32. ( I was running new Nitto drag radials). I know - ignorant of me. But even more absurd was leaving my suspension settings on road course so that the suspension was as stiff as a board.

So, having never used the car for drag racing, with heat soak ,and some traction issues, here is what happened:

9:38 AM - 11.974/121.78
9:42 AM - 11.656/123.76
9:47 AM - 11.653/124.79
9:51 AM - 11.582/121.33
10:02 AM - 11.427/124.55
10.08 AM - 11.688/122.3

Then I let it cool a bit and ran it at 10:52 AM - 11.415/122.99 with a 7.46 1/8th at 97.87.

My two best 60 foot times were 1.73 for the 11.427 run and 1.798 for the 11.582 run. The 60 for the 11.415 run was 1.849.

The main traction issue was not at launch. It was in the shift from second to third and the shift from third to fourth. I think that because of the high air pressure in my rear tires and the road course suspension settings I was not getting proper weight transfer. I had to make some subtle corrections to keep my rear in line. On each run it was slipping around a little bit on these two shifts.

With better weather, no heat soak, proper tire pressure and proper suspension settings, I think the car easily has a sub 11 second run in it. At least I learned a bit about how to launch it properly - not an easy task. The BOG is like a curse. I found that leaving at about 1750 RPM produced the best result. I did experience some wheel hop on a number of runs. I think that too may have been, in part from the high tire pressure.

It was a worthwhile learning experience but the bottom line is that my car is really a road racer and standing mile racer which is also used for cruising. It is not a drag racer. But, with that said, if I wanted to convert it, after today, I know what I would have to do. LOL.

 

[Timnineside]

Great numbers! Any mods to your 06?

 

[Bobpantax]

Thank you.

Paxton supercharger with DC custom calibration ( 685 RWHP a few years ago). Woodhouse engine and transmission mounts. Competition Coupe oil pan with swing arm pick up. Gen IV OEM hood. MGW shift mechanism with first strike racing knob. In 2010, John Donato upgraded the Gen IV transmission ( originally installed in 2008) - shot ball peened parts, upgraded second gear synchro pack, .8 5th and .63 6th gears. OS Giken performance differential inside new Gen IV rear end assembly( installed in 2010). Eibach and Moton suspension ( corner balanced and lowered 3/4" front, 1/2" rear). Corsa cat back exhaust. Racelogic Traction Control ( Installed in 2008.). Gen IV ACR front sway bar(installed 2013). ACR wheels. The inside door grab handles and the shifter bezel have been powder coated black. Only certified ( by Bob Woodhouse) Woodhouse Performance Edition Viper. Plenum signed by Herb Helbig when it was on the assembly line. Owner's Manual signed by many significant Chrysler/Dodge Viper people.


To make it a drag racer I would initially need to change out the rear diff to a different ratio than stock; adjust my suspension properly;and, lower the air pressure in my rear tires. I would also need more robust half shafts ( which I may get anyway). Other mods would be a different clutch and a lighter flywheel. But I am not going to make it into a drag racer. It is a purpose modded vehicle and drag racing is not its purpose.

 

[Green viper 1]

I would think with that much power numbers would be alot better, I was thinking car was stock with those numbers

 

[Bobpantax]

Numbers are not enough. You have to get the power to the ground. And heat soak in a supercharged engine significantly reduces the number shown above. I would guess that today, after the drive up there at pretty good speeds ( in some instances Mexico speed), it was heat soaked enough to be producing probably about 100 HP less. And that after my hot laps it produced even less power. The improvement in the E.T. is from my learning curve. I am a pretty quick study. Even as the power dropped, as you can see, the E.T.s improved until the 10:08 AM run where it was just too heat soaked to continue.

Traction issues were the rest. On a cold, low humidity day when it is fresh, it accelerates much more quickly. At one of the standing mile events it made an 11.1 in the first quarter mile and I was not even focusing on the quarter mile. It was about 60 degrees with low humidity and the car was fresh.

 

[viper04]

Bob you may need more track time or seat time ( drag raceing). The number are close to what mildly mod viper do, but congrats none the less.

 

[Bobpantax]

Hi. You are correct. The numbers are not good but I have layed out the reasons for that above. If the car was fresh and not very heat soaked, the suspension adjusted correctly and the Nittos were at the proper air level, the numbers would have been far better. The seat time would come in to get the 60 foot down to 1.55 or so. The shifts were crisp. But, as stated above, the car is not for drag racing. Note the stats in my signature.

 

[eucharistos]

congrats on your runs bob , i noticed your improving times right off and wish i was such a quick study. did your Racelogic Traction Control help or not?

 

[Bobpantax]

I had to turn it off. Burnouts are not possible with it on. Some have their Racelogic set up so the RPMs are maintained at shift points. I do not have that function. Back in the 60s I used to shift with the pedal to the metal all the way through the gears. Now I respect my legs too much to do that. LOL. But, I can still shift quickly with the MGW shift mechanism allowing certainty in the shifting. There is no way I would have been able to shift as quickly with the same level of confidence with the stock shift mechanism.

 

[anton28]

Times seem a bit high. I was running 11:4s in my 440rwhp c6 vette, All day consitently on 20inch rear tires and 37psi. Crappy 60 foottimes 1.8 1.9. Supercharged with exhaust. Root style magi blower. All else stock. Never tuned besides the bs tune that came with the blower. I think you might have a tunning issue. Maybe the car is leaning out in the top end.

 

[Nader]

Bob your car has some sick mods but I am with you regarding the heat soak issue. That trap speed should be in the high 120 to low 130 range with that kind of power.

 

[eucharistos]

thanks for the reply about the RTC

......Back in the 60s I used to shift with the pedal to the metal all the way through the gears. Now I respect my legs too much to do that. LOL. .....

back in the days of double pumper 4 barrels and an inverted breather cover, (i remember them but in the 70's)

.....But, I can still shift quickly with the MGW shift mechanism allowing certainty in the shifting. There is no way I would have been able to shift as quickly with the same level of confidence with the stock shift mechanism.

yeah i think my stock shifter makes me row slower, but i can live with it for most of my driving

 

[Bobpantax]

I am glad you enjoyed the day. Note my comments above. The calibration is fine. If it leaned out, it would have been a very bad day. If the engine gets too lean, it can go boom. The other factors I mention account for the less than stellar E.T.s. The main purpose was just to test the car in an environment different from its intended purpose. It was its first, and only time, on a drag strip and I do not race on the street. I learned what I needed to learn which is shown by the decreasing E.T.s as power continued to drop from heat soak. Remember, I ran it 110 miles to get there and then hot lapped it. No cool downs.

Your car is strong. I also bet that you are running better gearing. My 3.07 differential is fine for what I use the car for but the car needs a 3.55 to be effective in drag racing. The Maggie blowers do a great job. I used to have a Gen II Viper GTS with a Roe 8 pound twin screw blower. The power came in at 1800 RPM. It was a beast and I think it probably would have beaten my current car in the quarter mile. The Paxton system in its stock kit iteration produces power above around 3300 RPM. It is a more civilized system. The Challenger in my signature below has a Techco twin screw and an automatic with a 3.92 AMG differential. It is alot of fun. The Jeep below is the most fun because it is a sleeper. Enjoy your car!

Times seem a bit high. I was running 11:4s in my 440rwhp c6 vette, All day consitently on 20inch rear tires and 37psi. Crappy 60 foottimes 1.8 1.9. Supercharged with exhaust. Root style magi blower. All else stock. Never tuned besides the bs tune that came with the blower. I think you might have a tunning issue. Maybe the car is leaning out in the top end.

 

[Bobpantax]

Here is a video of a run. This is the 5th run of six between 9:38 AM & 10:08 AM. Suspension was on road course settings. Weight transfer limited. Tire pressure too high. ( I forgot to lower it. ) I lost traction at the start and in the shifts from 2nd to 3rd and 3rd to 4th. With a cool engine; proper suspension settings and proper tire pressure, I think the car has a 10.8 or so in it. But this was just a one time experiment.

http://www.youtube.com/watch?v=lNvVmMPfScQ

And here is a video of the dyno run from 2009. I did not realize there was one until tonight.

2006 Dodge Viper SRT10 Paxton Supercharged Dyno - YouTube

 

[BlackOutBoxing]

Its all about trap speed! You need high 120mph or low 130's to break 10's. I do as well think with that power you should be mid 130's. I did 11. 1 at 130mph with a 1.996 60 foot. I did a 1.60 60 foot on my next run but missed 3rd. That would hav been my 10 sec run. My car dynoed only 507 rwhp on a mustang dyno. Tuner said his dyno was 13% low or something? Maybe im 600 or close. Low or not im not near your hp. Somethings up. Youll figure it out and run mid 10s all day

 

[Bobpantax]

Between heat soak and traction issues, I was pleased at the run. By the fifth run, I would guess that between engine heat soak and my cats being red hot, I was down big time on power. (I have stock cats.). As I posted above, this was a one time experiment with a car set up for road course, standing mile and cruising. My Motons were set on 5/6 (compression/bump) during these runs. Those settings do not allow proper weight transfer for drag racing and, along with a tire pressure of about 38 instead of 26, were most probably responsible for the traction loss.

 

[Viper Grenade]

You do know your cars ET and trap speed are not any better than a bolt-on N/A car right?

 

[Bobpantax]

On that day, with the same heat soak and traction issues, a bolt on car would not have obtained the same numbers. Each run by each car is a separate occurrence subject to the variables that are applicable at the time of the run.