My 2002 Viper GTS was built and tuned by Underground Racing of Charlotte, North Carolina after another tuner pretty much did everything wrong and damaged the interior of my car...and charged me $28,000 and took well over a year to do so. (Report on Macedo Motorsports of Orlando Florida area)

Underground Racing was the exact opposite - professional, competent, quick, honest. I felt they were more like family by the time I flew down to pick up my Viper. I really can't say enough good things about my Underground racing experience.

My car runs great as promised and could easily be used as a daily driver. Other than the 1,000 RPM shakey idle and much louder than stock exhaust (has Random Tech Metal Substrate Catalytic Converters and will pass EPA test), my Viper gets 9-13 MPG street and 20 MPG highway.

Go to undergroundracing.com and click on Videos and then click the down button to get to 1000 rwhp SUPERCHARGED DYNO to see video of dyno test.

Kenny

 

how's the handling and the spin is it a big issue in the low gears ... ?

 

very hot. congrats.

 

I run Michelin PS2 tires, with 295 wide instead of the stock 275 wide tires on the front to counteract the extra weight of the supercharger. I wish the PS2 rear tires came in a wider size...I could really use it. LOL I run stock size 335 wide tires at the rear. All the wheels are stock = I like the look of the stock Viper wheels. The Michelin PS Cup tire does come in a 345 wide size, but it has very little tread depth and I will drive in the rain, so I went with PS2 tirres all around instead.

I had a Roe Supercharger system on my Viper before. It's a twin screw supercharger that gets full boost around 2,000 RPM. This made the big 488 c.i. Viper V10 engine perfect except it couldn't go much above 700 rwhp due to maximum air flow is reached at that level. I had a little over 600 rwhp when I was lied to about making "At least the high 700's in power..." by Larry Macedo of Macedo Motorsports of Orlando, Florida. He did an incredible incompetent job in working on my car and caused much damage to it as well.

The Underground Racing Paxton system gets a lot of help from the Jeff Morys Striker heads - heads designed and build by Jeff Morys that flow significantly better than even ported & polished stock Viper heads. Underground Racing of Charlotte, North Carolina, inspected the engine and had to replace almost everything Larry Macedo had done to it - go to Google search for larrymacedoms for a review of Larry Macedo's work and customer service, complete with many photos.

Underground Racing was a dream to work with - they delivered a lot more than they promised. A top notch experience. I highly reccomend them.

The Paxton system delivers around 500 rwhp at 4000 RPM, but gains another 500 rwhp going from 4,000 RPM to 5,600 RPM. It's a centrifugal supercharger and full boost comes on as the RPM goes up. The low end is very close to the perfect low end of my Viper before with the Roe twinn screw supercharger and the top end will take several years to learn how to master - very carefully. This isn't a car where you can just step on the go pedal and aim it straight - you must be in total control the whole time. That will take a lot more seat time.

Engine size now is 510 c.i. (stroked).

 

amazing Underground are building up a good name with there great work with customers i can see there's allot of people very satisfied Dealing with them ..

 

I am hearing more and more of these stories about UR. They truely are making a good name for themselves.