New viper owner and stock dyno #'s

[RStoker]

New viper owner and stock dyno #\'s

I picked up a 1998 red GTS two weeks ago and decided to get a base dyno of my stock numbers before I start any mods. The results were 388 rwhp and 440 rwtq. The rwhp number seems kind of low to me. The car has right at 10,000 miles on it and is completely stock even has the oem paper air filters. Are these numbers in line with a stock 98 GTS? I'm also looking into getting a Roe supercharger but I'm not sure if he has any in stock. So far the car has been a blast.

 

[Ron]

Re: New viper owner and stock dyno #\'s

It's low. Should be at least in the low 400's. Mine with K&N's & smooth tubes only dyno'd at 435 RWHP.

Should look at plugs, wires & air filters for starters. Also, make sure you have full throttle plate opening when flooring the pedal. Many Vipers have stretched a accelerator cable and /or bunched up floor mats that prevent full throttle.

 

[RedGTS]

Re: New viper owner and stock dyno #\'s

Welcome to Viperdom. The hp is somewhat low but there are a lot of variables that can affect dyno results. How many pulls did you make? One variable is the PCM really needs to adapt to full throttle conditions (which is why people recommend doing a few full throttle bursts on the way to the dyno), and my hp has always gone up considerably on the second pull. Other possible factors: floor mat preventing full throttle; incorrect throttle cable or throttle body adjustment preventing opening tb's fully; were those numbers corrected for atmospheric conditions?; how much pressure in the rear tires?

Do a search and you may find some more.

 

[GR8_ASP]

Re: New viper owner and stock dyno #\'s

and of course to indicate which type of Dyno.

 

[dwhitt]

Re: New viper owner and stock dyno #\'s

My '99 RT only did 362 rwhp - promptly sold it after that

too scared to check my '02 GTS -

 

[Russ M]

Re: New viper owner and stock dyno #\'s

I bet its just a poorly run dyno, go elsewhere and check again. And it would not hurt to put in some new spark plugs and wires.

Also where was this test done? Altitude and weather can and will have a very big influence on results. And were these numbers corrected?

 

[RStoker]

Re: New viper owner and stock dyno #\'s

The dyno was down here in Houston and the numbers are sae corrected. For some reason during the dyno the rpm needle on the dyno computer kept jumping around and they couldn't get it to stop or figure out why it was doing that. The psi in my tires right now I believe is 31 psi all the way around. The dyno was a DynoJet. The place that dyno'd the car for me deals mostly with Mustangs and a few F-bodies. Funny thing though everybody there made a comment about the rotten egg smell that the cats produced after the run. BTW, three pass were made first was lowest at 385 rwhp and last was highest at 388 rwhp with about a ten minute break in between.

 

[KenH]

Re: New viper owner and stock dyno #\'s

If the dyno is a Mustang Dyno, those numbers would be good. If it was a DynoJet, they would be low.

Most people believe the Mustang dyno reads low and the Dynojet is correct. However the numbers the Mustang gives when converted to HP using a reasonable driveline loss factor like 13%, actually usually comes out pretty close to the stated factory HP while the Dynojet always comes out more than the advertised factory HP. That's why everyone in the world thinks their particular type of car was underrated by the factor including us Viper owners.

When I first dyno'd my car, it was on a Mustang dyno and my numbers sucked. When I went to a Viper dyno day at a Dynojet facility, my numbers were not only much better, but I had one of the strongest cars there. I felt much better

--- Ken