dodge dyno's every viper

[viperpat]

My 08 viper stock dyono'd 508 HP i have been going back and forth with SRT and university dodge about the low HP numbers SRT says every viper is dyno'd before leaving the factory. they told me they have never had a viper hit 530 HP, they said they dyno around 498 to 510 and with parecitic loss at 18 percent this would be right on just over 600 at the motor. The problem is every one around the country are around 546 to as high as 560 HP what gives. every one can not be right. does any one in south florida want to put this to the test and dyno there car on one of the two dyno's i have dyno'd my car on, i will pay for the dyno run. i put a KN air filter and magna flow cat back exhaust on the car and now it makes 547 HP it is hard to stay at full throtle from first to second with out fishtailing all out of control but the air fuel on the dyno is at 10.5 should be at 13.1 dodge viper tech has ran tests with computer hooked up to the car and says its not runing rich and plugs look good so now im back to is my viper way down on power the only way to find out is to dyno another 08 viper on one of the two dyno's i dyno'd my car on, and see whats up can any one help

 

[Y2K5SRT]

First off, I don't know that they dyno every engine and actually think that is incorrect (I will double-check). They put every car on a rolling chassis drum and run it up to speed, but that is checking the full drivetrain and not measuring horsepower.

Second, what kind of dyno was used? If it was a Mustang dyno then your car is probably about right for a 2008. They generally come in considerably lower than a DynoJet dyno. I wouldn't get too upset at this point, nor be bugging SRT just yet. Double check your facts first, including your dyno numbers. It doesn't sound like your car is really that far off from what limited info we have here. Good luck!

 

[big-n-italian]

First off, I don't know that they dyno every engine and actually think that is incorrect (I will double-check). They put every car on a rolling chassis drum and run it up to speed, but that is checking the full drivetrain and not measuring horsepower.

correct. i didnt get the impression that this was a horsepower run.

You must be registered for see images

 

[Warfang]

First off, I don't know that they dyno every engine and actually think that is incorrect (I will double-check). They put every car on a rolling chassis drum and run it up to speed, but that is checking the full drivetrain and not measuring horsepower.

correct. i didnt get the impression that this was a horsepower run.

You must be registered for see images

awesome pic... any chance you have that in hi rez?

 

[big-n-italian]

thank you! many high-res pics of our plant tour can be found here:

Dodge Viper Historical Society Photo Gallery - Conner Avenue Assembly Plant Tour Jan 08

the pic seen above can be found on page 3.

 

[Paul Hawker]

Be careful relying on forum posting of Dyno numbers.

People tend to just post the highest number they obtain. Poorer numbered pulls are rarely mentioned.

Extremely rare to see two dyno's match each other. Even on the same dyno the numbers will vary from run to run.

If your engine makes enough HP to fishtail then things are probably all right ; >)

 

[Snakester]

18% driveline loss is high. Most people (who aren't just looking for higher numbers) use 13% as realistic drivetrain loss number. I'd say that the first test was simply measured a bit low, because gaining 40RWHP off an air filter and cat back is unlikely.

If I were you I would be happy that you are making around 630HP crank now and just enjoy the car.
Everything else other than that is just a distraction of what's important about having an amazing car like the Viper, which has little to do with the number results from one bad dyno test.

Dynos are very far from being an exact science, especially with different test machines, operators, and different weather. And having a rich A/F measurement is GOOD because it's safe. Remember that speed leans it out in real life (not on a dyno), so it's better to be on the slightly rich side.

 

[Nader]

I second that. the first run must have been low for one reason or another.

18% driveline loss is high. Most people (who aren't just looking for higher numbers) use 13% as realistic drivetrain loss number. I'd say that the first test was simply measured a bit low, because gaining 40RWHP off an air filter and cat back is unlikely.

If I were you I would be happy that you are making around 630HP crank now and just enjoy the car.
Everything else other than that is just a distraction of what's important about having an amazing car like the Viper, which has little to do with the number results from one bad dyno test.

Dynos are very far from being an exact science, especially with different test machines, operators, and different weather. And having a rich A/F measurement is GOOD because it's safe. Remember that speed leans it out in real life (not on a dyno), so it's better to be on the slightly rich side.

 

[Roadrunner]

The rolls at Connor Ave keeps the revs below about 4k... leaving the breakin up to the customer... any higher would be a bad idea until the rings seat. If you are running the piss out of your engine prior to break in you will not achieve maximum potential as the rings won't seal as well as they do with proper break-in. (As we've heard many times from Herb Helbig, etc.)

Intake Air Temperature is key to power delivery as well... you'll note dyno runs in the morning with cooler air will be MUCH stronger than afternoon runs at peak heat. Make sure the dyno is running a large fan to keep the heat down for the run.

The A/F under full power can actually get to as low as 9:1 if the environmental conditions call for it. Leaner is meaner, but you'll be punishing the pistons, exhaust valves, and cats. There is also a timed enrichment that will kick in if sustained high power operation is commenced.

Also make sure you have good fuel... low octane fuel will result in extra fuel being added and spark being taken out. Does your station have Gas or Gasohol? (Like E10) Many do... the alcohol acts as an octance booster, but you loose fuel energy by volume as well.

 

[ViperGal]

or you need a quaife

If your engine makes enough HP to fishtail then things are probably all right ; >)

 

[FLL-B/W-GTS]

I will take you up on your offer.However I only have 122 miles on my 08 now.I live in Fort Lauderdale.

 

[ivanrho]

I also suggest that you call Doug Levin at 954-434-9356. His shop is located just west of the Turnpike, off Griffin. He can give you some additional insite on what your car should or should not be making since he's always tuning these cars. And there's a Dyno about 15 minutes from his shop.

The problem now isn't that you're not making enough HP....it's transfering the power to the pavement without spinning out! Have fun.

 

[weightlifter123]

I'd dyno mine with you too if I lived closer. I have 1100 miles
on mine now. Of course 950 of it was driving it home from Woodhouse Dodge. Mine sticks like glue and doesn't break traction either in 1st or 2nd. By reading all the posts where folks are loosing control and crashing I just assumed that the car would spin out real easily. But puts power to the ground very well. If your fishtailing in 1st to 2nd your making more power than I am.

 

[Bobpantax]

1.508 HP on a Mustang Dyno equals 635 HP at the flywheel assuming 12% driveline loss. 508 HP on a Dynojet dyno equals 578 HP at the flywheel assuming 12% driveline loss. Which kind of dyno was it?

2. Who was "driving" the car when it was on the dyno and did he or she know what they were doing?

3. What shop dynoed the car and how well maintained and calibrated is their dyno?

4. You are testing the car too soon. wait until after the break in period is over. I used Fynetune next to Tamiami Airport. They have a top of the line dyno.

5. I do not think that you have enough credible data yet to determine whether the problem even exists.

6. Since no one is "always tuning" 2008 Vipers, I would be very careful about trying to alter the programming. The 2008 has very complex Venom programming and, to my knowledge, no one is doing anything to alter it. Be careful. Any attempt to alter the programming may void your warranty and harm your engine. Use the search feature on these forums. The mods to the '08 Viper that have been done to date are basically limited to Belanger headers and higher flow air filters.