Stock SRT dyno - 558 rwhp and 515 torque

mnc2886

Enthusiast
Joined
Sep 1, 2010
Posts
1,018
Reaction score
0
Location
Houston, TX
Didn't people throw a fit when the Edmund's dyno test only got 558 to the wheels and Ralph came on Twitter and said if you close the hood, it would've been a more accurate 580? Hmm.......
 

SilveRT8

Enthusiast
Joined
May 9, 2008
Posts
1,288
Reaction score
0
Location
Boucherville, Quebec, Canada
If dynoed in fourth gear with the same 1.00:1 ratio, shouldn't the new 3.55 gears ( 16% steeper) show less HP vs the Gen IV with 3.07 rear gears ?
My Gen IV showed 545 hp and 504 tq stock, I'm no expert on this but I find these numbers to be about right.
 

Jack B

Enthusiast
Joined
Nov 5, 2000
Posts
3,485
Reaction score
0
Location
NE Ohio
The losses are virtually inconsequential

If dynoed in fourth gear with the same 1.00:1 ratio, shouldn't the new 3.55 gears ( 16% steeper) show less HP vs the Gen IV with 3.07 rear gears ?
My Gen IV showed 545 hp and 504 tq stock, I'm no expert on this but I find these numbers to be about right.
 

ACRucrazy

Enthusiast
Joined
Jul 14, 2009
Posts
1,894
Reaction score
1
I Dynod my 08 with 4600 miles on it 2 weeks ago. Hight flow cats and corsa cat back.
558/525
 

DMan

Enthusiast
Joined
Aug 30, 2006
Posts
1,855
Reaction score
0
Location
Maryland
Seems inline with the 640 and the estimated 12-15% driveline loss. Some might be disappointed but it's what's to be expected. The gen5 isn't a car for HP bragging. It's a track car. I mean my GT500 is rated at 662 and dyno'd at 602 at the wheels, which is common so they're a strong 662, the gen5 is probably a finely tuned exact 640. But I'm sure future options will raise the number for those looking for more brutality. Thanks for sharing the vid.
 

ACRucrazy

Enthusiast
Joined
Jul 14, 2009
Posts
1,894
Reaction score
1
I bet we will see some higher numbers after others get their hands on them with some miles on the clock. But again the dyno is a tool, there will be differences. Would be nice to see a 570 stock IMO.
 

Torquemonster

Enthusiast
Joined
Jan 14, 2003
Posts
2,174
Reaction score
0
Location
Auckland, New Zealand
That's bang on for 640hp. We are bound to see higher once they get a few miles on them. Of course we're also bound to see higher numbers on more friendly dynos too, but trap speeds tell what you are really making.
 
OP
OP
N

Nine Ball

Enthusiast
Joined
Aug 30, 2007
Posts
3,411
Reaction score
10
Location
Houston, TX
Yes, rear gearing ratio DOES affect dyno numbers. I've done and witnessed this many times, on many cars. Going higher numerically in gear ratio (3.07 up to 3.55, in this case) will certainly show a lower hp with the higher 3.55 gear set. In the GM world, it was common to go from 3.42 up to 3.73, and that would usually cost about 10-12 rwhp on a dynojet. But, the car would run quicker with the new gears. Dynos don't mean much, only before/after comparisons on the same dyno mean something.
 

hou99gts

Enthusiast
Joined
Jun 25, 2007
Posts
1,244
Reaction score
0
Location
Rosharon, TX
My 09 did 556/531 in Austin with 1600 miles on the clock Tony, I hope there is a big difference in the dynos. It wouldn't be a direct comparision, but maybe I should put mine on Hennessey's dyno to compare (almost at 11k miles now).
 

bluestreak

Enthusiast
Joined
Dec 15, 2005
Posts
869
Reaction score
0
Keep in mind also that it will benefit Hennessey more to show a lower baseline and higher output after the mods. So expect to see the fan much closer to the car as well. This IS Hennessey we are talking about.
 

Jack B

Enthusiast
Joined
Nov 5, 2000
Posts
3,485
Reaction score
0
Location
NE Ohio
It is inconsequential, I have had 3.07, 3.33 and 3.55, they all dyno within 5 hp. Tryi ng to push a tire/wheel combo with a high moment of inertia will mean more. You can tie the car down in a way that skew the results even further.

Yes, rear gearing ratio DOES affect dyno numbers. I've done and witnessed this many times, on many cars. Going higher numerically in gear ratio (3.07 up to 3.55, in this case) will certainly show a lower hp with the higher 3.55 gear set. In the GM world, it was common to go from 3.42 up to 3.73, and that would usually cost about 10-12 rwhp on a dynojet. But, the car would run quicker with the new gears. Dynos don't mean much, only before/after comparisons on the same dyno mean something.
 

ACRucrazy

Enthusiast
Joined
Jul 14, 2009
Posts
1,894
Reaction score
1
Hennessy put one on the Dyno back in Jan also for Road & Track. They didn't use any cooling fans and the engine was heat soaked.
Ralph said something about the no fans, then the Youtube video was removed the following day. It put down about 527 & 499 to the tire if I recall.

This latest Dyno at Hennessey (video in the first post) was the same HP as the Edmunds car put on the rollers in Jan that caused all the noise online about it being a low number when the "stock" ZR1 hit the dyno at 580 or whatever.

http://www.youtube.com/watch?feature=player_embedded&v=bXcA6Q0M80w
 

V10TT

Enthusiast
Joined
Oct 15, 2001
Posts
452
Reaction score
0
Location
Miami Fl
Keep in mind those are STD. corrected numbers not SAE. Around a 3% difference.
 

SnakeBitten

Enthusiast
Joined
May 18, 2001
Posts
2,550
Reaction score
0
That's bang on for 640hp. We are bound to see higher once they get a few miles on them. Of course we're also bound to see higher numbers on more friendly dynos too, but trap speeds tell what you are really making.

Trap speeds is where its at I agree. We have yet to see any Gen V Viper hit closer to 130mph in the 1/4 like the old Gen IV's did so I don't know if that's an indication that the car isnt working as well in the straight lines as the old car. We know its better in the twisties. Maybe its just too soon to speculate either way until we get a bunch more 1/4 passes by the owners.
 
Top