High flow cats/catback, roe flash,3.55's 29HP less

[goldcup]

Title says it all in 2007 2001 GTS was dynoed at 438.57 hp/481.79 torque,at the time car had straight exhaust ,no cats or mufflers.
2008 car was dynoed at 409.93 hp/445.67 torque
Changes since 2007:
3.55 gears
3" highflow cats/catback exhaust
roe sct flash
An additional 3-5 thousand miles
One other note plugs and wires were changed before run in 2007 have not been changed since.
I won the prestigious KCVCA's runt of the litter award,and while I am honored I would prefer not to repeat

 

[billseast]

Did you use the same dyno?

 

[goldcup]

Same dyno and close to same weather conditions if that makes any difference.
Same operator also

 

[billseast]

Same dyno and close to same weather conditions if that makes any difference.
Same operator also

I'm at a loss this is weird

 

[goldcup]

Yeah I know my only concern is if there is something wrong with the car although it feels stronger than ever.The number doesnt do much for me as long as the car is running fine.

 

[johnk]

http://forums.viperclub.org/rt-10-gts-discussions/614177-loss-29-hp-upgrades.html

 

[MKB96Viper]

Goldcup,
I wouldn't panic. You have made two significant changes that could be causing the discrepancy but it will feel stronger.

The first was you changed gears - changing the gears will normally reduce the dyno numbers. From 3.07 to 3.55 you could naturally see 10-15hp loss but the car will feel much better and stronger because of the gears.

Secondly, your initial run was with no cats or mufflers. You have added both cats and mufflers which will again restrict the flow and cut back on the dyno numbers. That in itself could cause 15-20rwhp loss top end which accounts for the remaining number loss.

I believe these two factors could be your cause. Still check the plugs and make sure everything else looks good but I wouldn't panic yet. Could simply be the combination thats causing it. If you want to see what the exhaust will do then uncap the headers and make a pass and see if the 15-20hp comes back.

Just my 2 cents. Good luck.

God Bless,
Keith

 

[OKViper]

This wouldn't sound weird if someone posted - "I got rid of my cats and Muffler and went striaight pipe exhaust and gained 29HP"