Dyno Sheet - HP and Torque Question

[native1]

Originally Posted by Jimbocobra

native1,
No problem hijacking the post - even though I have DYNO ENVY, you indirectly may have answered something that I asked in another post. Is the only difference the side pipes between the red and blue on the second page of you dyno sheet only due to the change in pipes - without other modifications? I did notice they were not done on the same day. I have been trying to get accurate information on how much hp is lost with the BDR pipes. If you have 570 gross hp and you are picking up 15-20hp (I'll split the diff and say 18hp), then the stock Backdraft pipe lose about 3% to 3.5%. Does that sound right to you?
In my case, with 450hp, I'd net 13hp, seems like an expensive way to pick up power. Your thoughts?

Yes, that is correct. The second dyno sheet is the difference between the stock BDR pipes and the new ones. No other modifications were done in between the 2 dyno pulls. I was trying to find out for myself...

The side pipes are not totally custom. I simply ordered new glass packs from Stainless Specialities and had them welded in place of the restrictive BDR glass packs. I am sure you have looked inside your pipes and noticed that the exhaust is routed between 2 small pipes inside the glass packs. The new glass packs are straight through. The project cost me around 800 bucks in the end. I could notice the improvement through the seat of my pants. It also sounds so much better. It sounds a lot deeper but not a lot louder.

Just another note. I tried a different air filter "bigger" with the pleats on the top of the filter. I did it in between pulls for an experiment... Picked up 9hp at the wheels. I don't run that filter because I don't like the way it looks but I thought that was a lot for only an air filter.... "first dyno sheet"

Also I have read that Mustang dyno's are not as optimistic as the Dyno Jet dyno's... So don't feal too bad.