Stock Exhaust Really a limit or not?

[Enitalp]

So i did a couple of modification on my car, went to the track and i loose 2 MPH and my car a for the instant a little slower.
That's the reverse of the wanted effect.

Beside other modification (K-Member, A-Arm, EH2O, QA1 All corner, Aluminium Driveshaft), i swapped my

OffRoad Prochamber + Corsa
for
Offroad JBA LTH + H + Stock exhaust.

I did 10 mins out of the shop with the JBA & Corsa and it was LOUUUUDDD. So i switched back to stock (i go to work with my stang).
Are they killing me or not ?
When my car was stock ,i put the corsa and after a few miles my car started to change the way it was shiftting, changing gear earlier, the car was not the same. I started to believe that the corsa could really give some HP, but is it a myth or not.
I never saw a real answer on that.

 

[jroc07gt]

im pretty sure you have to get tuned for lts

 

[Caleb@BamaChips]

The longtubes need to be tuned for. The front o2 sensors are getting a delayed reading sense they have been moved farther away and this must be adjusted for.

Caleb

 

[CandyRedGT]

I have JBA long tubes on my car,JBA catted H pipe and JBA mufflers. Had it tuned when they were installed. Now i have a
Saleen blower added to it!

 

[Enitalp]

The longtubes need to be tuned for. The front o2 sensors are getting a delayed reading sense they have been moved farther away and this must be adjusted for.

Caleb

Ok cool. I send you a mail as i have a bamachip tune

 

[Enitalp]

I have JBA long tubes on my car,JBA catted H pipe and JBA mufflers. Had it tuned when they were installed. Now i have a
Saleen blower added to it!

Soon Soon i will whine to.