Ve SS exhaust power loss?

[Craig93]

Hi guys, i was on the phone to the exhaust shop today and asked them about 2 exhausts, a 2.5" system with 1 5/8 headers and 2.5" cats in xforce or a 3" system with 1 3/4 headers and 3" cats in xforce. They said that if i fit a 2.5" i would have less power than if i fit the 3" is this true? has anyone had this confirmed on the dyno?
He also told me that 3" wont drone in my sedan on these 6ltr motors.
thanks

[GenReaper]

On a worked engine, Yes its true, stock i doubt it.
1 5/8 headers are smaller than the exhaust ports on the heads, hence why you get 1 3/4 headers.
Im in that boat myself atm.

If you are not going to cam the car 2.5 inch would be ample but would recomend 1 3/4 headers, 4 into 1's are the go, Pacemaker are the best.
I would also advise hi flow cats of at least 200CPI

Moral of the story if your going to work the motor, cam etc down the track go 3 inch straight off the bat.

[wikky]

^^^ Yep, what he said.

[Craig93]

ah thankyou Genreaper that is very helpfull.
Were i work i can get xforce at a great price so figured id just get that. I am unsure whether they have a straight bolt up system with 1 3/4 headers and 3" cats and 2.5" catback ill have to give them a call.

[Lumps of cheese]

He also told me that 3" wont drone in my sedan on these 6ltr motors.
thanks

lol, that's a bold statement. Going 3" you will more than likely have drone, goes with the territory. Read up on some other threads here and look for brands that have been tried and have feedback on them before you part with your cash.

[bortous]

Hi mate. a 3 inch system will drone more than a 2.5 inch no matter what anyone tells you.
If you plan to do heads and cam go the 3 inch as you will need it. If you only plan to tune it and fit a cam, stick with 2.5 inch.
For headers the 1 3/4 size are the best. The pacemaker and difilippo headers are the best ones out there. the 1 3/4 size is the best. The 1 7/8 size is a waste of money and actually loses torque in the low end if you dont have a lot of power.
The best system to fit is a custom one IF the exhaust place knows what they are doing as they can get it very quiet inside the car with zero restriction while having an excellent note. Fitting 100CPSI cats is also good especially for a big cam.
Thats what i got on mine and its unreal.
let me know if you need anything.

Hi guys, i was on the phone to the exhaust shop today and asked them about 2 exhausts, a 2.5" system with 1 5/8 headers and 2.5" cats in xforce or a 3" system with 1 3/4 headers and 3" cats in xforce. They said that if i fit a 2.5" i would have less power than if i fit the 3" is this true? has anyone had this confirmed on the dyno?
He also told me that 3" wont drone in my sedan on these 6ltr motors.
thanks

[soop]

100CPSI cats are illegal. You might as well have no cats at all.