I am currently running JBA shorties to Magnaflow direct fit cats, SLP y-pipe and Magnaflow cat back system. This is all connected to an LS6 crate engine. After reading numerous threads and posting here on Tech, I have come to the understanding that I am maybe gaining 10 rwhp over the stock manifolds. As many people have stated, the JBA's are for many, not worth the time and money for such a small gain. Maybe the gain is larger under the curve rather then total peak gain with the shorties. This car was a California car and the previous owner took the $$$ hit. I have since moved out of Socal, so I am now looking to unleash some ponies. How much gain and where do you guys think that I would see by going to some TSP LT headers? I was thinking that if I may only see and additional 10 rwhp over the JBA's, financially, the money might be better spent elsewhere....???? What do you guys think???

Thanks...

 

Long tubes and ory will probably net another 15rwhp, this is irelevant because if you try to add a cam, intake heads etc, youll be leaving alot of power on the table with shorties and cats.

 

Cats yes. Shorties, I'm not convinced. I went the other way and feel nothing
lost, perhaps due to the crappiness of the Jet-Hot Y. The shorties flow well
enough to blow the O2 sensor out of the hole in the Mufflex tubes downstream
at WOT, meaning they are nohow the main remaining restriction.

If you want to build torque, long tubes are for you. If you are about power
and your converter sits at >5000RPM all the time WOT, then you want flow
plain and simple. Is it better for the gas to go 3 feet in 1-3/5" pipe or is it
better to get to 2.5" pipe early?

Let us know how it goes. Personally I'm happier especially with closed loop
behavior. Everybody's got a story from a friend of a friend who read it on
the Internet. I'd love to see the back-to-back, tuned-to-best pulls. But
that represents a lot of effort for the sake of science and I've never seen
it done. So to me it's all just a bunch of hot air. Heh.

 

The difference between long tubes and shorties isn't in the flow. If they each have the same sized primaries and the same sized collectors, they will flow similarly depending on the variances in bends. The big gain in going to long tubes is that they dramatically increase the scavenging effect.