7X exhaust splitter vs headers

Kdancy

Being that you still have an exhaust "choke point" before the exhaust splitter, how much power do you pick up using it vs exhaust headers?

RL Chilton

Certainly there will be some, but that "choke point" is relatively large and I think the hp loss would be negligible.  Only true way to tell would be to dyno the two and make comparisons.  

BillUSN1

I have the son making me one out of 1/2" plate and then will Siamese the 2- 1 3/4 elbows and weld them on.
Looking at the flange, I don't really think the loss is at the elbow flange but would be in the sharp turns of the manifold as the gases exit the head.
I think that's where the header would be of benefit.

bob ward

I would be surprised if there was any discernible HP difference between an engine fitted with a stock exhaust and the same engine fitted with a 7X splitter exhaust. The exhaust manifold, whether stock or 7X is just a poor design, all of its problems are before the exhaust flange.

The 7X exhaust is more to do with advertising and hype back in the day, if its more HP you are after, 'improvements' at or after the flange will, I suspect, do close to naught.

Headers on the other hand definitely produce more power. A few years ago I had the opportunity to have a 54 Hornet dyno tested, stock manifold v headers, no other changes, and the back wheel HP rose by 7% from memory, I'll see if I can find the test printouts.

BillUSN1

The other obvious gains would be in the reduced wall friction of going from 1- 1 3/4 pipe to 2- 1 3/4 pipes as the exhaust flows out.

Hudson_in_Seattle

bob ward said:

I would be surprised if there was any discernible HP difference between an engine fitted with a stock exhaust and the same engine fitted with a 7X splitter exhaust. The exhaust manifold, whether stock or 7X is just a poor design, all of its problems are before the exhaust flange.

The 7X exhaust is more to do with advertising and hype back in the day, if its more HP you are after, 'improvements' at or after the flange will, I suspect, do close to naught.

Headers on the other hand definitely produce more power. A few years ago I had the opportunity to have a 54 Hornet dyno tested, stock manifold v headers, no other changes, and the back wheel HP rose by 7% from memory, I'll see if I can find the test printouts.

did you ever find the dyno results - it would be great if you posted  - thanks!