Indycars
Well-Known Member
Now that the holidays are over for awhile, I got back into the header design project. It's real
tough to get the dimensions correct for the 4-2-1 or Tri-Y headers, so I wanted to also try a 4-1
design and see how close I could get. The mockup kit they sent me had enough collectors to
do both designs, but it also cost more at $650. But it all gets applied to the final cost of the
finished headers.
Without posting all the numbers from Pipemax, it basically comes down to the length of the
primary tubes. The collector diameter and length are easy to meet those requirements.
Primary length should be between 36.4" to 38.9". This version (version 03) came out at .....
Cyl #1 - 39.0"
Cyl #3 - 39.5"
Cyl #5 - 40.0"
Cyl #7 - 37.0"
With more tweaking I'm sure it would be closer, this is my first attempt at a 4-1 design. Then
HP Headers will have more flexibility in getting the dimensions correct when they build them.
Again, I'm not after the exact same dimension for all primary tubes, with a little variation, I
can make the torque curve wider and flatter since all the cylinders are NOT peaking at the
same RPM.
Version 03 Below (Next 3 photos)
So you don't have to go back to look at version 02, they are included below.
Version 02 Below (Next 2 Photos)
Obviously you can't determine the best performing version of the two header designs posted
above, but which one do you like cosmetically ???
.
tough to get the dimensions correct for the 4-2-1 or Tri-Y headers, so I wanted to also try a 4-1
design and see how close I could get. The mockup kit they sent me had enough collectors to
do both designs, but it also cost more at $650. But it all gets applied to the final cost of the
finished headers.
Without posting all the numbers from Pipemax, it basically comes down to the length of the
primary tubes. The collector diameter and length are easy to meet those requirements.
Primary length should be between 36.4" to 38.9". This version (version 03) came out at .....
Cyl #1 - 39.0"
Cyl #3 - 39.5"
Cyl #5 - 40.0"
Cyl #7 - 37.0"
With more tweaking I'm sure it would be closer, this is my first attempt at a 4-1 design. Then
HP Headers will have more flexibility in getting the dimensions correct when they build them.
Again, I'm not after the exact same dimension for all primary tubes, with a little variation, I
can make the torque curve wider and flatter since all the cylinders are NOT peaking at the
same RPM.
Version 03 Below (Next 3 photos)
So you don't have to go back to look at version 02, they are included below.
Version 02 Below (Next 2 Photos)
Obviously you can't determine the best performing version of the two header designs posted
above, but which one do you like cosmetically ???
.
