Stepped headers

[K4fxd]

Engine masters just did a stepped header test. The results are what I expected.

They do not work, at least without hundreds of dyno tests getting the lengths correct. Back in the 80's or 90's when these first came out Ed, Headers by Ed, said the only way these will work is if the headers are not sized properly to begin with.

The real surprise was the merge collector test, but I thought they used the wrong set of headers when they tested it. The merge collector killed power just like the stepped header.

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[GregO]

Engine masters just did a stepped header test. The results are what I expected.

They do not work, at least without hundreds of dyno tests getting the lengths correct.

No surprises there being a 4 valve motor with a VE of 110%.
2 valve would benefit from a proper step header.

 

[K4fxd]

No surprises there being a 4 valve motor with a VE of 110%.
2 valve would benefit from a proper step header.

They did the test on a big block chevy. No 4 V heads involved.

 

[GregO]

They did the test on a big block chevy. No 4 V heads involved.

I assumed your thread was a test on the Coyote 5.0 not a Chevy.

 

[K4fxd]

I assumed your thread was a test on the Coyote 5.0 not a Chevy.

I see no reason to think the coyote would have different results.

We tried stepped headers on a small block Ford race car back in the day and lap times fell. It's nice to see some dyno numbers to back up our results.

What did surprise me was when they tested a merge collector it lost power. There are a couple of faults with their merge collector test and I hope they correct them on another episode.

 

[GregO]

I see no reason to think the coyote would have different results.

We tried stepped headers on a small block Ford race car back in the day and lap times fell. It's nice to see some dyno numbers to back up our results.

What did surprise me was when they tested a merge collector it lost power. There are a couple of faults with their merge collector test and I hope they correct them on another episode.

My friends shop built several custom step tube for a few comp eliminator BB cars that ran at Rt 66.
Every set knocked 2/10’s off from prior off the shelf headers, call it luck or whatever.
All I know is any 4V can have sloppy headers and still made good power. 2V are not as forgiving.

 

[Juggernaut]

The stepped headers picked up power above 5k. How often in drag racing are you under 5k? The smallest headers in that test also was the shocker.
My stock heads intake ls1 went faster with just a change from 1-3/4 to stepped 1-3/4 to 1-7/8.

 

[K4fxd]

My stock heads intake ls1 went faster with just a change from 1-3/4 to stepped 1-3/4 to 1-7/8.

I wonder how that would have run with a straight 1-7/8?

I'll admit I'm biased away from stepped and the loss of torque is most likely why my road course lap times got worse. I would like to see more testing.

 

[Juggernaut]

I wonder how that would have run with a straight 1-7/8?

I'll admit I'm biased away from stepped and the loss of torque is most likely why my road course lap times fell. I would like to see more testing.

Prolly about the same, it was a cheap edelbrock stepped header on sale because it was scratched so I gave it a try. It was nice that it gave me a lil extra room in that tight engine bay.

I can see road racing where it would be a negative. What style header do you find works best for that?

 

[K4fxd]

So far just straight tubes. We would change primary length depending on the track.

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