VandykeT/A

Ok a guy I know started talking about the longtubes on my car. He asked if they were stepped tube and if they were equal length. So i explaind to him what they looked like and what not and he said I was leaving alot of power on the table not having stepped tube. His explanation of stepped tube is say the header starts at 1 5/8s and goes to say 2" before the collector. How in the hell would having growing primaries help anything other than scavenging? Wouldn't having say 1 7/8s all the way down be better than a 1 5/8s that grew to a 1 7/8s.

BigB02Z28

I don't personally know, but google says its to help with reversion on large cam applications. Also heard that they offer better low/mid range torque with minimal loss to the top end.

Blk98Vert

iTrader: (2)

1 7/8s will always make more, there is a reason no one makes stepped headers anymore, the big manufacturers are going with 1 7/8s.

01ssreda4

iTrader: (96)

My car had Hedman stepped 1 5/8 headers on when I bought it. Midrange was crazy, but 5-6k was nothing to write home about. I installed some full 1 3/4 and midrange suffered, but top end you could feel the difference.

redtan

iTrader: (5)

Kooks makes stepped headers 1 3/4 to 1 7/8 and they make just as much power up top with more torque down low. The smaller primaries near the head help with scavenging and exhaust velocity while the bigger primaries at the end help with overall volume.

So you get the best of both worlds.

mypoorLS1

iTrader: (4)

That's the idea. Does anyone have proof of this? I'd love to see it, I have these headers. It's what Kooks recomended to me about 6 years ago.

Blk98Vert

iTrader: (2)

Its been proven that 1 7/8s don't lose any low end and pull away from 1 3/4 above 4K. Stepped headers are certainly better but if you have the 1 7/8s dont worry about anything. Most people are mistaken about a lot of facts about what mods work on these motors. Like LS6 manifolds are all you need and true duals gain nothing unless you are making over 500

01ssreda4

iTrader: (96)

It isn't always about WOT, and thats what dynos show. Stepped headers produce part throttle response. They make the car FEEL like it has more torque. It's very appealing in a street driven car. If you haven't tried them then you wouldn't know.

redtan

iTrader: (5)

Where?

Blk98Vert

iTrader: (2)

Texas speed posted a graph of their headers

01ssreda4

iTrader: (96)

And again, this is WOT testing. How much time do you spend WOT at 3k rpms? Basically none.

redtan

iTrader: (5)

I would love to see that if you have it, I searched and have not found anything. Debating whether or not to upgrade my 1 3/4s for either stepped or full 1 7/8s

ss454327

iTrader: (10)

There was a back to back comparison on a Silverado SS that showed right at a 10hp and 10ftlb gain across the board when going from an American Racing 1 3/4" header to an American Racing 1 7/8" header. I bought the 1 3/4" before this test came out and regret it very much. This wasn't done by ARH either.