I've talked with Larry Meaux on the subject of merge collectors and his comment was "I've never seen an engine that has the correct size and length collector pick up (on the dyno) with merge collectors".
Jere was the first person to explain to me (back in 1963 when I bought my first set of headers from him) that primary tube size was related to hp... not ci or rpm. He and Larry Meaux are on the same wave length when it comes to headers.Jere Stahl told me the same thing especially when it pertains to a serious drag car ....... Gary I would play with collector extensions on your current set up first ......whether you have properly sized headers for your combo is another question
Jere was the first person to explain to me (back in 1963 when I bought my first set of headers from him) that primary tube size was related to hp... not ci or rpm. He and Larry Meaux are on the same wave length when it comes to headers.
In the book "How to hotrod Big Block Chevys" by H.P. Books there is a sketch on exhaust collector on page "23" showing an experimental exhaust collector as used in dyno testing a 427 of the day. It started with an overall 4" diameter collector and necked down to 2 1/2" over the next 7.5" and then flared out in a megaphone ending back at a 4" outlet, twenty inches back of the 2 1/2" spot. It picked up power and torque over the entire range from 4500 rpm on up. Be advised this is only a race setup. It could easily be built by Jere Stahl or Ed Henneman of "Headers by Ed".the primaries are 2 1/8 and 36-40 long andthe collecteris 4 " in diameter and about 11 long i think. launch rpm is 500 on a brake. thanks
Yes, somewhat, they're quite interesting too. In looking over some i saw at Houston Pro Stock Superbowl a few years ago i noticed that the had a 4-2-1 setup with different tubes paired on each side of the engine, they necked down where the four tubes became two pairs, then expanded back out. I can't recall how large the collectors were but they weren't too big. I bet "Burns" could tell you for sure.do the Pro Stockers still run a merge collector that necks down to about the same diameter as a single primary tube?