Good day !

Since I'm from Europe, and rather build as spend way to much cash (and especially to the import Tax) I'm building custom headers /system )with a mate.

It's going to be a 6-2-1 setup with fairly Shorty "honda" style-primaries , but my big question comes from the Secondaries.
Pete hagebuch said:"
Now 6 to 8 feet of Secondaries is really long and it'll be really close to my rear axle .

Is it worth the hassle? Or should I just keep them 2ft ish?

Kind regards from Enrico in the Netherlands

With short primaries I would not expect the long secondaries to be of much value.

Look at a pair of Clifford shorties with the old Y pipe they sold. It looked horrible from a performance standpoint but worked pretty good and was easier to fit in the car.

That would be what I would shoot for.

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Official Cookie and Mater Tormentor.

Read this thread in addition to what you are thinking about doing.
It's on FABO, Slant Six forum.

https://www.forabodiesonly.com/mopar/th ... 1974647364

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Hyper_pak

Now this is also interesting especially those pics. We where thinking of merging it just before the muffler thus in front the rear axle (and it being a 61 fury it's a fair distance). I also know BMW straight 6es have a long dual system merging together.

So the plan is to make the secondairies 7ft ish. Why?
Jag,BMW,Mercedes & toyota also all did this..Pete must have had right.

The primairies are going to be 15ish inches...enough to stop reversion. And the end pipe 60mm (a tiny tad over 2.25") I'm really curious how this system wil sound & act out

That sounds like a good idea. I ran 2" duals to the rear axle on my first iteration of my 64 Dart (250 HP) and it did seem to make better low and midrange power than later exhaust systems. This is with Clifford Shorty headers. I have said make the secondary pipe go to a Y that is 6-12" behind the trans X-member, but perhaps longer is better. This was on advice from Tilley. There are probably many geometries that work well, and yours is likely a good one. You will not gain top end power, but the available power at lower revs should be better.

What induction/carburetion will you use?

Lou

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Home of Slant6-powered fun machines

The primary lengths are 16-20" approximately. So long enough to get rid of reversion.


I'm using 2x1 Bbls (running on Propane).
Its in a 61 fury-Auto so a fairly heavy full sized Cruiser.

I still am also working on a 72 head (I cleaned it up need to get .100 off and backface the valves) as the next step..and the last step will be a Cam.

It's just a true low-mid rpm cruiser and it won't be racing..so this seems the best!
If I made it for power I'd made it 6 into 1 though!