Ironhead Informed reviews!

[Ferrous Head]

Mo, stick with 1 3/4". Going smaller effects the gas flow. What your attempting to do is use the pressure waves generated when the exhaust valve opens to help "extract" the exhaust gases from the engine.
A good exhaust shop will have tube benders (and expanders) and will be able to produce exactly what you want. You will need to decide on how long you want the primary pipes to be, what type of collector you want and how long the tail peice will be.

Now there will be compromises at times. While you may determine 36 inches is the perfect primary length it may put the collector exactly where you don't want it.
This setup is for the street so you can be more flexible.

The length of the tail piece can be changed later pretty easily. Start with it too long and you can shorten it later to move the torque curve.

That shortening is best done after dyno runs but of course you can just cut a bit off and try by seat of the pants.

[brucstoudt]

Originally Posted by 73HEAD

Hi mate. Is that what they’re off. I swapped em for a generator .

Patrick's 1966 XLRTT post#137 second pic

http://xlforum.net/forums/showthread...=44897&page=14

[73HEAD]

Thanks brother


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[GA_Ironhead]

Originally Posted by Iron Mike

I believe that ring can be found somewhere in the Screaming Eagle parts catalogs.

P/N 29179-88

Pretty sure it's obsolete now. HD called it a venturi ring. You could buy them individually or it came in the high flow air cleaner kit (29041-88B).

Kit instructions here -> http://sportsterpedia.com/lib/exe/fe...:is-j00049.pdf, from the Factory Instruction Sheets/Carburetor, Intake Manifold & Exhaust section of Sportsterpedia at http://sportsterpedia.com/doku.php/t...cres:miscres08

The rings seem to be available on a couple of websites (repops?) .

[GA_Ironhead]

Originally Posted by brucstoudt

^^^ thanks for that info.that means my original needle has been replaced and the lean pop is still there.i'll see if i can find any info on the velocity ring for you.

Have you tried shimming the DJ needle?

If you've got one available, the Sportster needle, aka N65C might help with off-idle carb farts. Or go the CVP route.

[brucstoudt]

^^^ thanks i haven't tried shimming it.i am considering raising it.the same result?i read the instuctions where they recommended it to be for begining there would still be notches available for adjustment.

[GA_Ironhead]

Same result.

[GA_Ironhead]

Bruce -

Keep in mind that DJ and MoCo parts may not be backwards compatible with each other. I don't recall the details - it's been an eternity since I looked into that. No idea what CVP parts compatibility is with either of those vendors. You may also have a drilled slide and cut spring thrown into the mix; loved by some, hated by others. Make sure the slide/diaphragm are maintaining vacuum and still working as designed...

[Ferrous Head]

Ah,..... The ease of tuning these things.

So much more satisfying than the simplicity of our poor second cousins, the butterfly carbs,

You can play endlessly with slide cutouts, needle positions, jets sizes, adjustable jets, accelerator pump settings etc etc etc.

Mind you, judging by "seat of the pants" results will probably leave your A/F graph looking like a mountain range.

[brucstoudt]

Originally Posted by GA_Ironhead

Bruce -

Keep in mind that DJ and MoCo parts may not be backwards compatible with each other. I don't recall the details -

i'm aware of some of that.the emulsion tube is one,i haven't thoroughly researched it i'm trying to tune it what i have now installed.after i verified i have a dynojet needle i'm not convinced switching to a cvp would help.