Rhs Indy X Head Thread
it's called tuned exhaust....
Just like header pri tube length can effect power.
I tell people all the time, mark the pipe with shoe polish every 6 inches back from the collectors, on the last line that burns off, thats where the pipe ends or muffler hooks up.
Tuned exhaust.
True on the primary tube length. It has been found that length is best working for the RPM range you want to run in. I have read and heard Dick Landy quip about the primary tube length being to long for what they were doing or a particular engine they had assembled. For the most part, it seemed they were to long for him.
Primary diameter is best suited for the expected power level being sought. 1/-58 - 1-3/4 are great for the street. However, even between these 2 street pipe sizes, the bigger one on a mild engine can kill torque while the smaller one on a higher HP car will choke it up top limiting it's pontentail.
The "Ye Ol'shoe polish" on the collector pipe is OK if you add 6 inchs to the burned off spot. That old method had been debunked several times, but not trashed as garbage. It was noted that was aboutthe area of absoulte min. should be and only if it was absoultely a must do. Which is not for mopst car we run.
Now Sunbeam on the otherhand....may have a under chassis issue, LOL>
It's probably too far out to matter.
It's more of a race thing
You'll find your mufflers end up right under you're seat, so no room for the ex pipe, unless after.he he
I wonder how many guys use an X/H pipe drag racing.
I've noticed a good number of wheel standing door slammers running X pipes. Rare to see a "H" pipe wheel stander. IMO, if these guys are running this, they may know something, however, that may be for there car and combo only otherwise eveybody would be running one. That is my guess.
For surley, most guys putting day light under there car seem to have the K.I.S.S method of 2 huge sewer pipes dumping at the rear axle.
(Or so I have noticed.)
I've done a lot of research on header primary tube size and length as well as collector size and length and what I found was most header builders agree that on a real race engine the primary tube diameter and length aren't nearly as important as collector length. Most race cars are pretty much set as to how long a primary tube you can fit in it and once that is set tuning can be done with collector length. This seemed to be proven true by several magazine articles I've read, one in particular that was an old (7 or 8 years ago) Car Craft article where they tested different tube diameters and lengths and as long as the tube wasn't too small the actual length and diameter had little effect on the power output but the collector length did. This of course did not take into account the shorty style headers which aren't considered a race header anyway.
Agreed, though I'm no wizard, I just pay attention to them and try and remember there spells and what they were on.
In a nut shell (And probably overly simplified) is that if you are racing, a shorter primary tube seems to be good for high RPM and the collector length is under the old addage of "More the merry." In example, if you have a 3.5 tube from the primary pipes, carry it as long as you can. IF you have to neck it down, wait 16 inch. LOL
