Header question

[Last Real Texan]

Now get your mind out of the gutter here for a minute fellas, At what point HP wise do you have to get into bug tube headers? Now this is forced induction not N/A. I have been told the E-tops are only good on a forced induction motor to about 900 and from there you need to go to a big tube design...That means big $$$$ on headers over the e-tops I have now, if I can use the headers I have now for 1000-1100 hp it will simplify my plan to have the back up motor easily swap in when the time comes. Any insight here on this , maybe Grizz can shed some light with his experience with Gary up there in NASCAR land around Dawsonville.

And if I have to go to a big tube the question is Stellings or Kieth Eikert or CMI...I will go used for sure so I guess it will depend also on what is available.
Getting 565 Cubic inches to breath with 10 lbs of boost is moving a ton of air.


Tex

[MOP]

Check this link! http://forums.boatfreaks.org/showthread.php?t=12100 If you must change the Eickerts seem to be the best.

[mjw930]

565 CI + blower @ 1000 hp means big tube headers. The KE exhaust is great up to about 650 hp, as are the small tube headers like the CMI e-top.

CMI Big Tubes seem to be the exhaust of choice for all the big $$$ motors.

[SilverBack]

How about some Zoomies???? that would be great!!:cool:

Buizilla once said...used headers are like used underwear!! Or something like that!!:shocking:

With a blown motor I think some good IMCO powerflow plus manifolds would be good. They say they run them to 1,200 HP. Headers are for pretty boys anyway!!:pimp:

[Carl C]

There was a whole pile of used headers here cheap not long ago. Yup, like buying used underwear. They wear out. CMIs are pretty. See my avatar.

[onesubdrvr]

How about some Zoomies???? that would be great!!:cool:


Hmmmmmmmmm

Wayne

[BigGrizzly]

Well you better look again there are some pretty big Elbow tops out there. I have sport tube as you know. just because we built the engine around them. Garry had a 1200 with forced induction, big blower, The owner came in panicking about the elbow tops. Garry swapped them and the guy lost about 35 to 40 hp, but almost no torque. Btw the hp loss was above 5500. The collector tube was 4.5 od. The wife and I were doing a speed run home and he passed me so fast I didn't even see the lightning bolt painted on the side. Talk about humble. He then put a couple of 150 NO2 kits on it. Last I heard it was in the 160 mark. The point is don't worry, unless your going to a 640 Donov an

[sweet 16 1966]

Wow!

[mjw930]

Griz,
I was referring to the small tube etops, they make a large tube version that would probably be the better choice here.

According to CMI the shorter runner length e-tops tend to work better with forced induction. See below:


All CMI headers are designed to outperform most conventionally cast manifolds because CMI headers are lighter and freer breathing. Long tube-style headers, like CMI Sport Tubes and CMI Big Tube headers, enable naturally aspirated engines to reach peak performance power through more efficient exhaust scavenging and improved exhaust tuning.

For blown and supercharged engine applications, short tube-style headers, like CMI Elbow-Top, CMI Elbow-Top Light, CMI Unitop, and CMI Big Elbow-Top headers, perform similarly to, and in some cases better than, long tube-style headers. Short tube-style headers are also typically less expensive.

For applications where CMI Big Tube and Big Elbow-Top headers are required, CMI offers a range of primary tube diameter sizes to optimize engine torque and boost horsepower.

Link here: http://www.custommarine.com/headerapps/HeaderAppChart.php

41325

[BigGrizzly]

Our tests on the dyno don't say that exactly. The theory in a blower system is the exhaust is just a dump and the bigger the better. The real issue is drivability in the other ranges with conservative numbers of boost. The other thing You don't compair big tube elbow tops with small tube sport tubes. I can only relate what I have seen and not advertisements. When I was there having mine made and fitted they told me a different story. To tell you the truth on my engine, the original harding hedders (Not tube type), there was almost no hp gains up top with the sport tubes. However exhaust temps and fuel usage was better with the sport tubes. Better hp throughout the range.