"Header Ho-Down"

Reply Subscribe

Thread Tools

Search this Thread

Feb 12, 2004 | 01:28 PM

vettery

Thread Starter

Racer

Joined: Jun 2002

Posts: 254

Likes: 0

From: Lonoke Arkansas

"Header Ho-Down"

Anyone read this artical in the April issue of Chevy High Performance? They are bragging about the street worthy performance of some 1-1/2" dia intermediate-length headers on a 440 hp 383. I bet you guys with the 1-7/8" dia looooong tubes of the Hooker side pipe headers are leaving a lot of low end torque on the table....but maybe you still still have too much!

:eek:

Feb 12, 2004 | 02:50 PM

crf311

Melting Slicks

Joined: Jan 2003

Posts: 3,029

Likes: 94

From: meraux LA

Re: "Header Ho-Down" (vettery)

I read it. Kind of suprised me too. I still went with the 1 5/8 size for my 350.

Feb 12, 2004 | 03:09 PM

Fevre

Race Director

Joined: Mar 2001

Posts: 11,322

Likes: 1

From: Living in the Hartland

Re: "Header Ho-Down" (vettery)

Saw some dyno tests with the GM HT383 after head and cam swaps and they found that it made more power with the 1 5/8" primaries than with a 1 3/4" primaries.

Feb 12, 2004 | 03:11 PM

verskel

Safety Car

Joined: Jan 2000

Posts: 4,143

Likes: 0

Re: "Header Ho-Down" (vettery)

Quote:

I bet you guys with the 1-7/8" dia looooong tubes of the Hooker side pipe headers are leaving a lot of low end torque on the table....but maybe you still still have too much!

:eek:

I have no stinkin' problems with lack of "low end"...... :D
Of course a 'stroker' small block ain't a Big Block neither ! :lolg:

Feb 12, 2004 | 08:22 PM

The Money Pit

Melting Slicks

Joined: Jun 2002

Posts: 2,842

Likes: 99

From: Orrtanna Pa.

Re: "Header Ho-Down" (vettery)

Besides the God aweful price of sidemount headers,this is the main reason I went with an under car header system. I've seen countless dyno tests indicating the benifits of small tube primaries on street driven engines.Of course at the topend the big tubes will always produce more hp at the peak rpm,but what about the other 95% of the torque curve?

On my website there's a buildup article that shows 40 lbs tq. midrange gain with 1 5/8" tubes with only 12 hp topend loss when the same engine ran 1 3/4" tubes.

Feb 12, 2004 | 08:29 PM

The Dude

Race Director

Joined: Mar 1999

Posts: 10,258

Likes: 1

From: Calif.

Re: "Header Ho-Down" (The Money Pit)

I've got a set of 1 5/8" Hedman long tube headers (with A.I.R. tubes) on my car now that I'd be more than happy to swap straight up for a set of 1 3/4" long-tube primary headers. Just so long as they're in comparable shape--i.e. cosmetic tweaking only.

Any takers?

Feb 13, 2004 | 09:32 AM

Fevre

Race Director

Joined: Mar 2001

Posts: 11,322

Likes: 1

From: Living in the Hartland

Re: "Header Ho-Down" (vettery)

In regards to the testing of the HT383 with TFS alum heads and a big o roller cam:

Quote:

Almost as interesting is the fact that even with the larger cylinder heads, this 383 still doesn't like larger headers. Despite these lofty power levels, this engine is breathing through a stock Performer RPM Air Gap intake and a set of production 1-5/8-inch Hedman street headers and a pair of Borla mufflers. Taylor tried a set of 1-3/4-inch tubes and came away with less power. This is flat-out amazing power from an otherwise off-the-shelf 383ci crate engine. We have never pulled a piston out of its bore or even yanked the oil pan. Taylor bolted in a big Comp Cams hydraulic-roller cam, a set of 215cc TFS aluminum heads, and a dual-plane intake. These are Rat motor numbers in a lightweight package. Idle vacuum isn't all that stout at around 8.5 inches of vacuum at 900 rpm, but the amazing torque is more than enough to live up to its namesake.

http://www.chevyhiperformance.com/te...48_0209_twist/

Feb 13, 2004 | 01:18 PM

vettery

Thread Starter

Racer

Joined: Jun 2002

Posts: 254

Likes: 0

From: Lonoke Arkansas

Re: "Header Ho-Down" (vettery)

I don't see the intermediate length Flowtech headers on Holley's site; must be new. From the picture in the mag, they look like they would be great for connecting to side exhausts; not as short and compromising as block huggers and not as long as a full length header which require a u-bend.