intermediate headers just as good as long tubes
Thread Starter
Registered User
Joined: Aug 2003
Posts: 420
From: brunswick ohio, small burb south of cleveland
intermediate headers just as good as long tubes
well its finally in a magazine. you can call me out all you want but you cant dispute the dyno in the april issue of chevyhighperformance. unfortunately it wasnt an
LT1 but at least it was a crate 383 from Smeding. they compared 1 pair of 1 1/2" flowtech intermediate length to 3 different pairs of hooker long tubes. they marked TQ and HP in 100 rpm increments from 3000 to 6000 and took the average for all 4 pairs. the hookers went up in size from 1 5/8 to 1 3/4 to 1 7/8.
the average for the hookers was 436/372 next was 438/375 and 438/374. the flowtech TQ and HP average was 437/371. almost identical.
the final paragraph talks about how the peak numbers were higher on all the longtubes but they also lost power in the midrange relative to where their peak power was made.
the largest primary had the highest HP of 451 to the flowtechs 435 and the smallest primary had the highest TQ of 468 to the flowtechs 461.
could anyone really tell that difference?? 7 ft lbs of torque?? thats a pretty calibrated a$$!!
go ahead start the flames. you longtube guys wont believe me so go buy the rag.
LT1 but at least it was a crate 383 from Smeding. they compared 1 pair of 1 1/2" flowtech intermediate length to 3 different pairs of hooker long tubes. they marked TQ and HP in 100 rpm increments from 3000 to 6000 and took the average for all 4 pairs. the hookers went up in size from 1 5/8 to 1 3/4 to 1 7/8.
the average for the hookers was 436/372 next was 438/375 and 438/374. the flowtech TQ and HP average was 437/371. almost identical.
the final paragraph talks about how the peak numbers were higher on all the longtubes but they also lost power in the midrange relative to where their peak power was made.
the largest primary had the highest HP of 451 to the flowtechs 435 and the smallest primary had the highest TQ of 468 to the flowtechs 461.
could anyone really tell that difference?? 7 ft lbs of torque?? thats a pretty calibrated a$$!!
go ahead start the flames. you longtube guys wont believe me so go buy the rag.
Flame on longtube boys...
Registered User
Joined: Sep 1998
Posts: 8,319
From: US 1 Mile Marker 52 in the Florida Keys
is it me or does this paragraph confuse you?
"the largest primary had the highest HP of 451 to the flowtechs 435 and the smallest primary had the highest TQ of 468 to the flowtechs 461."
this is good to know...maybe i'll change my plans from pacesetters to mac middies
"the largest primary had the highest HP of 451 to the flowtechs 435 and the smallest primary had the highest TQ of 468 to the flowtechs 461."
this is good to know...maybe i'll change my plans from pacesetters to mac middies
Registered User
Joined: Dec 2003
Posts: 2,724
From: Oklahoma where trees are made of wood.
I thinbk youre missing a few bits of pertinent info, primarily that the hedmans were stepped from the 1 1/2 to 1 5/8s this plays into the hands of the torquey 383, you'll notice though that the rpms you would mostly be in during a 1/4 mile run were way below the longer primary headers. also note that the engine only had 9 to 1 compression.
Registered User
Joined: Dec 2003
Posts: 2,724
From: Oklahoma where trees are made of wood.
heres an earlier article from the same magazine that is a lot more realistic and helpful.....
http://www.chevyhiperformance.com/techarticles/49178/
http://www.chevyhiperformance.com/techarticles/49178/
Registered User
Joined: Apr 2001
Posts: 2,195
From: Springfield, IL
Originally posted by teke184
is it me or does this paragraph confuse you?
"the largest primary longtube had the highest HP of 451 to the flowtechs 435 and the smallest primary longtube had the highest TQ of 468 to the flowtechs 461."
is it me or does this paragraph confuse you?
"the largest primary longtube had the highest HP of 451 to the flowtechs 435 and the smallest primary longtube had the highest TQ of 468 to the flowtechs 461."
its saying that the flowtechs in that comparo are a good intermediate header for all around power not just peak!
Registered User
Joined: May 2003
Posts: 263
From: Grand Rapids, MI
You need to look closer at the dyno charts. The shorties worked well between 2800-4400 and the long tubes excelled in the 4400-5800 range. My street car runs around at 2800-3000 a lot and has shorties. My drag car is never below 4000 and below 5000 only the first 40 feet or so. It looks to me like the long tubes are the clear choice above 4400 and if they give 10 more hp at 5800 then by 6600 they might be 20 hp better.
Registered User
Joined: Apr 2001
Posts: 2,195
From: Springfield, IL
to me that comparo goes to show what i've felt in my car after my LT install, was the whole power band was moved "up" in the rpm's, contrary to others saying that LT's make more lowend tq and hp then any other header
Thread Starter
Registered User
Joined: Aug 2003
Posts: 420
From: brunswick ohio, small burb south of cleveland
the average for the hookers was 436/372 next was 438/375 and 438/374. the flowtech TQ and HP average was 437/371. almost identical.
the purpose of the post was to dispell the RUMOR that long tubes are so much better than intermediate or even shorties. the only concrete shorty info i can give will be my dyno when the heads are completed. as for the intermediate the averages were minimally different. unless you need to tap every single ounce of power like 383Z4ME in his drag car you can do quite well with a solution other than long tubes. i would prefer 10 lbs of torque out of the hole instead of 20 HP at the top.
WS Sick i checked out the link.
The comparison test pitted the stock cast-iron exhaust manifolds against a set of 1-5/8-inch Hooker headers that were plumbed into the same 2-½-inch exhaust system
i am not sure how this applies to this post. no one would disagree that anything is better than stock.
david
