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block hugger headers + 60 HP loss


Guest kc6wfs

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I was shocked to read on Sallee web page that you loose 60HP when using block hugger headers.

Could this be true?

If so what make and model number of full size

headers will fit a 240Z/350?

 

Thanks.

Dave

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Hi Ray,

It was a post last week from Scott on the board over there.

Click to view posts from last week and click on the message named below.

 

Sallee 325 horse engine from '97

________________________________

 

Thanks.

Dave

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Depending on how wild the engine is the header can make quite a difference as almost every major magazine has done some sort of dyno testing with various headers and found the block hugger style the most restrictive but the easiest to install. They, for the most part, were are all done with a dyno so HP was accounted for and more was found with long tube. I only use dyno results or 1/4 mile time tests to go by since the seat of the pants test carries no merit for me. If you don't have a 450+ HP engine than it prob. doesn't matter or if this is a street vehicle than, like mine, huggers are fine. Its like comparing a tunnel ram to a single plane high riser. It depends on the use and the requirements, right???? icon_eek.gif

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Block huggers do flow much better than cast ram horns. Nothing flows like long tubes though. I am using block huggers by headman and buzz my motor real well with a nice bump stick. I will not competitively race so the point is mute for me 4 now anyways!! flamedevil.gif

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The length of the tubes effects the torque band and not the HP levels. The main points on the block huggers which make them less attractive are:

 

1. unequal length primary tubes.

2. the very tight bend in the primary tubes as they exit the head .

But I think that unless you are really trying to squeeze every last drop of HP out of the engine, this is not a big deal, but I think that by making the initial bends in the headers more gentle, and equaling out the length of the two middle tubes (equal with the two outers), that would make them better......but worth it...I dunno malebitchslap.gif

Tim

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Hotrod mag did a test motor a while back and they installed both block huggers and long tubes. The

huggers lost around 30 fpt to the long tubes but

were up 2 hp on the top end. If you have a light

car, stick shift or low first gear auto you will

not miss the extra torque. The z cars are great

for huggers. Now if you had a 4000 pound car then

the long tubes for sure.

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60HP? On WHAT engine?! That's not right. My friend's shop has dynoed both long tubeshortys on Mustangs - guess what, almost no difference! A few HP at most on cars making a bit over 300RWHP. If it was a 60HP loss then that motor must have been a monster! Don't always believe the magazines either - they prostitute themselves to the people buying ads like you wouldn't believe.

 

Some other interesting dyno testing:

Long tube vs short tube on a DOHC Cobra. Difference? 6RWHP Cost? Over a grand installed! Was this a Honda part?!

 

Xpipe vs H pipe. NO DIFFERENCE! Yup, sounds different but they saw no discernable difference. Torque is supposed to be enhanced, they didn't see it on the dyno.

 

Hi-flow cats vs striaght through H-pipe. About 6RWHP. That was a back to back test too.

 

Since they installed the dyno they've been having fun finding out hwat really works and what doesn't. It's amazing that some of the things that are gospel just don't seem to hold up in real life. Hrm, is the S&S main product line long tube or shorties? icon_biggrin.gif

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  • 2 months later...
Guest Rick Johnson

BLKMGK,

It sounds like your buddy with the new dyno could be a great source of information.

 

Keep us updated on his latest finds!!!

 

Rick

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He's not dynoed anything interesting lately I'm afraid. He IS getting massive power out of the new Lightnings though :D

 

Now that warmer weather is getting here I'm going to try and finally get my new headers and added mufflers installed. Afterwards I may try a dyno run again to see if any power was picked up with the larger headers. I never did get moving on EFI and my secondaries still don't open so we'll see. twak.gif

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  • 5 weeks later...
Guest 1fastz

K mustnag vs block huger headers is a totaaly diferent story ..

 

first the 302 is a SHORT stroke motor wich will want a smaller header tube with a shorted primary ..

 

block huggers wont hurt HORSEPOWER verry much up top maybee 10 15 horses on a 450 horse motor buT they lose low end tourqe dramaticly..

 

however with our week rear ends and halfshafts and light weight thats anot a bad thing

 

For the utmost in performance go with full lengths..

 

but on most street cars its just not worth the extra hassle.

 

i can tell you now I picked up 2 tenths and 3 miles per hour going from shorty block huger 2 1/2 heaaders to full length 1 3/4 sandersons on my NINE SECOND car..

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2 tenths on a car already going 9s? Spraying? Umm duh, I'd expect that. Pick up 2tenths on a 13 second car and I'll be surprised. For me the hassle isn't worth it and I've seen what the Ford dyno runs show - especially for the 4.6 motors. It's not worth the HP for the hassle of install, dragging the headers on speedbumps, frying starters, and problems changing plugs. Did I mention cost? I'd have to really pick up a bunch to be interested in longtubes for my car.

 

As for my second set of headers - these are Rewarder headers. Guys at the exhaust shop now tell me that the PASSENGER side doesn't fit. Grr! They said that it hits the block?! I'm pretty sure I test fit both sides before coating etc. so I'll try them myself in the garage. Very aggravating just to pick up some primary pipe sizing let me tell you. The Flowtechs fit great but th eprimary is small and there's a step from th eexhaust port to the header and I know that's got to be hurting me some.

 

On a brighter note - the additional mufflers really helped. Still resonates some inside the car but the woman says it's MUCH quieter from outside and no backrap when it decells :D Noticed a little of what looked like gear oil on the garage floor and some oil too so I've got some looking around to do under there. Not sure where the gear oil could've come from since I've got all new seals etc. Weird!

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