88gunmetalgta

iTrader: (1)

An offshoot from my motor swap thread, found here.

The short story is I should be making 500+ hp (that's just a little plus)
383 stroker
AFR 195 heads

A buddy of mine got these headers thrown in with an '87 drag bird he just bought, and I can get them for next to nothing since he's running a BB.
They are Hedman Hustler Hedders. PN 65180. I would be cutting off the dumps or otherwise connecting it to a full exhaust, maybe via cutouts.



They look sweet, but how will they perform? Are they too big for my little 383?
As I heard it, they were run on the bird with a ~700-750 hp smallblock, the numberboard in the window still says "9.17"

1989GTATransAm

iTrader: (3)

I would say they are to big. The exhaust velocity will be lower than normal and you will get almost no scavanging.

88gunmetalgta

iTrader: (1)

What do you make of this thread?
http://www.camaro5.com/forums/showthread.php?t=63640

Those dyno curves are close enough that it wouldn't be worth me dishing out the extra coin to get my 1 3/4" Primary headers, I haven't gotten a price on these ones yet, but it will likely be much less than the 600 I was gonna end up spending.

Twin_Turbo

iTrader: (25)

If you can get them for little money go for it, I have a set too (1-7/8 primaries) and they are around 1200 new, maybe even more

Camaro305SB

Unless its a race car I'm thinkin those primaries are gonna be too big. Hell, most bolt on LSxs only use 1 3/4" primaries, and modded LSx's use 1 7/8".... Someone correct me if I'm wrong, but your only gonna be able to really fill those things at high RPM.

88gunmetalgta

iTrader: (1)

The test in the link I posted above was on a totally stock LT1.

Every header option gained a little power over the smaller sized option. It really seems like ANY of the 3 sizes would be a good option for my car, and while I will not be turning high enough revs to get into the tuned range of these hedmans, it seems I wouldn't see any LOSS throughout my power and torque curves, if I do see a couple hp gain.

I guess at this point, my decision will be based on how much more expensive it would be to buy the 1 7/8" headers.
Or can someone explain why my results would be different from the ones in that test?

//<86TA>\\

iTrader: (14)

those headers have the stahl bolt pattern too, so unless your heads have them, you can even use them with adapters, and they wont fit the car with the adapters im sure.

Twin_Turbo

iTrader: (25)

They will fit with the adapters

88gunmetalgta

iTrader: (1)

Well the price is $450 for them, too much for an iffy fit/finish/performance header. I think I'm gonna go with a set of 1 3/4" from Doug's headers for an extra $150. Fit should be good and I won't have to use adapters, finish will be shiny and not dented or scratched, and they will be better turned for my rpm range.

//<86TA>\\

iTrader: (14)

really? thats good to know.

88gunmetalgta

iTrader: (1)

I would be surprised if the headers fit around my A/C box as it is. With the adapters, it would be pretty tight I'm sure.

New2Chevy

iTrader: (11)

They're kinda cool and all that, but they're overkill and too much of a PITA, when you can get the Hedman long tubes that work very well, for half the price.

88gunmetalgta

iTrader: (1)

Got a link? If I can get a set of Hedman 1 3/4" primary, ceramic coated, long tube headers for $225 I'm all in!

New2Chevy

iTrader: (11)

Oh you want ceramic coated. I see.

I think 1 5/8" primaries are plenty big for a 383.

Why do you want them to be 1 3/4"? Just curious.

Twin_Turbo

iTrader: (25)

1-5/8 is on the small side for a healthy 383, get the 1-3/4

88gunmetalgta

iTrader: (1)

1 5/8" is too small for my motor. And if they're not ceramic coated, they'll deteriorate too soon for my liking, and they'll also pour some extra heat into my engine bay.

New2Chevy

iTrader: (11)

Why are 1 5/8" too small? I understand why you want ceramic coated....I must've missed that part earlier in your thread. I guess Twin_Turbo pretty much answered the question he he he.

88gunmetalgta

iTrader: (1)

That I don't know. I was told that by those much more knowledgeable on the subject than me

bduffey723

they look pretty badass im not gonna lie

New2Chevy

iTrader: (11)

If you can't get those biggies to work, these would work well:

http://m.summitracing.com/parts/HOK-2210-1HKR

Kooks wants to charge me $2700 for a set of their custom headers, plus my car needs to be there for them to do it.....yeah, I'm going with the Hookers or Hedmans.

88gunmetalgta

iTrader: (1)

I'm gonna pick up a set if hedman 1 7/8" primaries, uncoated for ~$600. Then I'll weld in crankcase evacuation tubes an an O2 bung, and have them coated inside and out locally for $150.

New2Chevy

iTrader: (11)

crankcase evacuation tubes? What are those for?

New2Chevy

iTrader: (11)

and I'm wondering if I should use LT1 gaskets or the gaskets that come with the headers, since the header flange ports are larger than the d ports on the heads.

Twin_Turbo

iTrader: (25)

exactly what the name says, crankcase evacuation. The tube welded at a 45deg angle pulls a slight vacuum so you don't have to run PCV and contaminate the intake. The valves are regular reed valves, exactly the same as used on the emissions air tubes they keep exhaust from backing up through the pipe into the crankcase

New2Chevy

iTrader: (11)

Thanks Twin_Turbo. Can you answer my gasket question above as well?

Twin_Turbo

iTrader: (25)

Get a gasket that matches the headers in size, no need to use a smaller gasket. In fact it might promote pitting from moisture being trapped behind it. Notice on old heads how the pitting usually is present at the gasket surface.

New2Chevy

iTrader: (11)

So more moisture if the gasket is the same size as the head? I don't get it.

And.......Adapters? Why adapters?

Twin_Turbo

iTrader: (25)

The adapters adapt a stock head to the stahl pattern so you can bolt these headers on. Check the bolt pattern on the flange, 7 bolts instead of 6, diagonal and V arrangement instead of all inline. This was done so you can run a lot bigger primary without the bolt limiting size.

New2Chevy

iTrader: (11)

Ah I see. Thanks!

84firebird383

1 5/8" would be fine for A 500 HP 383. Better low end torque than 1 3/4". I definetly would not go over 1 3/4" for a 500 hp 383.

88gunmetalgta

iTrader: (1)

Well, I've pretty much decided on going with the Heddman Hustler 1 3/4" headers, but lets keep this going. There seems to be a lot of myths surrounding header choice.
From what I've seen:
There is no loss in performance from using larger headers within practical limits. If anything, there will be a slight GAIN throughout the midrange and high RPM. That's my theory, I encourage anyone to contest it, but please provide personal experience or dyno sheets or some other proof to back it up.

I'd like to see some dyno results showing a loss of power or torque anywhere in the RPM range from using a larger primary header.

84firebird383

Mine is personal experience. I had a low 11 sec 383 84 firebird that ran virtually the same with the hedman 1 5/8 and the hooker super comp 1 3/4. The super comps probobly did make More HP, but the 1 5/8 felt better just driving around. The 1 3/4 hustlers will work just fine for you.

84firebird383

1 5/8 shorty headers on the other hand made my 383 sound like an old truck motor, and killed performance all around. So bad I never bothered to take it to the track.

Orr89RocZ

iTrader: (20)

I dont have dyno results but all the big theories say too big. PipeMax predicts optimal primary size for a 383 operating from 4250 to 6700 rpms, which most 500hp 383's will run, is 1.70-1.83" primary. 31-34 inch long lengths. In fact, same size is basically used for 600-650hp 406" motor cars. I wouldnt run 2". Like mentioned elsewhere here, you'd lose scavenging.