Headers

Phoneguy

Cometic HG stress tester
I have a very nice set of stockers off of my 43k mile GN if you are looking to stay with stock headers. No crossover though.
The stockers flow well into the tens.

Bryan
 
Just went through all of what you have done, the ones from Protuning didn't fit so I got the ones from TA Performance but I bought them from Kirban. Good quality and good fit. I recommend them.
 

2QUICK2B6

Black Car Fever
Earl I like u a lot n a can agree. But if your going aftermarket headers get the best ! I only went 10's afrter burning uup evey cylinder with postons ,,, stock cam btw .. im only looking for low 10's high 9's on this stock block
 
I know I need more than headers, but these are a part of my planned upgrades. Valve springs, high performance chip, fuel pump hot wire kit, torque converter, etc..
 

scojack_2001

Livin' Like A Refugee
Like its been said, stock headers are good into the 10s. I went 10.97 on them. If, and I say this from experience, you can keep them from cracking. My stock drivers side header had been welded up four times, and the passengers side once. Last summer I found them both cracked. DS was cracked all the way around the collector, and the PS header was blown out between #3 and #5 tubes, in a nice rectangular fashion.

I went to TA stock replacements. Excellent quality, fit perfect. No issues. The turbo flange was a bit of trouble though, as it expands slightly right under the flange. No big deal, just use a wrench to tighten the nuts. Other than that, they're perfect.

Sound has changed too with the new cam, sounds throatier at idle and off idle. Also the 1.5" crossover improved spoolup over the 2.5" Kirban one I had previously.
 

GNICETRY

Cat&wife post starter
Sound has changed too with the new cam, sounds throatier at idle and off idle. Also the 1.5" crossover improved spoolup over the 2.5" Kirban one I had previously.

I just bought the TA headers and had them swain coated. They aren't on yet but I was under the impression that the headers make the car sound more throatier.
Did you install the headers at the same time as the cam?
 

earlbrown

runs with scissors
I know I need more than headers, but these are a part of my planned upgrades. Valve springs, high performance chip, fuel pump hot wire kit, torque converter, etc..


You're mistaken.

Springs, chip, hotwire, etc... are what we refer to as ''stock''. (along with all the other PM that needs to be done just to have a reliable streater)
 
The ultimate goal would to make it a 11-12 second car. Im not one to go to the track, but I like the power there when I want it. I would only drive to car to shows/cruises or on sunny warm dry days in the summer. Stays up in the winter. I guess if the things I am doing to it are "stock" to other members, than I am only doing stocks things to it.
 

NY Twin Turbo

All the good stuff.....Times 2.
If you goal is to be low 12s's to mid 11's, for performance reasons, aftermarket headers are a waste of money.

If cracking is the reason you want to upgrade, get a quality set. And it seems like TA is the favorite here.

If show is the reason, I would buy a spare set of stockers. I would remove the heat shields and smooth-out the spot weld marks, bead blast them, weld up the cracks, and high-temp coat them. Then I would do the same to the ones on the car. And them swap them out when maintenance was required.

It's a pain in the ass, but you get good at it after a while. It's like changing spark plugs.:p
 

Nick Micale

Tech Advisor
Staff member
Unless you're in the 9's, headers won't make your car faster.

Actually when we were developing and testing the TA headers we found up to .5 tenths improvement over other brands of headers.

These were mid-ten second and faster performance built GN's that were very consistent performers.

The cars being used were modified of course, and when using well-ported heads there was a noticeable and documented increase.

Another factor that comes into play at this level is the RPM range of the engine, as the added HP is being developed at 5000 and up RPM which most cars do not see on the street.

One additional improvement we found during our testing, if the engine is at 600 HP and RPM well over 6000, using a 1-5/8" primary tube over a 1-1/2" will also show a gain in HP.

We have spent much time on the dyno and at the track with lots of combinations, parts and mods to optimize many GN's that set records and win in competition.
 

20psiofevil

Active Member
My logic is this, (and someone correct me if I'm wrong) a v6 car has to use bigger exhaust primaries vs a v8 at the same power because there is more exhaust flow/cylinder pressure per bank trying to exit the cylinder. Would this apply to the cross-over as well?
 

NY Twin Turbo

All the good stuff.....Times 2.
My logic is this, (and someone correct me if I'm wrong) a v6 car has to use bigger exhaust primaries vs a v8 at the same power because there is more exhaust flow/cylinder pressure per bank trying to exit the cylinder. Would this apply to the cross-over as well?

I think it's more of a volume/distance thing. You don't want to struggle filling a volume up with exhaust gasses if your losing the pressure through an over sized turbine housing just as fast. And you don't want to lose the heat with distance. You probably would never want a primary smaller than the square area of the exhaust port either. But if that turns out to be bigger than you want, then I guess you can lower the volume by shortening the length (relocating the turbo/turbos closer)

I agree about primary size compared with a V8. Most home-built V8 combos probably use headers that could be smaller to optimize spool-up. Then the collector should be a little bigger to receive the additional primary. Those guys just don't know that yet.

Technically, there may be a different perfect diameter primary for every turbine/head/cam combination. But that's not possible. Tubing can't be infinitely adjustable. I't only comes in certain sizes as well. So, there are sizes and configurations that cover a broad range of flow. 1-1/2 for stock heads and mild combo/turbo, 1-5/8 for ported and aftermarket heads, 1-3/4 or bigger for stage heads and big flow motors.

The proof is in the testing. That sort of stuff we leave to Nick Micale and TA.
 

earlbrown

runs with scissors
My logic is this, (and someone correct me if I'm wrong) a v6 car has to use bigger exhaust primaries vs a v8 at the same power because there is more exhaust flow/cylinder pressure per bank trying to exit the cylinder. Would this apply to the cross-over as well?


Complete different set of rules. It's apples and giraffes.

Our headers are basically a signal medium that transfers pressure to the turbo. If the tubes are currently big enough, all bigger tubes will do is slow don't spool. A little bit bigger in diameter is a LOT bigger in volume.

A N/A set of V8 tuned headers are a completely different animal.
 
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