kooks 1 7/8 x 3" or kooks 2"x3"

[Juiced1]

On a boosted car it matters even less.

[ABADZL1]

I have the Kook's stepped headers. For the same reasons Brian mentioned. They are a little more expensive. Very nice headers that match the exhaust port. According to Maryland Speed, the stepped headers made 10hp more, and 7ft pounds more than the regular 1 7/8. They run them on their 750hp SS



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[jayno20]

Originally Posted by TXsilvy

I love reading regurgitated internet bullshit with zero proof or backup. nobody has even asked what the future looked like for this build.

OP, do you ever plan to install a blower, or nitrous? and by nitrous, I don't mean a dinky 200 shot or less. do you plan a 250 shot or larger at any point down the road?

What "regurgitated internet bullshit" are you referring to? You realize pretty much everything posted in this thread is FACT, right? Reading > you.

[ABADZL1]

There's always that one troll

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[jayno20]

Originally Posted by ABADZL1

There's always that one troll

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Isn't that the truth.

[TXsilvy]

Originally Posted by ZO6 Bryan

I have never seen the need in 2" primary tubes when the exhaust port in the head is only 1 3/4". The sudden jump in diameter from 1 3/4" to 2" will cause a drop in the velocity of the exhaust gases as they exit the head. Different story if you've ported the heads and the exh port is much bigger.
But this is exactly why I got the stepped Kooks headers. The first 6" of pipe is 1 3/4 just like the exhaust port. Then increases to 1 7/8" for the rest of the primary tube until it hits the collector and dia. changes to 3". This maintains higher velocity of the exhaust charge. Then the merge collector is designed to "pinch" the diameter so you don't lose velocity in that area.
And for those that don't know...Velocity = Torque This is also true in the intake track.

2" headers MAY provide a tiny bit more power at WOT on the very top end, But will result in less torque everywhere else. Especially idle to part throttle and mid range RPM.

Referring to posts like this. All theory, no experience.

Originally Posted by n0speedlimit

great info provided seems like you wouldn't noticeably feel a difference between the two and as far as common sizes i think the 1 7/8 would be a better choice, not taking anything away from the 2" tho.

Then the 10 post guy looking to learn takes it to heart and potentially spends money on the wrong parts...just one example. The rest of this thread is fine. Sorry i should have quoted from the start but my tiny iphone 4 sucks when using sausage fingers.

Originally Posted by ZO6 Bryan

Pay attention. He already has a blower.

Im not hip on the packages of a gen 5/6. Didnt know a zl1 had a blower...so its not anything i missed in writing my point is a blown 6.2 can absolutely use 2" primaries. Especially if there are any plans to cam or pulley down...lets face it- even if you dont plan to now, you probably eventually will.

Im even taking it a step further and going w a 3.5" collector and dual 3.5 exhaust. Theory says major loss on bottom, my gut says my blown 408 will enjoy ghe extra flow. Maybe its a flop and i do lose...atleast ill have the experience under my belt after the fact. Its easy enough to rip out the 3.5 exhaust and replace it with 3". Doubt it will come to that.

Once upon a time nobody ran more than 1 3/4 headers on a lsx. When a 1 7/8 header hit the market all it got major pushback from the "bigger loses bottom crowd". Now they are accepted as the go to size for 5.7+ CI. Its just a matter of time before 2" becomes the go to with ls3 heads and factory blowers.

[jayno20]

Originally Posted by TXsilvy

Referring to posts like this. All theory, no experience.

You must be new on this site so I'll give you a break but ZO6 Bryan is no newb, he has PLENTY of experience. Again, what do you think he is saying here that leads you to believe he has no experience? Everything he is saying (and everyone else in this thread) is not only true, but it has been PROVEN.

[GoldCartridgeGamer]

Have done tests on the street with all sizes. 1-7/8" is the sweet spot for street, racing, and most applications. 2" is only good for big builds with ported heads.

[TXsilvy]

s. Im new here, but been around the lsx since 99. 1 7/8 is the answer for a na build. Were talking a blown motor here. Lol, yhanks for giving me that break chief. To say there is not a need for 2" primaries is closed minded.Take your internet guideline against real world experience i guess.

[GoldCartridgeGamer]

Anytime you need some input cutie pie. ;-)

[TXsilvy]

Not sure where i got input from you...just defense for your ill informed BFF and a "break". I'm truely not trying to come across as a troll here. i'm not doing a good job though lol.

Btw. "On the street" is not a test. Dyno or track is the only acceptable results cutie pie

[GoldCartridgeGamer]

Easy you responded to what I and others had to say sugar.

On the street is acceptable. No real difference than on the track. Dyno results mean nothing to me. Street and numbers on the track mean more honey buns.

[jayno20]

Originally Posted by TXsilvy

s. Im new here, but been around the lsx since 99. 1 7/8 is the answer for a na build. Were talking a blown motor here. Lol, yhanks for giving me that break chief. To say there is not a need for 2" primaries is closed minded.Take your internet guideline against real world experience i guess.

You are on the ZL1 forum, we all have blowers STOCK. No one ever said there wasn't a "need" for 2" primaries just saying it MIGHT not be worth the extra cost outweighing the benefit. 2" primaries have their place, sure, but is the cost/added weight/fitment issues worth an extra 2 or 3hp you MIGHT gain over 1 7/8 headers? Probably not.

There is more than enough data out there to prove this. I don't get why you are fighting this so hard.

[TXsilvy]

Originally Posted by Lgndryhr

Easy you responded to what I and others had to say sugar.

On the street is acceptable. No real difference than on the track. Dyno results mean nothing to me. Street and numbers on the track mean more honey buns.

Street is " sotp" track has real numbers to back it up...dyno is measurable. Track is measurable. Street is not.