Jadedbird

iTrader: (27)

i might be a naive. but 7/8 has more room the 3/4... so thus more can be pushed through and more power right?

ill believe 3/4 is better when i see a side by side dyno sheet

1989GTA

It is all about getting the exhaust velocity to the right speed. You want the exhaust gases to exert the biggest pull on the intake track during the overlap period. Kind of a mini supercharging effect.

lemons12

iTrader: (71)

When have you ever seen 0-60 testing on this site?

I'm sure if you search you can find track results. Dyno results show people picking up power everywhere in the curve, impossible not to ET and MPH better with them.
No you won't... After you see the dyno results you will believe 7/8 is better.. LOL

Hi-Po

iTrader: (4)

Perfect!

LS1MCSS

iTrader: (18)

I'll ask the question that everyone else forgot to ask. Did you measure the ID or OD of the tube? If you measured the OD, the you got what you ordered.

dlandsvZ28

Exactly - I think he will find that he got the correct headers if he measures them correctly with the proper tool.

1989GTA

Tubing is measured in OD. IMHO all you need is a set of dial calipers. Measure a section of straight pipe as a bend will shrink somewhat.

hiram007

iTrader: (19)

Just call them back and let them know what happen, I have done it before and its not a big deal. Its not even really a money thing, more of an honesty thing. Will they miss the dollars, maybe not but I think anyone who sells anything would like to know and be aware of what happen.

On a seperate note, can you post pics after the install?

2011grandsport

Hey OP! if you fill that you have the wrong headers and you purchased kooks, call or e-mail both kooks and the other vendor you actually purchased from and give them a heads up about the problem. I purchased a set of kooks headers and catted x-pipe from a supporting vendor on here and both were very helpful when i found that the x-pipe was the wrong one, i contacted kooks and gave them the part number i had recieved and they told which one i should have recieved. I then called the vendor i purchased from and they immediately contacted kooks and ordered the correct part and had it shipped. The vendor sent out a call tag for the wrong part and it was picked up the next day. I recieved my correct part and it had the wrong tag showing it fit another vehicle, immediately contacted kooks and with-in an hours time they saw i had the correct part just mislabled.
Kooks will work with you and make sure you have what you asked for and the other vendor will also, i know from experience.

FormulaTA327

I called them today and let them know what happend, they said to keep them and that i got one good deal out of it which is no lie. the box they came in said 1 7/8 and the tag on each header said 1 7/8. Just to double check from being mislabeled how do i correctly measure to see if it is 1 7/8. I will post pics when done.

2011grandsport

Tubing is measured by the outside diameter where pipe is measured by inside diameter until you get to 12" diameter pipe and larger then it is measured by outside diameter. If you have a tape measure used for making clothes, wrap it around the o.d. of the header tube write the measurement down take a calculator and divide by pi or 3.1416 and that will give you the measured o.d. Should be approximately 5.8905 inches which comes out to about 5-15/16" in. wrap dimension. This will calculate out to about 1-7/8" . If you measure 5-1/2" wrap dimension then you have 1-3/4" headers.

BrntWS6

iTrader: (7)

Quote from Brian Tooley....

99peweterls1

iTrader: (1)

Everyones quick to say the 1 7/8 are better, when they really need to read up on velocity like svede said... Of course exhaust valve size, exhaust port, cam lobes, primary length and collector length don't matter. Yall just keep throwing on "the big ones" lol

hiram007

iTrader: (19)

Wow, despite dyno after dyno after dyno, statements like these are still being made................

lemons12

iTrader: (71)

While we read up on that to see why you guys think you are right... You read up on the proven real world facts and see why we are right.

lsxc4vette

iTrader: (9)

I don't care about a dyno results.I want to see 1/4 mile results.

Guitar

iTrader: (9)

Good man.

Do you expect something making more power to magically run slower numbers in the same scenario with the only difference being the headers?

1989GTA

"Wow, despite dyno after dyno after dyno, statements like these are still being made................"

It is because the statement is correct. It is all about getting the exhaust velocity correct for the given application.

hiram007

iTrader: (19)

I probably should have been a little more specific. What I was meaning to respond to was this part of the quote:

I've "read" enough dyno numbers to know that even in stock application, they are better. This is what I was referring to.

lsxc4vette

iTrader: (9)

Yes, because whens the power coming in at.What rpm?You could be losing with the bigger headers on his car,in the lower rpm's.Sure he will get the power back up top but will it be enough to make up what he lost down low,say 0-60 or 1/4 mile times.And I'm only saying the op's car.Sure if you have a stoker or a bigger built motor than the bigger headers will help you down low.Just saying I would'nt say it's good that he got the bigger ones unless I new for sure.It all depends on what he's running for the rest of his exhaust system too.