Header question???

[Blackdevil77]

When I look at long tube headers, there are usually 2 options. 1 7/8" and 1 3/4". What is the difference between the two and what effect's would it have on the car? And on passing emissions?

[Rob@WretchedMS]

Size wouldn't have any effect on emissions, as long as you local laws allow long tube headers. One thing to keep in mind is that the cats need to be changed out with long tube headers, and most states limit you changing cats before 8/80. The question is whether the person doing the test knows, cares, or looks. In most cases they will not.

The bigger headers will be better for forced induction cars, while the smaller ones are more for cars that do not have super chargers. There is a fairly good debate at bigger being better, but both will do a good job, and in most cases gains are very close on both.

[GRRRR8]

I truly think 1 3/4 is more then enough and it WILL make more lowend torque. It is published and proven. If there is any chance you will put a cam and converter, 1 7/8 is the correct choice. They make more hi end HP, which you will have and the converter is bringing you above the point where the 1 3/4 is giving you the extra torque.

[Blackdevil77]

then that makes things a bit more complicated. I am considering getting a cam. Not 100 percent sure yet, i wanna hear more of what other people think and what are getting in their cars. The converter, I am also still thinking about. Only one i saw was 3200 which i think is too high.

[-Ray-]

Even if you don't get the cam later, the 1 7/8" primaries will not hurt your performance.

[Mike P]

I truly think 1 3/4 is more then enough and it WILL make more lowend torque. It is published and proven. If there is any chance you will put a cam and converter, 1 7/8 is the correct choice. They make more hi end HP, which you will have and the converter is bringing you above the point where the 1 3/4 is giving you the extra torque.



Oh shit! So I should have went with the 1 7/8"!?? That sucks......


...

[Andy@Livernois]

yep, We use 1 7/8 on all of the ls2 cars in here, whether its head/cam or not... We will be using 1 3/4 on the G8's just because of how small the cam is, but if boost, cam, or spray is in the future we would do 1 7/8...

[GeorgeInNePa]

Nick at ARH told me to use 1 3/4, even though I told him a converter and a cam were in the future.

I am beginning to think I/he made a mistake.

[Andy@Livernois]

I will ask rick for a dynograph, but we had a customer with our stage 2 head/cam package upgrade from 1 3/4 to 1 7/8 and picked up low end/midrange torque and HP throught the RPM range. it didn't lose hp or torque anywhere...

[GeorgeInNePa]

http://www.ls1tech.com/forums/showthread.php?t=981234

[GRRRR8]

I will ask rick for a dynograph, but we had a customer with our stage 2 head/cam package upgrade from 1 3/4 to 1 7/8 and picked up low end/midrange torque and HP throught the RPM range. it didn't lose hp or torque anywhere...

They wont either once heads and cam are changed.

[Andy@Livernois]

They wont either once heads and cam are changed.


I also know on the older ls2 cars we did we usually installed 1 3/4, but now we do 1 7/8... Same thing, more power and torque, which is why all of the LS2 stuff gets 1 7/8...

[Andy@Livernois]

http://www.ls1tech.com/forums/showthread.php?t=981234

I agree 100% a well engineered 1 7/8 will make more power and torque then a 1 3/4".