Nissan 370Z Forum - F.I. Long-Tube Headers installed

Nissan 370Z Forum (http://www.the370z.com/)

- Intake/Exhaust (http://www.the370z.com/intake-exhaust/)

- - F.I. Long-Tube Headers installed - Review/Pics/Vids/Dyno (http://www.the370z.com/intake-exhaust/18022-f-i-long-tube-headers-installed-review-pics-vids-dyno.html)

Quote:

Originally Posted by F.I. Inc. (Post 510329)

Looking good, looking good! Torque and power throughout the curve are by far the most important.

I want to point out one thing. Some of you will think I am taking a jab but I have a hunch. I am extremely confident that the reason is top end power tails with our long tube headers is due to the Stillen CBE. I feel from a design standpoint that the Stillen CBE is now causing a restriction at that RPM level when combined with our long tube headers. In a nutshell, I think the headers flow too much for the CBE!

Take it as you will, but ask yourself why else would the power drop off. It is not like our headers are more restrictive than the previous setup on the car. Well, if it isn't the headers causing the restriction it has the be the one other component.

Before anyone says anything in reply, please mow my theory over in your head. I am not trying to bash. Personally I think Semtex's car sound great with his current setup. I just want to put all of the cards on the table...

Thank you, Tony

Tony, your theory is certainly plausible. But if the CBE is too restrictive for the increased flow at the top end, wouldn't that just prevent any gains from being realized? In other words, why would it cause actual loss? Wouldn't we just see the numbers stay flat?

Quote:

Originally Posted by semtex (Post 510419)

It is possible but it would all depend on how restrictive the CBE became at that RPM level. Now obviously the CBE is not restricting the exhaust in the low end or mid range or you would have the same effect there.

semtex: 154

It's available.

Quote:

Originally Posted by WShade (Post 510475)

semtex: 154

It's available.

Actually he would be #155.

#153 & #154 are taken. I just haven't added them to the list yet...

Tony

Thanks for the review and dyno's Semtex

Rep to you

Those dyno graphs show a nice fat power increase right where you want it, who gives a rat's *** about what the engine puts out at 7500rpm, that mid-graph HP AND TQ increase is huge.

Great writeup. I'm hoping to get the whole F.I. enchilada myself. :D

Ugh.. I was hoping that I was going to snag #154. Tony expect a phone call...sooon

Semtex, Tony might be right because if I remember correctly, the diameter in the Stillen exhaust varies from head to toe. Its something wierd like 2.25 > 3?? > 2.25 > 2.5 > out. Please dont quote me, I just thought I remember thinking that to myself when I hacked up the exhaust. They dont use a consistant diameter throughout and that might be a restriction as it reaches the top.

Wow can't believe I missed the tq being there. Lol. Oops

Quote:

Originally Posted by F.I. Inc. (Post 510482)

Actually he would be #155.

#153 & #154 are taken. I just haven't added them to the list yet...

Tony

I sent you pm, Tony. ;)

I just noticed that the paper printout of the dyno I got from Sharif is actually a little easier to read than the screen capture, so I scanned it in. The lines are thinner so you can see the deltas better and more precisely.

http://www.the370z.com/members/semte...2310-sheet.jpg

not sure if this has been covered but since i didnt want to go through all the pages of stuff, will the lth with aftermarket exhaust be able to pass emissions? or will i have to pay to have them removed before taking the test?

if you cannot be bothered to read we cannnot be bothered to help oyou

Quote:

Originally Posted by SkyZ (Post 510871)

I doubt it would pass....lol.... where in Canada are you from?

Emission tests don't exist where I live....lol