Momentum header people! I have a quick question

DEpointfive0 · 08-21-2013, 10:42 AM

What's the inside diameter at the header to cat flange?

OEM DE is 2.25"

And some guy at Z1 said he THINKS theirs is 2.5" and that they made many improvements to the Momentum design, so I can't take his word

Megan370z · 08-21-2013, 11:54 AM

Quote:

Originally Posted by DEpointfive0

What's the inside diameter at the header to cat flange?

OEM DE is 2.25"

And some guy at Z1 said he THINKS theirs is 2.5" and that they made many improvements to the Momentum design, so I can't take his word

I will be back home tonight and will provide with true number as I still have them on my wall waiting to be modified

On top of my head if I remember correctly, the Inside Diameter at the exit flange was around 2.125'' which should give about 2 1/4'' OD.

DEpointfive0 · 08-21-2013, 10:05 PM

Quote:

Originally Posted by Megan370z

I will be back home tonight and will provide with true number as I still have them on my wall waiting to be modified

On top of my head if I remember correctly, the Inside Diameter at the exit flange was around 2.125'' which should give about 2 1/4'' OD.

Ok, because I bought TPs that are 2.25"

And I looked at my HR TPs and though, FUUUUUUCK... Those are bigger...
And if the Momentum headers have a 2.5" exhaust going to a 2.25" would make turbulence and you're choking it down

And my only solution is to either MAKE a HR flange and weld it to the headers, or MAKE a DE flange and weld it to my HR TPs
(I have a small window because the headers come in Friday and I gotta go weld it on my lunch, and Saturday I drive out to the dealer with my box of parts to install)

martin82 · 08-21-2013, 11:08 PM

The momentum header is slightly less 2.25", my z1 test pipe 350z is 2.5" or bigger oval

First pic momentum, 2nd pic is test pipe
ImageUploadedByTapatalk1377144441.937968.jpg

ImageUploadedByTapatalk1377144465.335259.jpg

Megan370z · 08-22-2013, 08:21 PM

so I just verified again with a caliper and the average Inside Dia is around 2.115'' +/-0.015''
add 2x .065 (thikness) the OD would be very close to 2 1/4'' (2.245'' +/- 0.015'')
this is the true Momentum and not the Z1 copy.

DEpointfive0 · 08-22-2013, 09:29 PM

Quote:

Originally Posted by martin82

The momentum header is slightly less 2.25", my z1 test pipe 350z is 2.5" or bigger oval

First pic momentum, 2nd pic is test pipe
Attachment 75143

Attachment 75144

Quote:

Originally Posted by Megan370z

so I just verified again with a caliper and the average Inside Dia is around 2.115'' +/-0.015''
add 2x .065 (thikness) the OD would be very close to 2 1/4'' (2.245'' +/- 0.015'')
this is the true Momentum and not the Z1 copy.

You guys are AWESOME to say the least!
I wish I could rep you guys more!

DEpointfive0 · 08-23-2013, 04:05 PM

Thanks again guys!!!

Headers just came in!!! Awesome to have a set of brand new Momentums!

Megan370z · 08-23-2013, 06:44 PM

Quote:

Originally Posted by DEpointfive0

Thanks again guys!!!

Headers just came in!!! Awesome to have a set of brand new Momentums!

brand new Momentum ? or Z1's Copy ?

DEpointfive0 · 08-23-2013, 08:07 PM

Quote:

Originally Posted by Megan370z

brand new Momentum ? or Z1's Copy ?

Brand spankin new Momentums

Owner never opened the box

brucelidat · 08-23-2013, 08:32 PM

Did you get them form that 350z owner I mentioned or did you find another source?

08-21-2013, 10:42 AM	#1 (permalink)
DEpointfive0 A True Z Fanatic Join Date: Jan 2012 Location: SoCal Posts: 14,824 Drives: a lot Rep Power: 17152	Momentum header people! I have a quick question What's the inside diameter at the header to cat flange? OEM DE is 2.25" And some guy at Z1 said he THINKS theirs is 2.5" and that they made many improvements to the Momentum design, so I can't take his word __________________ Do YOU want to know what/where I got my username from? ( Click to show/hide ) NSFW due to language:

08-21-2013, 11:08 PM	#4 (permalink)
martin82 A True Z Fanatic Join Date: Nov 2011 Location: los angeles Posts: 2,636 Drives: 12 Nissan 370Z MB M6 Rep Power: 20	The momentum header is slightly less 2.25", my z1 test pipe 350z is 2.5" or bigger oval First pic momentum, 2nd pic is test pipe ImageUploadedByTapatalk1377144441.937968.jpg ImageUploadedByTapatalk1377144465.335259.jpg DEpointfive0 likes this.

08-22-2013, 08:21 PM	#5 (permalink)
Megan370z A True Z Fanatic Join Date: Oct 2009 Location: Canada Posts: 1,156 Drives: 370z Rep Power: 24	so I just verified again with a caliper and the average Inside Dia is around 2.115'' +/-0.015'' add 2x .065 (thikness) the OD would be very close to 2 1/4'' (2.245'' +/- 0.015'') this is the true Momentum and not the Z1 copy. DEpointfive0 likes this. __________________ Megan Journal Click Me ....................One Man Team Motorsport Click Me Last edited by Megan370z; 08-22-2013 at 08:24 PM.

08-23-2013, 04:05 PM	#7 (permalink)
DEpointfive0 A True Z Fanatic Join Date: Jan 2012 Location: SoCal Posts: 14,824 Drives: a lot Rep Power: 17152	Thanks again guys!!! Headers just came in!!! Awesome to have a set of brand new Momentums! critical likes this. __________________ Do YOU want to know what/where I got my username from? ( Click to show/hide ) NSFW due to language:

08-23-2013, 08:32 PM	#10 (permalink)
brucelidat A True Z Fanatic Join Date: Jun 2011 Location: temple city, ca Posts: 2,432 Drives: 2011 370z 7AT GM Sp Rep Power: 32	Did you get them form that 350z owner I mentioned or did you find another source? __________________ Works Emotion CR Ultimate - FI CBE w/ 18" resonators - Ecutek - eibach sways - Quaife - FI LTH w/race cats - kw v3 - spl - Topgunz SC - 488whp 398trq

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
To those with Momentum headers, exhaust fitment question	chrischhorn	Intake/Exhaust	7	05-09-2013 11:56 PM
Question for people with Jdm fog light..	Yutnaka	Exterior & Interior	11	02-09-2013 03:57 PM
Quick question for people with custom fenders	Apoc370z	Exterior & Interior	2	04-15-2012 02:01 PM
Quick question	370guy	Intake/Exhaust	4	03-06-2012 10:31 AM
question about stillen header	chirojin	Nissan 370Z General Discussions	0	07-12-2009 02:38 PM