[Genesisboupe]

What’s the better header? I believe the ngm exit is 2.5” while the J2 is 2.30” I am using the stock downpipe which u believe is 2.30”. So which one would be better?

 

[B3.8R-SPEC]

I can't speak much about the J2 as I couldn't find one when purchasing headers but I like the 2.25 exit on it rather than the 2.5 on the NGM which I do run now. I'm also running stock 2.25 downpipes as I believe the 2.5 exit and 2.5 downpipes are just too big for the 3.8. I believe they both run 1.75 inch runners which I think is perfect unlike the 2.0 ARK header runners.

J2 Cons
Circle inlet on runner that connects to exhaust head. Ports on Head is oval.
Can't speak on quality.

Pro
2.25 Exit
1.75 runners

NGM Cons
2.5 inch Exit

Pro
Great quality/welds. Going on 2 years no issues.
Well made collector.
1.75 runners

Hope this Helps.

 

[Genesisboupe]

I was thinking off getting the ark downpipe to match it to 2.5” but I heard 3.8 lose power from changing the downpipe cause it changes the power band. Not to sure about that tho

 

[bk1_3.8]

i got j2 headers on a bk1 3.8, you will definitely hear the difference lmao, as for low end power i have lost a lot but once i’m retuned i’ll be chillin

 

[B3.8R-SPEC]

I was thinking off getting the ark downpipe to match it to 2.5” but I heard 3.8 lose power from changing the downpipe cause it changes the power band. Not to sure about that tho

Stick with the stock downpipes and grind down the lips in them to get them to a 2.25-2.36. 2.5 inch downpipes are too big….

BTW the NGM’s I have are actually 2.25 on the exit which is perfect.