i have a jdm 4-1 and was wondering if it was worth putting on an actual 2.5 inch collector instead of the "SUPPOSED" 2.5 INCH collector that is on there, also anyone port the flange and have a dyno chart to compare?? was wondering if that was worth it also, My motor has over 200whp N/A now so i was just curious if this was a good mod or what?

 

If you have that much power, I would definately recommend getting a better header like a toda, smsp, or hytech.

 

I thought the JDM 4-1 is 2.5" *scratches head*

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid ctr &raquo;</TD></TR><TR><TD CLASS="quote">I thought the JDM 4-1 is 2.5" *scratches head*</TD></TR></TABLE>

It IS...but it is double walled so not a true 2.5" collector.

And in response to the original question...I think grinding out the welds on the primaries would yeild more gains. Do both if you feel energetic...but if you only have money/time to do one, I'd do the primaries.

 

There is a smaller tube "inside" the 2.5 collector.

 

getting a decent price on anything like that up here is rare since i got the jdm one i am going to stick with it unless a good deal comes around,

i here that porting the header flang is good but has anyone put an actual 2.5" collector on?

also is there any links to people that have actually done any of these mods?

 

get a SMS header, you wont regret it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by T.O.STREETRACER &raquo;</TD></TR><TR><TD CLASS="quote">getting a decent price on anything like that up here is rare since i got the jdm one i am going to stick with it unless a good deal comes around,

i here that porting the header flang is good but has anyone put an actual 2.5" collector on?

also is there any links to people that have actually done any of these mods?

</TD></TR></TABLE>

Never seen the 2.5 inch conversion, but D or someone on http://www.sandmracing.com/ ported the primaries and I followed their pix, i dont have any dyno results, but it cant hurt!

 

i would love to but could you imagine it would be nearly $2000 after shipping and coversion to canadian funds, and then i may still have to pay duty.....ouch unless i find one used for a good price .....i can't see myself spending that kind of money on a header....