quick question i have a fmic on my car that i did using a diy article on the forum in which the guy used a 2.5" inlet/out fmic, and on the turbo side used 2" piping and on the outlet side used 2.5" piping. i have run it for awhile with no complaints, but i noticed all the kits run either 2" or 2.25" ic piping on their kits.

QUESTION:

Is the 2.5" piping helping or hurting my performance? should i make it all 2.5" or 2" or keep it the way it is now?

 

If you dont have pressure drop, dont worry about it.

 

as in boost pressure? it doesnt appear to be dropping except of course the bleed off from a leak i have to find. does the 2" on the one side help or can i swap it all to 2.5" up to the inlet piping?

 

With a k03/04, the closer to stock dimension i/c piping the better.

 

is that due to a spooling issue?

 

Itsdue to a need for minimalvolume of space to maintain aconstant pressure that a turbo the size of your fist is blowing.

 

gotcha, thanks for the advice.

 

2.25" all around would be best. Elitetuning or something like that has 2.5" and he has a great deal of pressure drop and im sure his core is a little to large also.

 

yeah i had 2.5 piping and was at 11 psi. i just put on 2" piping and now im still at 11. im checking for boost leaks and i think my mbc is faulty cause no matter what i do the boost never changes.

 

see i have run this setup for awhile and since i run stock software i was always at 9.5 psi i always had leak issues too and elbows popping off. then i upgraded the couplers and put t-bolts on. no pop offs but like a week ago it would hit 9.5 then slowly bleed down to 7 or 8. now it wont go any higher then 7 or 8. confusing...any ideas?

Does9.5 psisound like i had a huge pressure drop. maybe a 1/2 psi not sure what stock psi is exactly, i heard like 10 psi. i have dumped a bunch of money in this diy so far and the wife is gonna kill me soon. switching to 2" on both sides or 2.25 would be another 100 - 200 dollars. good couplers are expensive!