it'd have to be a BIG change to impact ride height meaningfully - which again, mine did not

so - replacing the UICP & turbo inlet tube. I think my intake currently only uses 1 vac line, the new one has 2. I was recommended to just install & cap off the unused one. re: the connections to the BPV, hoepfully it'll just be a 1 for 1 change. The positioning might be a little tricky/require some angled hoses to connect the BPV to both parts, but otherwise this is relatively straightforward, correct? I might even be able to do it while leaving the front bumper on, seems like there will be enough room.

Are you still using a MAF? I assume so since you are talking about recirculating the BOV. If you change that intake tube to the turbo, you likely will need to adjust the tune since it will alter the MAF readings.

yes on the MAF - and shoot, I thought it would be all right without a retune, didn't think that tube going from the OEM rubber to an aluminum hardpipe would introduce that much change?

I haven't had a MAF on my car since 2008, but I know that when I swapped to a metal intake back in my MAF days, I immediately had issues with running lean in low RPM conditions (stalling in intersections) and a change in AFR in open loop WOT conditions. It makes a difference. If you have confidence in your tuner, next time get an SD conversion so you don't need to worry about it or not being able to drive back to the pits if you blow off an IC coupling on track.

weird... ok, good to know, thanks. i guess a retune is in order.

I have that stumble issue occasionally, especially if I bog taking off and Ive had a MAF + Solid Metal intake for always. Never even though that was the cause or I woulda swapped back to an OEM.

i seem to have lost the lean and unstable idle when i removed the orig pcv system

well it, and the uicp, will be the only thing i'm changing relevant to power, so if something comes up i will be sure to mention it

I’m not trying to say that a non-stock inlet pipe is bad. It just alters the MAF signal, so your AFR changes in open loop conditions and your trims change in closed loop. I think it leaned out the low end and richened the top end on my car before tuning for it. These pipes are not all the same and don’t affect the MAF readings similarly from one pipe to another though. Mine has an S bend FWIW. The upper IC pipe shouldn’t matter unless your BOV changes and leaks less or more.

mine has an s shape as well, i heard that is necessary for our cars to run right with aftermarket inlet tubes. bov staying the same, hopefully no leaks ha.

Id imagine its not altering the MAF as such but the volume of the pipe if it is different to stock would cause issues potentially.

Right. The MAF signal is scaled for the stock pipe not anything else.

ahh ok i see what you mean

Yea, correct me if im wrong but as i understand it the MAF is reading the volume of flow past the sensor and then it has a known volume and therefore time before that volume of air reaches the combustion chamber and if you go and make the flow path twice as long or twice as wide for example that whole calculation is now incorrect.

I would assume if you had a intake pipe the exact same length and diameter as factory you wont have an issue but if you change either of these parameters it will affect the MAF calculation?