Bad idea to run FP intake on stock turbo??

[School Boy]

I've heard it's a bad idea to run a FP intake with their 4" to 2.25" reducer coupler set up on a 14b/16g. I just wanted someone to elaborate on why it's not desirable to run that intake set up. I have a chance to buy a FP intake at a really good price but if it hurts performance I don't want to buy it.

 

[92AWDHX40]

It wont hurt but help getting air into that thing just buy the reducer and grab a k and n filter I have a fp intake pipe on my car and I really like it.

 

[JusMX141]

I've heard it's a bad idea to run a FP intake with their 4" to 2.25" reducer coupler set up on a 14b/16g.

Yup.

I thought people might get some useful info out of this. I tried a few things to squeeze more power out of my 16g. With the FP 4" intake pipe, I was flatlining at about 390 w.h.p. (ECMLink) on multiple pulls in the 65-70*F range. This is about 384 w.h.p. on a dynojet for comparison. I slapped on my old Dejon 2.75" intake pipe and bought a very short 3"-2.25" reducer, not completely optimal (because of the coupler NOT the intake pipe) but it was a major improvement. Damned if that intake pipe doesn't look good, chopped about 1.5" off the BOV return pipe and it fit 95% good. Anyhow, car started pulling 400-402 w.h.p. at the same mid 60*F temps. So definitely, the 4"-2.25" reducer hurts topend flow.

From the CFD analysis I knew this part was going to make more power, I took my Injen style 3" compressor intake pipe, cut it in half, cleaned up the casting and shortened it to make it fit better using a 3" coupler for now until I could head to the welder. What makes this intake superior is the 3" to 2.25" merge. It isn't perfectly ideal as the merge isn't centered on the compressor inlet, but it is damned good for what it is. The BOV pipe needs to be lengthened a bit though to fit better. Anyhow, the car immediately laid down 406 w.h.p. at about 68*F, back on the 2.5" downpipe plumbed back into my 3" catback. Topend airflow in 3rd gear is up to 42.5 lb/min which is about +1.5 lb/min more than with the FP 4" intake pipe. The superior funneling to the compressor inlet allowed me to pick up some topend airflow and cranking the boost higher allowed me to take advantage of it. This same "high" boost setting did nothing for me on the FP 4" intake pipe and in fact I made a touch less going that high, so the improved intake flow goes hand in hand with cranking up the boost.

Basically, I was predicting a +20 h.p. increase going from the FP 4" intake to a completely optimized intake pipe, the Injen got me about +16 h.p., which still has room for improvement.

 

[92AWDHX40]

So it is I never knew that jus.

 

[School Boy]

Wow over 15 awhp just from a coupler...

 

[ErikTande]

Well shit, good to know. I need a new intake for my 1g then. I have a 14b with a 2g MAF. Any suggestions?

 

[901gtsi]

Well shit, good to know. I need a new intake for my 1g then. I have a 14b with a 2g MAF. Any suggestions?

If I were you I would get a stock 2g intake pipe a vibrant 4inch filter adapter and a 4 inch k&n air filter.

 

[School Boy]

So it's just the FP coupler that causes aif flow issues? Is there a different coupler that can be ran that will fix the issure?

 

[snowborder714]

It's the FP coupler based on the reduction (4"-2.25") length of 6" or so. Trying to cram all the air you can suck in via a 4" intake pipe into the 2.25" inlet of a 16g in the length of just a coupler is not ideal. You want to try and best match your intake pipe size to your turbo inlet size so as to allow air to enter as smoothly and streamlined as possible.

If you want to run a 4" filter though, then you'd want to design your intake pipe to accept the filter and gradually reduce down to the turbo inlet size over as long of a run as possible to keep everything smooth.

 

[92AWDHX40]

Ah it makes sense now.

 

[School Boy]

Yeah, makes sense.

 

[Sjd6795]

Old post but if the coupler causes such a disturbance in airflow what about the BOV re circulation tube that runs half way down the stock intake pipe ? That is more of an obstruction then a 4"-2.25" coupler that has slanted edges to help flow the air.