LQ4-E39

iTrader: (7)

I'd like you folks to make some recommendations to my intake setup. I'm wondering if I'm running a restrictive intake tube and/or MAF. Mostly, I'm looking to improve throttle response, and intake sound (looking for it to be louder if possible).

Current intake setup is a 3" short filter -> 3" 304SS pipe, 6" long -> stock 2003 LQ4 MAF -> 3.5" to 4" 90 silicone elbow into the throttle body, which is a stock LQ4 van throttle body, ported and polished, with the IAC cavity filled and drilled.

I am wondering if I have anything to gain by going to a 4" aluminum pipe with a matching ID filter. I hear the stock LQ4 MAF is pretty unrestrictive as is.

Engine details:
2003 LQ4 Iron 6.0 pulled from van with 134K
Stock bottom end, rods, pistons, etc
Stock rod bearings, cam bearings, main bearings, etc
GTO oil pan, pickup tube, windage tray
Stock Z06 Cam from 2002 Vette
AC Delete (not running an AC compressor at this time)

Top end:
317 heads milled .026” for 66cc chambers (verified by the machine shop that did the work).
Stock pushrods, rockers, lifters, etc
LS6 “yellow” valve springs and retainers

Stock LS6 intake manifold
Stock LS6 fuel rail, with 42# Ford Greentop injectors

Exhaust:

CTSV cast iron manifolds with the cats removed, paired to OEM BMW exhaust





any thoughts? 4" pipe up from a 3"?

thunderstruck507

iTrader: (18)

I can't say for sure, but I went from a small cone filter with a 3" outlet and a stock MAF up to a HUGE cone filter with an over 4" outlet with a velocity insert and 85mm MAF on my car and didn't really gain jack.

I had also tried a 3" pipe extension to put the filter down low to pull cool air from under the bumper and it showed no results either.

I am thinking you are probably fine and if you decide to change it should be for some sort of ram air setup rather than just a bigger cone/pipe.

LQ4-E39

iTrader: (7)

anyone?

maf_diver

Do you have a scanner? Log the MAP reading at full throttle high rpm and compare to key on engine off MAP. Each kPa of pressure drop = about 1.15% power loss. I've played with a few setups and would guess you are losing 5+ kPa with that intake and would get down to 3 kPa with a 4" tube and bigger filter. May or may not be worth it to you, but it's relatively cheap and easy gains with no downsides.

1964_442

iTrader: (5)

Yes the shorter the less restrictive and louder will be, and running same diameter on all intake components is the key for a good flow

FAD2BLK93

Why not run a ram air from under front bumper like the chris1313 or the SSRA? Just curious, i love mine! Felt like i picked up some HP! Havn't been to track yet.

thunderstruck507

iTrader: (18)

Guessing you are on a phone and can't see his picture...no room for such things on most swap cars.

OP: looks like you have plenty of room there, go on ebay and order one of the cold air kits for trucks. Has a 4" aluminum tube, 90* fitting, and a LARGE filter with a velocity ring inside of it.

It will be a larger and smoother setup than you have now and only run you $60 shipped. Mine is loud on both the truck and the car and it's about as free flowing as you can get.

LQ4-E39

iTrader: (7)

I have no room in the front bumper for cold air. aluminum crash bar and crap are all in the way.

Thunderstruck, can you link me to something like that? I want to also have one of these:



http://www.ottperformance.com/store/...-Bung-p115.htm

welded in place to ditch the whole plastic crappy looking MAF sleeve. That way it's a smooth transition from filter, straight past the cartridge, through the 90 into the TB. Right now I have a crazy combination of filter, 3" SS pipe, coupler, MAF sleeve, coupler 90, into TB. The MAF sleeve and 3" intake seem like the biggest restrictions (smallest diameter) along with the small filter.