VRSF 4" intercooler is on and here's my review
 

Just got my 4" VRSF intercooler and Muse LICP from Tiago at VR-Speed.com today (super-fast shipment :D ) and I just mounted them a few hours ago.... I replaced my old TurboXS 3.5" tired and gunked up intercooler and my Injen LICP (FINALLY) ....let me tell you... This thing fits so nicely under the crash beam that all I had to do was slip it from under it... Without touching anything else, I went for a test drive ....my evo seems to be spooling up faster and is now peaking at an extra 1-2 psi ....this intercooler is a heavy solid piece..... I will probably need a retune, but overall I am happy with my purchase.... The only hiccup and gripe that I had, was that the supplied couplings were an inch too short on the Muse Lower-side and 3/4" too short on the Injen Upper-side ( Hey Tiago: take notes, make your silicone couplings an inch longer please :P ) ........lucky for me, I remembered I had some extra 2.5"-3.0" 45 degree silicone reducer bends laying around ....just wasted an hour trying and trying to get my pipes to line up, and another 30 mins looking for my spare couplings in the garage ... I will let you all know how my tune goes, when I get a chance to get her back on the Dyno .....thanks again to Tiago !!!

Got any photos on how it fits with the crash bar? Im in the market for a new intercooler and this looks like something I might invest in

It was getting late when I finished it but Tom I will go out and take some pics in the sunlight

Actually was looking at these VRSF intercoolers tonight. Trying to decide between the 3.5 or 4".
Glad to hear the fitment is good. What whp are you around?

I'd go for the 4" ....fits perfectly and it will flow more when you need it to... I am around 550 on 93 using an ef4 map turbo

I don't know how spool up would have increased with a larger IC?

And a heavy intercooler isn't desirable :/

the heavier the core the denser it is and the better it is at doing its job

A denser core would slow down air more, which would slow spool, not improve it. So the question as to how it spools faster vs the previous IC is a valid one. Could have been boost leaks in the old configuration or improvement from the different LICP I suppose.

Density (finpack)and weight are not necessarily proportionate. Considering thickness of bar and plate plus end tank...

Pre and post iat would be interesting.

After my install, my spool was About the same, maybe a little less. I had a stock IC before, I have the VRSF 4" now. I was able to tune the timing better too with this new IC, Im still not done with the tune thou, its been raining here and i cant seem to get some good logs done.

My TurboXS intercooler was pretty gunked up with oil from my old leaky turbo seals ....which is prob why my spool was sucky ....I am sure a couple of bars were clogged

Exactly ... My little 1.5" neck on the injen LICP and oily IC was def. hindering me from making more power... And I am "finally" getting around to addressing the inhaling issues in my prior setup

Not necessarily. Fin density on both the inside and outside will affect efficiency. If the fin density on the outside of the core is too high then it impedes airflow through the core so much harder to remove the heat. This holds true for using a core that is too thick as that also affects the ability to remove heat. A core that is more dense will act as a heat sink initially and pull out the heat, but in a road race application will become heat soaked quickly. I run a 4.5" thick core on my GTR and wish I had gone with 3.5" because I am ~27F of ambient at the end of the quarter mile (10.24@138).

Best to log IAT before the throttle body and then compare to ambient temps. This is a good indicator and I strive to see within 20F of ambient, which I see using the Garrett 24"x12"x3.5" core on my EVO.

/\/\ What he says. Thicker is not always better. Bigger thicker intercooler means spool will go down, simple physics