evelhalo

So i have done research, maybe i missed somethings so feel free to flame, or if you dont want to be an ***....maybe point me in the right direction??? but it seems as though there is some disrepancy as to the best way to install the s5 intake manifold onto my 87gxl.
I know the vdi increases the peak hp by about 10 when it opens, but beyond that it seems like the forum has alot of opinions and no solid facts, so if one of you rotary experst ould post, thatd be reallly helpful!!!!

So my question is really a buy question.
i am eaither goig to pick up full s5 intake/injection (tb/tps/ratsnest/uim/lim/dc/maf)

or for half the price just the basics (tb/uim/dc)

in the forums icemark says that installing the full manifold, with the lim actually decreases peak hp??

so then would i only see power increase from the uim and vdi?? I was planning on putting an s5 ecu in, or an rmp switch for the vdi,
but
my gxl has significantly less mileage than the parts so as long as it doesnt present a problem wouldnt i just want to replace the uim/tb/dc and not the electronics ???

just some solid info and experiance from s4 owners who have done this swap would be awesome

Icemark

Actually I am not the only one that says the entire S5 intake on a S4 car is a mistake. The infamous write up that most people follow actually found the same thing when using the set up on a newer condition S4 motor and actual dyno testing. The much better set up is port matching the S5 middle and upper intake sections with a S4 lower intake section. This also prevents having to JB weld filling up ports that the S4 motor does not have and ensures proper mating.

I have done several of these now.

You will not be able to run a S5 ECU without replacing the entire engine harness, pressure sensor, AFM, and new front cover and electrical MOP. In addition you want to use your S4 TB, not a S5 throttle body unless you are swapping the front covers and going for a S5 electrical MOP.

The non turbo S5 engine gains are from a revised rotor design, the new intake, higher compression rotors, new spark plug locations. So just bolting on a S5 intake to a S4 will not provide you with the same level of performance as an entire S5 motor would. The intake is just one part of the 14 additional HP and 2 additional foot/lbs that a S5 motor has over a S4 motor.

evelhalo

so your saying to see any kind of oticeable gain/vs/cost i would just want the s5 UIM/DC, and use all my s4 parts, port match the s5 to the s4LIM and hook up an rpm switch???
sorry to bug you ice, but this is my first 13b, i just want to know what parts i need for the swap. Im only intereste in the power gain from vdi.
an d like all fc owners, im broke, so id be nice to know what the essensials are for the swap

also do i need an s4 or s5 gasket for the attachment, or does it matter?? (tb and uim to lim)

OH BTW some info i couldnt find, since i have a car already devoid of vdi, dos it atually add hp when its closed of only after it is open??

Unseen24-7

can somebody post some pics of this swap, i'm having some trouble visualizing not plugging the s5 middle port.

Sideways7

iTrader: (7)

So how would the s4 TB attatch to the s5 UIM? Is it a direct fit or does it require an adapter?
Also, what's the difference in the spark plug locations. In all of my research and posting here I've never heard of that.

Icemark

Again you don't use the S5 LIM, use the S4 one so you don't have to plug the ports

You drill the S5 middle (VDI section) of the manifold to match the S4 bolt

Icemark

You cut off the lip in the lower front corner and it bolts up perfect

Before:



after:

kungfuroy

iTrader: (6)

Ive done the S5 UIM onto the S4 LIM. some other things you will need to do is:
Grind a bit of the rear plate down.
One of the top studs for the throttle body is too short for the S4 throttlebody, you can grind the throttle down, or swap studs from your S4 UIM.
Some slight rebending of the vacuum rack if you keep it.