s4 n/a to s/5 swap
 

i was wondering if there were any major changes you will have to make to but a s5 n/a motor in to a s4 car im i tried to search it but nothing came up i know its almost the same but the intake ports are diffrent on my s4 motor than my s5 motor so if any one could tell me or if there is a rite up that would be great

well I am not aware of any write ups on this...

I would imagine though that you would need to use the S5 ECU and harness given the added functions it has on the S5 model such as the electric MOP....

Im sure it could be done, and more than likely has - try a google search.

i have done the swap with my friend on my car...lets just say its harder than it looks. you have to hack up the wiring harness and splice the body wiring(S4) into the S5 engine harness and basically trace every wire to see where it goes and what it does, yes, thats right, EVERY WIRE! don't mean to scare u but make sure u intimately know your way around your car before u start the swap if u want it done quicker.

wut if i used my omp and my whole intake systembecause from wut i hear if you take off every thing from the s4 and put it on the s5 iwould be pretty easy but some thing look diffrent where the intake bolts up to the block

then what would really be the point if you aren't swapping intakes?

do it just for the lighter rotors?

because my motor is about to go i have a blown coolent seal and it has almost no compression

I believe you could use the s4 front cover and keep the mechanical OMP. You could then make the intake assembly work using electronics or such. Many people that swap on s5 intakes to s4 cars have done this.

but could i just use the block see this is my only car and i have to do this swap in one day and im not looking to take apart the motor that just got its an s5 with only 40,00 miles on it so if i can just use the block then all this would be so much easer see im not wanting to convert any thing i just trying the easys way to do this in one day so im am trying to prepar my self as much as i can foe this

IIRC an s4 lower intake manifold isn't compatible with the middle iron on a s5 (maybe it's the other way around)... plus how are you going to operate the s5 5th and 6th ports/VDI? i did this swap myself because of the availability of a good engine core.

anyways here is how i put a series 5 engine in my series 4:

rebuilt the series 5 block using the middle iron from a series 4 only, series 5 flywheel/front counterweight to match the rotors, s4 front cover/omp, s4 intake set.

someone correct me if i'm misremembering about intake compatability but i think there is an extra passageway on s5 intakes/irons just under the middle intake ports

see thats wut i was talking about but is there any i can go thats easy and could go around this problem

you can use the series 5 lower intake, then use a series 4 upper, and s4 tb/everything else.

you may still be able to activate the s5 5th/6th ports with s4 exhaust backpressure, just have to rig up a little t fitting or something.

the s4 upper intake will require modification to the hole on the bottom flange closest to the firewall to fit the s5 lower intake... you'll see if you try and mate them, it's an easy mod with an angle grinder or maybe even a hack saw and a file. the thing is the far stud on the s5 is closer to the firewall so you have to turn the hole in the s4 upper into a slot

be sure to plug the extra hole on the s5 air control valve you have on the s5 lower intake.

this should work well and allow you to use the s5 block with s4 electronics and mostly s4 manifolds etc so it still functions close to stock.

thank you that should work but i was also was wandering is i could still use the whole s5 intake but use my tb and my oil meatering pump

you'd have to find a way to make the TPS and all the other electronics work correctly, they wouldn't be plug and play even if you put the right connectors on them... for example i think the s5 tps is two units instead of one... i doubt you could interchange the throttle bodies either.

in my opinion the best way would be to take the s5 block, leave the s5 lower intake manifold on and make everything else on it s4 excluding things that don't matter or need to match the block, like the flywheel.

if anyone else knows of an easier way that would still work as well as stock, speak up, but i think that's it...

the inectors are different too, so make sure you stick with the stock ones

i think the only reason the tb wont fit is this little stub thing that hit somthing on the
s5 intake