are there are any marks to differentiate a S4 from a S5. I have a variety, unmarked so it is very confusing for me. I've searched but I cant find any leads. pix please. I'm not a FC lover but in the process of stock TII conversion on an old school RX.

thanks

 

S5 UIM has a dent in the front runner for the intercooler, the runners also progressively get higher towards the firewall. S4 has no dent and all runners are equal height.

for the S5 LIM versus S4, S5 has no EGR on the firewall side of the manifold, S4 has an EGR boss on it. S4 JDM intake manifolds have no EGR boss but they do have a port on the rear runner outside for a banjo fitting for the brake booster.

an S5 UIM won't directly fit on an S4 LIM and vice versa without modification to the mounting holes in the UIM(a few mm difference in the outer bolt holes). with port matching and some dremeling either can fit.

 

Also the S5 lowers will have fittings for the secondary injector diffusers.

 

thanks Ben. that was easy, EGR on the side.

 

i always spot the S5 lower because its got that vacuum hose between the two injectors.

 

i noticed that. thx

 

forgot to mention that, i always just look for the lack of EGR and/or brake booster port on the LIM.

 

This one may have been beat to death already but is there any performance benefit with an s5 over an s4?
I have a s5 tb but an s4 lim/uim.

 

s5 throttle body won't work on a s4 car and there is no benefit between the 2 throttle bodies. the LIM is nearly identical between the 2. the UIM has variant runner lengths on the s5 and flows slightly better for a hair more top end performance.