I, have just installed the t2 upper and lower intake on my s5 Na. i just bought an oem s5 turbo and i am in the process of buying a haltech ecu. I was wondering what modifications i need to make to my engine before i boost it. do i need to change my apex seal size to 2mm or anything? im still trying to learn and figure stuff out so any advice helps

 

welcome to the board.

your apex seals are already 2 mm (assuming someone did not put older rotors in it).

i was going to mention the compression, but if you're going Haltech, then it shouldn't matter as much as if you were going to try to make the stock ECU work. you actually have real control, so that's good. obviously, you will also need to address fuel and intercooling.

you're going to need to find ways to provide oil and coolant to the turbo, and also create a place for the oil to drain back to the sump (you can get a T2 front cover or modify yours)

 

I concur with the above.

If you're using an S4 throttle body, you may want to consider using a different TPS so that you get a full range reading. I had real issues trying to get my transient throttle response before I changed to a GM TPS. I believe mine is originally for a Cavalier. It shouldn't be too hard to work up a simple bracket to attach it.

You'll want to make sure your fuel pump is able to keep up with the demand. You're probably already aware that you need to make sure you use the highest quality fuel and keep your intake temps as low as possible especially with your higher compression. I wouldn't go much past 10 psi on the stock turbo because it will start putting out hot air on the factory compressor. If you go with a larger turbo later on, keep in mind that even the reinforced dowel landing on some S5 rear irons can break under higher power levels. However, the exact cause of this at what power level is highly debatable. There are 6-port rear irons out there which have the FD-style dowel casting that will provide the most protection against cracking. Some will say to stud the block, but in my opinion the revised rear iron I just mentioned is a better alternative. It's just something to look into if you plan to move into the upper 300's.

I have no problem running 11-12psi on a BW S300 with about 500cc water/meth, Evo 8 FMIC, and 91 octane on 9.4:1 rotors. The AI is used only as a safety measure; I dyno tuned the car without it then turned it on afterward.

 

I would really recommend getting a T2 front cover. The oil drain is really easy to mess up.

 

Dope thank you so much. i am in the process of getting an fd fuel pump and my goal is to run like 7 ish psi so i think i would be good on all fronts. all the parts i have are s5 so i should be good on that front. thank you so much for your advice bro i really appreciate it

 

Thank for the warm welcome. i might buy the built to apex oil pan. and then hopefully find a t2 front cover soon. that should solve most of my issues. any other advice? i'llappreciate any haha

 

Its certainly recommended to get the proper front cover! But you're also in luck if you cannot find one. The S5 NA front cover has the casting already there for oil drain. you COULD drill it out and tap the holes to accept an AN drain fitting or the factory Oil drain tube/flange.

Do not remove the front cover while the engine is in the car. You could ruin your front stack torrington bearing. It's ideal to have the engine OUT of the car and the front hub facing directly UPWARDS when removing the main 19mm hub bolt.

You'll need to have the Lower intake manifold port matched to the 6 port iron air inlets. You can use the gasket as a template. Also, there are some area's that will need to be filled, Aluminum welding is HIGHLY recommended over JB weld.

you'll need to tap and thread an m8x1.25 for the "7th" UPPER center lower intake bolt in the center iron housing above the two primary ports as the NA engine doesnt have the hole there. You can get away without running it but you have the potential for a boost AND OR vac leak in this area.

Have fun! I'm in the middle of a 6 port s5 turbo myself. and still learning

 

OP doesn't mention whether the engine is in the car or not (though the fact that he has installed the manifolds implies that it is). But then again he also asks about replacing the apex seals so the engine may be apart. If the engine is assembled I wouldn't risk the drilling and tapping of the center iron myself. I would rather use a skim of RTV on the gasket, less risky.

If you decide to drill and tap it OP, use lots of oil and back the tap out and clean it every 1/4 turn. Otherwise you risk cracking the iron which means a rebuild.