I have an S5 TII and i am getting ready to put the SSautocrome turbo-back dual exhaust on. My car already has

cone intake filter
Jacobs ignition box
FCD

With the exhaust, my boost may start going crazy from what ive read. I dont want to pop my engine. I want it to be reliable. So, without going overboard... what mods do I need to do to support the exhaust? Im guessing

WalbroFuel Pump (which one should I get?)
Larger secondary injectors (What size would be best?)
Maybe an electronic boost controller (is this necessary? If so, what brand?)

I am NOT going to port my wastegate. So, please let me know anything else that MUST be done to keep my boost under control and not pop my motor. Thanks

 

Well....being an S5, you *may* not see boost spikes that are too wild.

However I can tell you that you can avoid putting in larger secondaries if you port your gate. Its not hard.

Theonly thign I would say is throw a walbro in it and port the wastegate. Larger secondaries without any fuel control ill make you run way rich in the upper RPM range and actually make less power.

Port the wastegate.

 

If i port my wastegate I dont have to get larger secondaries? Either way, I dont need a electronic boost controller? Is there a specific model walbro that people prefer? Thanks

 

If you port your wastegate, you will be able to control the boost and keep it around 10-12 PSI (12 being the MAX)....therefore you don't need larger secondaries. And either way, the factory turbo can't really breathe enough to justify putting in 720's and maintaining a good AFR.

IF YOU WERE goign to put in anything larger than stock, put in 680's(IIRC) from a GSL-SE and get an S-afc.

well, the boost controller is going to allow to turn the boost UP....not down, so if after all your work you only get 6psi, buy one.

Walbro 225LPH go or 100 bones on ebay, and are a good saftey measure since your stock pump (of unkown age) may not be able to keep up.

 

Great, thanks for the info. Ok, I dont totally understand a boost controller.
From what i gathered, if I want 10 pounds boost max, then I set it for 10lbs and it wont exceed that. I was told I would need a boost controller to control boost surge? Is this right?

Are the 680 from the GSLSE a direct fit? I would imagine that I would need the resistor, but otherwise drop in replacement? What would be a good S-afc be? Sorry, Im really new to turbos.

 

all the boost controller does (Ive only ever dealt with maunal ones, EBC's suppoedly work the same way, they're just easier to plumb into the cabin becuase its only wires to a solednoid intead of vac line) is modifies the vaccum/boost that the wastegate sees.

So, if your wastegate is designed to open at say....6psi of boost, and you add a boost controller, the boost going to the wastegate would be lessened by the controller and in turn the boost pressure climbs up and up until the actual pressre at the wastegate is 6psi. Then it opens.....all the while the motor was actually seeing ¬10psi or so.

However, as I said....the wastegate has a set pressure it opens at, the controller cannot lower this point.

The 680's will directly fit, but depending on the series of your car you may need to add or remove resistors from the injector wiring.

A "good" s-afc is really and oxy-moron haha.....but really either of them S-AFC I or S-AFC II will allow you to adjust you fuel to a very minor degree.