So in purchasing my parts for my S5 to S5 tII swap (with all USDM parts), I bought a full racing beat exhaust system (DP, presilencer, etc...). This recuires a Fuel Cut Controller (so fuel doesnt get cut to rear rotor in exhaust setup). Honestly Im not fully educated on why this piece is required. Am I going to run into any kind of overboosting problems with this FCC in my car if everything else is stock?

 

your car will make more boost with the rb exhaust, hence the fuel cut defendor

 

The feul cut defender will trick the ecu into not cutting fuel when you go over stock boost levels. With a full exhaust you'll prob be close to 10 psi and youll wanna look into supporting mods and porting your wastegate. The S5 wastegate is superior to the S4 but its better to be safe than sorry. You can raise your boost with a boost controller if youd like. A boost controller will not lower your boost any less than your wastegate allows.

 

A ported wastegate is a must.

Don't buy an FCD either. Go with an Rtek chip for your ECU instead. It's similar cost, , much better for the engine, and has other nice features.

 

Lol more work. Great. So ideally I want to keep my boost below 10 psi correct? This will be driven alot and I would like some longevity. What exactly will a ported wastegate do for me? (explain the mechanics please)

 

also is there an Rtek chip that doesnt require an injector swap?

 

On stock fuel, yes, keep it under 10 psi.

By porting the wastegate, you allow it to flow better, which means more exhaust energy can be bled off. The job of the wastegate is to open when the desired boost level has been reached, and keep the turbo from spinning up even faster (more boost). The stock wastegate (S4 especially) is too small, and will not get the job done once the exhaust and intake get opened up.

 

Well that makes perfect sense. I would like to keep my boost levels down to regular specs while still running a nice exhaust. where can I get my wastegate ported, and is there an outline for the port I can get?

 

Ok I found a writeup for my S5 wastegate.
http://fc3spro.com/TECH/HOWTO/KWG/kwg.html
As for having a Fuel Cut defender, will it be okay to keep if I port my wastegate? Or do I really want to get an Rtek Chip? I would like to avoid larger injectors and that chain reaction.

 

If you plan to run about 8psi or so, which is just barely over stock boost, an FCD will be fine for an easy fix. If you happen to creep up to 8.6psi, you won't get fuel cut.

But, the problem is that the FCD sends the ECU false pressure data, at least for values over 8 psi. This means that the stock ECU will not supply as much fuel as it normally would at the higher pressure levels, so something like an SAFC would be needed to correct this.

Rtek chips on the other hand just remove the fuel cut code altogether, so the ECU will continue to reference the boost vs. rpm fuel map properly. Also, if you don't want to use bigger injectors for now, the 1.5 chip is made for 550cc stock injectors.

 

So for below 10psi, porting my wastegate like teds link I posted will be fine with an FCD...
and...
If I get the Rtek 1.5 it will be just as easy as putting the FCD in, except If I do happen to boost higher, it will allow for proper fuel to flow?

Sounds like a port and an Rtek 1.5 would be ideal for my situation and could provide some longevity. Sound okay?

 

Yeah, get the rtek chip. If you can afford it get the 720 injectors as well. They won't change anything unless for some reason your boost spikes up. In which case they could save your engine.

On the same note, I had a stock ecu with 550s all the way around and an fcd, 3 in exhaust and downpipe and a walbro 255 and I never saw it lean out even at 12 to 15 psi. I was using a wideband O2 as well.

 

thats the exact setup I have... 550s walbro and the wideband and stock N370 ecu and harness. I really dont want to spend money on 720s right now. lol.

I feel sorry for those cars which have been riced out and consideration to such things havent been made lol

 

Yeah, the Rteks provide a good starting platform, that you can build on later.

Also, I'd recommend an FD fuel pump. You can buy them new, or get a cheap used one in the 3rd gen classifieds. I recently installed a walbro, and it completely jacked up my fuel pressure. Idle and low load conditions were getting way too much fuel. The FD pump won't do that , and it'll be more than enough under boost (especially under 10 psi).

 

I heard that the FD fuel pumps require a little fabrication.... and everyone else has told me the walbros were fine. You sure it was the fuel pump that jacked up the pressure?

Also, where can I get an Rtek 1.5? I started looking and didnt find anything

 

No, the FD pump is exactly the same size/shape are the stock denso pumps. The walbros fit, but they're actually smaller and require a little wiring.

Here are my fuel pressure numbers for the two pumps. The stock fuel pressure regulator is completely overwhelmed with the walbro.

Walbro
Idle (vacuum): 46 psi
Atm (0 psi): 48 psi
Boost (10 psi): 54 psi

FD
Idle (vacuum): 34 psi
Atm (0 psi): 41 psi
Boost (10 psi): 51 psi

The pressure is WAY too high with the walbro, and it's no longer linear as vac/boost is applied. For each 1 psi of boost, there should be 1 psi of fuel pressure added, like you see for my FD numbers.

Don't get me wrong. The walbro works, but idle will not be smooth, and mileage will suffer.

 

Here's a picture I took last weekend, when I put the walbro in. FD pump is on the left. Walbro on the right.

 

How much wiring compared to the Walbro would the FD pump take? And it will bolt right in there?

 

If you can keep your boost under 10psi with a full exhaust and intake your doing good. Mine was around 12psi with a big port on the wastegate. That was an S4 turbo though. If your gonna go with an Rtek just get the 2.1 with injectors, that way your good for future mods.

 

The FD pump doesn't require you to do anything. The only reason the wires on it are cut in my picture is because I had to cut the stock wires to put a walbro in. You can even put the fuel sock from your NA fuel pump onto the FD pump (this is best, the FD's sock is a little too long).

 

Ok ill look into an FD pump using my N/A sock. As for future mods, I really dont see myself doin any in the near future as my career wont really allow it. I just want a good clean turbo that will last me until my next rebuild.

 

does this look good?

http://cgi.ebay.com/ebaymotors/93-95...Q5fAccessories

 

Just for your information, the reason my car didn't lean out could be because I was running richer from the extra fuel pressure that the Walbro supplies ( so for the same amount of time my injector was open more fuel came out). That extra fuel pressure wont be there with the FD pump.

 

seems kinda pricey to me, considering I got my walbro kit NEW for $100 and it came with a fuel sock.

 

this is what you really need to be looking at

http://www.pocketlogger.com/index.ph...age=1&ecu=S5T2

get the 1.5 for now and that will work with the 550s if you decide to get 720s down the road its a $15 upgrade. This will also control timing adjustments once the boost increases above stock.

Also, the walbro is a super easy install, if you are capable enough to get your sending unit out I cant see why it would be any problem.