Okay, I've read quite a few things about this and I'm just a little confused. I've just added on to my car a Apexi Gt Spec cat back exhaust and a Hks intake. I will soon be adding on a Corksport Midpipe (Cat delete) and a Corksport downpipe. My question is will I need anything else after doing this? I have seen many people writing that it would be a good idea to get a fuel cut defender (FCD) or a new Ecu to monitor my boost. I've also read that it would be a good idea to port the wastegate. Please help me to understand what I will need so I don't blow my engine. Thanks guys

 

Porting the wategate is absolutely necessary when opening up the exhaust/intake. S4 turbos have an especially tiny wastegate (13mm!). If you make the wastgate large enough, you'll be able to control boost & keep it at stock levels.

Don't buy an FCD. They're outdated, and without fuel/fuel control modifications, they will just allow you to blow the engine. Hitting fuel cut at 8.6 psi is much better than blowing the engine when it spikes higher.

 

So all I need to do is port the wastegate then. Thank you very much sir.

 

Along with porting the wastegate I'd look into getting a basic Rtek ECU upgrade: http://www.pocketlogger.com/?pid=rtek7_techinfo to go with whatever fuel setup you'll be running.

Also, fuel cut blew my engine, which is why a fuel cut defender is good (which all the Rtek ECUs have)

 

If you're constantly hitting fuel cut, you need to address the problem IMMEDIATELY. Hitting it a time or two should be your wake up call that your setup is not optimal. I still don't buy the idea that it can blow an engine, as all fuel is cut to the rear rotor. It's harsh, but you can't get detonation if there's no fuel to detonate.

An FCD is not the same as the code change with an Rtek chipped ECU. Pocketlogger deletes the code that would allow a fuel cut because everyone wants to up the boost. An FCD alters the boost signal to the ECU, so it will think pressure is lower. This will have a negative effect on fuel and timing. Combine that with overboosting on a stock fuel system, and you will blow the engine.

 

Currently I am running a stock fuel system. Do you think that fuel cut will be an issue just with these mild performance mods? It sounds to me that I will need bigger injectors and an upgraded fuel pump to up the boost further.

From what I got from this it sounds like I should buy a fuel cut defender to well simply put avoid fuel cut because that may blow the engine. But on the other hand if I use a FCD then I might blow the engine from over boosting. Is this correct? Please excuse my ignorance.

 

If your wategate porting is enough to control the boost level, additional fuel mods won't necessarily be needed. Although, adding an FD or Cosmo fuel pump would be a little bit of cheap insurance (drop-in and cheap used). The stock TII pump is the weakest link in the fuel system.

For your 2nd question, some people insist that fuel cut can blow an engine, while others say it can't. There are a number of turbocharged cars that use fuel cut from the factory (Subaru, Mazda, and others...). Manufacturers tend to stay away from things that will require them to replace an engine, so it should be a safe bet that fuel cut is better than the alternative.

The bottom line is that an FCD should never be used as a safety feature. Being able to control the boost level is the only safe way to regulate.

 

Very much appreciated. I will look into an FD fuel pump.

 

I've been looking into the Walbro 255lph fuel pump. Any idea if I upgrade to this kind of fuel pump that I will also need to upgrade the regulator or will it be fine? Thanks again

 

Walbros overrun the stock FPR. An aftermarket upgrade would be advisable, but some people choose to keep using the stock one. Idle and low throttle mixtures will be extra rich due to the increased fuel pressure. They're noisy little pumps too.

 

Back to the basic question so you understand....you're risking boost creep with that mid-pipe along with the other exhaust mods. It's a common issue with FDs as well. A simple solution until you get some of those safe guards in place would probably be to just leave the cat in place.

 

Hate to thread jack but is there a write up for the wastegate porting?

 

This is specific to the 3rd Gen. but may help. https://www.rx7club.com/3rd-generation-specific-1993-2002-16/how-port-wastegate-426526/
Basically a dremel and carbide bit. Then close the flapper, spray a little contrasting paint around to mark the coverage of the door. Then dremel back as much as you can while still leaving enough material for the door to seal against. Go slow, keep it as even and round as possible and don't take too much off.

 

2nd gen (S4) wastegate porting:

http://fc3spro.com/TECH/HOWTO/ZWG/zwg.html
http://www.aaroncake.net/rx-7/s4wastegate.htm

 

How much power would you get after these mods?