WRX FA20 FUELING LIMITS

1. What is the stock fueling limits power wise?

 

Answer: The stock DIT fueling system seems to provide around 430-500 whp highly depending on the dyno used.  Once you hit about 42-45% Injector Duty on these cars the system will start running out of fuel. 

 

2. How do I go beyond the stock fueling limit?

 

Answer: There are two ways you can go beyond the stock fueling limit, but one way is wrong while the other is right. 

 

Meth - You can use meth as fuel to get more power then the factory fuel system can provide. THIS IS THE WRONG WAY and shit can go bad quick. 

 

Port Injection - This one is the right way and it provides a lot more support. You will have to install a port injection set up and an ecu box to control the port injection. 

 

3. How long will my stock pump last?

 

Answer: This answer will vary. I suggest upgrading it anytime going stage 2 or having a tune with an ethanol content of e30+. Guys that are stock and want to go e30 can do so, but in time the pump may die. 

 

4. How much ethanol can my stock HPFP handle?

 

Answer: This will vary from car to car. I have seen some cars take e85 fine while others will only take e50. I believe this has to do with the clearances in the hpfp from the factory. The bigger the clearance the high the content you can run. I would start with e50 and then go up from there to see what your car will take. 

 

Some tuners set an ethanol limit in the tune to not go over to avoid issues. I set mine to 65. E50-60 seems to be the sweet spot. Plus the gains from e50 to e85 is very little. 

 

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