ok - car was being set up on the rolling road on Friday. Long story short the engine shuts down at 440whp apparently cos the ECU thinks its overboosting.

 

I'm looking at getting either 555's or 720 injectors ; can I just use an FCD or should I go for a chip. If so any suggestions on make/model eg JWT, Mines etc.

 

Another option I was looking at was an Apexi power FC to replace my SAFC & AVCR.

 

Any comments will be appreciated.

 

Cheers

 

AdamR

Originally posted by AdamR

ok - car was being set up on the rolling road on Friday. Long story short the engine shuts down at 440whp apparently cos the ECU thinks its overboosting.

 

I'm looking at getting either 555's or 720 injectors ; can I just use an FCD or should I go for a chip. If so any suggestions on make/model eg JWT, Mines etc.

 

Another option I was looking at was an Apexi power FC to replace my SAFC & AVCR.

 

Any comments will be appreciated.

 

Cheers

 

AdamR

 

Apexi power fc is cool. And a guy int he states has it working on a zed, so should be available soon.

 

 

Apexi unit is complete unit , its all you need.

Got any dyno sheets? sounds very cool.

440whp - that could be the airflow meter maxing out tbh. FCDs are a bad idea IMO - they simply 'cap' the airflow voltage at a certain point so the ecu doesn't know the extra air is entering the engine. The problem with this is the ECU then can't fuel accordingly because it still thinks the same amount of air is entering the engine. If an FCD was fitted (I seriously doubt this will cure the problem as AFAIK the 300 doesn't have a fuel cut) the SAFR would have to be set up to supply the extra fuel above the capped point - HOWEVER, the SAFR does this by upping the airflow meter voltage! Therefore the FCD is just being cancelled out..... You will have to look into getting the car chipped for a start. After that you will need to upgrade to a twin induction system as the single airflow meter cannot measure enough air. There are two options for this. Both require the intake reworking to fit a filter on each bank. You can then use 2 airflow meters and wire them to the SAFC and it will average the two readings to supply the ECU with the correct value (the ecu WAS measuring the air for BOTH intakes but is now only measuring one each side if that makes sense). Another option is to simply have one airflow meter on one of the banks and get a chip that effectively multiplies the reading from the single MAS to obtain the correct reading for both intakes.

 

All options considered, I would go with the chip.

 

HTH

 

CheerZ,

 

Andy

I have to say that I was expecting sarcy comments - thanks for holding yourself back!!!;)

 

The 440 was achieved by running the SAFC at +26% (apparently - it means nothing to me!)

Currently the car is set up at 389whp with the boost backed down to 1.05 bar (its funny to think I wasnt running anywhere near that on my old set up at 1.25 bar - it just goes to show that boost pressure isnt everything).

 

Apparently with 555's ruunning at 4 bar(fuel pressure) and an 88% duty cycle up to 600bhp could be developed - running I guess 2 bar boost. However I think 500hp at around 1.5 bar of boost will be plenty for me - I've still got to try and drive the thing:p

 

All I need now is to find out how to get past the f**king fuel cut:D

You are right on the limit of the stock injectors - thats the problem. Even though the SAFC can increase the duty of them you still can't go past the 100% mark - this is where the injectors never actually close - you should NEVER run anywhere near this limit. I am sure 300s do not have a fuel cut on the ecu - the stock maps just aren't up to that kind of airflow figure. Once you get a chip this will replace what is currently set into your SAFC. You will however, need to get some 555s to go above your current power figure. Also you are certainly looking at going 'twin pop' (seperate induction). Its not the limit of the filter - it is the fact that the MAS cannot measure above a certain flow of air - it reaches its maximum output voltage. One other option would be to use a Greddy Emanage with the optional map sensor harness. This simply takes over when the stock MAS maxes out....

 

And us? Sarcy replies? Never ;)

 

HTH

 

CheerZ,

 

Andy