Hi All,

How this fuel cut things work on our EVO ? if I hit 8k rpm, do I get a fuel cut ?? or if I hit 1.7 bar of boost, do I get a boost cut ?? Can someone explain this to me ??






Thanks
Trustz

 

Humm... i believe when you hit the rev limiter it will cut fuel.. but i do know for a fact that at 27lbs WOT thats where boost cut is, or fuel cut? hell i dunno, i just know that at 27lbs something happens

 

i don't even think the stock turbo can be realiable at the amount of pressure

 

Someone must know and please help !!






Trustz

 

well i hit the rev limiter a few days ago and it just stopped my engine from revving any farther but didn't drop rpm's. and when setting up my boost controller i hit 26.4 psi and something cut because it felt like i locked up the brakes. wasn't much fun but it spooled right back up so it works ok.

 

The rev limiter on my EVO is around 7,500 rpm and it feels like the car is "stuttering" as fuel is cut off at the rpm limit then back on below the limit maintaining the rpm constant at WOT. The rev limiter is a hard coded limit based upon rpm.

Fuel cut is based upon a number of parameters included mass air flow rate, boost, air temp and barometric pressure. Fuel cut feels like you hit a "wall" as both spark and fuel are instantly cut off. The car physically "bucks". The exact boost pressure at which fuel cut occurs is dependent upon mass air flow rate (how much air your intake is sucking), boost and outside barometric pressure and temp. Fuel cut does not usually occur below 20 psi boost pressure.

edit: As the weather turns colder in the north, more EVO owners with high boost settings are going to experience fuel cut. Also, 26psi on pump gas is a good way to detonate your motor.


Speedlimit...

 

When you overboost, the fuel cut kicks in so you dont blow up your engine. When you overrrev, I've only heard it called the rev limiter but I guess you can call it a fuel cut too since that's what happens.