rx7b13

OK i was told that N/A's dont have a fuel cut but when i was doing some tuning and i ran my car up to 8k it chugged down. and i had a friend take a look at it and when he drove it he told me that the fuel pump cant hold up at that high of rpm. so is the fuel pump not being able to keep up sound Logical.

Thanks
Marc

Icemark

S4 models have a fuel cut at around 1000 to 1500 RPM past redline.

Luke_Tech

this is a friends account, how can i get rid of that

NZConvertible

NA's don't have an overboost fuel cut. They do have a over-rev fuel cut. According to the FSM this is at 8500rpm. Unless you have a race-prepped engine, it would be pointless and stupid to rev any higher than that.

Luke_Tech

well this engine is ready and built to go beyond this. just tryin to figure out how to get ride of it

Icemark

You would need to go with a stand alone, since the factory ECU is unable to go past that.

In fact the S4 ECU has trouble going past 7500.

NZConvertible

If you have an engine that actually makes power that high then you shouldn't be trying to run it on a stock ECU, so the question becomes moot.

Luke_Tech

well it's been programed with safc2, and its top notch right now, but all i need is to be able to get rid of the rev limiter...what is the rev limit on the s5 ecu?

NZConvertible

Do you have dyno proof that power is still increasing at the limiter?

And no you can't use the S5 ECU...

Luke_Tech

on the s5 ecu i have a custom harness and ecu, couldn't i just put that in this s4?

NZConvertible

Custom meaning what?

Luke_Tech

its built to our emissions laws thats it

NZConvertible

You can't use an S5 ECU. If you need more revs (and you haven't proven you do), then you need a better ECU than the stock one.

Icemark

You can't reprogram the timing and coil firing with a Safc2, so again, if you have motor that needs to rev beyond 8000 rpm you need an aftermarket ECU (since even the S5 non turbo ECU starts breaking up spark wise at around 7000-7500 RPM.

and a SAFC is simply a band aid, not a real ECU. It simply tricks the factory ECU to think the engine is operating different than it really is.

Luke_Tech

thanks icemark, at least someone can explain things out right!!!