I own an 88 GTU. I had put a new motor in with a stage two street port and also had oil mods done for longevity. I also have turbo 2 injectors for my secondaries and stock for my primaries. At 8k the car decides to stop revving, it bounces of what I think is a rev limit in the ECU. I know it is not cutting the fuel because my air/fuel gauge still reads rich. I also have an APEXi Fuel controller. I plan to have a lightweight flywheel and other goodies to help at higher RPMs. How can I get around this rev limit problem??

 

i have close to the same mods and i get the same thing. whats the deal?

 

Yes thats the rev limiter. Guys theres no reason you need to rev past 8k rpms. Unless your engines were purposely built for high RPM use then I would recommend going any higher.

 

There is no rev limter on the S4 cars, however the Torque and HP radically drop off on stock engines at above 8200-8400 RPM. If there was a rev limit it would be dropping fuel, just like the T2 ECU does for the overboost.

And as covered last week the Stock S4 flywheel is not safe past 8500 RPM.

I am assuming that you are using the stock ECU with the AFC piggy backed. Did you revise the intake runners to work with the Port, or are you still using the S4 intake???

 

Are you speeking about N/A S4 cars that dont have a rev limiter? I know for a fact that my S4 TII had one when I had my stock ECU in. I hit it many of times.

 

The Rev limit is a fuel cut. It cuts fuel to the rear rotor until the RPM's drop back celow the limit. The stock limit is 800 rpm above redline, so 7800 for S4's.

There is a way to remove (and I know exactly how to do so), but why do you want it? Do you have a dyno graph to show that you are indeed making power up there? There is no need to rev the snot out of this engine. You should ask the person providing your rebuild; wonder how he/she would feel about you revving the snot out of an engine he'she built?

Your Turbo secondaries were a waste of money. There was no need for them, the stock injectors provide enough fuel for 250 hp at the flywheel (more than what you are making).

Show me the dyno graph that you are making the power up there to need the extra RPM's, and I will tell you how to remove the limit.

 

Ah yes I meant NA cars, such as his. I used to take my 87 Sport up to 8600 all the time.

 

they all have rev limiters. it's just a mater if the solder on them is still together allowing them to work LOL...