My 00VI seems to start to fade at 6300rpm. I have no Dyno's to prove it, but it feels a lot faster when I shift it at 6300 vs all the way to just before 6500rpm. (It doesn't sound like its hitting the rev limiter.) The last couple rpm it seems like it fading plus when it shifts the next gear it surges forward like it has lost some momentum, vs at 6300, the next gear keeps pulling. I can't imagine my engine revving to 7000 rpm like i have seen other VI with ECU mods.

I only have 00VI and Y-Pipe for Mods. Its also an automatic and I am using the stock 5th Gen Air Box. The 00VI actuator opens properly. I replaced the plugs, fuel filter and air filter when doing the 00VI and it has had the knock sensor replaced in the last couple years. The engine seems to run great. The scan tool doesn't show anything wrong, but the scan tool itself is limited.

Could it be the stock tune or is my stock exhaust holding the engine top end breathing back. Or is it something else? or is it normal.

 

The stock engine seems to fade above 6300 as well if I recall correctly. I think to fully utilize the 00VI (for high RPMs) it should be tuned. The Y pipe should be enough for exhaust, the only real bottleneck on these motors (for N/A) are the precats.

 

You don't want to shift at the HP peak anyway. Butt dynos can be extremely deceiving. Shifting several hundred RPMs past the HP peak will put you higher on the curve in the next gear, increasing the total HP area under the curve that you utilize.

You'll also always feel a slight surge into the next gear when you are shifting fast due to the slight torque multiplication that happens when the engine has to be slowed down to match the wheel speed in the new gear.

As said above, a real tune would help a lot... EU should do the job.

 

Time for a dyno

 

I had my emission test yeasterday. The were nice enough to pass me, but my stock muffler is starting to leak, so its time for a 2.5" exhaust.

I looked my scan tool and it said my Long Term fuel trims are richening the fuel 10% on bank 1 and 13% on bank 2. I also noticed the bank 2 is lazy for quite a while and stays on the lean side. I should change the O2 sensor and perhaps clean the injectors.

 

Are you using the 5th gen fuel rail? I think the DEK injectors run rich on the 4th gen ecu.

 

I am using a 4th Gen lower intake with the 4th gen fuel rail and Injectors.

 

Well I starting getting an intermittent misfire and tach reference signal. It turns out a mouse had chewed some of my wiring going to my back ignition coils. it seems to pull hard to redline now. It doesn't feel any faster besides not tapering off at the top of the RPM range.