Hi guys I been looking around about my issue but couldn't find something that fit exactly to my problem. My car is an 03 base model 95k miles

I drive my car from stop I speed up then on second gear around 4k rpm I will press the gas all the way down, my car has an slow response and it will have a hard time to pass after around 5.5-6k rpm. It will do the same on 3 gear as well.
Any ideas?

 

Stock?

 

Assuming you know how to drive and not a noob, your car is old, it's not putting out the same power as it did from the factory. And 230 rwhp isn't that great to start with. Only way to know for sure if you're having acceleration problem is to do a 0-60 run and time it

 

light flywheel and intake, my big concern is why the car don't reach higher rpm than 5.5-6k

 

The main problem is after 5.5k rpm the power start lagging

 

The car pulls better in the lowered rpm. At 6k you're about maxed out. If you're redlining the damn thing you're falling off your power band

 

It should still pull through all the rpms. There should be no significant lag at 5.5. Have you checked to see if you're throwing any codes?

 

i am going to say starting to lose compression in one or more cylinders

 

Is this a recent issue after a change or did it just happen one day?

Jon

 

I got in a speed comparison test on a street the other day with a 06+ Z and my 04 with 112k miles stayed door to door the whole time with it...

 

How do you know the 06 didn't have 130k+ miles? Or that you're a better driver? Old car loses power. Parts are old, grease are worn out. Only way to know is on a dyno. And even then, it's not that accurate but more of a ballpark.

 

I think he is saying the car literally won't go over 6krpm. I had this problem in a kia I used to own. It was the VSS, but no idea what could cause this on the Z

 

Ahh. That would make more sense. I though he was having problem passing cars when it's at 6k rpm.

 

Hey Jon I just install a zex nitrous kit with 55 shots , The only change I did to the engine was the spark plugs with an smaller gap. 0.35. I'm not sis if that could be doing something with it

 

No codes, I will take a video of my problem

 

I'll check back when the vid is up.

Jon