spent some time dynotuning the Z today.

Started off with a baseline pull of 331 rwhp with a 14.5 AF

Ended with a 365 rwhp 330 tq with a 12.3-5 AF.

The car was falling on its face at 6000 rpm. The torque curve was flat all the way through the pull and the HP was still climbing but I could not get past 6000 rpm. The car felt like it hit a wall!!!

I was actually feeling it fall on its face the last few times I had it at the track. Even at the track it was only falling on its face in high gear running through the traps or just before.

I have changed the plugs recently but did not change the wires.

The opti is new as of my heads and cam rebuild about 8000 miles ago.

I believe and Sean believes there is more in the car if we can just get past the high RPM stumble. I can see at least 380 RWHP if I can get it up to 6500+ RPM.

We did not even play with timing just got the AF set right.


any ideas/suggestions for the stumble? Coil, coil wire, wires, etc.

Ken

 

Sending this back through the gauntlet one more time.

Any thoughts on the high RPM miss/wall issues?

Ken

 

Someone posted on here a while back about the opti being notorious for a high rpm break up starting right at about 6000. Food for thought. I was having the same problem, and am replacing my opti next week. I'll let ya know if that fixes it if you'd like.

 

Have you checked valve springs?
Maybe you are getting some knock retard.
Two things that I would check.

Kevin