Ok so I had my Z dynoed today and I am suprised at the results. Granted my air/fuel read out said I was running pretty lean, but I didn't think the numbers would be this low. I peaked at 246.26whp and 234.98 ft.lbs. Here are my mods...

Injen Cold Air Intake
Kinetix V4 Plenum
Kinetix High Flow Cats
Injen SES Exhaust

My air/fuel reading says 15.09. I know that I need to have my computer reflashed to get the correct a/f reading, but is that a pretty accurate number?

 

P.S. They were having problems getting a clean RPM reading on all of the 9 350Zs and G35s there, which is why I ask.

 

Something doesn't seem quite right there. That's way too lean a reading for just those bolts on's you have done.
What kind of dyno, are they going off the coil for rpm reading?
Tripp

 

This was my first dyno experience, so I don't know much of anything about the types or process. I know that there were two rollers in the ground where the drive wheels went and they stuck a smog test type sniffer up the exhaust pipe. They were having troubles getting a clean rpm reading because some other wire close to their sensor was interfering.

 

Could be a Mustang Dyno, since those tend to read lower than Dynopacks or Dynojets. And that A/F ration is EXTREMELY lean. Does it say where your A/F reading is that lead?
Near idle its not good, but if in the high RPM's thats dangerous.

 

A mustang DYNO usually reads a lot lower than 246WHP...... sucks about the numbers though....what kind of DYNO was it JET/PACK/CLAYTON????? The A/F being that extreme could be because of you high flow cats... It happened to me and after I sent off to Techno Square my ratio went back down into the 12/13 reading....

 

Now that you gave me a multiple choice on what kind of dyno it was, I remember it bieng a Dynojet. If my memory serves me correctly, my A/F is around there the entire time, but 15.09 was the peak. If that is dangerous then I better get down to Technosquare ASAP!

 

15.09 at redline is dangerous, get it adjusted

 

I think it was around 4k rpms or so that it hit 15.09, but I am just going off of memory. I will check for sure when I get home. What kind of damage can this cause?

 

He said Peak...Peak can occur at idle.

 

....Check your air fuel on the graph they gave you, if at WOT 4K rpm above your at even 14.0 DON'T RACE. Stay off the throddle until you tune for fuel.
Sounds like you were on a dynojet 248, that's what I have. I'm concerned of the lack of their rpm pickup, if not right that can throw alot of things off including A/F.
Go to another shop and dyno again.

 

But he said he thinks it occurred at around 4k RPM's. Thats bad.

 

Well I set up an appointment to go to Technosquare and have my ECU reflashed next Monday, so that should take car of the A/F.

 

there is a RPM pickup wire on the 350z and G35, its on the passenger side of the plenum coming out of the wiring harness by the coil packs. Its just a little loop, and its for this stuff. The dynojet cable can get a PERFECTLY clean rpm signal here. Before I noticed that I was always jerking around getting poor signals off the coils.

 

I drove for months with 15.3:1 a/f's a little leaner than you. I ran it @ the track, I drove it hard, I never had any issues, its not like FI, its very hard to blow a motor n/a, and I never heard any detonation. I sent my ecu to Technosquare-now have perfect 13.1 a/f across the board.

 

A wide open throttle that is high. Cruising that is alright a little lean. Your car is probably pulling timing because its so lean and your not getting good numbers.

 

I will remember that when I take it back to the dyno. Thanks.