Hello all

Have had my 8 a week so far and am loving every min of it ! (900 miles in a week lol).

For kicks i took my 8 to the drag strip this sunday. Had a blast even though i only got to race twice due to long lines and a few mishaps with some of the heavily built cars.

First, here in albuquerque, NM the evelvation is 5,500+ above sea level. the temp on sunday was 50 bright and sunny, overall a very nice day. My first run was 16.2, the second was 17.2. On the 16.2 run i rev'd to about 6500rpm and let the clutch rip... the wheel hop was impressive. On the second run i rev'd to 4,000 rpm.. less wheel hop but the car bogged down. Was real fun even though i got spanked both times by friends twin turbo 300Z.

Well, on to the reason im posting :D

After breaking the car in (600 miles) i dutifully took her out for some fun.

The car makes a sound starting at 6000+ rpm, at FULL throttle, in ANY gear. The sound is NOT constant, it lasts for one maybe two seconds. It also seems to happen sporadically after 6,000 rpm (like at 7,500 and a 8,500) It seems to be worse when going up hills.

The sound itself is high pitched and metallic sounding. My friend says it sounds like a bearing.

Has anyone else noticed this?

Thanks for any replies and advice !!

 

What happens when :
RPM___SYSTEM_______WHAT
3750__Fuel Injectors__#2 primary and secondary injector start
___________________controlled by ECU fuel maps
___________________(All in use during WOT!?!)
3750__SDAIS________#2 primary intake ports open
5500__SDAIS________VFAD may open (Yamaguchi p 115)
6250__SDAIS________Tertiary intake ports open
7250__SDAIS________Primary intake ports interconnnect
___________________adds a second shorter path
7250__SDAIS________VFAD opens on WOT

 

sorry here is the pic

 

<------------- doesnt wonder why i have bad gas mileage after looking at the above pic.

 

wow, thanks zoom44 !

Im relieved it's just valves.

In your diagram it does'nt specify if it's full throttle or not. I'm wondering if the valves open regardless of throttle position and just go off of rpm?

 

yes regardless of throttle position. at wot i believe the VFAD opens sooner though.

 

not related to your problem...

Road and Track reported best launch times when dropping the hammer at 7500 rpm. Of course there was a great deal of wheelspin, but they reported that this was the best speed because it is on a flatter part of the powerband. Thats how theyve been getting the 5.9 second 0-60mph times. And they have professionals doing the testing most of the time.

 

well you have the primary and secondary injectors in use at that point PLUS the secondary intake trac open