I have a 1991 twin turbo, after 6000 rpm my car stops hard. from 3-6k it pulls like crazy. but from 6k to redline it stops pulling. the boost is where it should at 10 psi. and the engine sounds really loud between 6-7200k. I was woundering if this is common in the z's. thanks

well on just about any car youll stop pulling as hard when the cams start maxing out, they arent as efficiant when spinning at 7200 rpms. this is why aftermarket cams are sooo appealing, to change the torque curve and rpm power band. with the right cam set up you can get your car to pull at 7400 + rpms., (with other mods of course)

i dont know...i have driven a few Twin Turbo's and they both continue to pull hard all the way to 7000rpms. try resetting your ECU by disconnecting the battery cables. you also may want to check the codes.

air filters been changed lately or you may want to clean your pop-charger if you have 1...

I cleaned my pop charge not to long ago 1 month or so Ill clean it again. How do I check the codes and what specail tools will i need to check the codes? But it does seem like the cams are maxing out.one my sentra if felt the same way.

if it has always done it then dont worry about it. im guessing your in 2nd or 3rd gear when you do this to tell that is stops pulling...

you dont need any special tools. flat head screwdriver and couple of sockets.

here is a write-up... http://www.ttzd.com/tech/diagnostictech.html

ive never driven a twin turbo so i wouldnt know if they normally pull hard that high or not.

i have the same issue...i just figured it was the cams becoming less efficent..like you can get on it and you'll feel power till about 6200 on mine then if u keep going on till redline in say 3rd gear the pull will stop.... so i just shift

yeah, but the only thing is that the pull stops in every gear 1st-4th. Im not sure about 5th gear because I havent hit redline in 5th, only abuut 4.5k. I cant remember how fast I was going. I only hit 130 mph, but I was short shifting due to my "pulling" after 6k.

could just be the torque curve dropping off... find yourself a copy of a stock dyno sheet and then you'll know...

yeah, but the only thing is that the pull stops in every gear 1st-4th. Im not sure about 5th gear because I havent hit redline in 5th, only abuut 4.5k. I cant remember how fast I was going. I only hit 130 mph, but I was short shifting due to my "pulling" after 6k.

umm...you might have a problem...the RPM's in 1st gear should fly up fast enough where you shouldnt be able to determine if there was a power loss or not. :dunno:

yea i only notice it on the top of 3rd gear, im pretty sure its a mix of the point to where the turbulance of the air fighting the car and the power curve dropping....because once i goto 4th its a whole new ballgame

that does seem a little odd, i rode in my buddies twin turbo with stock cams and upgraded ecu that has the redline set to 7400 rpms and his car pulled all the way to 7400 rpms. i would check your ecu for any error codes. also, i would change your fuel filter and check for any fuel leaks, your Z might be starving for fuel at the higher rpms because there is a fuel leak or something.

i just replaced my filter but didnt get to go hard on her because i put her away for the winter already

Ill change my fuel filter but I changed it about 2 1/2 months ago. are the fuel lines visable from under car? and where is hte fuel pump? I havent had a chnace to check for codes but I will this weekend on my days off. thanks

the fuel lines from your fuel tank to your engine probably wont ever leak, the ones you have to wory about are the rubber lines ontop of your engine.

Just sounds like when the torque curve starts to fart out...sounds normal to me.