z32 gurus.

If it isnt a problem or a suggestion it probably goes here.

Moderator: Matt

Post Reply
kenbam
Posts: 131
Joined: Sat Sep 15, 2007 9:46 am

z32 gurus.

Post by kenbam » Tue Jul 01, 2008 12:51 pm

Just run my car up on a dyno, did 2 runs, standard tune (blue) and the tune i've been playing with(RED). All ive really changed is the fuel maps and a conservative increase in timing.

My question is with reference to the torque curve. Looking at the shape of the torque curve, i beleive its meant to stasrt rising again at around 4900rpm's. The fact that it doesnt leads me to believe that the VTC solenoids are not working.

Would that sound right?

Does anyone have torque curves of a Z32 so i can compare.

Thanks
Attachments
scan.jpg
scan.jpg (80.52 KiB) Viewed 3450 times

GZ@hybridka
Posts: 112
Joined: Wed May 03, 2006 5:51 pm
Location: Id, USA

Post by GZ@hybridka » Tue Jul 01, 2008 3:43 pm

I cant offer much help really, but from what I see it appears something is wrong with that dyno run.

A standard horsepower calculation dictates equal hp/torque at 5252rpm, always. HP=TORQUE * RPM / 5252

The operator may have not divided the tach pulse input properly for your 6cyl, or it may have been missing a few ignition events (this can easily happen with inductive pickups/filtering).

I would bring this to the attention of the operator, maybe get a couple more dyno runs.

kenbam
Posts: 131
Joined: Sat Sep 15, 2007 9:46 am

Post by kenbam » Wed Jul 02, 2008 7:39 am

Dyno is the bare bones basic model, due for the upgrade this week. Power is in kilowatts and the torque was just newtons. More concerned with the shape of the torque curve, seems the VCT is not switching.

Matt, does the "Consult display" window have all the display switches working, i have never seen the red button light up for the VCT solenoid (does for idle switch and neutral). I know for certain that the ECU is switching on at around 1200 rpm with load (Tested using a carmen scan tool whilst driving on road), just doesnt seem to be switching off at 4900rpm.

Got this from another forum, although RPM's are different from whats in mine.

Will do some more testing today.

"
79F2 = minimum coolant temp for VTC actuation (checked first)
79F4 = maximum coolant temp for VTC actuation (checked second)
79F3 = minimum vehicle speed for VTC actuation (checked third)
79F7 = minimum TP for VTC actuation (only if RPM is UNDER ON point) (checked last)

As for the RPM, it doesn't seem as simple as I first thought.

Basically, the VTC "OFF" point (F9F6) is the maximum RPM for VTC ON. If it's not ON by that point, it's not going on.

The VTC "ON" point (F9F5) is the RPM at which you turn on VTC based on RPM alone.

If the RPM is below BOTH RPM points, it turns on when it exceeds the TP at 79F7.

So, the NA cars have an RPM-based VTC. on at 1800, off at 5800 (actually 6000 if VTC is already ON). Below 1800 RPM (actually 1600 if VTC is already ON), the VTC is controlled by load (TP).

The TT cars have a mostly load-based VTC. Since the ON point is above the OFF point, it is effectively rendered inactive. Below 5900 RPM VTC is turned on by TP, above 6100 by RPM. But since the OFF RPM is 5900, you'll never turn it on with RPM..."

Matt
Site Admin
Posts: 8244
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Post by Matt » Wed Jul 02, 2008 11:40 am

the Z32 address file you are using should have those VTC cut/recover points already defined in them. You can double check them by opening the address file and comparing in word pad

I've never looked at the indicator for VTC to be honest. You need to enable all the flag registers in consult for these to become active. Then you can monitor those

I'll see if I get time tonight to look at those on the bench with a Z32 ECU to trigger (assuming I dont get flooded with emails like I did yesterday!).

Since you need to be at normal running temp and valid RPM/TP points for the VVT to kick in

GZ@hybridka
Posts: 112
Joined: Wed May 03, 2006 5:51 pm
Location: Id, USA

Post by GZ@hybridka » Wed Jul 02, 2008 4:55 pm

My mistake, didnt realize graph was in kw/nm

kenbam
Posts: 131
Joined: Sat Sep 15, 2007 9:46 am

Post by kenbam » Wed Jul 02, 2008 5:00 pm

Matt.

No biggy, i thought it might have had something to do with the registers.

Run some tests today, seems my problem may be the return springs in the cam advance units. Everything is working how it should except piston is simply not releasing when ecu turns off oil control solenoid. Turns out return springs are meant to be changed with timing belts so i'll order some springs.

Again, nothing to do with Nistune.

Still, fairly impressive power increase with no changes other than fuel and minimal advance. Both runs on the above dyno readout were done within 2 mins of each other.

Matt
Site Admin
Posts: 8244
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Post by Matt » Thu Jul 03, 2008 1:48 am

Yeah I tried it on the bench and kept all the sensors within limits. With all the flag registers selected, I got fans and EGR etc but couldnt trigger VCT. Also tried inside NissanDataScan

My only problem is that I dont have speed input working right now so that might be stopping me from triggering it here

RB30-POWER
Posts: 62
Joined: Fri Jul 20, 2007 4:43 pm

Post by RB30-POWER » Sat Jul 05, 2008 1:14 pm

the auto z32 roms need a speed input of 8km/h+ IIRC.

the manual roms do not need speed input and should work without changing that value, just make sure the tps input signal represent more then idle voltage and the neutral position sensor input is not on.

kenbam
Posts: 131
Joined: Sat Sep 15, 2007 9:46 am

FIXED IT.

Post by kenbam » Tue Jul 22, 2008 6:43 pm

Ok, replaced the springs in my VCT actuator, removed restriction in exhaust and run it up again. Below are 3 printouts from the same run, first shows the fixed up torque curve, looks great. Second is the boost pressures (Shown in ABSOLUTE pressure, so its actually 10 psi only. Third shows A/F ratios, should probably put in abit more fuel but it wasnt pinging at all, still very conservative timing maps.

BTW, car is an auto, and the test was done in second gear, using tacho for torque curve.
Attachments
AFR.JPG
AFR.JPG (75.77 KiB) Viewed 3357 times
boost.JPG
boost.JPG (76.29 KiB) Viewed 3357 times
torque.JPG
torque.JPG (76.73 KiB) Viewed 3357 times

txq45
Posts: 9
Joined: Fri May 16, 2008 1:54 am
Location: Plano. TX
Contact:

Post by txq45 » Tue Aug 12, 2008 7:25 am

You didn't lock up the torque converter in 3rd gear?
Easy to fix see write up by Greg Dupree on dyno Z32 Auto..

kenbam
Posts: 131
Joined: Sat Sep 15, 2007 9:46 am

Post by kenbam » Tue Aug 12, 2008 8:22 am

you have a link?

Post Reply