gregfcarlson

I'm working on my first 350Z build and am starting the tuning now using UpRev. I put in the ID1000 injectors and UpRev MAF GT (to go along with the twin turbos). I asked UpRev for some common tuning values as a starting point since I bought everything from them but they won't respond to my emails. Anyway, I have the minimum pulse width and latencies set for the injectors and ROMEdit set up the MAF table for the MAF GT. Fuel pressure is good and steady at a bit over 50psi. I have WB O2 sensors in each bank for measuring. I calculated a new K multiplier based on the larger injectors (1000cc vs 380cc) and the wider range of the MAF (about 180% over OEM) and came up with a K multiplier of around 15000. The problem is that as soon as it gets out of crank mode, it starts leaning out a lot. Using real-time tuning, I ended up with a K multiplier of about 31000 to stay close to target AFR across a small RPM range (idle to 3k) under no load. This seems abnormally high like something is wrong. Any thoughts or advice would be appreciated. Thanks.

jdm-v35

iTrader: (7)

its because you dont adjust k value for the maf/ if you have an uprev maf, set the maf type to Uprev GT. K multiplier is used for tuning of maf piping diameter change and injector change.

wannabuy350z

iTrader: (27)

since the upgraded MAF dont really change the voltage slope from what i have seen. usually it will be a bit lean and i would as a start multiply the maf curve 100% double it

mailman101

hey greg f carlson did u ever get any good answers to your questions? Im doing the same thing tuning gt maf and went from factory to 1000cc injectors.

Cengineer

Hey, I am tuning my 04 g35 coupe 6 mt on uprev as well.

I am having trouble getting the afr to be stable when the car is idling. i have 775 cc "fuel injector clinic" injectors, powerlab gt3582r kit. I am using a wideband innovate afr as well, (no fuel return system).

I used minimum pulse width value as 1.3 (anything above 1.6 and I cant start, anything below 0.9 and the car starts to do weird things, also extremely unstable afr values).

I have the latency values from the manufacturer as well however these are generic values for the same 775 cc injectors since I didn't give them my product id code (they were already in the car). I tried to use them, however the afr at idle still bounces between 14-16.5 (tried to load up the battery using seat warmers, high beams, radio, etc to get it down to 8v and increase/decrease slope that way but no real improvements).
Do you think any possible vacuum leaks can be a source of this bouncing (lets say from the couplers holding the charge pipes together?)
Any recommendations on what to do/look out for to stabilize the afr during idle?


Thanks
Rafal

Cengineer

Update: I didn't make any changes to the mpw or the latency values, i did some removed some % from fuel compensation table and changed maf values (corresponding to voltage) seems like it made a huge change. afr is somewhat stable now at 14.7-15.1 at idle

from data log afr corrections in both banks were about 96%-102% , much better than the previous 125% lol