Nistune Forums

I have a N60 MAF which I got from a 1989–1994 maxima that has a vg30de engine like the one here:
http://i119.photobucket.com/albums/o142 ... C00058.jpg

I'm trying to put it on a '93 240sx s13 ka24de.

I selected the option to change mass airflow meter and chose the J30 one.
I also adjusted my K constant. However when I get the k constant so my
idle is normal, at WOT I run 9-10:1 AFR where I ran 12.5-13:1 with old MAF. When I adjust K constant so that WOT is normal my idle is way off..
(I turned off o2 feedback.)

Other problem is that I'm hitting the far right on the load table on the a/f map at low RPMS's where I should be in like the 71%-87% columns.


Any idea what VQ Map I should use?

I tried the M30 VQ map, J30 VQ map, and the A32 VQ map and none of them seem correct..

You should change the Injector Latency to adjust the idle once you've gotten the correct K for WOT. You need to rescale your load scale so that you're not hitting the far right columns. Check the documentation provided at http://www.nistune.com/documentation.html - Check the "NIStune ECU Tuning Basics" pdf. That will explain some of the basics to you.

iaredam wrote:You should change the Injector Latency to adjust the idle once you've gotten the correct K for WOT. You need to rescale your load scale so that you're not hitting the far right columns. Check the documentation provided at http://www.nistune.com/documentation.html - Check the "NIStune ECU Tuning Basics" pdf. That will explain some of the basics to you.

I shouldn't have to adjust the load scale if I select the proper VQ map.

(I also already read that DOC, check out my post from a few months ago on the N62 MAF.)


Also you are suppose to adjust your K constant for idle and then it'll work under WOT too. K constant adjustment affects the whole map not just some area.

From the guide:
"The Injection Multiplier (AKA “K Constantâ€

J30 VG30E is the MAF listed in that dropdown. Dont have the J30 VG30DE on there right now.

I do have the ROM file. It probably has a different VQ map. I'll extract that out and post it here tonight. You will have to fiddle with K constant with 'auto' ticked to get it right as the estimated HP are only ballpark figures to get you started.

We dont have extact flow figures for all these different MAFs

Matt wrote:J30 VG30E is the MAF listed in that dropdown. Dont have the J30 VG30DE on there right now.

I do have the ROM file. It probably has a different VQ map. I'll extract that out and post it here tonight. You will have to fiddle with K constant with 'auto' ticked to get it right as the estimated HP are only ballpark figures to get you started.

We dont have extact flow figures for all these different MAFs

I did some more reading..
The same N60 maf might come on the "HCR32-RB20DET (300 HP)" but I'm not sure..

the n60 maf is a 300hp maf that is the same as the RB20 maf.

maxmaxim91 wrote:the n60 maf is a 300hp maf that is the same as the RB20 maf.

Thanks dude!
I'll try out that VQ Map and play with the K Constant until I get it right.

Yeah you're right. So HCR32 is the same VQ map. I'll update the VQ map definition file to match

Right off the bat it sets the K Constant at 62715.
Obviously I knew I'd have to play with it, and only had 30 minutes or so to mess around with it, but 67215 is way to high.

42,556 to 4,7662 seems closer, I'll post the final one when I get the number as perfect as I can.

Well I finally started messing with the N60 MAF again.
I noticed with the newer versions of nistune the K constant doesn't go up as high as much as it use to when changing to the N60 MAF.

It gets set to 41,XXX from 39720 when converting.
When using the default K constant idle is too lean and WOT is too rich.
(I was running 12.8:1 AFRs, after converting MAF in nistune I run 11.9:1.)

I then adjusted the K constant to 38,774 and it produced too lean WOT with AFR's around 13.5:1. (I know it doesn't make sense to go lower then orginial K constant, I was just learning what moving around the K constant does to AFR's.)

I then adjusted the K contstant to 38,775 and was still a little too lean.
(~13.0:1)

I'm still working on getting the right K constant, but I think it's some where between the default K constant for the stock s13 ka24de maf and 41,0XX..

I don't know man..
It seems that a K Constant for the N60 MAF which is suppose to measure up to 300hp should be LOWER then the K constant for the stock ka24de s13 MAF which is suppose to measure 290HP.

K Constant with stock ka24de MAF is 39,720.
K Constant with n60 maf that is best is 39,500-39,650 or so..

This make no sense.. Anyone have any ideas?
At this point I guess it doesn't really matter because my AFR's are really close to what they were before I swapped the MAF over with the lower VQ.

Still confused..
Turned off all o2 sensor feedback and set all lower fuel/air map cells to 0.
Idle was really rich with K constant's that produce similar AFR's to old MAF at WOT. The K-constant that the idle would run 14.7:1 with would cause WOT to run way too rich.

perhaps the HP measure for the S13 KA24DE is not quite right. the HCR32/N60 should be

try and aim for mid range AFRs about 14.7:1

Matt wrote:perhaps the HP measure for the S13 KA24DE is not quite right. the HCR32/N60 should be

try and aim for mid range AFRs about 14.7:1

I gotta turn off my o2 feedback and try that, but I'm looking pretty good..

After logging for a couple of days, and playing with K constants I think that a number between 40750 and 41000 are correct. These numbers make sense too because this would mean the n60 maf measure just a little bit more hp then a stock ka24de s13 maf. (like 305hp vs 290 or something.) I think that logging in "tuner" mode was misleading me as I almost always log in "stream" mode.

Using a K of 40750 I'm within .2 or so of my old afrs.

I think part of my problem is I've blocked off my EGR tube, so I'm pretty sure even if I went back to my stock maf with stock bin, I probably still wouldn't idle at 14.7:1 if I turned off o2 sensor and change map cells to 0..