Thank you guys for all the useful info in here!!!

 

Ya depending on what boost pressure the cars going to run will be the determining factor of what map sensors best suites you.

For most cars I tune we end up using 4 bars. Some use JDM Maps also. Depends on boost the cars going to run.

 

I am having a problem with 96531706. When the car was on MAF it drove fine but now that it is on SD it misfires as soon as it comes on boost (5 psi or so). Where the car misfires the AFRs are in the low 12s. I have tried leaning it out some and richening it up some but neither makes a difference. The ignition timing is not extremely high or low either and it is not knocking.

I have also swapped coil packs/wires and spark plugs from another car and this made no difference.

Anyone else experience this? I am thinking to go back to MAF to confirm if it is or is not a hardware issue. The other thing would be to change to a different SD ROM ID, but I have used this one on other cars previously without trouble and I don't see anyone with this issue in this thread.

 

scheides
While I think at it: could you correct the sentence because it can mislead people
If trim is negative you would:
Reduce MAP VE = LESS FUEL
Reduce RPM VE = LESS FUEL

You probably know it since a long time, but the new owners/DIYers still have these questions

 

subscribed

 

This happened to me.. I went step by step and tried to adjust my fuel trims going by what scheids post and ended with worse fuel trims then when I started with 1:1 with kpa:load

 

OP edited! Thanks for the feedback guys!

 

No thank you for the tutorial!!

 

Hey Guys,

Hopefully we can ask questions here. If not, let me know and I'll start a thread.

I finally felt comfortable enough with my tune to switch over to SD.

Edited the maps this morning to mostly mimic my MAF tune. (Boost, fuel, ignition, idle, etc). I saved and flashed the map to a warm engine and started to work on my idle to 3000rpm. Wideband gauge and log both show around 15 which is generally where my car hangs. Feedback was up in the 12s. I had to change my SD RPM VE values up to 100 to get the feedback to average around zero. AFR is just about the same.

Driving is really nice. Cruising around my wideband reads like it always has. 15 to mid 14s. Nothing to be concerned about. I put some miles on it gave it a little gas a few times to see how things looked. Pretty much what I'm used to. Gave it a 3rd gear pull just to hit peak boost and see how things looked. My full boost load matches up right where I've been logging for weeks. I was happy to see that. And AFR at full boost wast right at 11.5 where I've been tuning it. Spool was substantially leaner than what I've been logging, so I have some work to do.

So, do I need to bring my values up over 100% to get my AFRs in line? Could I possibly have some table values or scaling incorrect? 94170715, btw.


Thanks,

Brady

 

Raising the VE values will richen the tune, lowering them will lean it out. It's kind of a fine line between MAP VE and RPM VE. You have to find the right mix. If you're only having issues during spool up and full throttle you might want to leave the RPM VE alone work on the MAP VE. At least, that's the way I see it.

 

I'll try to post up my log.

Just doesn't seem right that I'm at 100% from 500rpm up. I feel like something is off.

 

You can try adjusting the MAF Compensation as well, but going over 100% on VE isn't a big deal. A lot of people, including myself, are tuned that way.

 

So, same fuel map on my maf tune as my SD tune. At 1000, 1500, 2000, 2500, 3000 I'm about half a point leaner with 0 STFT while monitoring my O2 feedback. I've compared my ROMs and I don't see any tables that should make this difference. Any ideas?

 

0 on stft sounds like the sensor isn't working, or isn't on. I don't care how perfect the tune is, you're going to have O2 feedback..

 

Sorry, that didn't come across well. It jumps around a bit, but it's pretty close to 0. I rev it and it comes back down. Settles on values close to 0.