just curious, say we dont tune the fuel trims out and just leave it at that. What happens later down the line when the ecu relearns the trims? leaner? richer? more knock?

 

One of the reasons is that when we lose our trims our tune gets thrown off.
And if you've noticed whenever we flash our car our trims reset.




Has anyone rescaled their RPM column for the timing map?
I want more resolution in the higher RPMs rather than the lower RPMs.

Instead of:
4000
4500
5000
5500
6000
6500

Rescale to:
4000
4250
4500
4750
5000
5250
5500
6000
6500

So that the timing map is more fine tuned and has smaller increments when increasing with RPMs. Can this work for our ECUs?

 

Yes, you can change whatever values you want, but you're gonna have a rough low end if you happen to switch into open loop too soon lol.

 

well during WOT we go through the low RPMs so quickly. On the higher RPMs, 3500 to redline, the RPMs climb slower on the higher gears, like freeway pulls. And we are mostly in this section of the powerband the whole time during WOT
So if we create a higher resolution in the higher RPM areas, we can have a more controlled specific timing.


So what are you going to do next? Buy a FPR?

 

Yeah, I definitely need an FPR. Maybe it'll help with my top-end leaning lol. I think that I just may go with that AEM one that evodreamer posted. I've just gotta get some cashflow lol.

 

i was leaning towards the AEM one in the beginning... but it didnt look like it had a gauge port. So idk if does or doesnt, but you do need the gauge to set idle fuel pressure.

I really hope the FPR fixes our problem. During WOT i watch the AFR just climb from 11 AFR to 12-12.5 AFR as the RPM/Boost climb... It has to be the FPR.

Now Im waiting for summitracing to ship out my other fittings... so i can put it on. Luckily the adapter to mount the FPR to our stock fuel rail fits, and its for the EVO too, thank you mitsubishi haha

 

Yeah, I can see the AFRs climbing on my end too. There's not enough fuel for the amount of air that's rushing in. Let us know how it works for you =P.

 

It should do the trick. When i still had my RRM stage 2 piggyback + FMU + RC 370cc I had no leaning out problems. It was actually too rich. Rich enough to create knock and stock ECU timing + boost = bad

Reese tuning dyno'd my car and it was knocking with that setup, he didnt like the whole piggyback idea. So we tried it without the piggyback, it lost power and it was still rich due to the FMU, but now the ECU was able to pull timing now that the piggyback wasnt installed. Im surprised other RRM kits lasted so long...

 

Make sure you get a rising rate fpr else it will do nothing for your leaning out problem. I got a 1:1 rising rate i think, and it seems to do the trick.

rescaling the higher rpms could help out if you really need to have exact timing between specific rpms. But just throwing some numbers out here... say you have +10 for your timing at 3000 rpm, k and say you have +8 timing at 3500rpm. If you are reving at 3250 rpm your ecu is gonna use anything from +8 to +10 as the timing. If you want it to use Exactly +9 and nothing else then you could make a 3250rpm column with +9 as the timing i guess. I think the benefit will be negligible as a one degree variation in timing is minimal at most. If you are trying to run the ABSOLUTE most timing possible without any knock then I can see where this would help but otherwise the 500rpm span should do.

 

yes it is a rising rate FPR. did you get your AFRs stable now?

 

I was just thinking about OEM parts that might work ... you can get a Evo FPR for $65 and that will bolt right up. It's a rising rate 1:1. Also, on my old VW I swapped in a regulator from an Audi A4 (B4 chassis ... '99 to '03 or so 1.8T) and it was a 4bar 1:1 ... it was only like $35 and might be worth looking on to. It might be PnP as most OE FPRs are similar.

EDIT :: Looking for a local 1.8T guy that might have a OE VW FPR. These are plentiful and are 3bar 1:1.

 

Fuel trims don't generally affect WOT, but the can cause a CEL for a rich/lean mix that can DUMP fuel at idle/cruise and kill fuel mileage. It's not worth it.

After a bit of time on Daniel's car last night, I've concluded that my next approach will be to leave the MAF size for now and adjust the injector scaling to a point where WOT fueling is manageable, and then tune the low end of the MAF scaling table to manage the fuel trims (if this is possible).

 

Hey guys, thought I'd update again. I've realized that with my goals, ecuflash just wasn't cutting it anymore. I've hooked up my old emanage and wired up the injectors to it to increase duty cycle, with amazing results. I've hit 18psi, still at about 40% IDC. I ended up getting a fuel pressure regulator as well, and that seems to help out. With a little more work, I'll have it pushing 20+psi.

 

i was installing my FPR regulator on this weekend and i noticed that the fitting that is made for the EVO is too huge for our little baby fuel rail
So I had to bore it out to .625" and I also bored the fuel rail to .375"
Cant wait to install it now!





slips right in now

 

i forgot to mention senate told me that the stock ECU is good up to 12 PSI only...