Why is it running rich?

[Garry]

OK, just got word back from the shop yesterday they have my 'Hawk back together and running ... According to the boss who drove my car down before the engine upgrade, it's a night and day difference to before ...

Anyway, we're both a bit surprised it seems to be running rich at the moment ... I had the stock setup AutoVE tuned SD pretty much Dead On, MAF disabled. Now, with all the upgrades (see below), it appears to be running fine, albeit they said it felt like too rich ... I (and the mechanic) was expecting it to be rather lean, given the extended intake duration on the Cam ...

Could the FT be over-correcting? Or do I have the logic somehow reversed? Also, if it is running rich (which I'll test before doing anything), I guess adding another 7-10% to the fueling before re-starting AutoVE might not be a good idea ;)

Oh and once warm, it is hunting idle ... guess I can't keep it at 850 or so that it is stock ;) I guess that's when the initial warmup-enrichment is cut by the PCM, right?

Anyway, can't wait to finally get it back on Saturday!!! :w00t::banana::coool: (except for filling it up with current fuel prices ...)

[SSpdDmon]

Thanks to another member on here, we've found that NBO2's can be off by about 10% or so in long tube header applications. Therefore, it's necessary to reduce the NBO2 switchpoints to get the car lined up with maintaining a stoich AFR. That's where part of the richness will come from.

Another part is, yes, the VE table has now shifted a lot at the lower RPMs due to the new cam. At idle and rpms below 1600 or maybe even 2000, you're probably adding too much fuel. The fuel trims can fix this some, but it may not be enough.

As for his assumption that it'll run lean, he is correct - when you have your foot into it. Chances are, if you went WOT while untuned, you could easily hit 14's for your AFR on a WBO2. So yes, increasing the higher kPa cells over 2400rpm in the VE would be wise.

That car should pur like a kitten at 850rpm with 24* of timing at idle assuming your desired airflow table is set correctly. See the idle tuning thread I created. ;)

Essentially, your tune is due for an update. :D

*Hint* Set WOT timing to 26* or 27* for WOT from 2800rpm~6800rpm and keep an eye out for KR. If you live in higher altitudes, it may take more timing. What works best can only be found on a dyno. :)

[mr.prick]

Thanks to another member on here, we've found that NBO2's can be off by about 10% or so in long tube header applications. Therefore, it's necessary to reduce the NBO2 switchpoints to get the car lined up with maintaining a stoich AFR. That's where part of the richness will come from.
this would be interesting to try with the RR,
but this table seems to have no PIDS to link to it.:rolleyes:

[Garry]

Well, I know I will have to go through a new AutoVE tune, no doubt there ... I just haven't been around to do it yet, picking the car up this weekend and tuning it on the way home ... Thanks to the Autobahn and a couple no-limit areas on the way home ;) I reckon the 160mi distance should be enough, with a couple of stop-and-retune stops in between, to get it back in the +-1 area on the VE-table.

Thanks to another member on here, we've found that NBO2's can be off by about 10% or so in long tube header applications. Therefore, it's necessary to reduce the NBO2 switchpoints to get the car lined up with maintaining a stoich AFR. That's where part of the richness will come from.
Where do I do this? Do I have to change anything on the LC-1 (using one stock NB on one side, and the Innovate on the other with NBO2 simulation through the controller)


Another part is, yes, the VE table has now shifted a lot at the lower RPMs due to the new cam. At idle and rpms below 1600 or maybe even 2000, you're probably adding too much fuel. The fuel trims can fix this some, but it may not be enough.


As for his assumption that it'll run lean, he is correct - when you have your foot into it. Chances are, if you went WOT while untuned, you could easily hit 14's for your AFR on a WBO2. So yes, increasing the higher kPa cells over 2400rpm in the VE would be wise.

OK, so for AutoVE, I shouldn't add the 7-10% to the VE table across the board, but only from maybe 2000 or so up to get a starting point?
[/quote]
That car should pur like a kitten at 850rpm with 24* of timing at idle assuming your desired airflow table is set correctly. See the idle tuning thread I created. ;)
[/quote]
Idle is the next step ... ;) I'll just see to it that I got a good drivability, then when I'm back home (got a long weekend ahead), I can take care of the fine-tuning ... ;)


*Hint* Set WOT timing to 26* or 27* for WOT from 2800rpm~6800rpm and keep an eye out for KR. If you live in higher altitudes, it may take more timing. What works best can only be found on a dyno. :)
[/quote]
Not exactly high altitude ... I think the track/airfield we go to for racing is like 1200ft or so ... no "performance" driving at any higher altitudes ... as for dyno, I might be going to one in July if that one tuner should be back over then ...

Tnx for the infos!!!

[Dale]

Something I have noticed is I that I was tuning my car over winter, on winter gas. Now that its spring time, they have swapped gas. My car now runs about 3% richer... just from change in gas formulas and air-temps.

[SSpdDmon]

Where do I do this? Do I have to change anything on the LC-1 (using one stock NB on one side, and the Innovate on the other with NBO2 simulation through the controller)

Under Fuel>O2>Swith Points. That suggestion was if you noticed the AFR being rich in closed loop (since you're running LT headers).


OK, so for AutoVE, I shouldn't add the 7-10% to the VE table across the board, but only from maybe 2000 or so up to get a starting point?

Yes. You'll probably find yourself taking 40~60% out around idle and 15~20% around 1600rpm.

[Garry]

Initially, with the tune I did for the stock setup, idle was down in the high 13's, but at higher RPMs the expected lean was there ...
Managed to get most regular driving RPMs/BENs inside the 1% margin on my way home ... car drives really nice, but idle will still need work ... just took care of the regular driving first ... ;) Hope to get some numbers from the track in two weeks ;)