NOOB KPRO Question - How dangerious to run lean

[cyllarus]

I am getting ready to do some street tuning of my k24 swap that is running on a really good base KAL supplied by SLIP_ANGLE (THANX).

I know that seeing knock during a pull is an instantaneous - "Shut it down and tune knock out" since just a little knocking can cause alot of stress to the bearings.

But what about running lean? if i see the A/F go over 16 should i react the same way?

or is it ok to let the motor run to A/F of 16/18 for single pulls to get a good datalog?

[AKEP]

i woudln't go above 16. if its getting that high you need to click the check mark to enable "adjust all tables" and add at least 10%-15% fuel if not more. roughly 10% fuel is 1 afr. eg, if you're hitting 16.3AFR, if you add 10% the rule of thumb is you should see ~15.3AFR. you want to see about 12.1-13.1 AFR on WOT. the lower afr is usually where you're just using fuel to cool the combustion when you're going forced induction. so if you're n/a you want to (usually) be a little higher. it all depends on what engine it is and mostly wont be able to notice without a dyno. if y our using a k20 map your going to need to add about 15% over everything to make up for the engine size (k24 is 16.66% bigger than k20) and flow. heres a lesson, its better to run rich, so fatten up that fuel and pull back and lean it out to where its safe. dont run it lean trying to make it rich. you are more likely to blow the engine running lean 10 times than you are running it rich 1000 times.

[cyllarus]

Thanks AK.

I am seeing AFs as high as 18.1 in some partial throttle points..

Overall the map is VERY CLOSE which makes me loath to rich the whole thing and have to back down EVERYTHING.. because right now i'd say there are just 3-4 points where its too lean.

But i guess its better than blowing it up during tuning.

On the flip side, i've read that running too rich can also cause damage to the cat and exhaust manifold due to the exhaust gasses still burning as they come out of the head..

SO that being said, how rich is TOO rich to the point that im in danger of doing damage?

[AKEP]

anything richer than 12 really. i can't find the page to save my life but the absolute most power you can get from pump gas in around 12.1, some parts of the stock a3 map (WOT over 6K) will read well below 11.5 (the lowest the o2 sensor can read, so theorectically its even richer then that) so i'd say its safe to run mid 12's. the burnt fuel will burn cooler than the lean stuff you're burning right now, which will also burn up the cat and 02 sensors.

[Slip_Angle]

I am getting ready to do some street tuning of my k24 swap that is running on a really good base KAL supplied by SLIP_ANGLE (THANX).

I know that seeing knock during a pull is an instantaneous - "Shut it down and tune knock out" since just a little knocking can cause alot of stress to the bearings.

But what about running lean? if i see the A/F go over 16 should i react the same way?

or is it ok to let the motor run to A/F of 16/18 for single pulls to get a good datalog?

What areas is it running lean? Is it in closed loop or open loop? If in open loop, that is way too lean. My calibration has lean cut enabled so it will shut you down if the A/F goes above 14.7 for more that 250ms over 90kpa. If this is in closed loop then 16/18 is still too lean and you should add fuel.

This makes me very curious to know where you run lean and rich vs me.. If I recall correctly our mods are very similar right?

My car

06 cams
Race header
CAI
RRC manifold

[cyllarus]

I disabled open loop and lean cut for a few short pulls to get a feel for where the maps were in comparison.

With lean cut enabled, i was hitting the cut as soon as i hit 4k.

our setups are close, i have:
'06 K24A2
TSX Manifold (RBB)
DC5 Type R header & Cat
Injen CAI.

based on this i expected to be RICHER than you in most places since i should flow LESS due to having a cat, and the more restrictive RBB.

What i am seeing is that my idle is running quite rich 12.5 or so.
at WOT A/F is hovers around 13.5 until 3k, from 3k to vtech engagement at 4 it jumps to around 16,

Once Vtech engaged it spikes HIGH (18) and then comes down from there to about 13.5 at 5500.

I didnt take it much past 5500 because the A/F numbers i was seeing were scaring me.

But if you think about it, this makes sense. The RBB manifold is designed for mid range torque, where the RRC is designed for High-End HP. Based on that, you would expect my motor to flow more in the mid range, and hence run lean when running on a map for your motor, which would be flowing less in that range. inversely, your motor will flow more at the top end, and hence my motor will run rich when running on a map for a your motor.

[Slip_Angle]

I disabled open loop and lean cut for a few short pulls to get a feel for where the maps were in comparison.

With lean cut enabled, i was hitting the cut as soon as i hit 4k.

our setups are close, i have:
'06 K24A2
TSX Manifold (RBB)
DC5 Type R header & Cat
Injen CAI.

based on this i expected to be RICHER than you in most places since i should flow LESS due to having a cat, and the more restrictive RBB.

What i am seeing is that my idle is running quite rich 12.5 or so.
at WOT A/F is hovers around 13.5 until 3k, from 3k to vtech engagement at 4 it jumps to around 16,

Once Vtech engaged it spikes HIGH (18) and then comes down from there to about 13.5 at 5500.

I didnt take it much past 5500 because the A/F numbers i was seeing were scaring me.

But if you think about it, this makes sense. The RBB manifold is designed for mid range torque, where the RRC is designed for High-End HP. Based on that, you would expect my motor to flow more in the mid range, and hence run lean when running on a map for your motor, which would be flowing less in that range. inversely, your motor will flow more at the top end, and hence my motor will run rich when running on a map for a your motor.

Ah, yes. That makes sense now. I had the RBB on my car previously and it had wonderful low to mid range. I switched to the RRC because it was said to make the same torque in the low/mid range and greater power up top. After the switch, I too noticed I had to remove a ton of fuel low to mid, which would seem to say the RBB makes better power in those areas. Once you have your car tuned to suite your setup send me a 2nd gear run and I'll graph it over my RRC.

Here is the graph I did after switching. Honestly, even though it says the RRC is better everywhere, the RBB still felt more powerful in the lower RPM's...

5929

PS: If you need any help tuning, send me your DL and I can give you a hand.

[Slip_Angle]

Send me your email. I have a previous calibration for the RBB that I dug up. It should be better for your setup.

[cyllarus]

Email address PM'ed..

Nice looking curve, A/F looks really flat.

Based on the numbers shown in that grapth, makes no sense NOT to have the RRC since it appears to flow better in the upper ranges, but really not hurt you in the low end at all.

Perhaps that should be my next investment..

Do you still have the coolant running through the throttle body? or did you disconnect that?

[Slip_Angle]

Email address PM'ed..

Nice looking curve, A/F looks really flat.

Based on the numbers shown in that grapth, makes no sense NOT to have the RRC since it appears to flow better in the upper ranges, but really not hurt you in the low end at all.

Perhaps that should be my next investment..

Do you still have the coolant running through the throttle body? or did you disconnect that?

Coolant still runs through the TB. Also, with the RRC it has the coolant port built in like the RBB so no modifications needed.

[cyllarus]

HOLY SH!T SLIP_ANGLE GETS A COOKIE!!!!!!!!!!!!!!!!!!!

Loaded up your KAL and made a few adjustment to the parameters.. runs beautifully!

Initial datalogs of a couple of pulls in 2nd and third show a slight A/F Bump right around 4500 RPM but everything else looks smooth.

I will get more time this weekend to do some good 4th and 5th gear pulls and really get a good picture of where it stands.

Two questions:
I am noticing a sharp spike in A/F right at throttle tip in, is this normal? Guessing that its the split second between opening the throttle and the ECU turning on the injectors?

You said there is a danger in running A/F below 12.1... as it was described and i understand it, there is no DANGER in running A/F below 12.1, you just are running the motor inefficient.

[Slip_Angle]

HOLY SH!T SLIP_ANGLE GETS A COOKIE!!!!!!!!!!!!!!!!!!!

Loaded up your KAL and made a few adjustment to the parameters.. runs beautifully!

Initial datalogs of a couple of pulls in 2nd and third show a slight A/F Bump right around 4500 RPM but everything else looks smooth.

I will get more time this weekend to do some good 4th and 5th gear pulls and really get a good picture of where it stands.

Two questions:
I am noticing a sharp spike in A/F right at throttle tip in, is this normal? Guessing that its the split second between opening the throttle and the ECU turning on the injectors?

You said there is a danger in running A/F below 12.1... as it was described and i understand it, there is no DANGER in running A/F below 12.1, you just are running the motor inefficient.

Running lower than 12.1 is very rich/waste of fuel - it's not dangerous in the short term. Ideal A/F is 13.0 - 13.5. Too lean is over 14.0 and dangerous is over 14.2-14.7 for 250ms @80-90kpa or greater.

The short spike at tip-in is normal.

Glad it's working out for you. Also, on the road you don't really need to go above 3rd to get what you want. I find even 3rd too fast on the 5 speed.

Send over a 2nd gear pull and I'll graph it to see what power you make.

[cyllarus]

Will do.. hoping to get some free time to do some road tuning this weekend.

Planning on locking the cam at each angle and doing a set of 2 and 3rd gear pulls .

Will make sure you get looped in on the results ;)