My v6 Drag Week build

[Shadow24V]

It may be inherent to the 24v SOHC design. Granted my idle isn't well tuned yet, but it didn't like lean idle at all. I think mine was stable at 13.x AFR when she was running last.

When I get Lucy 2.0 back up and running, I'm going to swap over to the gslender 2.8 (or latest) code. Its a fork of the MSII-extra that has adaptive idle ignition and a couple other things that make getting a good lean stable idle really easy.

Latest thread is HERE on the MSextra forum

EDIT: that is also only on 270cc injectors too

[c2xejk]

Quote:

Originally Posted by Shadow24V It may be inherent to the 24v SOHC design. Granted my idle isn't well tuned yet, but it didn't like lean idle at all. I think mine was stable at 13.x AFR when she was running last.

Interesting... My tentative solution is to keep it a little on the rich side... (low 14.x AFR)

Quote:

When I get Lucy 2.0 back up and running, I'm going to swap over to the gslender 2.8 (or latest) code. Its a fork of the MSII-extra that has adaptive idle ignition and a couple other things that make getting a good lean stable idle really easy. Latest thread is HERE on the MSextra forum EDIT: that is also only on 270cc injectors too

I will have to check this out...

[Shadow24V]

Was thinking about your rich at idle issue today, what is your injector firing configuration? 1 simultaneous, 6 alternating, etc?

[c2xejk]

I believe 2 alternating.

[Shadow24V]

That should be slow enough for better PW control on larger injectors, i.e. not too short. Do you have your injector dead time set correctly? that can totally screw with your tuning, AFR and such

[c2xejk]

Quote:

Originally Posted by Shadow24V That should be slow enough for better PW control on larger injectors, i.e. not too short. Do you have your injector dead time set correctly? that can totally screw with your tuning, AFR and such

On the injector dead time, my question right now is "what should it be?" I have it set for a fairly standard 1 msec. These are the newer style smaller injectors with an EV14 connector. Some initial digging indicates that maybe it should be shorter than that (0.6-0.8 ms range).


That said, I think I have found much of the AF issue. Too much accel enrichment and not enough decel enleanment. The AE is done in terms of ms and the new injectors provide a LOT more fuel (600cc vs ~300) in a ms than the old ones.

Before the AE/DE change the engine would often want to stall when I put the clutch in. The AF gauge would go way rich as RPMs drooped very low/stall. If I coasted down in gear and let the AF gauge read lean (16+), then the engine wouldn't stall.

Since the AE/DE change the engine always drops nicely to the idle RPM and stays there and the AF is about right on the money.

I am putting a little more enrichment back in because I started getting a lean stumble on launch and throttle tip in.

[Shadow24V]

that does seem to make sense. I know I still have a lot on the table when it comes to accel and deaccel enrich/leanment. .8ms dead time sounds about right as well. Sounds like your narrowing down on a good N/A tune so far. You like the torque of the 3.5 so far?

[c2xejk]

Hey Shadow24V, did your engine run hot?

Yesterday I swapped a stock thermostat back in for the one I drilled out. This one was marked as 88C (190F), but in the engine it seems to run a consistent 209F despite it being ~30F outside...

[Shadow24V]

If you consider 205* hot, yes. Coolant temps barely get over 200* even when ragged on. the +-4* could be from gauge accuracy/calibration between our cars.

also, according to autostoned, both the 3.0 and 3.5 run a 180* thermostat stock

[c2xejk]

If you have a 180F thermostat and are running ~200, then that would be consistent with my engine having a 190 thermostat and running ~209-210... RockAuto has a 170F thermostat so I ordered it... (The engine should run ~190F with it...)

I need to rework the hoses to the heater core. I think they are kinked enough that the don't flow well... Right now I only get a minimal amount of heat.

[Shadow24V]

that makes sense. Any reason why you think 210* is too hot? seems like many newer cars are running hotter anyways...

The heater core hoses are a pain as there is not much room between the 24v block outlets and the stock 12v inlets. I have to have mine coiled behind the motor to get the core coolant.

[c2xejk]

Mainly that the engine is turbocharged...

The other side of it is I was not expecting a 190F thermostat to have the engine at 210F...

[Shadow24V]

Quote:

Originally Posted by c2xejk Mainly that the engine is turbocharged... The other side of it is I was not expecting a 190F thermostat to have the engine at 210F...

good point on the turbocharging and heat thing. I think there is some latency between the thermostat opening and it fully cycling, hence the 200+ temps on a 190* thermostat.

EDIT: I lied, finally found some of my logs from '09 (reloaded my computers a few times since the car has been running) - AFAICT, i never broke 200* on the 180* thermostat. mid to upper 190*, but that's about it.

[c2xejk]

Mine ran a steady 209 +/-2 degrees during a half hour drive (started with it warmed.) Took me a while to get used to it running that hot. In the past when an engine started getting that hot, temps continued to climb. This one seems to be stable at 209...

[Shadow24V]

interesting, Hopefully the 170* thermostat gets you below 200*. Is the 210* reading from a gauge or from the MS? placement of the sensor could show diff temps.