XFI 2.0 and alky tuning

[leirch]

Hi,

I'm working on tuning my 109, ported irons heads , 206/206 roller , stock intake and throttle body, te44 and 50lb injectors, stock intercooler.

I had the motor running on a TT 5.6 alky chip at 24lbs of boost, ran great, switched to xfi and didn't set the boost down to tune the alky properly, I ran the car super rich. 8.5:1 for a week while trying to lean it out(was afraid to drastically pull gas out), and blew number 3 cylinder headgasket, I was using stock graphite gaskets and have replaced them with rjc bulletproof gaskets.

Since getting the car up and running, I've set the boost down to 15lbs and turned the alky off, attached is a calibration file and a wot scan. As you can tell, this was a fairly hot/humid day, 85degrees or so outside(150degree air temp, IAT sensor is in the doghouse now as well). But the car ran fine, no knock(assuming I have the knock parameters setup properly).

I then put aweaker spring in my rjc manual boost controller, set boost up to 17psi, turned razor alkycontrol to "6", and pulled a lot of fuel out, did 3 blasts, kept pulling more and more gas out.

Attached is my latest WOT log and current .gct file...


My question is this, I'm already down to 65 on my VE table at the 17-18psi area but my WB is still bottoming out 9:1, is this normal and I need to pull more fuel?

 

[ttypewhite]

Your numbers in your table is irrelevant, if your wide band is reading correctly. Keep the timing down and get your target air fuel in line to handle your desired boost levels first, then pull fuel out of the map until your in the ball park. 9.1 is way too rich for 17 to 18 psi, you need to be closer to 11.8 depending on what grade pump gas you run the car on. You can also turn the knob down on your alky controller if your pumping too much alky in.

 

[norbs]

11.8 would be OK with no alky at those levels of boost, It won;t hurt to run it richer as @24 psi 10.8 ish @25 psi would be a good target, on a single nozzle kit for example.

 

[leirch]

Thanks for the tips. I've been trying to tune this setup, half of my WOT blasts are very clean and will blow the tires off , the other half as soon as the boost rises, I get some bucking/popping from what it sounds like through the intake, I don't see any lean spikes though.. I suspect that its my AE vs Map or TPS that's causing this? or could it be an electrical problem?

I just changed from r44ts plugs to some ngk br6fs plugs and I still have the same issue, gapped at .30.

I've attached logs of a clean run and one with the car popping.. when the car pops, I try to let out as soon as possible.. this can't be good on the motor.. needless to say this is getting frustrating.

 

[CGASTON]

Thanks for the tips. I've been trying to tune this setup, half of my WOT blasts are very clean and will blow the tires off , the other half as soon as the boost rises, I get some bucking/popping from what it sounds like through the intake, I don't see any lean spikes though.. I suspect that its my AE vs Map or TPS that's causing this? or could it be an electrical problem?

I just changed from r44ts plugs to some ngk br6fs plugs and I still have the same issue, gapped at .30.

I've attached logs of a clean run and one with the car popping.. when the car pops, I try to let out as soon as possible.. this can't be good on the motor.. needless to say this is getting frustrating.

Switch to a non-projected tip plug. If you have iron heads run a AR133 plug. Will help with detonation.


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[Nick Micale]

Switch to a non-projected tip plug. If you have iron heads run a AR133 plug. Will help with detonation....

I am not a tuner, but I do know you need a race plug like Clint stated, and you should tighten the gap even more.

Your too rich tune is as bad as too lean, since both are very prone to pre-ignition which is what most likely what killed your head gasket, and WILL kill any head gasket, or do more expensive other damage.

Like what was also said, your WOT timing should be relatively low, 20 deg. or less while trying to figure out the proper tune?

Just remember if you want more HP out of your current build, it will take more fuel to do this so be sure the supply chain is more than adequate for this level.

Here is a projected tip plug from a performance engine that I always used a race plug, but the owner got lazy and pre-ignition cracked the 109 block. He still has the other plug that was missing the porcelin as well as the ground electrode.

 

[norbs]

The logs are not showing anything abnormal, except slight tire spin and small kpa spike, sounds like it could be a module/coil pack just starting to get weak...

 

[bison]

Don't be deceived by the ve table. Your engine isn't using a lot of fuel because the mass flow is low.

 

[leirch]

Thanks guys, I have a used coil pack on the car, I'm going to swap in my other spare now. I kept getting hung up on possible AE vs MAP or tps tables but the inconsistency in the popping is sounding like an electrical problem.


I thought the br6fs were non-projected tip plugs?