Polished Kirkham with V12 engine at London

[olddog]

Be careful if you are burning too rich, as washing all the oil off the cylinders is a bad thing. With closed loop control turned off, what ever the ECU is commanding the lambda to be, you must get that same lambda reading with the O2 sensor. Until you achieve this, you will chase your tail trying to get the fuel right.

To get the timing right, the ECU has to have some understanding of engine load. What ever strategy is used, somehow it needs to estimate how much air is in the cylinder relative to how much air the cylinder displaces. Mass Flow is the most accurate as it is directly measured (but it is only as accurate as the MAF sensor).

If it thinks the load is less than it actually is, it will put in too much timing. If it thinks the load is greater than it actually is, it pull too much timing out. Once you have an accurate load calculation working, you can tune what the engine needs. If you do not have a good load calculation, you will fail to tune the timing.

To get the fuel right you have to know how much air is going in. So accurate air flow is critical to both fuel and timing. Some people do not know how much fuel the injectors are putting out so they just diddle with the air flow to get the fuel correct. When they do this, they screw up the load calculation for the timing.

Good luck

[AZCobra12]

Everything said is totally correct. The system is operated by one throttle position sensor and 2 Lambda's, one on each bank. No mass flow or speed density yet. I updated the original Pectel ECM to the the SQ6 that had closed loop feedback. By the way Pectel is NO HELP at all as the ECM is "race only" and is not supported for street use. Wish I would have known that $$$ ago. The ECM has full capability to run all the sensors and up to 12 of each with data recording. The SQ6 ECM was set up the same way are the old one plus Lambda. In a boat the engine operated Great as it was at half to full throttle most of the time. In the car it is idle to 15% throttle most of the time. Fuel dilution and fouling plugs is a big issue so not running it until it is retuned!! My tuner is a genius but getting him to finish anything is an issue, AADD I thing. I just wanted to get the V12 running good with minimal sensors and wiring but may change. The ignition is wasted spark and crank triggered, I think one cyl on each bank is not degreed right as it is the same misfire or no fire on each side. An easy computer fix. There is not much timing advance as it is detuned to under 1000hp/1000trq already.
I'll check out the tuner you mentioned, thanks. I had PRO EFI as a tenant in one of my buildings for years, he has a stand alone system also and was thinking of swapping out the SQ6 for the PRO EFI ECM. Just no support and only about 5 guys in the USA that can tune it.

[olddog]

If you contact the fellow, he knows me by Olddog and he knows of this site. Let him know that I mentioned it to you, as that will likely trigger his memory. He may be able to help you and I believe he can. He would even help you get your system running without buying his. I think the link to his site was on that post. You could just join his site, free like this one, and start a thread. He may have worked with your ECU in the past. If so he might be able to tell you how to resolve your issues or tell you if the ECU is never going to work properly. Either way it could save you a lot of time.

I will warn you he is short with answers and gets over my head quickly, but he has always slowed down to my level and helped me when I have asked. Honestly I think he, like most of us, will get pretty giddy about playing around with a V12 like you have. It is awesome, and I want you to succeed with it.

[olddog]

Originally Posted by AZCobra12

. There is not much timing advance as it is detuned to under 1000hp/1000trq already.

Pulling timing lowers Hp, and that's fine to lower the Hp some. If you go too far, in my opinion, that is a poor way to kill power. If you get to the point that you are lighting the fuel so late that a lot of un-burned fuel is going out the exhaust this will make the O2 sensor believe you are lean when you are not. The ECU may compensate and make you burn rich while thinking it is spot on. High over lap cams can do the same thing at idle.

Burning a bunch of fuel after the exhaust valve is open, is a waste of fuel, which might explain your poor fuel mileage. I'm not certain but it might heat the exhaust valve too.

It would be better to tune the engine to run right and just limit the throttle to not open all the way.

[Gaz64]

Originally Posted by olddog

Pulling timing lowers Hp, and that's fine to lower the Hp some. If you go too far, in my opinion, that is a poor way to kill power. If you get to the point that you are lighting the fuel so late that a lot of un-burned fuel is going out the exhaust this will make the O2 sensor believe you are lean when you are not. The ECU may compensate and make you burn rich while thinking it is spot on. High over lap cams can do the same thing at idle.

Burning a bunch of fuel after the exhaust valve is open, is a waste of fuel, which might explain your poor fuel mileage. I'm not certain but it might heat the exhaust valve too.

It would be better to tune the engine to run right and just limit the throttle to not open all the way.

Yes, better to run it like a throttle stop class car than to make it pig rich and retarded timing. Get that first 15% correct, and even if you limit the throttle to 50%, it will still be so much nicer to drive.
Gary

[AZCobra12]

Originally Posted by Gaz64

Yes, better to run it like a throttle stop class car than to make it pig rich and retarded timing. Get that first 15% correct, and even if you limit the throttle to 50%, it will still be so much nicer to drive.
Gary

With all the issues with the current tune I agree with going back to old school power limiting, a light left foot. That has been my approach with my other cars and it does take a little moderation and only me driving it, I have two big issues, 18 and 19 year old sons.... The throttle stop is the most logical way to have a definite limit and the engine would be tuned right in the first place, just plan logical.

[GT Trooper]

When I saw this I couldn't stop looking at it.

[Gaz64]

Originally Posted by GT Trooper

When I saw this I couldn't stop looking at it.

I would have been the same. Lovely car.

[Snake2998]

Thank you to all involved in the project for sharing it - the result is something to be proud off and gives great pleasure to all petrol heads to look at, talk about and I am sure to hear as well - no matter how im?practical it may be.

Truly a Hillary & Everest car - it was done because he could (paraphrased quote/misquote but you get the idea.) Thanks once more - I love it.

[AZCobra12]

Finally an up date to the tuning issues. It is running on ALL 12 cylinders and a year after I picked it up at KMP. A smile on your face while taking a drive is priceless... finally. Timing is not retarded any more, took A LOT of fuel out at idle and a little at midrange. We still have a way to go but defiantly on the right track now. Moderation of power is simply a function of the left foot. Took advice here and ordered stack boot filters and will finish the tune with them in place. A few other issues, oil pressure, sent the pump to Barns and had a wider 1.5 inch section put in, now pressure is linear with 750rpm@15-20psi, 5000rpm@75psi, and 210 degrees temp, real good numbers. Remade the pulleys into 5 groove, up from 3 groove ones, no more belt slipping. Renu the tuner from California is a great lady and knows her stuff, thanks to her...
Now it is time to put some miles on the Snake and the weather in Az is just tuning perfect to do so.

[1795]

Nice to her that things are finally sorted out. Now get out there and put some miles on it and scare everything in desert!