Efi Supercharged Blow Through
Turbo Mini Forums

Hi, initially I was going to use the single pulse but I forgot to make a plug to disconnect the b,d,f and h injection drivers. To do it I have to dismantle the dashboard, lengthen the wires so that I can position the plug under the dashboard . For now I will continue to try with the double pulse system. The only drawback is that the tunerstudio fuel trim table resolution is a bit low. If the problem persists I will modify the loom to except a plug under the dashboard.

OK. I've got the wires in the loom up to the injectors, just need to splice them in when I decide to change over.

There are a number of ways of progressing from where you are but I would start by trying to get the VE table right by using VEAL. The holy grail of siamese port injection is getting enough fuel in the outer cylinders so I would start by using VEAL on the outer cylinder wideband (unless you have a third common wideband).

At lower loads with short pulse widths, injection timing with the 2-pulse mode will not be as critical if it is about right. Only when pulse widths get around 8ms are you likley to start losing fuel to the inner cylinder.

I suggest that if you take of the cylinder trim and use VEAL to get the fueling somewhere right, you should get the balance about right with the inners slightly richer than the outers unless the timing is out. If necessary, sort the timing to get some consistancy, then bring back individual cylinder trim to bring the AFRs in line.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Hi good suggestion, tomorrow if weather permits I will reset the trim to zero and use veal with the outer cylinder O2 sensor only and I will advance the injector timing to see if the difference in AFR is reduced. Just one question to use the veal on the outer cylinder only do I need to disconnect the inner cylinder O2 sensor?

No need to disconnect the inner cylinder O2 sensor.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Hi here is the link for the latest log

https://drive.google.com/open?id=1D8J3glNgX...AcGYGt_b3msE1l7

this is without injector trim

Here is the injection timing table

Edited by turbominik on 4th Mar, 2019.

That looks like a distinct improvement. The log shows inner cylinders consistently richer than outers.

It's a bit rich at the top end. Are you using VEAL? It's probably not had long enough to get to the target AFRs. It may be a good idea to manually shave 5% off the VE at higher MAP values to help it along.

I suggest more work on VE to get average AFR in the right ball park, then we can start trimming.

Edited by Paul S on 5th Mar, 2019.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Hi yes I used veal but because of traffic and short road in Malta its a bit difficult to maintain a certain speed. I will adjust the ve table manually and advance by 10 to 20 degrees the injection timing map and see if the difference between inner and outer AFR will reduce.

I doubt you will close the AFRs by adjusting the injection timing table. It is not that critical with the 2-pulse method. As long as the slug of fuel is passing through the correct inlet valve, then it is OK.

You will need to use cylinder trim to balance the AFRs.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

It's better to reduce fuel from the inner or add fuel on the outer cylinders?

As you are using VEAL on the outer cylinder AFR, I would just trim the inner cylinder. That way VEAL will have little work to do to correct the VE table.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Hi this evening I done some progress with the injection timing map. This is the maximum advance that works best.



This is the log related to the above map
https://drive.google.com/file/d/1v37uPY4cOv...iew?usp=sharing

The next log is with 20deg added to the above map which increased more the difference in AFRs
https://drive.google.com/file/d/1CYYBb8fEKw...iew?usp=sharing

It seams that the above map gives the best results. Tomorrow I will use the fuel trim to correct the last bit of difference in AFR, because more advance leads to worst results.

I like what you have done there. Advanced the timing until you can actually see more fuel going into the inner cylinders and then backing it of a bit. I assume that you are still using begining of pulse timing. This means that any VE change should not affect the balance.

Good work.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Yes it beginning of pulse timing. Hopefully by reducing from the inner will balance the AFRs

This is the last log with the fuel trim, I think that the AFRs are very close now.

https://drive.google.com/file/d/1u2nZtsNnum...iew?usp=sharing

and this is the fuel trim table

Great. Looks like the theory is holding out so far. More inspiration to get mine sorted.

How does it drive? Does it feel better than with the carb? Smoother, more responsive?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Hi it drive so much better its much more smoother and mush more responsive even bellow 2000rpm

Hi these are the last two logs, the first log is without AFR correction.

https://drive.google.com/file/d/1BIbqEP2CIe...iew?usp=sharing

The second one is with AFR correction, I assigned the outer injector drivers to the outer O2 sensor and the inner drivers to the inner O2 sensor and I saw a significant improvement in AFR balance without any changes to the injection timing or injector trim maps.

https://drive.google.com/file/d/1Xx7b5AQoh7...iew?usp=sharing

Hi this is the last log, up to 5400rpm and 10psi

Edited by turbominik on 16th Apr, 2019.