Alky PSI question.

[NY Twin Turbo]

if the car has no knock with a good afr and runs real good I would leave the curve alone.

It takes about 30 seconds to pull a point or 2 out of the VE map in those very few cells. Maybe even add a little timing to take advantage of the cooler intake air temps and higher octane too. Even distribution of alky can easily be seen on a data log. I have 6 EGT probes and except for idle, I have my corrections set-up to be all within 50 degrees of one another. Most times even much closer.

As a group, I don't think we ever leave well enough alone. I know if I did, I wouldn't be where I am right now.

 

[Mr.Spool]

I have 6 EGT probes

you can see a lot with that kind of setup,my friend tunes his 6 sec car off the egt probes.

 

[NY Twin Turbo]

you can see a lot with that kind of setup,my friend tunes his 6 sec car off the egt probes.

I planned for them long ago when building my twin turbo headers. I use to have the Red Alert system by Altronix. But when I decided to go with the XFI's EGT set-up it just worked so much better! EGT probes and alky go so well together. The funny thing is, alky distribution on my car seems quiet good according to the EGT readings. However, without alky even though my injectors are flow matched correction is required.

Those of you who don't have individual EGT probes, be aware. You are certainly going to have a lot of variation in temperature from one cylinder to the next. But you guys should see this easily on your plug readings.

 

[Mr.Spool]

You are certainly going to have a lot of variation in temperature from one cylinder to the next. But you guys should see this easily on your plug readings.

yup,thats why I try to get guys to pull the plugs and see whats really going on.

 

[NY Twin Turbo]

yup,thats why I try to get guys to pull the plugs and see whats really going on.

Even with individual cylinder correction. Trying to achieve a balance is difficult when reading plugs. Because the difference in temperature is not consistently rich or lean per cylinder. It varies based on load/Map. So plug readings are an average. Or when new, and checked after a blast, just a snapshot of what took place most recently.

Example. Cylinder 1 may be leaner than the rest under light load and need positive correction, while cylinder 6 may need positive correction under only heavy load/MAP then be fine the rest of the time. Or, with alky, it may change everything.

Unfortunately, XFI doesn't allow for correction to be based on load/Map. Instead it uses RPM. So, I found the safest way to approach making individual cylinder corrections is to have equality under the RPM conditions of heavy load/MAP. Then, what ever happens under non boost conditions must be just tolerated.

Or you can have 2 correction maps to enter. One for cruising and one for racing.

Another important thing I have noticed. When making corrections, every injector should at least have a zero correction somewhere on its correction curve.

 

[Mr.Spool]

So plug readings are an average.

we read the plugs by making a wot hit shut the car off, then pull the plugs.i wouldn't call that and average but inmo the best way to see whats happening.getting them uniform is the real trick.

 

[NY Twin Turbo]

we read the plugs by making a wot hit shut the car off, then pull the plugs.i wouldn't call that and average but inmo the best way to see whats happening.getting them uniform is the real trick.

Yes. Like I said earlier above "Or when new, and checked after a blast, just a snapshot of what took place most recently."

Now an update. I got back from the garage today after messing around with the alky controller. Turns out, I got my alky to hit just how I want it. The first blip on the radar happens at 1 psi. By the time I'm at 3 PSI I'm at 15lbs of alky pressure. It's exactly just the little bit I wanted for a start.Then at 7 PSI of boost, I'm at 37ish on alky pressure. Then I had to turn the gain down a little bit. Only tested it up to about 10 lbs of boost and here the alky is up around mid 80ish.

Pulled a few points out of the VE leading to and after this area. But I always have it in slight negative correction anyway. Can't test drive it yet. This will wait untll the entire winters punch-list is complete. Also double checked the Individual Cylinder Correction. Needed to take a hair off 1, 3, and 6 down low. Now there within 16 degrees of each other!

I'm happy so far. Now for the next thing.

 

[Mr.Spool]

Now there within 16 degrees of each other!

good curve adjustmenti would think with your combo you would need a whole different curve,either a quicker turn on or more initial

 

[No disintegrations]

Even with individual cylinder correction. Trying to achieve a balance is difficult when reading plugs. Because the difference in temperature is not consistently rich or lean per cylinder. It varies based on load/Map. So plug readings are an average. Or when new, and checked after a blast, just a snapshot of what took place most recently.

Example. Cylinder 1 may be leaner than the rest under light load and need positive correction, while cylinder 6 may need positive correction under only heavy load/MAP then be fine the rest of the time. Or, with alky, it may change everything.

Unfortunately, XFI doesn't allow for correction to be based on load/Map. Instead it uses RPM. So, I found the safest way to approach making individual cylinder corrections is to have equality under the RPM conditions of heavy load/MAP. Then, what ever happens under non boost conditions must be just tolerated.

Or you can have 2 correction maps to enter. One for cruising and one for racing.

Another important thing I have noticed. When making corrections, every injector should at least have a zero correction somewhere on its correction curve.

I say let it have some extra fuel. You can be rich and still make a bunch of power. It won't drop off in power much until you go quite rich. Don't try to split hairs in other words.

 

[NY Twin Turbo]

I say let it have some extra fuel. You can be rich and still make a bunch of power. It won't drop off in power much until you go quite rich. Don't try to split hairs in other words.

Yes a little extra fuel is not a bad thing. But it is best to leave this to be done in the AF table. The injector balancing should be dead on if possible and not be made to provide additonal fuel as a total. The VE should be as close to possible maybe allowing for a small negative correction. Sometimes you may cheat VE to make up for some lack of tunning in the AE graphs, but only if the bubble is going to shoot through and not stop in one of these locations. Because if it does, then the cell will be wrong.

The fail safe is in the positive/negative correction maps. Allowing more positive correction and very little negative. But the VE and AE has to be close when you only allow very little negative correction for it to still be able to get the AF correct.

This stuff has worked for me. Not an expert, but I drive it often and long distances on the street. I think I'm doing OK though.

 

[gunzandgearz]

Yes a little extra fuel is not a bad thing. But it is best to leave this to be done in the AF table. The injector balancing should be dead on if possible and not be made to provide additonal fuel as a total. The VE should be as close to possible maybe allowing for a small negative correction. Sometimes you may cheat VE to make up for some lack of tunning in the AE graphs, but only if the bubble is going to shoot through and not stop in one of these locations. Because if it does, then the cell will be wrong.

The fail safe is in the positive/negative correction maps. Allowing more positive correction and very little negative. But the VE and AE has to be close when you only allow very little negative correction for it to still be able to get the AF correct.

This stuff has worked for me. Not an expert, but I drive it often and long distances on the street. I think I'm doing OK though.

Pretty good r&d work, especially for a fabricator.

 

[NY Twin Turbo]

Pretty good r&d work, especially for a fabricator.

It looks like I may take it out for its first 'real' drive this weekend. No telling yet if I'm going to like any of these little changes. Maybe I'll be putting it back where I had it.

 

[gunzandgearz]

It looks like I may take it out for its first 'real' drive this weekend. No telling yet if I'm going to like any of these little changes. Maybe I'll be putting it back where I had it.

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