cewrx7r1

iTrader: (2)

Read attachment since it is too large to type here.
I'll attach my maps used during the test on the next post.


Go to later post to read doc format, it is better.

cewrx7r1

iTrader: (2)

My test maps.

cewrx7r1

iTrader: (2)

Since the forum text editor completely ruined my nice
structured post, here is the comparison table.

PIM Voltage PSI PSI PSI Diff
(Autometer) (PFC)
--------------------------------------
2.64____0______-.5_____.5
3.33____5______4.6_____.4
3.91____10_____9.5_____.5
4.23____12____11.2_____.8
4.43____14.25__13.0____1.25

cewrx7r1

iTrader: (2)

Here are my notes in doc format, ,hopefully this will not be ruined.

atihun

Chuck,

These are great; thank you for your efforts and info.

I am still running Ray's maps since I bought my PFC a year ago. I am now a little concerned after I read your post on some of his settings.

Do you think you could help me out with my map? My engine is relatively stock, I have 93k on the car and I have the PFC set at .9 primary and .85 secondary for boost. At these settings the car runs perfectly; the DEFI gauge shows a 14psi boost.

If you can take a look at my map I would appreciate it; please e-mail me at rx7@atihun.com. I will have my car back from the body shop hopefully by this weekend so I can get the settings off the PFC.

weaklink

Chuck,

RE: your probs with win2k. As I understand it, W2K is not DOS based at all, as earlier OS's were. Even though you can get to a "command prompt", it's not a true DOS. Many programs say you have to use true DOS, not a shell. You could try making a system or boot disk from an earlier OS (98 or 95). Boot from that, then run your UEGO program. If it is small enough, you could fit it all on one disk and just run from the floppy.

Mach2

Cewrx7r1,
That's some great info you got there, but I have a question for you. You were running on the "leaner" side of the table and you have 1200cc secondary injectors installed and were only running 12psi of boost. What if someone with stock secondary injectors were to try out your maps? Would they be running "way" too lean? What if they had boost at 14 instead? How soon would they need a new engine? I noticed that your fuel maps haven't changed much when compared to an older one that you posted before you had the 1200's. Is there are reason for that? Good luck, and keep up the great work!!

cewrx7r1

iTrader: (2)

Mach2,

Theoretically; when you make injector size changes on the PFC, all should still be about the same. But that is not realistic with this $1200 unit. That is another reason to run tests like I am doing. I also have a J&S installed for extra protection. The J&S required me to also change my timing split which was discussed a few months ago. One must not retard the leading ignition to fire before the trailing ignition. This is almost as bad as detonation.
With Rays maps which are based on the mod base set, it would and did happen. But I was testing at 7psi. Whenever I make large changes, I start testing at low boost first before going up higher. To answer your question, if you have similar mods as mine and stock injectors; and run 12PSI boost, you will be overdriving the injectors and this would be unsafe. That is why I went to 1200s.

About my high of 12.2 AFR. For the boost I was running with my mods of large MFIC and good fuel system, it was not really unsafe. Gorden who runs a large single turbo with large ports runs his at 12.1 AFR above 14PSI boost. I just prefer to run safer at 11.8 AFR max. My maps do give more fuel above 12PSI so I was not worried about going to 14PSI accidentally. I have run these maps at 13PSI a few times without problems.

Along with changing the secondaries from 850 to 1200s; I also replaced my Greddy SMIC with a Blitz FMIC which is over twice as large, and replaced my hi-flow cat with a MP. The last two mods required a change in fuel requirements which I did a little. But
evidently, my engine breathes better than I thought.

Mach2

Cewrx7r1,
Thanks for clearing that up a bit. I have 1300cc secondary injectors, but I haven't put them in yet cause I don't have a good map to run them and I'm still unsure about the lag times to put in for them. So yes, as of right now I still have the stock injectors. I have similar mods to yours, except for the IC. I want to install the 1300's that I have with your maps and want to be sure that I'll be ok, but it looks like you are happy with a higher A/F than I would be able "live" with. Thanks for all the input and keep us posted on your progress. Good luck!

machinehead

Chuck, Tell me if I am understanding this. You are saying that the PFC reads boost correctly, it just doesn't display it corretly? I have been wondering about this for some time now.
Cliff

cewrx7r1

iTrader: (2)

Mach2,

Notice that in my test report, I have added 4% more fuel on the PIMS voltage map but have not tested this yet. It should put me down to about a 11.8 to 11.5 AFR range. You can do the same or even add more.

rceron

I have been carefully adhering to Chuck's maps since we have very similar mods. Per the post, I just added 1.03x fuel (3%) to the individual cells where boost is an issue. I chose not to do this via the PIM route. However, I can't seem to modify the fuel above 150 (1.50) in the cells on row P20. Am I doing something wrong?

Just so I know row P20 does represent 14.7 lbs of boost, correct?

cewrx7r1

iTrader: (2)

Machinehead,

My PFC reads and displays PIM voltage correctly, but when it converts it to pressure and displays that; it is inaccurate.

Rceron,

I do not have my PFC data here so will have to estimate from memory. You can not go higher than 1.496 n the fuel cells. That means you have to add extra fuel by PIM RPM or VOLTAGE.
Row 17 is about 13.5psi and R20 is about 19.4psi.
Row 20 is 24,000 abs in my PFC. When I finish my UEGO O2 AFR mapping, I will make the changes in the actual cells where posible. Where not posible, I will use the PIM VOLTAGE map.

Tim Benton

iTrader: (1)

Chuck,

When you say its correctly displays voltages, but incorrectly when it converts and displays it on the commander, what are you basing it on? The fact it differs from the autometer boost gauge or looking at what the voltages is supposed to be out of a technical manual that tells what differing voltages mean as far as boost. If its the autometer showing somthing different, well, I think that's a mistake since the autometer line is the lower end of gauges. Mine autometer boost differed when I had the PFS PMC and now with the PFC. I don't even look at it now other than to ball park the boost made from the first and second turbo. Also in an earlier post, or maybe it was in your attachment, you said you thought that most people's pressure cell 17 seems to indicate roughly 12 psi, but just now, you say 13.5. Does that mean yours now is set for 13.5 in pressure cell 17? Sorry for the questions but it just didn't make sense. Has anyone who has installed the 3 bar map sensor posted anything. I was wondering what the pressure cells meant with it compared to now. Like I asked before, does the same 20 pressure cells cover vacuum for the first 10 cells and 1....I think I jsut answered my question looking at your post. Pressure cells 20 is up to 19.7 boost. Our stock 2 bar is for up to 17. The 3 bar would just allow the sensor read correctly, but how many cells would be given for added boost. 10 cells now for 19 psi with the stock 2 bar map sensor ( 2 psi not used since it can't accurately measure it) what would the 10 pressure cells be used to measure if someone wanted to measure more than 19 psi, say 22 for example.

Tim Benton

cewrx7r1

iTrader: (2)

BOOST GAUGES:

When I replaced my "HIGH END" HKS with the Autometer, I ran a comparison pressure test off a "T" line. They both read the same pressure from 0 to 14psi. I consider that accurate. The reason for replacing the HKS was that it read in Kg/Ccm^2 and had dark orange lettering. I was converting to gauges that looked stock.


MAP SENOR/PIM VOLTAGE:

When I pressurized the map sensor; I read the output voltage at the sensor with my digital voltmeter and read the voltage on the commander. They both read the same.
When comparing the map sensor voltage to pressure as per the Mazda manual for 0 and 14.3 PSI, the voltages were almost exactly in the middle of the listed voltage ranges. I consider that accurate. But when you convert the commander Kg/Ccm^2 pressure to PSI, it does not match the boost gauges or PIM voltages. Thus the commander diaplayed boost pressure is not accurate.


FUEL MAP ROWS:

To convert rows to relative pressure in psi, you have to convert the absolute listed pressure for that row from Kg/Ccm^2 to PSI then subtract normal atmospheric pressure. Our boost gauges read in relative pressure. I said that row 17 should be about 10+ range and that row 18 should be about 13+. What happens when you are in between the exact pressure listed for two rows, like 12.5 PSI? The ecu logic interpolates by some logic to determine the needed values. The ecu then has two choices to show what row you are in, either row 17 or row 18. My PFC shows row 17.

Tim Benton

iTrader: (1)

Great, thanks for the clarification, I assumed that you had tested it since, well you usual do, I was just wondering about how you came up with the boost number comparison. So if my commander say .84, then I'm actually a bit higher.
My boost gauge says 13 psi., commander say .84. I'll start paying more attention to it then. Seems like that would be a easy patch or fix for APexi to offer.
About the boost gauge, did you get the one with the chrome bezel, if so I did too. I'm on my second one now, but have had that model for the past 5 years.

Thanks for the response,

Tim Benton

RX-7 Pilot

[QUOTE]Originally posted by cewrx7r1
[B]Mach2,

"The J&S required me to also change my timing split which was discussed a few months ago. One must not retard the leading ignition to fire before the trailing ignition. This is almost as bad as detonation. "

Can you please explain this statement. I want my IGL numbers higher than my IGT numbers right? So the trailing fires 1st due to the lower numbers? Just want to understand this better

thanks
Kelvin

machinehead

Chuck, that makes sense about the display on the PFC being off. I also tried several different boost gauges and they all read higher than the display on the PFC, also my AVCR matched the boost gauges. I am glad to hear that the PFC is actually reading corretly. It would seem strange that the sensor be the culprit... good work!

cewrx7r1

iTrader: (2)

Kelvin,

The J&S only retards the leading ignition.

Positive timing numbers are before top dead center (BTDC) and negative numbers are after (ATDC)

If my timing was 20 leading and 15 trailing, that gives gives a timing split of 5. This means the leading(lower) plug fires 5 degrees before the trailing(upper) plug. If at this timing my J&S detected detonation and retarded the leading 6 degrees, then the timing would be: 14 leading and 15 trailing. This would probably stop the detonation but now the trailing would fire first by 1 degree. This causes sort of a reverse flowing combustion front/force similar to pre-ignition.
Thus you still get pinging and this can ruin an engine also.

The older J&S only retarded up to 10 degress.
Thus to be safe you need a minimum split of 11 to be safe. If you look at my map timing split, you will see an uniform split curve. You adjust leading timing first to control power and detonation and then adjust trailng for the split you want. Less split means more power. Go to the single turbo forum and look up their long older threads about timing and split.

RX-7 Pilot

Thanks Chuck,
That makes more sense!

-Kelvin

Tim Benton

iTrader: (1)

Chuck,

Next time you are using the wideband can you also compare the O2 readings from the stock unit to the UEGO unit? You imght have already done this. It would help a lot of those without a wideband to know that the stock O2 reading at WOT at .90 and dropping to .86 volts corresponds to a 11.8 to 12.2 reading on the UEGO, for example. Instead of shooting for a number on the Stock O2 we assume to be safe, we could alteast have some data showing that maybe that .82 to .84 wasn't really safe at all.
Thanks in advance,
Tim Benton

Leadfoot

Chuck,

Did you find anything out regarding Tim's question and the corresponding volts and the stock 02?

thanks

Wade

iTrader: (1)

Comparing volts with a stock o2 doesn't work. I have compared them, but the stock o2 voltage varies too much. I have seen my stock o2 read .7 and my wideband read 10:1 and I've also seen my stock o2 read .88 and my wideband read 12:1.

With a normal o2 sensor, it isn't just a matter of range/slope and resolution, it is also a matter of temperature affecting the readings.

Wade

Tim Benton

iTrader: (1)

Now that's some variance for the stock O2. I really can't believe Peter used to tune the PFS PMC by it, or tell customers what voltage to shot for. Thanks for the input Wade.

Tim

Wade

iTrader: (1)

Tim,

If you are very consistent with your testing methods, the stock O2 can be useful, just not totally dependable. Try to stabilize the temperature whenever you are watching the O2 volts by doing several (5-10) back to back WOT runs on the same strip of road.

Wade