TeamRX8

iTrader: (25)

The AP will allow OMP values to 100 maximum. My first recollection of the '60' steps idea came from Racing Beat in their description of a now discontinued OMP modification service.

There are more than 3 MAF/LTFT scale ranges but it can be broken down in three. That said I disagree with the middle one listed here. Since highway cruising will generally be in the 35 - 40 g/s range you can cleary assess that it is too low on its high value end point. The three ranges would generally be broken down in description terms as idle/cruise/wot though their end points tend to overlap to some degree for practical reasons.

And the 1/2 3/4 map review is only applicable to 2004-2005 models as this was changed on 2006+. The biggest issue with these threads is the sloppy assuming and eventual twisting of good information in the proper context into bad over-generalizations.

:youcan'tmakethistupidbullshitupfacepalmxinifinity :

.

olddragger

iTrader: (3)

its a fact Team. The fuel pump with its 2 staged output functions has voltage drops at certain points while on track. On the street and normal driving --its not a problem at all. But on track many people lock the fuel pump into the high output mode by taking the resistor out of the loop. There is a reason they do that.
Have you ever monitored your fuel pump voltage? I have. The fuel pump has a large enough capacity to provide much more fuel than most people need at the current hp levels. But, if you lose just 1 volt to the pump ( which does happen at times) it greatly diminishes the pumps ability to not only keep the pressure up but also in keeping the tanks balanced. The s1 pump also needs all the help it can get. Remember I am coming from the forced induction world--not na. NA should be fine for every day driving.
so face palm back at ya.

Hey Brett I will send a pm to you--dont want to highjack this thread about the ssv

WreakLoosE

INFO LOAD!! this is a good thread.

HiFlite999

iTrader: (2)

The RT/AP will also allow fan turn-on temp settings of 300 F. The fact that it's allowed does not imply that's it's effective, wise, or safe. The thread I recited previously shows a step motor for the OMP which runs off the gear at 72 steps. A 100 step command would have to invoke a limit somewhere, either mechanical or in deeper level software to avoid a problem. However, I dislike the idea of depending on such protection and would much rather send sensible commands in the first place. Hence the question. If you don't know how the table translates into motor steps (as motor steps or as a percentage of full output), fine. I'm not finding the 'because AP allows it' a compelling argument, however.

oltmann

The limits in AccessTuner are either based on the scaling of 1 or 2 byte values to 4 bytes in IEEE float format or a limit that Cobb put in place based on what appear to me to be their best-guess.
IIRC (on my phone or I'd check) the table is 1-byte with a 1.0 scaling. So 255 would be the actual max, and 100 just a number Cobb came up with.
On the other hand, the 10k max for the rev limiter is just an arbitrary limit. Sure, almost nobody would want to go over that, but it is a float value, you can set it at 20k or 20million. For that matter, most people would be better off if it was lowered to 8600. Arbitrary.
It is probably a good idea to keep 60 as max for omp tables.

HiFlite999

iTrader: (2)

Thanks for the OMP info. BTW, it took me a while to remember the article, but Eric Meyer recommends not going leaner than lambda = 0.89 (AFR=13.08) because of high EGTs and side seal spring failure.

https://www.rx8club.com/showpost.php...&postcount=248

Of course, he's roadracing, so it may be less of a problem for a street car.

wrightcomputing

iTrader: (5)

Subscribed, I recently got the Cobb AP and really want to do some tuning and see if I can improve my Rx8

1.3_LittersOfFurry

iTrader: (4)

Same here lol.

TeamRX8

iTrader: (25)

I simply stated what the limit is. I did not otherwise either comment or recommend what settings to use etc. let alone attempt to 'make a compelling argument'.

I would beinterested in changing or eliminating the redline limiter if possible

1.3_LittersOfFurry

iTrader: (4)

Alright so who is going to hold my hand to turn up my omp rates?

I got the Cobb installed on my car and the atr on my pc, been reading a lot but totally lost... And now I see the numbers for the omp and they seem very low, stays on 3-4 most of the time while cruising.

Should I install the stage one map from the Cobb website?

Fame suit on!

HiFlite999

iTrader: (2)

Stage 1 doesn't change the OMP settings from the MSP-16 update. It mostly reduces the front/trailing ignition split from 15 deg to 5 deg for more power (I wouldn't use less than 91 octane with it). Do you have an essentially stock intake? If so, go for it. If not, start messing with the cobb stock tune and go thru the process. OMP values are low at low load. I conservatively multiplied the entire table by 1.33, then set all values over 60 back to 60. Others have different schemes. Load the Stage 1 (or stock) into ATR, make your changes, then save it with a new name. Just in case, I save all the original maps into a seperate directory on my laptop. It's a good idea to make a text file under the new name describing what you did, since 'tunes' tend to multiply quickly. IMO the most important thing to do is to lower the fan speed turn on temps.

1.3_LittersOfFurry

iTrader: (4)

Hmm... Thanks for those tips!

I have / use..
cheveron 93
10w40 gtx
gutted cat
Race roots single exit exhaust
Intake is oem, but modified. Vfad - disabled, air box baffles? -removed , accordion tube silencer - removed, TB by-pass mod.
BHR Ignition (should I be concerned with dwell settings?)
MEE cooling mod, which brings me to another question.. My normal code reader only shows one code (p0420), but the cobb shows 3, p0420 and 2 for the radiator fan (sorry I'll grab the codes tomorrow). This is most likely the fan mod causing the code? I have noticed higher than normal coolant temps, but nothing over 210 yet with the a/c on in heavy traffic. Fans seem to working but they are not as loud as they use to be, and it has been extremely hot.


Anyway, I'm not very interested in increasing power (for the moment at least), just want to up the omp rates, lower the fan temps (and sell the kit), and maybe up the idle. I'll try messing with it tonight a little.

Thanks again.


-EDIT-
Here are some things I have changed, am I on the right track?



-Edit- One says 80, but should say 60 (7k rpms / max load) just caught it.

HiFlite999

iTrader: (2)

Your intake is the same as mine except I left the accordian resonator in (effects of removal unknown) and removed one screen. Stage 1 works fine for me. I didn't mess with the cold rev limits. OMP is the same as mine. Your fan temps IMO are a bit too low (183 F), risking a lot of unnecessary running. I chose 88/92 C but will go a little lower if experience indicates it's wise. IIRC the low fan speed comes on when the AC is running anyway.

Dwell, yes absolutely! I can't prove much yet, but I'm pretty sure going to the Oltmann/TeamRX8 dwell settings made a big difference in both mpg's and power. https://www.rx8club.com/showpost.php...9&postcount=99 and https://www.rx8club.com/showpost.php...&postcount=108 Oltmann's is more conservative but still (mostly) more aggressive than the MM CW wisdom of multiplying the whole table by 1.45 Realize the the number in the dwell table divided by 256 gives the dwell in msec. Play with Oltmann's spreadsheet, quite nice!

Attached is where I am so far. MAF balancing next.

1.3_LittersOfFurry

iTrader: (4)

Sweet, but my main concern right now is the afr's when doing wot +6krpms, it jumps up to the 15's. Should I be worried? I didn't load the data I changed, just wanna practice a little first and get familiar with what I'm doing before I start adding all these changes.

olddragger

iTrader: (3)

with the rotary engine --tune for power--not numbers. Within reason of course.
a/f's at full load and high rpms ( na engine) may even be in the high 13's.
Dont forget to look at the sparkplugs/ check for misfires ( Teams mention is great), fuel injector cleaning, good gas and not over premixed etc etc.
tuning is not just about the pcm. Just reminding everyone that may be reading this thread.
I wish we had more information on the running conditions between the front and rear rotor.

1.3_LittersOfFurry

iTrader: (4)

My a/f's were in the 13's before putting the stage 1 in. There is also a lack of power when it happens. Between 5-6k rpms there is more power than +6k when it starts going into the 15's.

HiFlite999

iTrader: (2)

Then start with their "stock" tune instead until you get your AFRs down to a safe level. I think you can even start with your own car's stored map as stored on the AP. Hook the AP to laptop, go to ATR, and select "stock map" from the menu. Save that file under a new name to your laptop - I think that then will be the one copied from the car's ECU to the AP. Probably though, you have something else going on. My AFRs at WFO above 6k range in the mid 12s down to 11 with both the MSP-16 factory map and Stage 1. That's pretty close to the AFR commanded. 15 or even 13 is not. Note that an ignition misfire will result in a higher measured AFR. Do you have an oil catch can? That will really screw things up if not done right.What are your LTFTs? Mine is +6 or +7 in the range above 20g/sec. As I think I understand it, this closed-loop LTFT gets applied (more fuel for +, less for -) to the open loop tables. (To confuse things, there is a sensor delay that results in the measured AFR lagging the rpm, but no need to get too exact at this point). BTW, if it's not clear to this point, I'm hardly an expert - trying to distill info from a bazillion posts on the subject and sort "philosophies" from facts or semi-facts.

HiFlite999

iTrader: (2)

Very hard to tune for power without a dyno!

Eric Meyer was very specific about not going leaner than lambda = 0.89 (AFR 13.1); 0.93 (13.7) gave him more power but killed side seal springs with the higher EGT. For "moments" on the street, it may not matter, but I prefer to play it at least a little safe.

1.3_LittersOfFurry

iTrader: (4)

I have a catch can, and it routes from the filler to the can then to the intake.
Ltft was around +3 last I looked, normally it sits around +7.
I'll try loading up the cars stock map and messing with that one today, thanks again for the tips and help. I feel a million times more confidant today about messing with it than yesterday.


-Edit-
Ok now that I'm home I can think more clearly...

Can't find the "Car's Map" on the ap, so I'm going to go with the "Stock style map" and go check out the a/f's. Is it safe to add the adjustments I made above? Still a little confused on the fan temp settings, for example, what setting is for turning them off? I assume all the ones I changed are "turn on temps".

Also, if I am still seeing high a/f's @WOT +6krpms, then perhaps my fuel pump is getting ready to go? Car has 106k on it and no clue if it was ever changed, no records of it from the previous owner.

LTFT on the way home today were +5

When I floored it in 3rd gear @ 4k rpms, initially the a/f's dropped to 12's but as the rpms rose so did the a/f's around 6.5k I was at 15.1 and already felt a drop in power so I let off. It never felt ruff or like it was missing, felt smooth, just losing power. I never really payed that much attention to the a/f's before the Stage 1 tune, but I know I never saw this happening before.

HiFlite999

iTrader: (2)

I assume the catch can then has an inlet, an outlet, and is not open to air?

Every time you load a new tune, the LTFTs get set to zero; the PCM then has to relearn them. Before, you may, at 70 mph, 40 gm/sec steady cruise, have had LTFT=+7 STFT=0, and now, LTFT=+3 STFT=+4.

What turns the fans off is the "hysteresis". If you have the turn-on at 185 deg with a hystersis of 3, it will turn off at 182.

I haven't tried WOT from such a low rpm in 3rd - will look tonight. It might not be coming out of closed loop cleanly (the STFT will read a steady number near zero when it goes into open loop). But I can't explain why it would be specific to the the cobb stock tune which is very stock. Remember you can datalog now and don't have to go from real time impressions.

It could also be a fuel pump problem, read this thread starting with post #23 https://www.rx8club.com/series-i-tech-garage-22/ongoing-fuel-pump-issues-pump-4-fuel-cuts-out-8k-7k-6k-etc-231198/

1.3_LittersOfFurry

iTrader: (4)

Yes for the can, its basically a sealed system.

I have been reading about ltft's, guess it was too soon to look them.

Thank you for explaining the fan hysteresis.

I loaded the "stock map" provided by the ap with the changes I made this morning. A/F's now do not go over 12.7 above 6k @ WOT. I stayed up all night comparing the maps and see the difference now and what I need to adjust if I want to use that map again (stage1).

But now I'm on a new issue unrelated (oil leak). Where ever its coming from its getting on the belts and making a mess. Looks like its coming from between the alt and water pump but I do not see oil on top the engine where the omp oil lines run, so I guess I'll be under the car next..

HiFlite999

iTrader: (2)

I hope nothing bad happened. I don't know how an old engine may respond differently to a fresh. Here's a post from a thread where he also had the Stage 1 run lean. https://www.rx8club.com/showpost.php...95&postcount=6

1.3_LittersOfFurry

iTrader: (4)

Na, the oil leak was there before, I had actually cleaned the engine to help locate it, then a buch of crap went down at work and I ended up working 29 days straight and forgot all about it till now when I was topping the oil.
The last engine went in at 47k so it has about 60k on it. Home compression test showed its still ok, but on the lower side of ok (105 psi @ 330 rpms) but she starts and runs like a champ still, can still get 22mpg on the hwy. Mpgs have been going down, but I have been driving more aggressive.

Thanks for the link I'll look into it with the others.

WreakLoosE

Hay guys.. I got a question... I plan on doing some data logging this weekend and I wanted to know when I am cruising, what speeds should I keep to? or rpms for that matter??

wcs

iTrader: (2)

It doesn't matter or it matters a lot

It entirely depends on what you are doing the cruise log for ... there is no set spot