Fuel dynamics mafless?

[hymey]

Still having the same ole issues with dynamics(accelerator pump). Put simply it doesnt work mafless. With the maf on I can command higher numbers in B2005 and I can get a lot more fuel in throttle tip in. With SD tune it doesn't respond at all. With the stock cam it wasn't to bad...but it is noticable with a bigger cam installed and manual transmission. I am aware of several cars that have the issue. Even including one with vcm suite. With the MAF on it's fine but I have an OTR now and with the MAF in place there is reversion issues and the MAF is much more sensitive directly in front of the TB.

Basically if I am driving through traffic and apply throttle there is a small surge that occurs less then half a second. With the same scenario MAF on it generally wheel spins(as B2005 is working). If racing at the drags its even worse with a delay between shifts. Disabling CFCO and DFCO doesn't help. Nor just richening the VE in problematic areas. Hopefully we can get a patch and get dynamics working correctly. Something that needs working on.

Joel

[hymey]

Did some more testing today. Swingtan has spent some time sorting through my tune and I have too, but Simon made some adjustments to my tune to other tables under dynamics and its a lot better now. What's required with a MAF tune is different then that of a SD tune by a long shot. Also settings are more critical with a manual gearbox because of shifting.

B2002 and B2003. The values are reversed. This is a table for when fuel begins to decay after fast throttle transitions. I tried this initially it didn't appear to help. B2005 was another I tried, it worked but was slow to respond. B2011 is what I believe that made a considerable difference. Also use B0148 open loop table to your advantage to creep up on PE.

Simon has done countless hours on going through this. A big thanks to him. I only touched on half of it. The settings in the tune are perfect and I would even doubt most workshops would have done the research in e38 tuning to the extent of Simon. We have shared ideas over the past 11 months or so and have gone leaps and bounds.

[swingtan]

Hi Joel,

Glad to see the changes had a positive effect. I'm still working on fine tuning them though and have a thought on what may be happening. I need to log a heap more data and see what goes but I think I'm on the right track. I've just been fixing a slight hesitation I get in 6th when cresting a hill that was a bit annoying but again I think I've got that one sorted as well.

Simon

[Tre-Cool]

Hey Simon, do you have any more experiance you can share on this matter?

I've retuned a mates Twin Turbo VE and from the logs at the drags and street it gets lean between the shifts and i believe because of this i start registering knock in 4th. (all other gears are ok)

I will upload logs and tune when i get home tonight, if i cant get it to work my only other option is to put the maf back on and i don't really want to have to do that. :-(

[GMPX]

Nice to see you guys diving so deep in to this, I must confess I've forgotten a lot of the tables already, my hands smell of Diesel these days :)

[swingtan]

OK, here's where I got to with Dynamics and MAFless......

For the record, I've tried full OL-SD, OL-MAF and CL-MAF. All were tested over a considerable period of time each, with at least 3 or 4 months of driving in each mode. OL-SD was run for around a year while looking at many different settings. The current mode, CL-MAF is what I'll be staying with for now as I find it gives the best "all round" results for the driving that I do.

Ok, on to dynamics...

My View On Dynamics

Delving into the settings and how the amount of dynamic fuel was calculated, I came to the conclusion that dynamics and MAF measured airflow went hand in hand. The main table involved here is B2013, "Impact Factor, Airflow", this being a "Factor" effects the final calculation for dynamic fueling.

B2013 uses "Airflow ( gm/Sec in my case )" to provide a multiplier for the final amount of "dynamic" fuel to add when stomping on the throttle. If the MAF is disabled, then the table will always read "0 gm/Sec" and use that figure for all dynamic fueling calculations. There is no way to do fine tuning of the dynamics in this case because the airflow will never change.



OL-SD

In this mode, I found that the dynamics were a very fickle setting. They were sometimes working well and other times way too rich or too lean. This was where my views on B2013 really came from. I could set the dymanics up to work well for stomping on the throttle and moving up through the gears, but then had rich spikes when just cruising around. If I got the cruise settings working well, then I was lean if I gave it a bit. This resulted in a rough feeling change that felt like the car hesitated slightly when getting back on the throttle after a gear change.

My views on this are that you have 4 options....

Set the dynamics up for WOT and live with the richness when cruising. This would be fine if you do a lot of track work or have a specific track only car / tune.
Set the dynamics up for cruising, and live with the roughness of the gear change. If you really wanted, you could flat change between gears and hope you don't miss shift.........
Set the dynamics up as a mix of both and be stuck in a position where neither is optimal, but neither is way off. It would be like getting some of the worst of both without really getting any of the good points though.
Set the dynamics up for WOT and get an auto :p


So my thoughts were that while OL-SD worked very well for me most of the time, the dynamics issues were enough for me to go looking for something better.



OL-MAF

Enter the OL-MAF era. Given my thoughts on the MAF being the key to controlling the dynamics, I figured I should turn it back on and see how things went. After a year of OL-SD tuning, it took a very, very short time to dial in the MAF and get the dynamics close to perfect. With the MAF signal back and B2013 adjusted, I was able to control how much dynamic fuel was being applied. It was quite easy add more or less by looking as the MAF signal and the WB-O2 together. Shifts were noticeably better across the board and the car was more "fun" to drive. 0-100KMH times were on par with OL-SD and the best economy was achieved at 8.6Lt/100km or 26mpg. At this time I was also playing with lean cruise and seeing how things worked out there.



CL-MAF


On to CL-MAF, where some interesting results were observed. I originally went back to CL to work on some light throttle, low speed surging I had. I soon found that CL mode had some other benefits that helped dynamics, specifically with throttle close. Many people are only concerned with the initial stomp, to get the best power out of the motor. Not many care about the throttle close, but this can have significant effects on gear changes in a manual.

For example, if you go very rich on throttle close, than stomp on the throttle again for the next gear, you may end up way too rich and flood the motor for a second. This could see a hesitation in the motor as the clutch is let out making the change feel rough.

When the STFT's were turned back on, they helped control the return to "stoich" for the fueling. This helped control dynamic fueling on throttle close, not only on gear change but any time the ECM went back into CL mode after being in PE mode. The WB-O2 showed a much faster return to stoich than when STFT's were not being used.



I mentioned "lean cruise" earlier and should mention something about that, though it is a bit OT to dynamics. I think that lean cruise is a bit of a "misnomer" in the E38 - Gen IV due to the way the engine makes power. While the car can run fine at 15.5:1 AFR, it feels stronger if it runs a little richer. I've played with PE settings and found the car to pull up hills better when...

[list]
lean cruise is active at 15.5:1 afr.
there is no change in the throttle possition
the ECM detects a rise in MAP readings and enables PE mode
commanded mixture becomes 13:1
[list]

The idea I have is that while you can run a leaner mixture, the engine will produce less power. This results in you using more throttle and therefore, more fuel. Running slightly richer results in a little more power, so you use less throttle.... The end result is that the final economy figures for both are similar, but the car feels more "effortless" when running a tad richer.

I just got back from a trip to Eden New South Wales (http://maps.google.com/maps/ms?ie=UTF8&hl=en&msa=0&msid=107093872649037229540.00047d179e5bad6ff6185&ll=-36.066862,147.700195&spn=4.590944,9.448242&z=7), while towing a very full trailer. Running CL-MAF, I got a total average of 12.8Lt/100KM @ 98kmh, or 17.8mpg. That was a pretty good result given the size of the trailer.

Simon.

[hymey]

As I discussed with you Tre, Fuel dynamics needs a lot of work mafless and differs from engine to engine. I have even changed intakes and it upset the settings.

FI is a much different ball game, I am lucky enough to have nutted it out, The impact tables need to be increased A LOT past 100kpa. So when you shift fast boost comes up really quickly it needs the fuel to support it. If you aren't seeing vampire teeth in the logs you need to increase it, if still lean increase it more. It will end up very steep looking. The beauty of FI is below 100kpa will be stock, above 100kpa is where the changes occur, dont be scared to add a lot more in, the car will feel a lot more aggressive on gear changes and you will end up busting donuts like I just did this afternoon:hihi:

BUT after you get it right the VE may need reducing slightly. This is where road/track tuning the e38 is so more important then dyno tuning.

Look at B2012. Try setting values from 104+ IVT and from 100-200 kpa to around 0.35 to 0.4 start with 0.4 you will see positive results.

cheers

Joel

[Tre-Cool]

Cheers for the feedback fella's.

I initially did increase some of the tables, however it appears i didnt get them all or increase them enough. I remember from the fastest log of the night that there was almost no lean out in the first 2 gear changes (1-2-3) but the 4th resulted in a much larger "lean-out". (I dont tend to lift completly on shifts at the drags, but i dont keep my foot buried either)

it's good to get other peopels experiance/knowledge on this matter, as i suspect my brother's tt will have a similar issue, so i will be able to make the required changes when it comes back to me.

[swingtan]

This is why retaining the MAF helps ( unless of course you are running FI or a big overlap cam ). You can get the dynamics a lot closer.

The other trick I did for gear changes, was to raise the VE table where it matches the engine conditions between gears during track use. For example, at full song, the engine RPMs are probably between 4000 RPM and 6400 RPM during the change event. At the same time, MAP is probably down around 25 or so. These conditions would rarely, if ever be met during normal driving so you can "fudge" the VE and richen it up. This helps stop the lean out between gears.

Tuning the VE and fueling in a manual is a lot different than an auto. The gear change conditions need careful work in a manual to get nice crisp changes. Unlike an auto where the throttle stays wide open, the on - off throttle conditions in a manual need to be catered for.

Simon.

[L31Sleeper]

I'm sorry guys I am having a hard time following this thread, I just don't
get how you can run MAF-less with a coefficient system.

[4wheelin]

I have a customer with an E38, Maffless in a Nissan Patrol, it is used in competition and has a manualised Auto. The vehicle is perfect except for in tight trees where the throttle is opened and close repeatedly rapidly, under these circumstances it will lean out to the state of a missfire, I played with the dynamics for a day with no result, I suggested the customer refit the MAF as it was my feeling that the SD was the issue, I'm glad to see that seems correct even if there is no SD optimum fix.


Joel

[mr.prick]

I wonder if re-enabling the MAF would cure this for the LS1. :confused:
The dynamics stuff didn't help at all and I wondered if it could be injection timing or
because the exhaust flow across the WBO2 slowed down too fast for the sensor.
It only happens when TPS% decreases quickly.

[Tre-Cool]

as promised, 3 logs from the night.

the attached tune isnt the exact tune we ran, but it will give u an idea on the dynamics that we were running.

stock ls3 with springs and 71c thermostat and twin turbo 2871r.

[joecar]

Simon, nice write up of your observations...:cheers:

What would happen in CL-SD...? Would you get the same MAF-less limitation on dynamics, but with return to stoich aided by STFT's...?

[redhardsupra]

Simon, this is some cool stuff... I've seen all this before, but I usually have attributed the AFR spikes on shifts to a fuel system. I still believe it's partially correct, as I've seen improvements after the fuel systems were upgraded, especially to return systems. Have you noticed anything similar?

[swingtan]

L31Sleeper: There are no calculations in the VVE that use MAF airflow. The VVE is a theoretical map of predicted airflow, so there is no need for any actual air flow figures to calculate it.

4wheelin: Exactly the point I was mentioning. Any time you have repeated and rapid on/off throttle events when in SD, you get the lean out. However, for a full race vehicle, I'd just up the stomp factor a bit to mask the effect as well as richen the VVE during off throttle events. If fuel consumption doesn't play into the competition, it shouldn't worry too much.

mr.prick: If you are referring to the "rich on throttle close" issue, there is a table in the E38 B2011 - Wall Wetting Asymmetry Factor. This can be used to balance the throttle open vs throttle close events. It doesn't appear that the LS1 has this table, or it may not yet be defined. Looking at the log though, I don't think it would worry things too much.

joecar: Yes, I think you are right. CL-SD would have the dynamic control issue, but the O2's would help to control the return to CL. This may help to stop any lean out on throttle close but you still have to compromise the settings for throttle open ( entering PE mode ).

redhardsupra: I've not altered the fuel system in my car so can't comment on that. What I have noticed is that

The bigger MAF is no hindrance to power
If the VVE is set correctly and the tune is good, running the MAF feels better in a daily driver than running full SD ( due to the dynamics I think )
Running CL helps greatly with the fueling and lean cruise does not seem to work quite as well in the Gen IV.


What I would like to try though, it to get the O2 switch point settings to work in the E38 and try some adjustable CL fueling. I think that that would have some very interesting results.

Simon.

[kangsta]

swingtan, when you say 'OL-MAF' and 'CL-MAF' is that full maf or maf + tuned VVE

[swingtan]

I guess that will depend on how the tune is set up......

If you alter B2804 / B2805 to switch over to MAF only air flow very early, then the VVE will have no effect on fueling. In this case there would be little need to adjust the VVE as it's not referenced. This would be an option for CL-MAF as long as you trust that the MAF will not drift too far. The O2's will compensate for minor differences in air flow when cruising, and the PE mode airflow can be set up and left.

If you leave B2805 and B2805 so that the VVE is still referenced, then you will need to optimise the VVE for the area where is is used. This is because under the "High Speed Air Mode", the VVE is used as a "rationality test" for the MAF to ensure it's reading correctly. If the VVE is off, then the ECM will alter the MAF reading, skewing it toward the VVE setting. This is probably the major reason why SD tunes appear to be better, as most "MAF" tunes do not address any VE or VVE errors. As many have mentioned, to do a "proper" MAF tune, you still need to dial in the VE / VVE where it is still referenced.

I've tried both and found that switching to MAF only air flow readings works very well. I have B2804 set to 1000 RPM ATM.

Simon.

[LinearX]

Is it safe to assume that you're failing the MAF in the stock OS to get SD functionality? Does this same limitation exist in COS?

[5.7ute]

Is it safe to assume that you're failing the MAF in the stock OS to get SD functionality? Does this same limitation exist in COS?

It would.
From what I have researched the "pump shot" which would prevent this condition is disabled when the maf is failed.
BTW a great write up Simon.:cheers:

[ringram]

Good luck on the o2 switch points. Ive dropped them to 50mv with no visible change to fueling.
But I guess if you use programable sensors like the LC-1's you could get them to switch on say, 15.2:1

[swingtan]

Ringram, exactly right. Currently the switch points do not work at all in the E38. Your idea of using a programmable WB with NB output would work, but only for a fixed offset. I'd like to be able to fully utilise the CL-Mode settings to command leaner light cruise and slightly richer for things like hills. Then when it really needs more go, switch into PE mode.

[alian]

Ringram, exactly right. Currently the switch points do not work at all in the E38. Your idea of using a programmable WB with NB output would work, but only for a fixed offset. I'd like to be able to fully utilise the CL-Mode settings to command leaner light cruise and slightly richer for things like hills. Then when it really needs more go, switch into PE mode.

Wouldnt that be great Simon.:)
Ian

[Wasted Income]

I'm seeking some clarification...

I am running OL-SD in my turbo 5.3 setup. I am looking to improve my off-idle response, and until reading this thread, it seemed like the transient fuel tables were the ticket....but it appears that they do not work with the MAF failed??

Do I have any other options?

Thanks!

[swingtan]

Transients still work with the MAF disabled, you just can't fine tune them. If you check the other posts, the Transients are all based back to MAF airflow. If you fail the MAF, then it will always read "0 gm/s" or air flow, so you just B2013 to a flat line. If you want more transient fuel at WOT, then make this table all a higher number, say 0.8 or even 1. If you want less transient fuel at part throttle, then make the whole table a lower number, say 0.6.

If you get it working well for WOT, it'll be rich at part throttle, if it's right at part throttle, it'll be lean when wide open.

Your only other method of "fooling" the ECM into providing more accurate transient fueling would be to alter the injector timing. It's not a perfect way, but it does work. Generally speaking.....


Advancing injector timing will simulate an increase in transient fueling.
Retarding the injector timing will simulate a decrease in transient fueling.


Interestingly, if you check the stock injector timing, it does advance the timing as RPM increase, but I don't think it's for the transients. You still need to make a couple of fairly wide reaching assumptions though....


Transients in HIGH PRM areas will only really be needed for WOT applications.
Low rpm areas will only need small amounts of transient fuel


The break over point would be around the 2,000 RPM mark I guess, so that under that, where normal driving occurs, you have low amounts of transient fueling. Then over that, for gear changes, you have higher amounts of transient fueling. This seems to work OK, but is no substitute for the MAF signal.

Finally, if you drive an auto, the transients are no where near as critical when compared to a manual. Unless you "flat change" in the manual, the off / on throttle event plays havoc with fueling. Transients play a big role on making gear shifts feel good in the manual.

Simon

[TuneMaster]

Hi Guys, the only time i've seen this has been on cammed auto E38's that don't have a stall convertor. What i found on the dyno was the VVE cells were being hit from 800 - 2000 rpm and 70 - 105 kpa as soon as you nailed it suddenlly, the wideband here was going very lean causing surge, mis and backfire but only on quick acceleration, i tried changing dynamics but the best way was to increase VVE settings in these areas. Remember rescalling zones helps this as well. Done plenty this way and no negative feedback yet. My two cents....

[Wasted Income]

***Lots of good info***

Simon,

Thank you very much. I will play with those a little bit. :grin:

[Highlander]

This is some valuable info. People don't seem to get the importance to dynamics section. I broke an engine because of it. I learned this tables the hard way.

[mr.prick]

I've not seen any changes to fueling after altering the impact factor or evap time.
Maybe it's my technique.
How would you cure this?

[Highlander]

The way to cure it would be to reduce the minimum injection pulsewidth. Try that out.

[swingtan]

To be honest, I wouldn't think that was too bad. There are twp things that I can see though.


Delay between the commanded AFR anf the WB AFR:

At throttle close, the air speed through the motor will slow down, so the WB signal will lag the rest of the engine parameters. The mount of lag is determined by the position of the sensor. Obviously, the further away from the motor it is, the more lag will be present in the log data. So this probably isn't a huge issue and I'd not be overly worried about it.

Slight richening of the WB AFR signal on throttle close:

In the E38, this is controlled to some degree by "Wall Wetting Asymmetry Factor". Low values in this table add less fuel when the throttle is closed. Again, your log only shows a very mild increase in richness.


To really work on dynamics, you need to look at...

RPM
MAP
TPS
Airflow
Inlet Valve Temp. ( though this can be guesstimated for systems that don't have this PID ).




Simon.

[mr.prick]

The way to cure it would be to reduce the minimum injection pulsewidth. Try that out.
Interesting. :secret:



To be honest, I wouldn't think that was too bad. There are twp things that I can see though.

[list=1]
Delay between the commanded AFR anf the WB AFR:
[indent]At throttle close, the air speed through the motor will slow down, so the WB signal will lag the rest of the engine parameters. The mount of lag is determined by the position of the sensor. Obviously, the further away from the motor it is, the more lag will be present in the log data. So this probably isn't a huge issue and I'd not be overly worried about it.


I've thought about the possibility of the exhaust pressure rapidly reducing when the throttle is slammed shut or when the clutch is depressed, engine load rapidly reducing causing this.
The smoother TP% decreases the smoother AFR ramps back to commanded.
It's more pronounced when shifting gears during PE,
AFR gets quite rich but it's better than having DFCO on and
the harsh re-engagement of the clutch.

It may not be that big of a deal, LTFTs and PE AFR are where I want them
it just makes a log look a little ugly.

[gmh308]

This is some valuable info. People don't seem to get the importance to dynamics section. I broke an engine because of it. I learned this tables the hard way.

Broke an engine due to dynamics! How did that happen?

[swingtan]

It may not be that big of a deal, LTFTs and PE AFR are where I want them
it just makes a log look a little ugly.

That looks better than some of mine. I've been thinking about closed throttle fueling today and need to do some testing......


Broke an engine due to dynamics! How did that happen?

I reckon this could happen if it went very lean on throttle tip in. Massive lean spike and heavy load resulting in predetonation. This would destroy a piston pretty quickly. I know when I was messing around and had a big lean spike, it would feel like hitting a brick wall when smacking the throttle on gear changes. Needless to say I didn't like that very much.

Simon.

[Highlander]

Engine was a boosted engine. Customer was wheel spinning and he was pushing in gradually the throttle. Car went lean ~13.8:1, massive knock. This was before we had access to the dynamics section. I had this same issue with a colorado turbo with an E67. We already had access to this and we were experimenting with it. I fixed it using impact factor 0% ethanol. All other tables had absolutely NO effect on super lean while modulating the throttle.

I have another boosted vette that I will deal with very shortly and will post the results on it. I don't want to make the same "mistake" twice (although it was NOT my fault).

[Highlander]

What bothers me out of all this is that GM's ZR1 has basically STOCK Dynamics section. Even for a boosted engine... GRRR...

[swingtan]

I've not seen any changes to fueling after altering the impact factor or evap time.
Maybe it's my technique.
How would you cure this?

Just wondering what your PE ramp out rate is like. If you increase the ramp out rate, it might help to speed up the return to the commanded AFR.

Simon.

[mr.prick]

It's pretty much instant.
http://forum.efilive.com/attachment.php?attachmentid=7516&d=1270244758
The more I think about it the more I lean towards it being pressure differential in the exhaust.
I know O2s are pressure and heat sensitive.

[mr.prick]

Playing w/RTACS & {B3605} (impact factor) I found that it would have an effect on fueling but only in OL.
Once PE ramped out and EQ1 was commanded it had no effect and AFR was still rich
even though IBPW was low.
If you look at the chart I posted previously you can see what I mean.

The lean tip-in can be reduced w/{B3406] but not the tip-out.

[swingtan]

What OS / Tune file are you working on? I can't find either of those in COS-3 or the E38 tune I use......

I'v e been looking at dynamics a bit more and found another interesting point.

When running CL, if you get a large rich spike on throttle close, the O2's will pull a massive amount of fuel to bring the AFR's back to where they should be. If you then snap the throttle open again, you get a huge lean spike, as the O2's have pulled all the fuel out.

Reducing the impact factor / dynamic fueling and increasing "Wall Wetting Compensation" reduces the rich spike, which reduces the O2 correction and in turn reduces the lean spike on the next throttle opening.

I still think that the increase in richness in your example if just residual fuel in the intake at throttle close. You may be able to improve the fueling by altering settings to let the controller know that there is more fuel available to the cylinder at very low MAP settings. In the LS1, you would reduce the figures in B3401 and in the E38 you would increase the figures in B2014. In both cases just the 20kPa column would need adjusting.

I might try loading a bog stock tune in my car and see how the dynamics react, then try tuning them ( if needed :p ).

Simon.

[gmh308]

I'v e been looking at dynamics a bit more and found another interesting point.

When running CL, if you get a large rich spike on throttle close, the O2's will pull a massive amount of fuel to bring the AFR's back to where they should be. If you then snap the throttle open again, you get a huge lean spike, as the O2's have pulled all the fuel out.


What sort of time frame/load? Any logs of the lean/rich spikes? Have found similar quick throttle opens under no load to give a rich blip followed immediately by a lean blip then of course back to L=1.

[mr.prick]

OS 12212156/LS1
I know this is a GENIV thread but I figured the dynamics stuff works the same. :hihi:

The thing I worry about is if I change impact or evap what will this do to MAF/VE?
LTFTs and WOT are good I don't want to change impact and/or evap then have to mess w/VE and/or MAF. :sly:

[swingtan]

OK, here's a few images of the dynamic overshoot....

Commanded AFR remains at stoich.

This was a take off from a stand still and shows the shifting up through the gears. The rich spike on throttle close is causing a subsequent lean spike on the next throttle opening.

http://farm3.static.flickr.com/2047/4506809944_7702b90a0b_o.jpg (http://www.flickr.com/photos/swingtan/4506809944/)

Commanded AFR tranition to / from PE

This shows the transition to / from PE with throttle change. Again this was a take off and shows the overshoot getting worse.

http://farm3.static.flickr.com/2379/4506809684_312b93d651_o.jpg (http://www.flickr.com/photos/swingtan/4506809684/)


Throttle Blip

This shows the results with throttle blips. Blips will always cause issues due to the rapid change in engine conditions.

http://farm5.static.flickr.com/4034/4506172893_b036ed8432_o.jpg (http://www.flickr.com/photos/swingtan/4506172893/)


Simon.

[mr.prick]

How is the intake valve temp measured?
Can it be calculated based off ECT?
All the dynamics stuff for GENIII are based off ECT.

[gmh308]

How is the intake valve temp measured?
Can it be calculated based off ECT?
All the dynamics stuff for GENIII are based off ECT.

Its a mix of load, ECT, run time, fuel type. And maybe more...but those items do influence it.

[auspeed]

This was an interesting read.... now 6 years later are the findings/theories still the same for modifying dynamics?

[rich24v]

Also more than a vested interest since I have a SD maffless tune which "feels" better in OL rather than CL.....and am noticing some of the observations within this thread. Has a path been found for getting transients working without MAF ?

[5557nut]

I know this is an old thread but would like your thoughts on my LS3 e38 setup. Texas Speed cam 229/236 .629/.615 112 LSA, Hi-Ram intake stock injectors 90mmTB. As you can see I have a dual air intake which makes a maf sensor impossible.
To me it shifts great and pulls great, except concerned wbo2 reads rich all the time (11.7-12.4). Only issue is not returning to idle, it hangs longer than it should and sometimes won't come down at all.
Appreciate it if you have the time.

[hymey]

I know this is an old thread but would like your thoughts on my LS3 e38 setup. Texas Speed cam 229/236 .629/.615 112 LSA, Hi-Ram intake stock injectors 90mmTB. As you can see I have a dual air intake which makes a maf sensor impossible.
To me it shifts great and pulls great, except concerned wbo2 reads rich all the time (11.7-12.4). Only issue is not returning to idle, it hangs longer than it should and sometimes won't come down at all.
Appreciate it if you have the time.

Hi mate, I have not downloaded your tune, however there is a VVE tutorial on here, also look at the e38 idle page on the last Cpl pages should help you.

Joel

[5557nut]

Hi mate, I have not downloaded your tune, however there is a VVE tutorial on here, also look at the e38 idle page on the last Cpl pages should help you.

Joel

Hymey, Thanks...I have read both several times but have trouble with the airflow/spark relations, so many tables. Its a lot to take in but I do get more after rereading but I guess it takes time. Without a background in air/fuel/spark relations, it is a big learning curve.

[hymey]

I know this is an old thread but would like your thoughts on my LS3 e38 setup. Texas Speed cam 229/236 .629/.615 112 LSA, Hi-Ram intake stock injectors 90mmTB. As you can see I have a dual air intake which makes a maf sensor impossible.
To me it shifts great and pulls great, except concerned wbo2 reads rich all the time (11.7-12.4). Only issue is not returning to idle, it hangs longer than it should and sometimes won't come down at all.
Appreciate it if you have the time.

Hi 5557 nut , I have just downloaded Tapatalk ,
Makes it easier !!!! Max idle air set to high . Or another high limit .