When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I switched to the EBL Flash II last week to get a more updated Computer system in my 85 corvette and more tunable platform. My Car never hits the track and is a daily driver. It might top the 4800 RPM mark on the tach once in a month to get past that fool on the highway to get around them. I live out in the middle of nowhere and Walmart is 25 miles away with a trip down the interstate. I have had the car for about a year and she has 1500 miles on the new engine and transmission right now. I spent the year working on the driveability of the car and had reach an average of 21-22 MPG on the old MAF system while at 75mph on the Interstate. This weekend I took a 120 mile trip between towns and let the VE Learn run the whole time. It did make some corrections and flashed the new BIN for the way back the next day. Even after 20+ VE learns the highway average is around 14-15mpg. Anyone have suggestions or steps to help get my Gas mileage back up in the 20s?
Work on your timing tables. A few degrees more advance at cruising speed makes a big difference in MPG. You should get the same or better MPG than before the EBL switch. Do you have timing tables from your old setup?
For reference, I have a 2nd gen Camaro with a 90-92 speed density system on a Miniramed ZZ4, mild cam, 3.42 axle ratio and TH700R4 with lockup converter. I was getting 26-27 mpg highway before putting on the gear vendors overdrive unit... now I'm getting 29-30 with the double overdrive giving me about 2200 rpm at 80 mph.
I activated the highway mode fueling and dialed in the AFR to about 16:1 on light cruise with my wide band O2, which netted about a 2 mpg increase. Not sure if EBL has that.
But I don't see why you shouldn't be able to get 25 mpg or more with your set up provided you don't have some crazy gear ratio or wild cam or something like that. If you have a lean cruise feature on the EBL that you can dial in with a wide band O2, 27-28 should be easily achievable, especially with the aerodynamics of the corvette.
You may want to get a wide band on the car and see what AFR you're actually getting. 21-22 mpg seems low... I was getting that with a carb and the TH700 25 years ago.
The trans is a 700R4 stock trans with 3.07 gears. EBL does have a lean cruise and it is enabled. I run around 2100 rpm at 75 mpg right now.
Engine is stock except a 48mm TB, the original has leaks on the blade shafts, a SUMMIT SUM-1102 can was installed on the rebuild. Just a very mind RV cam a tad over stock.
WB02 is getting installed next week for tuning, I hope it helps.
The trans is a 700R4 stock trans with 3.07 gears. EBL does have a lean cruise and it is enabled. I run around 2100 rpm at 75 mpg right now.
Engine is stock except a 48mm TB, the original has leaks on the blade shafts, a SUMMIT SUM-1102 can was installed on the rebuild. Just a very mind RV cam a tad over stock.
WB02 is getting installed next week for tuning, I hope it helps.
Yeah that's a pretty mild build. Definitely need to see what the actual AFR is before planning next steps.
You do need a WB to get a good open loop tune but Narrow band VE learns work well for idle and cruise. In closed loop It should put your AFR where it needs to be in that area. You can click on the diagnostics tab and see the cross counts to check your AFR in closed loop. If you have Late ignition timing the cylinder pressure goes out the exhaust and is wasted. I suspect that is why your MPG is suffering. When you change SA you will have to do VE learns over. The first table I would do is SA-latency. Grab a timing light and see if the actual timing matches the WUD at different rpm's. Mine was about 5 degrees slower than the WUD reported at 2000 and higher rpm's. There is a thread about how to set it on this forum. It would help if you post a post a data log but I would check the SA-latency first to make sure you are getting the correct data.
@Larry I have the WB being installed this week, Im holding off anymore real tuning till then. I'll post a data log when i have a good learn done after that. I set the SA to 10 degs and also in the BIN and the HUD shows 10 degs also, but kind of hard to look under the hood, watch the HUD, and be in the drivers eat too LOL. but will see if I can get a helping hand asap and do that test
Thanks
I did a little drive today to the next town over ( 10 miles interstate) so this is a good log of Interstate cruise and some in town driving around. About 15 mins. This is with the latest BIN currently running also attached. Hope this helps.. I tried getting the WB02 bunge installed this morning at 3 shops with zero sucess, Im going to try again in the morning. I have an appointment so hoping it will be an in/out stop and I can hook up the WB for better turning.
Can't upload the .dat file so here is a link https://awcwebdesign.com/Vette_Clear_00025.dat
Dave, looks like you're a tad rich in the 50-kPa and up area in the lower 2000 RPM's at 70 to 75-mph. You appear to be averaging 27 to 30-mpg between 40-kPa and 50-kPa at 70 to 75-mph, but once you gradually go over 50-kPa in the same RPM area and speed, the MPG take a nose dive......
Im am suppose to have the WB02 installed in the morning (10AM) should I hold off doing any tuning till this is done? Then do new VE learns?
I keep seeing posts about turning off EGR and other settings while doing the VE learn, but none of that was mentioned in the instruction received from Bob with the EBL.
So consider me a very newbie and trying to learn the steps, I need step by steps the first time then I get it I take LOTS of notes..
Increase your BLM - RPM Learn Threshold to 6000-RPM from 3600-RPM in your Bin, then temporarily increase your PE - TPS Enable Threshold to 100.00 in each entry to keep it out of Power Enrichment while you're Learning, and power brake the engine during a VE Learn from a standstill. See which way the O2 sensor is bringing the VE table during a Learn, then manually fill in the rest. Try to hold the throttle while watching the VE Learn tab, and try to maintain 2000-RPM covering as much of the kPa values that you can by holding then letting go of the throttle, in gear and out of gear...
- Rob
Last edited by Street Lethal; Jun 1, 2021 at 05:59 PM.
You do need a WB to get a good open loop tune but Narrow band VE learns work well for idle and cruise. In closed loop It should put your AFR where it needs to be in that area. You can click on the diagnostics tab and see the cross counts to check your AFR in closed loop. If you have Late ignition timing the cylinder pressure goes out the exhaust and is wasted. I suspect that is why your MPG is suffering. When you change SA you will have to do VE learns over. The first table I would do is SA-latency. Grab a timing light and see if the actual timing matches the WUD at different rpm's. Mine was about 5 degrees slower than the WUD reported at 2000 and higher rpm's. There is a thread about how to set it on this forum. It would help if you post a post a data log but I would check the SA-latency first to make sure you are getting the correct data.
This is the thread on validating spark timing vs ignition modules...
Street : Noted and taken down in my notes, will do this when the WB is installed.
ULTM8Z: I went looking for that thread for 2 hours and never found it. THANKS!
This is the thread on validating spark timing vs ignition modules...
Well that just threw my mind in a tail spin to nowhere... read every post 4 times...
1. Innova Timing light with lots of buttons and options.. <check!>
2. Know how to check timing with the blink blink light <check!>
3. 54 yr old brain that keeps going back to old school 1960s tuning and brain melts reading that thread...... <CHECK!!!>
Increase your BLM - RPM Learn Threshold to 6000-RPM from 3600-RPM in your Bin, then temporarily increase your PE - TPS Enable Threshold to 100.00 in each entry to keep it out of Power Enrichment while you're Learning, and power brake the engine during a VE Learn from a standstill. See which way the O2 sensor is bringing the VE table during a Learn, then manually fill in the rest. Try to hold the throttle while watching the VE Learn tab, and try to maintain 2000-RPM covering as much of the kPa values that you can by holding then letting go of the throttle, in gear and out of gear...
- Rob
Ok WB02 installed...
I changed the settings you have listed above. I told WUD to VE learn via WB instead of BLM. I did the 2000rpm steps you listed and also took it for a drive about 2 miles down the road with RMPs from 750 - 3600 holding in each range with braking to catch as many points as possible. Right off the bat it changed the 600-1600 rmp and MAP 40-60 ranges A LOT in the VE Corrections, I had at least 15 spots with +10-15 point corrections. But I got up in the 200-3000rpm rages and hardly anything was changed at all. I flashed this BIN with changes and did another VE Learn session duplicating the route and another datalog. There were a few changes with -1 but not near as many as the session before. Here are the results.
Do you see the difference in the cruise area in your VE now? Look at the area that was corrected (second pic below, I uploaded a before and after). Now just smooth out the surrounding areas in the lower 2000-RPM range in the High Speed VE Table, the areas ranging from 50-kPa and above because that is where you were losing MPG due to all of that wasted fuel...
Ok I did another VE learn run off this table after smoothing, this is what came back.
Not a whole lot of difference, so I need to smooth out that section a bit more.. Instant MPG was up to 15mpg so its better then the 10-11 it was getting.
In the mean time did you look at the SA-table? I look like Mt Everest!!
Yes, when you look at these stock timing tables you immediately see how GM was able to restrict horsepower on some of their vehicles favoring their flagship vehicles. If you look at the table carefully, you will see that timing increases way after the Tuned Port Injection runs out of breath.
Yeah, when you're out of mpg mode and you want some performance, most of the time you'll spend with the TPI is between 2400-RPM and 4000-RPM, look at the timing values in those particular areas up top near 100-kPa. See how they drop/fall away from the 2200-RPM mark, but then make a come back at the 4400-RPM mark? So between those areas (2400 through 4000-RPM) is where you will want to bump it up some to average out the two points where it falls away, then comes back. You'll see what I mean by referencing the grid in the upper kPa areas. You'll be surprised at what a difference it will make. Use the grid, not the graph...
Ok New VE learn (number 34).. Pumped up and smoothed out the SA table also. Did my 4 miles run down the service road between 45-60mph various loads, then hit the Interstate coming back and ran up to 85mpg and 4500rpm steady. NO knock counts the whole time. It did add a couple of +9/10 at the bottom end.
So far pretty smooth, and the idle has even smoothed out more.. I can get you a datalog in about 10 mins LOL.. Just jump in and take another run down the road.. BRB
Don't forget to restore your Power Enrichment settings when you're done with the VE Learns, because you're going lean up top without them as kPa increases...
Also, which Wideband are you running so I can see it? Brand, and volt settings...?
Dave, with the key on and engine off, look at your WUD screen and floor the throttle. Is your TPS% column reading 100%? If it isn't, make sure the carpet under the throttle isn't bunched up blocking it from going all the way down, and if it's not, go into;
TPS - ADC Gain Term for TPS
... and increase that value in increments of ten until you're reading 100%. I mention this because in your datalog it appears you're flooring it, but the TPS is only reading in the 70% and 80% range.
Will also need another datalog with the PE values put back into place.
Dave, with the key on and engine off, look at your WUD screen and floor the throttle. Is your TPS% column reading 100%? If it isn't, make sure the carpet under the throttle isn't bunched up blocking it from going all the way down, and if it's not, go into;
TPS - ADC Gain Term for TPS
... and increase that value in increments of ten until you're reading 100%. I mention this because in your datalog it appears you're flooring it, but the TPS is only reading in the 70% and 80% range.
Will also need another datalog with the PE values put back into place.
- Rob
Yes the TPS was an issue before and nobody said how to correct it.. I just changed the PR values back, let me go adjust the TPS and get a quick log again..
Your timing table is definitely not set up for performance or economy. You only have 35 degrees of advance cruising at 2200 rpm's and light throttle. Wide open throttle is only 20 degrees at 4000 rpms. I run 43 degrees @ 2200 and 50 MAP, and 32 degrees wide open throttle @ 4000rpm's. You now have your VE in the ballpark, I would would work on the timing tables. You will have to do new VE learns when you get your timing where it need to be. If anyone has a good timing table for a relatively stock motor maybe they can help you out. Mine is not stock, I idle at 28 degrees. At wide open throttle it is 32 degrees from 2800 rpm's and up.
@Street Lethal Sorry a customer came in and i had to stop playing.. Damn the luck.. Will make the changes to the BIN and post updates in the morning as I have a good 4 mile run to the office.Once I have TPS corrected i'll run a datalog and post. Thanks for all the help. @Larry Yes the WB has help pin down the VE tables, now I need to play with the SA tables. I KNOW they are off, I just have to find the sweet spot. I increased one area almost 10 degrees and still had no knock. Im sure I can bump it up more..
@Larry Here are the stock L98 SA tables compared to what im running now. Im not sure of the factor calculations matter (Spark Advance VS RPM VS Load) matters as the EBL just shows the table with no factors listed. But the EBL SA values are WAY lower then the stock L98 values. especially around the 2100-2200 RPM highway cruising
Larry is absolutely right, that is why I was hinting up top when I mentioned the stock timing tables being flawed from GM. With your Tuned Port Injection, unless you open it up substantially, or swap to a better breathing intake manifold, the system will usually run out of breath at around 5000-RPM. At wide open throttle, I normally run around 32* as well, but mine has been opened to the max. With E85 I'll take it up to 35*, but remember that once you have the momentum and the car is moving, you don't really need that much timing. I would cut and paste the extended tables SA tables and fill in the 2400-RPM to 4800-RPM with them to see how the engine likes it. If no knock is prevalent, then you can continually add 1 degree until the timing increase makes no difference anymore. You'll know by observing the Injector Duty Cycle and the Wideband AFR when you reached its' limit...
Ya I have run the current BIN all over the RPM range up to 4500 under various loads and no a single knock was detected in the HUD. I'll change these value and flash in the morning and see how it does on the way to the office. I have a good selection of highway sections and service roads I can jump around on and watch the knock counts. I seriously have no reason to worry about anything over 5K as its a daily run around town and between town toy. Will never see a track just town and highway drives. Of course the next town over is 15 miles away and then another 60 to the next. 90% of the driving is highway drives back and forth and running down a few back country roads..If I can get good mpg (highway) and still be fun to play with on the back roads I'll be tickled pink..
Dumb question... but does the formula being used in the datalogger have the right injector constant for the injectors you're running?
I know in Tunerpro you have to make sure the formula has the right injector constant such that the instantaneous mpg reads correctly.
Honestly I have no idea. I know the HUD MPG INSTANT reading is way to high. It will show 24mpg and the dash is showing 15-16MPG which is pretty darn close to what im getting now.
I have stock injectors now, but i honestly dont know how to check/change what is needed for that reading.
@Larry Here are the stock L98 SA tables compared to what im running now. Im not sure of the factor calculations matter (Spark Advance VS RPM VS Load) matters as the EBL just shows the table with no factors listed. But the EBL SA values are WAY lower then the stock L98 values. especially around the 2100-2200 RPM highway cruising
YES! If it were my car I would copy this table to the EBL. It looks like a good starting point. The other one makes me wonder if GM engineers drink on the job. A WB VE learn works great and is easy. The SA tables are not so easy, there are too many variables from car to car for anything other than a starting point. Too bad there isn't a cheap tool that can measure cylinder pressure in relation to crankshaft position that would do SA learns! Sometimes too much advance can slow you down without knock counts. As Street Lethal said, only advance it until it stops making a difference. And if you get knock counts, back it off. The more you learn the more fun it gets.
I have made all the afternoon changes and saved a new BIN file to be flashed in the morning on the way to the office. WIll data log the session also
Thanks Guys
Ok morning updates..
1. This morning I set the "TPS - ADC Gain Term for TPS" value so I get 100% when WOT with KOEO as @Street Lethal suggested.
2. The SA - MAIN Tables from a stock L98 were copied over to the EBL, this raised several cells at least 7-9 in value all around.
3. PE values put back into place.
Waited for engine to get up to temp (190degs) and took her for a spin trying to hit as many cells as I could and highway runs.
With steady throttle all the way to WOT I still had zero knock anywhere, I think I can bump another few degrees and see what she will take.
I see 1 big hick-up around the 34-3600rpm cells, will have to look at that on the VE table
The SA table looks much better then yesterday and she has more torque seat of the pants all around.
W
From your data log, this is at idle, engine at normal operating temperature and in closed loop. O2 mV is staying in the 700 - 800 range. Why am I not seeing cross counts? Very few cross counts at any rpm. O2 sensor problem or software problem? Or am I missing something?
From your data log, this is at idle, engine at normal operating temperature and in closed loop. O2 mV is staying in the 700 - 800 range. Why am I not seeing cross counts? Very few cross counts at any rpm. O2 sensor problem or software problem? Or am I missing something?
Your guess is as good as mine. Im still learning the ins and outs of the HUD software. I do have the NB still enabled and I have the WB plugged into the ECU and its reading it.
Looking at the Bin and the Datalog, there are a lot of things that I would change in the Bin, but that is besides the point. One thing noticeable are the times you enter into Power Enrichment. You will want your INT/BLM to "lock" at 128/128, as the idea is for the VE to be 14.7 across the board. The closer it locks at stoich, the closer your VE is where it needs to be as it happens and in that area. Example, I seen one instance when you entered into Power Enrichment at 2500-RPM, I seen it locking at 128/124 (rich). Then I seen you enter Power Enrichment at 1800-RPM, with a perfect 128/128 (perfect). Then again at 1950-RPM, it was 128/126 (rich), then again at 1600-RPM it was 128/126 (rich). But then later you entered into PE at 2100-RPM but at a much higher kPa than the other times where it locked at 128/131 (lean).
This is where the VE Learns shine, as rather than having to review every entry at every given point in time (RPM/kPa) when you enter into PE, the Learn does it for you. You just need to set the window for the Learn to be as tight as possible. So if you're running a 185* thermostat, set your Learn window in the WUD to be between 190* and 200*, with your fan triggering at 202* and releasing at 187*. Then just take the car for a spin and allow it to Learn in every cell as possible. Compare the before and after, then shape the VE giving the engine what it wants. Don't worry so much about the wideband, as the one thing the narrowband knows best is stoich. Just be sure the narrowband is getting hot enough to be working properly.
There was also a question regarding injector compensation with the EBL. We just tune that table similarly the way we would with the IAC step compensation, making sure there is adequate supply with a sudden change in load. Not sure about everyone else, but I only touch the dwell to smooth out any idle issues, and to make sure there is sufficient fuel when there is a sudden load placed on the electrical system. The Bins already have the offsets pretty close, but there is also a small pulse width area for corrections that works in tandem with it. Even if we didn't know the offset voltage for the injectors being used (aftermarket injectors will usually come with the offset voltage), there is a way to set the unknown injectors by zeroing the offsets all out and starting from scratch. In both cases, this allows us to zero out the small pulse width correction table. Time consuming, and the worth of going through all of that is still very debatable...
Ok so PE is still enabled as well as the EGR, nothing is "taken out" of the BIN settings. So do the following as I go.
1. Increase the SA table a bit at a time till I get knock or no performance increase.
2. Continue doing learns across the whole band and catch as many cells as I can.
3. Smooth the VE tables after each VE-Learn with .7? and repeat till I see nothing but 0s or 1s in the corrections.
4. Do I need to change a setting to get close to 14.7 across the board or will the VE-Learns take car of this over time?
5. I'll go back now and change the Fan values and adjust the learn limits in the HUD
Since the last few Learns and changes the idle has really smoothed out I have noticed..And the throttle response across the spectrum is getting better and cleaner. MPG hasn't gone up that much but it is getting better.
Dave, I wouldn't recommend adding anymore timing, you're already at 33* wide open throttle with those cylinder heads. I would also flatten out the VE from left to right based on what the VE Learns were already telling you in any one specific area...
I take LOTS of notes.. 
