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.
The timing is actually unchanged from the previous set up; I know it's real low and was planning on slowly and safely increasing it. And it was running strong with the old paxton/lower boost.....
The last vehicle that I came across with similar symptoms to yours had its' timing locked at about 15-degrees at wide open throttle. His particular setup had the aftermarket ECU controlling the fueling, and the stock ECM controlling the timing, which was locked between base timing and whatever the stock ICM allowed for additionally at higher RPM, which the datalog showed 15-degrees. On the dyno, the engine simply refused to spin past 4500-RPM, and boost was around 8-psi...
The timing is actually unchanged from the previous set up; I know it's real low and was planning on slowly and safely increasing it. And it was running strong with the old paxton/lower boost...
Pete, if you look at the datalog at 6:00 into it, you will see that the engine is building boost nicely and mph increases rapidly, but then you get a little tire spin which increases boost to 12-psi at 5250-RPM (showing 59-mph on the speedo) momentarily, but once the tires grab when shifting, boost is then relegated back down to 7-psi at 3900-RPM (showing ten mph less at 48-mph on the speedo), and it stays at 7-psi after that the whole time after with your mph increasing slowly up to 67-mph when you then you let off of the throttle. During that whole time the TPS and MAP are both pegged at 100, your duty cycle is good, your O2's are reading good, and your getting no knock. It is your timing. You momentarily seen 12-psi because your tires broke loose and there was no load behind the engine...
hello everyone im looking at getting the ebl as well now im totally new to the tuning world and I know there is tons of people here that could help out with this im purchasing a ebl tuning kit in the near future and Im wondering if this will work with a ecm from a 1989 gta I know it has the cold start injector totally not programmed in so im good there also would this kit work with getting rid of egr and also is there a way u can add in what the duration of the cam is and the lsa. another thing too im also running with a t5 transmission instead of the 700r4 but the ecm is programmed with the auto transmission so im wondering would I have to reprogram that as well
Pete, if you look at the datalog at 6:00 into it, you will see that the engine is building boost nicely and mph increases rapidly, but then you get a little tire spin which increases boost to 12-psi at 5250-RPM (showing 59-mph on the speedo) momentarily, but once the tires grab when shifting, boost is then relegated back down to 7-psi at 3900-RPM (showing ten mph less at 48-mph on the speedo), and it stays at 7-psi after that the whole time after with your mph increasing slowly up to 67-mph when you then you let off of the throttle. During that whole time the TPS and MAP are both pegged at 100, your duty cycle is good, your O2's are reading good, and your getting no knock. It is your timing. You momentarily seen 12-psi because your tires broke loose and there was no load behind the engine...
Well hell......
I tried new plugs gapped to 28thou, then new coil to rule that out.
Then I tried your suggestion of giving it more timing-decreased the boost retard, then tried one with no boost retard.
File attached-same thing, only with no retard wouldn't go past 4K.
I noticed that I've got a lot of blow by out the valve covers now. Beginning to think that this engine that was supposed to have been built with a 9.8 or less compression ratio is actually a lot more( supposed to be all forged too!).....and the extra boost above the old paxton did it in, at the least the rings.
I'll do a compression test before I pull it again but it doesn't look good....
Further-compression test all low/90 to 145 with a 40 on #8- borescope shows broke off the ring lands; and it was supposed to be forged pistons and total seal rings....
So guess I'll be takin a break from tuning for new pistons and rings.
Last edited by drive it; 03-25-2015 at 07:10 PM.
Reason: more info
Can anyone offer me any incite on what an acceptable minimum pulse width would be. I'm currently at 15 psi with 80# injs. I just recently realized I don't have enough fuel pressure to achieve less then 85%dc at wot so I'm going to have to increase fuel pressure and redo my VE tables. I have yet to increase my pressure and start redoing my VE learns because I'm unsure if I should invest in a VAFPR first. My engine idles perfectly smooth at about 12-12.5:1 AFR in openloop. Once it goes closed loop I begin to have issues with stalling. This was much much worse before I greatly reduced my PROP gains tables. Adjusting them has helped a ton. I've noticed when it idles closed loop it trys to lean out the AFR to 14.7:1 the PW drops to .9 and it almost stalls and catchs it self and AFR drops to 12:1 then on its way back up to 14.7:1 it almost stalls or stalls. I know I could just run an openloop idle but I'm currently trying to get everything squared away so that I can get through my states emissions testing. I've read there are things that can be done with the tune to work around this issue. But if I can save myself headaches by adding a VAFPR I with likely purchase one since in the future I plan on having to increase my pressure even more when I add a larger came better intake and possibly better heads.
I have 75 lbs injectors at 21 lbs. I use a Aero VAFPR with stiffer spring. I believe the reg pulls FP to about 14 lbs at idle. I idle at 1.9-2.0 m sec pw. I idle OL(under 15 mph) at 13.8/1. My WOT DC is about 82% at 21 lbs FP.
I believe your VE table at idle and around idle needs to be increased.
I have 75 lbs injectors at 21 lbs. I use a Aero VAFPR with stiffer spring. I believe the reg pulls FP to about 14 lbs at idle. I idle at 1.9-2.0 m sec pw. I idle OL(under 15 mph) at 13.8/1. My WOT DC is about 82% at 21 lbs FP.
I believe your VE table at idle and around idle needs to be increased.
If I added to my idle VE area wouldn't this provide a even richer openloop AFR and make my openloop idle problem worse since it would be trying to pull even more fuel to achieve the commanded 14.7:1 AFR? Maybe I need to spend more time reading up on how the PW is calculated. From what I could find surfing the forums I've read TBI injectors start to get an eratic idle at about 1.6 msec and im seeing .9 at 600 rpm...
Hey guys, hopefully someone can help me with two questions.
Single Fire Mode for TPI - I'm battling a surging idle as well as a lean condition when driving at steady throttle. I've traced them both back to the car going into single fire mode. My SF enter & exit values in the bin are 1007 & 1205 microseconds respectively. My sPw values are above that (>3 milliseconds when it goes into SF mode). What would cause the car to go into SF if the pulse width is above the enter setting?
Second - I have Option Word 2 Bit 1 checked which should lock my idle state spark advance at 20*. However, the Whats Up display bar fluctuates and the datalog matches with SA fluctuating between 15* & 21*. Is this normal, or is there something else that affects idle SA when it should be constant?
The injector PW shown on the WUD is the actual programmed PW. So it is doubled in S/F mode along with the injector compensations added in. Which is why you see it above the S/F enter/exit values, which are based on double fire mode.
At idle there is Idle SA Compensation, this is used to prevent a rolling idle speed. Can zero the two tables out if you want a rock steady idle SA.
have some questions here about the 3001 bin that is supplied with the EBL Flash installation. it seems the BPC range in there is a bit skewed for 22 psi fuel pressure? i thought maybe it wasn't scaled for 85% duty cycle or something. i suspect the VE table would also mirror something of this scaling effect? it just so happens that i built a pretty similar engine with my buddy (heads, cam, intake, exhaust, 80# inj) and so we tried that bin, however we used higher fuel pressure (24 psi) and calculated BPC accordingly with the excel spreadsheet. it would always end up flooding the engine.. then put in BPC calculated for 26 psi and it ran a little rich but generally worked like a charm. just had to do some flat-tappet break-in here - again, after the first cam came out with a trashed #6 exhaust lobe
second question, is there a way to find out what version of firmware a binary is based on? and can you use, say a v2.2 binary on a v2.4 EBL Flash device or vice versa? what are the (in-)compatibilities here? and for the WUD version, i guess this one is not as critical because the datastream was never altered?
I'm going to try zeroing out my single fire enter exit values to see if it helps.
Thanks RBob.
**Update** - Zeroing out the single fire values gave me a very smooth idle and the car does not jerk during deceleration.
Good to go. The biggest issue with the S/F <-> D/F transition is having the correct injector compensation values. They have to be dead on for it to work correctly.
have some questions here about the 3001 bin that is supplied with the EBL Flash installation. it seems the BPC range in there is a bit skewed for 22 psi fuel pressure? i thought maybe it wasn't scaled for 85% duty cycle or something. i suspect the VE table would also mirror something of this scaling effect?
Looking at it now, it is off. There is too much slope to the range of values. Then at 45 KPa the value isn't quite correct. Checking my latest BIN for that car has the correct BPC vs VAC table values, hmmm.
second question, is there a way to find out what version of firmware a binary is based on? and can you use, say a v2.2 binary on a v2.4 EBL Flash device or vice versa? what are the (in-)compatibilities here? and for the WUD version, i guess this one is not as critical because the datastream was never altered?
thanks
Yes to interchanging v2.2 & v2.4 EBL Flash BINs. After the update from V2.0 to v2.2 of the firmware we make sure that from v2.2 and up is compatible. Lots of issues with folks trying to interchange BINs between v2.0 and above.
One change to the calibration from v2.2 going to v2.4 (and v2.3) is the addition of the MPH parameter for reverse lockout. If you use a v2.2 BIN the MPH will be 0, where it is set to 5 MPH in the V2.3 & v2.4 BINs.
But since it is a newly used location in the calibration they are compatible. Nothing was moved to make room for it.
Going from v2.0 to the newer versions there are a lot of changes to the calibration layout, so they are not compatible. However, the EBL firmware update utility can also update a V2.0 BIN to the latest layout.
Hope all that makes sense.
The WUD isn't an issue as we take care of any changes in the data stream within the WUD. So far it is fully backwards compatible.
ok thanks for your detailed reply on the updates and compatibilities between them.
too much slope, range of values, 45 kPa - you are referring to the VE or BPC table of the 3001 bin?
i have a pretty trick question here (i think).. assuming a freshly built flat tappet engine.. how do you break these in if you don't have a calibration for it? you're supposed to immediately fire up and run it in the 1500-2500 rpm range for 20-30 minutes..
having issues getting it cranked up. had her start fine more or less some days ago (a little intake backfiring and flooding as described in previous post), then got to do some breaking in, verified lift at the rockers, changed weak springs out and now i can't really get it to start. somehow all we really get is fireballs out the intake. if/when it starts up, need to give it some throttle for that and then it will rev to 3-4-5krpm, then die again. any idea as for the heavy intake backfire? using a weiand x-celerator single plane here, BBC TBI, 80# and 24psi fuel pressure & VRFPR, calibration based on the mentioned 3001.
CTS is 10-20°C, not using an IAT (yet).. so i set the IAT/CTS blend to 100%?
as said, lift checked out kinda fine (all lobes at least .525 of cam spec .550) so i at least think it's not a dead cam
i have a pretty trick question here (i think).. assuming a freshly built flat tappet engine.. how do you break these in if you don't have a calibration for it? you're supposed to immediately fire up and run it in the 1500-2500 rpm range for 20-30 minutes..
Not that tough, really.
The reason for that RPM for a time, is the cam lobes, so make sure you've got break-in additive in the oil !!
Engine load doesn't matter.
Pick a mill as close to what you've built as possible.
For my '71 Wildcat, I picked a '71 Wildcat. Since anything electronic didn't yet exist, there is no calibration for that motor, so.....
( there's also not another dist in the world that will fit this motor, and provide the electronics to the EBL, or any other ECM for that matter, since we built it from the bottom half of the stock dist and the top half of an '87 GM dist, and welded them together )
Looked up the dist curve, and plotted it in the spark map against tuner pro's charts as close as reasonably possible. Draw the centrifugal as a line from the published curve, assuming 100% VE, and the vacuum adds to it as map drops ( less throttle ) so the MAP entries are just additions to the centrifugal at lower map entries, extrapolated as best you can over the entire possible range.
Close enough to run. ( actually, run rather well )
Between the centrifugal and vacuum, a range of 10 degrees to 55 degrees total. ( remember, it can only hit 55 throttle closed at high RPM, so it's not as ridiculous as it might appear ) As I recall, without looking, the centrifugal total range was 27 degrees, and the vacuum 9 degrees at the distributor, which is 18 degrees at the crank, and a stock GM static of 10 degrees with no advance.
Fuel/VE is a little trickier, on the surface, but not really.
Looked up the torque curve for that year mill, averaged them because there were about 5, and came up with a "reasonable" ball-park torque curve.
Assume 90% VE for the torque peak, and a typical 10% or so at idle.
Plotted a curve that pretty much resembled the torque curve for that motor as published back in '71, and extrapolate VE values from that curve.
Opened up the BLM limits A LOT ! ( give the ECM room to work )
The big thing, was to give the EBL a LOT of room to work. Extreme limits on spark and BLM.
Close enough to start running learns, and the corrections were surprisingly small. ( relatively speaking )
The learn algorithm is much faster, and much smarter than you or I, so let it lead you.
My torque curve differs from that published by GM, of course, but VE Learn will take care of that in relatively short order.
Hope this helps...
Looking for any suggestions about this tune... looking for anything y'all think might be good to tweak.
Attached is the current BIN and a data log dump. The car is in closed loop in the attached file. VE learns since the data log have only suggested changes +/-3 in either direction for VE within 50-100 KPAs. Also, I didn't really push it too hard on the take-off in the attached dump file.
I don't have any driveability problems with it- the car seems to run really, really strong. It has a lot better acceleration, grunt, and take-off than stock.
At this point, I think it's about little things... maybe. Maybe not. I could have something massively wrong... and simply don't know it. I do know either the speedometer cable is on its way out or the speed transducer is on its way out (mph swing after 40mph). But it runs well otherwise and if that is any idea of massive problems or not, well... I'm unaware of them at this point.
RBob helped me out with some thoughts on AE last week, which I've addressed and is in the dump and BIN.
And... I can get around 96 KPAs on WOT (100% TPS) when static (engine off & key set to run) is around 99/98 KPAs.
The car...
Yes- it's a crossfire. Running EBL. And yes it has a '70s cam. And smog heads. It's not a drag car- it's supposed have a little more punch than factory. FWIW- I am not looking to put it down the 1320. I want to keep it visually as close to stock as possible.
Cam specs- .465IN / .488EX Erson Injectors- 80lb TBIUnits- Twin 49.5MM (slightly bored- I didn't go to the full 2" concerned about velocity because you can't add metal back in as easily as you take it out.) FPR- VAFPR (GM marine housing mod) Intake- Renegade OE Air cleaner- removed some of the bottom of the housing to allow more air in; looks stock unless you run your fingers around the bottom & feel the filters Gears- factory 2.88 / ~5,450 shift on governor at WOT
All of that said, the only thing it does that is a little weird is a slight roll (200rpms or so) when in overdrive between 1.5 and 2k rpm when I am going down a hill and at 0% TPS.
DE?
DFCO?
SA?
It's not a problem- just an observation. Cam perhaps?
Looking for any suggestions about this tune... looking for anything y'all think might be good to tweak.
Depends on your objective. Once you answer "why" then what and how generally take care of themselves.
VE learns since the data log have only suggested changes +/-3 in either direction for VE within 50-100 KPAs.
For me, that's well within the range the computer is designed to work.
Can you get it "perfect" ? Until the weather changes, maybe. Once the VE Learn starts correcting itself, for me that's close enough to move on to other things. I'd average the corrections, so it's about mid-way between the + and - corrections it wants to do, and leave it.
At this point, I think it's about little things... maybe. Maybe not.
That's when the "addiction" sets in strong.
You start looking for things to twiddle, when it really needs nothing.
<snip>
And... I can get around 96 KPAs on WOT (100% TPS) when static (engine off & key set to run) is around 99/98 KPAs.
So you've got a little air restriction. Dirty air cleaner, maybe ?
You'll find the last 2% will take 90+% of the work.
For me, getting no vacuum at the horsepower peak, ( 5500 RPM WOT ) took a good deal of math, but almost surprisingly the stock big block TBI unit flows *just* enough. It starts developing vacuum at 5600, which tells me it's "good enough" for the objectives I set. It's also too big for the vast majority of driving to which the vehicle gets put.
There was also quite a bit of math, and chemistry, at that same point that led me to true dual 3 inch exhaust. The exhaust flows just enough to have velocity, momentum, and some evacuation at the horsepower peak, which then led to more intake flow, which led to more exhaust, which led to.....
Fortunately, all that for me happened on paper. The actual hardware came in pretty darn close.
Smaller and I lose flow. Bigger, and I lose the velocity, momentum, and evacuation.
Also, hitting the "optimum" tends to make it a little peaky.
TBIUnits- Twin 49.5MM (slightly bored- I didn't go to the full 2" concerned about velocity because you can't add metal back in as easily as you take it out.)
For me, not so much of a worry, because....
Putting it in perspective, it's already grossly over-sized IF your objective was only 2000 RPM. Sized for WOT at the max RPM you ever expect to hit, and everything below that is a compromise anyway.
This is where you get into those "little things" that will take a tremendous amount of thinking, calculating, and work to get as perfect as it can be.
When is "good enough" good enough ?
It's theoretically possible with ideal length runners, etc. etc. to exceed 100% VE. For my calculations, I assumed 100% VE at torque peak, as the base to start from. All in all, worked out pretty well.
All of that said, the only thing it does that is a little weird is a slight roll (200rpms or so) when in overdrive between 1.5 and 2k rpm when I am going down a hill and at 0% TPS.
It's not a problem- just an observation. Cam perhaps?
Again....
Mine does that a little too. Possibly a lean surge, possibly spark chasing, possible proportional gain.
Under decell I'm not so concerned that it's dead smooth, so long as it doesn't stumble on tip-in if I need it at that point.
I'm not running a vacuum reference on fuel pressure, so I know I'm running out of injector control under decell. I'm cycling between no fuel at all, and too much fuel, so it rolls a bit. Without a vacuum regulator, there's just no way I can get the little bit of fuel it wants, smoothly.
BUT, I'm OK with it, so I live with it.
Besides, it impresses passengers when I tell them it's because there's just way too much engine for that little load.
Should we assume u didn't parallel plumb the TB's since ur still running the GM FPR?
Dominic- no... I didn't parallel plumb them.
The reason was pretty simple: I could hide the GM marine pressure regulator housing that's been modded into a VAFPR under the OE airbox. An Aeroquip VAFPR wouldn't be as easy to hide- and I didn't want to give up the OE appearance.
I get about 15 and 20psi out of the set up.
Originally Posted by cflick
So you've got a little air restriction. Dirty air cleaner, maybe ?
For me, getting no vacuum at the horsepower peak, ( 5500 RPM WOT ) took a good deal of math, but almost surprisingly the stock big block TBI unit flows *just* enough. It starts developing vacuum at 5600, which tells me it's "good enough" for the objectives I set. It's also too big for the vast majority of driving to which the vehicle gets put.
There was also quite a bit of math, and chemistry, at that same point that led me to true dual 3 inch exhaust. The exhaust flows just enough to have velocity, momentum, and some evacuation at the horsepower peak, which then led to more intake flow, which led to more exhaust, which led to.....
Fortunately, all that for me happened on paper. The actual hardware came in pretty darn close.
Smaller and I lose flow. Bigger, and I lose the velocity, momentum, and evacuation.
Also, hitting the "optimum" tends to make it a little peaky.
I'd pretty much forgotten about the role of exhaust in all of this. Thanks for talking through all of that and how it all fits together.
I'm still running all of the OE exhaust- from the manifolds to the y-pipe and out through 32 year old mufflers. The cat is still in there... but the contents are gone.
Max VE hits at 4400rpm. For my engine combination (cam & heads)... max torque hits at about 3600 and stays fairly flat until 4400 and then it drops off. Max HP is at about 5300 and it shifts (on the governor) between 5400 (hot transmission) and 5550 (cool transmission). I set the tranny with weights and springs to shift there so I could get to just the other side of where max HP should occur.
I am still using the OE fresh air chamber in the hood, although the flap & operating rod/solenoid has been removed.
You'll find the last 2% will take 90+% of the work.
The reason was pretty simple: I could hide the GM marine pressure regulator housing that's been modded into a VAFPR under the OE airbox. An Aeroquip VAFPR wouldn't be as easy to hide- and I didn't want to give up the OE appearance.
I get about 15 and 20psi out of the set up
Well but you're getting different flow from each injector and as pressure goes up the delta gets bigger. If you've been able to mitigate this fine, but my experience when I did it was that the air/fuel was imbalanced bank to bank, front to rear. Then the other issue w the Xfire was that it used only 1 NB O2. So you were optimizing one side at best. I had a ported Xfire manifold on mine. Maybe using a Renegade helps alleviate the problem but I'd be interested in seeing how.
Well but you're getting different flow from each injector and as pressure goes up the delta gets bigger. If you've been able to mitigate this fine, but my experience when I did it was that the air/fuel was imbalanced bank to bank, front to rear. Then the other issue w the Xfire was that it used only 1 NB O2. So you were optimizing one side at best. I had a ported Xfire manifold on mine. Maybe using a Renegade helps alleviate the problem but I'd be interested in seeing how.
That was something I thought a lot about- the flow differences between the front and rear injector because of the impact of the location of the regulator.
It's a trade-off that I was aware of... actually because of youand your posts & thoughts you'd shared with me and others.
So... I've been checking the plugs to see if there is any appreciable difference too- and I haven't seen anything yet. It's been only a few thousand miles though. I also tend to run it a little rich all over- which was GM's solution too. My AFRs are between med/low 12s (up to about 5k rpms) and high 11s (5k rpms +) on WOT.
Not sure if the 84 had the NB on one bank, but the 82's sits after the y-pipe. So I'm at least getting a blend between the banks. The WB sits just ahead of the cat too, near the NB.
I can take a guess- albeit a wild guess- but maybe the design of the intake helps a little. Likely not a lot though- and not enough to compensate completely for the fuel pressure impacts. I'm not expecting a magical resolution to GM's staggering- but the plenum is a bit wider left to right and front to back than the OEM intake. That could marginally help distribution I'd think... along with runner design.. but to your point about it getting worse the more PSI you add... it is what it is.
If it's all about expectations at this point... I guess I'm thrilled the plugs even look similar from bank to bank.
Nice, gonna be interesting to see that Renegade CFI build work out
Had something similar in mind for a friend's 84 C4 but then went down the BBC TBI route instead of retaining CFI since DCS wasn't very responsive about their latest manifold batch back then, and after half a year my buddy decided he wanted his money back
Anyways, I have another question now concerning cold and hot starts. I understand that in OL, the cAFR is still the target for the ECM to calculate the PW, but it won't use the O2 feedback for correction. But what parameters can you actually modify in order to make a cold engine hit the desired AFR as dictated by cAFR? The cAFRs I get are fine but I can't make the engine match it. If I'm not mistaken, all I could do is bump up VE and we all know that aint gonna work out once it's warming up. So in order to make it run richer after a cold start, I can only reduce the cAFR by using Choke and/or the OL AFR vs CTS tables... right!?
All of that said, the only thing it does that is a little weird is a slight roll (200rpms or so) when in overdrive between 1.5 and 2k rpm when I am going down a hill and at 0% TPS.
A word on DFCO (because downhill and 0% TPS for me is a classic DFCO application) ... in my observation & opinion, stock setup for DFCO is pretty poor. It has a 2 seconds (=forever) delay to enter it, and will only enter over 2krpm or so and over 40 mph (off top my head).
I usually set the RPM enter/exit threshold way lower, same for the enter delays (typically a couple of hundred ms). Also lower the DFCO Exit SA Multiplier a whole lot AND take out a little of the Exit Fuel Pulse (depends) to reduce jerk when exiting.
The trick is to set the DFCO enter/exit hysteresis up in a way not get it into a DFCO loop where it will switch from DFCO-exit to DFCO-enter Also need to pay attention to the MPH enter/exit thresholds.
I used this on most automatic vehicles I tuned with EBL so far.. I like to use it so it will protect the cat, save some fuel, reduce wear on the brakes among others.. It will also mask an inconsistent DE/low-MAP problem but also need to disable DFCO completely at some point in the tuning process and figure out low-MAP VE (and Async/SF, etc) to get it consistent.
...your mileage may vary
"That was something I thought a lot about- the flow differences between the front and rear injector because of the impact of the location of the regulator.
It's a trade-off that I was aware of... actually because of you and your posts & thoughts you'd shared with me and others."
Actually, I followed what had been pioneered by Bruce Plecan aka "Grumpy", RIP. Bruce was the first I'd read about making a Xfire run 13's. He was the one that brought up the issue of the unbalanced fuel flow due to the sequential setup on the twin TBIs. I went w larger TBs (2.13"), different cam and heads. Perhaps it's because your cam is more tame than what I was using. It was a CompCams full roller setup w a 108* LSA, 218*@.050, and a .535" lift.
In any case, don't want to take any credit for something I was just repeating.
Anyways, I have another question now concerning cold and hot starts. I understand that in OL, the cAFR is still the target for the ECM to calculate the PW, but it won't use the O2 feedback for correction. But what parameters can you actually modify in order to make a cold engine hit the desired AFR as dictated by cAFR? The cAFRs I get are fine but I can't make the engine match it. If I'm not mistaken, all I could do is bump up VE and we all know that aint gonna work out once it's warming up. So in order to make it run richer after a cold start, I can only reduce the cAFR by using Choke and/or the OL AFR vs CTS tables... right!?
On a cold engine the cAFR and WB reported AFR will hardly ever match. I don't worry about it and just tune for a decent running engine.
Nice, gonna be interesting to see that Renegade CFI build work out ...
It's been a lot of fun to build a sleeper.
I superimposed a post-mod datalog over my baseline with the same conditions. I've optimized a few non-WOT areas of VE and SA somewhat and bored the TB since the post data log.
The result is pretty dramatic in similar rolling starts to 60mph & 80mph.
Eddie Motorsport manufactures the Renegade now. The intake is sold through Eddie, Eckler's, Mid America, and even Hawks. Eddie has the resources to get the quality right on the second generation of Renegades.
As for OL & CTS... I adjusted those after a few cold start datalogs. I found that I could add about 20% to the CTS for the temps I needed a couple of times and then my idle cAFR was closer to the WB. Driving around, it got the AFR in the ballpark too.
So, I kinda did like what RBob said- got it close and not worried so much
For production iron heads on a GM L83 crossfire, my SA table is based loosely upon the BUC 86 iron head BIN.
My heads are the same casting numbers as the '85 and '86 iron head Vettes. I'm not running nearly as much advance in the low MAP & high speed areas as the '85s and '86s run, so I've capped it off at 36 degrees. I could probably do a little more clean-up on the SA (non-PE & high KPAs) since I've got quite a few things switched off and/or removed, but I feel the WOT is pretty set at this point.
I've ended up adding in a lot of spark through the PE adder- after lots of conversations with my engine builder, RBob (he put up with a lot of emails & questions from me!), and a few others who have tuned cars with the same heads from "the golden era of smog control". I've also pulled the plugs to look for signs of detonation too- none was evident over the last few thousand miles.
It seems to run very well throughout low and high speed tables. My engine was built to specs for a carb & vacuum advance HEI with a total of 36 degrees of advance, so I've tried to get there as best I can.
No knock- and has gobs of response to the throttle.
It's taken almost a year to get the tune to where I feel like it's more "set" than "work-in-progress". Huge learning curve for me and I think I've had every bad idea or wrong assumption and asked every dumb question known to man.
I've had lots of help along the way... and I am very appreciative of it.
hey guys I have a question what table do I need to use to add more fuel on cold initial start?
also what do this tables do and their values?
*choke-decay multiplier?
*crank-prime PW?
On a cold engine the cAFR and WB reported AFR will hardly ever match. I don't worry about it and just tune for a decent running engine.
Originally Posted by RBob
add more fuel on cold initial start?
During cranking use the crank AFR table.
The choke is after-start fuel. Cold engine, decays out in several minutes. Warm engine, in 10 - 20 seconds.
Can also work with the open loop - AFR vs CTS table.
*choke-decay multiplier?
Determines how fast the choke AFR is decayed out. The more negative the faster the decay.
*crank-prime PW?
Adds additional fuel on the first injection during cranking (port, TBI is first two).
So, one more follow-up question on this if I may.. How do you distinguish between a need for working on the Choke AFR tables or the OL AFR vs CTS, since the first one will decay out over time and the other one is bound to CTS?
Thanks
"When running port injection the aePW doesn't show dTPS AE.
Only dMAP AE, which is minimal to none.
For dTPS AE look a the aPW data. Due to the once per revolution
injection of MPFI, dTPS AE is added via async injection. Otherwise
there are lean stumbles."
This is what Bob told me in the email about the aePW.
I have another question on PFI aePW. Have a run here where aePW is 0 all the time whereas dMAP AE is not zero, however as pointed out above is by far smaller than dTPS.
Also, tpsAE is a lot smaller than aPW (about factor 10).. According to above statement, aPW should mirror the tpsAE? Or is this an artefact being seen from AE calculations being done 80 times per cycle, and we can only look at the sampled 17 data points? What else could aPW include in a typical AE situation, that would make it that much bigger?
Thoughts?
So, one more follow-up question on this if I may.. How do you distinguish between a need for working on the Choke AFR tables or the OL AFR vs CTS, since the first one will decay out over time and the other one is bound to CTS?
Thanks
If it is too lean or rich right after startup work with the choke AFR. If after a few minutes of running then the open loop CTS compensation.
I have another question on PFI aePW. Have a run here where aePW is 0 all the time whereas dMAP AE is not zero, however as pointed out above is by far smaller than dTPS.
Not shown is the RPM and CTS compensation that occurs after the dMAP & dTPS PW look ups.
For production iron heads on a GM L83 crossfire, my SA table is based loosely upon the BUC 86 iron head BIN.
My heads are the same casting numbers as the '85 and '86 iron head Vettes. I'm not running nearly as much advance in the low MAP & high speed areas as the '85s and '86s run, so I've capped it off at 36 degrees. I could probably do a little more clean-up on the SA (non-PE & high KPAs) since I've got quite a few things switched off and/or removed, but I feel the WOT is pretty set at this point.
I've ended up adding in a lot of spark through the PE adder- after lots of conversations with my engine builder, RBob (he put up with a lot of emails & questions from me!), and a few others who have tuned cars with the same heads from "the golden era of smog control". I've also pulled the plugs to look for signs of detonation too- none was evident over the last few thousand miles.
It seems to run very well throughout low and high speed tables. My engine was built to specs for a carb & vacuum advance HEI with a total of 36 degrees of advance, so I've tried to get there as best I can.
No knock- and has gobs of response to the throttle.
It's taken almost a year to get the tune to where I feel like it's more "set" than "work-in-progress". Huge learning curve for me and I think I've had every bad idea or wrong assumption and asked every dumb question known to man.
I've had lots of help along the way... and I am very appreciative of it.
Just so that you know, 36* timing recommendation on a HEI is without vacuum advance. Vacuum advance adds ATLEAST 10* more timing. The TPI Corvettes are pretty slippery and it honestly does not surprise me to see the timing at 46* BTDC or above. Even my Express vans 350 Vortec likes to cruise between 42 and 48* BTDC under lighter loads and between 32 and 40* under moderate loads.
Just so that you know, 36* timing recommendation on a HEI is without vacuum advance. Vacuum advance adds ATLEAST 10* more timing. The TPI Corvettes are pretty slippery and it honestly does not surprise me to see the timing at 46* BTDC or above. Even my Express vans 350 Vortec likes to cruise between 42 and 48* BTDC under lighter loads and between 32 and 40* under moderate loads.
Thanks, Fast! That makes a lot of sense after seeing the SA tables on the 86 iron headed Vette. I was very reluctant to put the full table in for 20-70 KPAs because it crested that 36 degree mark.
I guess I could add in those areas for spark and see.
Thank you- this is what I was hoping to hear about in terms of the tweaks!
Would what you described be mirrored in this condition here? Looking at t=2177..
I can only see that dMAP is quite large at 18.4 kPa (184 in data cursor box) here, but only 7% of dTPS (70) is shown. For tpsAE that results in only 0.412 ms of added PW, however aPW shows 2.75ms PW.. would that come from just the RPM compensation (600 rpm, taking off) and CTS (97°C or IAT/CTS = 72°C) as you stated,. or does it seem a little high to you too? Also, how is "asynchronous" defined in that case, when is it triggered? Is it a fixed time-periodic event?
It can also be seen that aePW (blue) remains at 0 although there's some occurences of marginal mapAE which it should mirror?
Trying to cure a bog-down at tip-in / take-off, probably due to it going too rich. Let me know what you think please!
Would what you described be mirrored in this condition here? Looking at t=2177..
I can only see that dMAP is quite large at 18.4 kPa (184 in data cursor box) here, but only 7% of dTPS (70) is shown. For tpsAE that results in only 0.412 ms of added PW, however aPW shows 2.75ms PW.. would that come from just the RPM compensation (600 rpm, taking off) and CTS (97°C or IAT/CTS = 72°C) as you stated,. or does it seem a little high to you too? Also, how is "asynchronous" defined in that case, when is it triggered? Is it a fixed time-periodic event?
It can also be seen that aePW (blue) remains at 0 although there's some occurences of marginal mapAE which it should mirror?
Trying to cure a bog-down at tip-in / take-off, probably due to it going too rich. Let me know what you think please!
Async is firing the injectors every 12.5 msec.
Appear to have way too much dMAP AE. On a MPFI engine very little to no dMAP AE is required. If this started as a TBI tune, take a look at some of the port tunes to get an idea of how little AE is required.
Appear to have way too much dMAP AE. On a MPFI engine very little to no dMAP AE is required. If this started as a TBI tune, take a look at some of the port tunes to get an idea of how little AE is required.
Started it based on the 3005 bin template, and this is what the dMAP AE PW table looks like. Started working on it and reduced it by vast amounts but still having trouble dialing it in.
could I use this ebay sensor for my fuel with my ebl to datalog it?
and how do I wire it?
Ground goes to the engine block, signal goes to the ADC terminal strip on the EBL board, power is up to the seller. Don't know what is required to power those sensors.
That is the dTPS PW table. Try zeroing out the AE - MAP PW table to eliminate AE from the MAP. Then work with the TPS PW table.
Note that when the injector size is increased the AE needs to be decreased.
RBob.
Ha, I'm a jackass, got about 12 hours of tuning messing with my head today Sorry for pasting the wrong table in here.. See below for actual table, but it is straight from 3005 bin. I actually worked it down to zero just as you said Only problem I could see so far is from small dTPS in P/N where MAP is quite quick to change. Also some upshifts at steady TPS go a bit lean with the added MAP.
Thanks for your input!
I have another question, this time on closed loop idle or general CL operation with getting the prop gains right. Everything but idle seems pretty decent, as it should we an almost stock L98. However I have a situation in idle where it will sag quite bad (at about 0.5 Hz I believe) with the AFR all over the place, I already tried pulling out 20% from the Gain vs. O2 error. It will eventually settle after like 5 seconds but the NBO2 just stays at 600-ish mV? I'm not quite sure why it would do this.. Do I also have to adapt the duration values for it to oscillate? And is the ultimate goal getting it do cross counts fast enough for the idle speed not to change much? Still kinda new here to PG and CL tuning..
Ground goes to the engine block, signal goes to the ADC terminal strip on the EBL board, power is up to the seller. Don't know what is required to power those sensors.
I have another question, this time on closed loop idle or general CL operation with getting the prop gains right. Everything but idle seems pretty decent, as it should we an almost stock L98. However I have a situation in idle where it will sag quite bad (at about 0.5 Hz I believe) with the AFR all over the place, I already tried pulling out 20% from the Gain vs. O2 error. It will eventually settle after like 5 seconds but the NBO2 just stays at 600-ish mV? I'm not quite sure why it would do this.. Do I also have to adapt the duration values for it to oscillate? And is the ultimate goal getting it do cross counts fast enough for the idle speed not to change much? Still kinda new here to PG and CL tuning..
Set the open lop idle flag and see if the oscillation goes away. If not then it isn't a PG issue, more likely a VE table or possibly SA issue.
> after like 5 seconds but the NBO2 just stays at 600-ish mV?
Hard to say why, it may be that the O2 sensor is becoming slower to respond.
I've noticed my VE learns vary with the ambient temperature. They will vary the most outside of PE mode and in the lower KPAs.
Warmer IAT and the WB shows richer... cooler IAT and it shows leaner. My VE will swing between 9-12 on the lower KPAs at the most... as in deceleration. PE changes are usually only 1-4% +/-.
CTS will be constant 180-189*, but then there are days where the air will be around 104* on the IAT and then as high a 134* (heavy traffic... 90 degree temps outside... slow and lots of idle).
Again, this is in open loop for tuning.
Is it time to adjust the CTS/IAT blend filter?
I am using the fresh air chamber in the hood, which means as soon as I move the IAT will usually drop. As I sit in traffic, the air cleaner housing warms up and so does the IAT.
I've noticed my VE learns vary with the ambient temperature. They will vary the most outside of PE mode and in the lower KPAs.
Warmer IAT and the WB shows richer... cooler IAT and it shows leaner. My VE will swing between 9-12 on the lower KPAs at the most... as in deceleration. PE changes are usually only 1-4% +/-.
CTS will be constant 180-189*, but then there are days where the air will be around 104* on the IAT and then as high a 134* (heavy traffic... 90 degree temps outside... slow and lots of idle).
Again, this is in open loop for tuning.
Is it time to adjust the CTS/IAT blend filter?
I am using the fresh air chamber in the hood, which means as soon as I move the IAT will usually drop. As I sit in traffic, the air cleaner housing warms up and so does the IAT.
The second table (iat-cts2) is from a performance engine. It has the air ducted from the cowl sealed off from the engine.
That's about what the fresh air chamber does as it pulls air from ahead of the radiator. I am pulling some air from around the filters too- but the biggest source of air is from the fresh air chamber.
I've dropped the values in my table, which looked like iat-cts1, to about 1/3 of what it was. Not quite as much as iat-cts2, but still considerably less.
I'm hoping to increase the consistency in my VE learns as the IAT temp increases.
03-22-2015, 02:32 AM
and your posts & thoughts you'd shared with me and others.
