**update**
Gave up trying to tune idle on this TB, WOT and DD characteristics were good, it was idle and decel that needed more work. I believe the data from the twin 65 was not enough on it's own to get the idle correct, that or idle airflow tables needed more adjusting. Either way, the TB was removed and will be going with a mono blade instead.
Last edited by Jn2; 01-14-2017 at 04:43 PM.
The only help I can offer is my tune that worked with my Twin 67mm TB from VMP. But seeing as you have heard nothing in 10 hours it might be worth something to you. Similar mods and I think I can find the Gas tune over the E85 only difference being I was running a Ported CJ. (It says GT500 but thats what was used with my VMP67 when I upgraded, I switched mainly because Bama had the Vibration issue about 120 and couldn't get the results a Cobrajet should MPH wise. I got the same MPH I had on a ported stock manifold)
This tune is from Bama and above 120 had issues that my Lund Tune does not but I can't access my Lund tune with HP Tuners.
Bama E85 Cobra Jet GT500 TB Tune T5.hpt
Bama 91P Cobra Jet GT500 TB Tune.hpt
According to my data, you have the correct TB info in the tune. Have you checked for mechanical issues, since the gears were transferred?
Thanks, I'll compare and see how it does.Originally Posted by Cross
Gears were not transferred, only the electronics, TPS sensor and motor. The L&M has its own gears. The gears look to all function perfectly, they don't bind and move smoothly
Last edited by Jn2; 01-11-2017 at 12:50 PM.
Okay, looks like they increased your idle airflow and adjusted the idle throttle angle for said airflow(row values for angles were also different). This makes sense, I didn't change any of these from stock values since the twin 60mm idled and drove fine, but maybe the difference from stock to twin 66 is too great and is causing the hang up. I will know more tonight when I swap the TB back on the car and try your idle airflow and angle settings;
So I updated the idle airflow settings and I was able to make it out of the parking lot and drove around for a short bit. How ever soon after a WOT pull on it's return to idle the throttle stuck and ended up going into limp mode. Only way out was to shut the car down and turn it back, after that, the RPMs would hang and run negative spark timing the entire time until I restarted the car. Each restart would give me about a mile of driving before the RPMs would hang again...
Here is the log, the issue begins at the end of log where you see the spark timing just drop to negatives and throttl angle sticks to 8*
Last edited by Jn2; 01-14-2017 at 02:55 PM.
So I have tried various things and am going to try and dial in the the lower end of the MAF curve a bit more. A lot of the research I've done on this TB shows that it is very picky and usually needs a accurate curve down low to prevent the wrench light and failsafe mode(which is what happens). During actual driving under various loads it works fine, issue only pops up during decel into idle when there is almost no load. My trims also seem to be a bit erratic during that period. Once settled at idle, they are +/-2%, but during the drop in RPMs they go +15 and then -15, then settle out +/-2%.
Well, MAF curve was dialed in to +/- 2% last night, it no longer spikes then dips when clutch is pressed and throttle is released, however the issue persisted, it will drive fine, go WOT fine, but on decel to idle rpm's it will go into RPM guard with a high idle, if you keep driving it will throw a wrench light and throw you in limp mode.
I'm thinking maybe this TB requires a better tuner to get the angles and area data correct. We are going to sell it off and use those funds to just buy a mono.
Have you logged the throttle error at all to possibly see if its that? The throttle map is unfortunately very important for DBW cars, so if you're not able to get a solid FF and INV table for those you're kind of SOL.
Yeah, there were a ton of throttle errors, I had a histogram set up to monitor them and some of the cells had values averages as high as 1000, averages were all around 5-600...def tuning related, but I lack the experience needed to properly adjust the TB maps
just for fun did anyone look at this e85 tune and check out the cam exhaust cam table for op requests
Didn't notice that but I just briefly scanned through them. Definitely an interesting approach there. lol Spark maps didn't seem bad. I did notice that they have the rev limiter a good bit higher than the knock sensor RPM cutoff.
yea I wonder how retarding this exhaust cam -13 degrees works out
I can tell you when I run that tune the Car get's above 20 and it's like the Driveshaft is out of balance it shakes... I was surprised my Lund tune fixed it I thought I needed a new driveshaft.
There was another typo I noticed on your bama file...forgot where but the row was mislabelled in a way that would cause a contradiction...the rows were suppose to be ascending then in the middle was a contraction, the row was a RPM row, something like 800 1000, 1300, 900, 1700, 2000...the 900 value was suppose to be 1600 but they typo'd it to 900...
interesting, went to check spark maps, they are commanding much more spark than I normal do, wonder if those tunes run into KR bc the spark modifiers are still in place and they usually add 4-5* based on conditions...my 22* spark advance always end up being 28* after all the modifiers are done doing their thing...an their modifiers are still there, they aren't zero'd out...
I didn't really pay much attention to that. It seems like most tuners have agreed that it's safe to trust the system to manage knock in a NA setup.
They are taking a somewhat backwards approach to most that I don't really prefer for a safe tune but it does work well. I like to allow the sensors to add a few degrees if the conditions are right because then if something causes things to not be going as expected (bad fuel) the spark is starting lower so one knock event pulling spark will typically get you away from the knock threshold until it starts to add it back in. If you start with spark where you want it to be knock can occur for a longer period of time before resolved if the unexpected occurs.
The advantage to tuning the way that tune is setup with zero adder and a higher starting spark is no waiting for the computer to add spark when you go WOT. In a higher gear it's not usually noticeable but I have noticed lower gears get the spark much earlier if a tune is setup this way. For a tune setup specifically for E85 I do this.
I was trying to edit the post you quoted to add that I realized I commented on the knock sensor RPM earlier but I accidentally deleted it.
Yeah the higher values will help when initially going WOT so you aren't waiting for it KR to add advance or waiting for it to go 100% into OP. I tend to go simular to you, I tune until I see KR, then take it back 2* and let KR advance add timing as needed...I end up around 28.5* spark advance on 93 doing this method, but average is 26ish until 6k+ rpm when it goes to 28
The approach I like to take is to raise the "limit" tables some so they don't get in the way(IPC, Pre Ignition, cylinder pressure, ect.). Most books and information that I can find say to "zero out" enviroment compensation tables(IAT, ECT, lambda, ect.). I'm not a big on doing that and think it will optimize the tune for the environment you are logging in. you could then add those tables back in but you would need to base them around the conditions you tuned in and not stock other wise you could be doing more harm than good. If possible logging total spark and BKT spark can tell you how much these tables are involved.
Just like everyone else I get the BKT to the point of 0 knock retard/advance. I then add 1 or 2 degrees so the knock sensor is reporting knock. To counter this I use the octane adjustment table. This way with every fill up the octane table can compensate for better or worst gas when I get it. The engine may knock a little when I get bad gas but it quickly adjust and learns the knock out for that tank. The next tank when I get better gas it adds the spark back in and doesnt rely on the knock advance. This way there is a window of risk, no more than on the stock tune going from 93 to 89, but I can be assured my tune is optimal at all times and not being limited by waiting for the knock advance. I prefer to use the tables that you have available and let the ECU optimize variables to the changing factors of the environment for the best tune in all conditions. This method could also be used for the FF spark adjustment when the normal adjustment tables, like in most the 11-14s, are not there.
Idle airflow > drive.
Last edited by murfie; 01-26-2017 at 01:46 AM.
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