Stuttering/Hesitation completely removed! - car never smoother

We have some great tuners on this board. It had been some time since I had looked into what solutions people were coming up with for fixing the stutter/hesitation that most LGT's have experienced. I was Cobb Stage 2 for a couple years and while it reduced the stutter, it was still noticeable for me at times.

 

A couple of months ago I decided to try open source tuning and purchased a professional e-tune from a reputable tuner. While it was better than the Cobb map I still experienced many of the same issues. Since I went open source I have been working with a local open source tuner for road logging and tweaking the map and we have tried various things without much success.

 

Recently we had an idea to try adapting a STI tune to my LGT. Since the LGT shares most of the same engine components as the STI, our goal/idea was to make the LGT run and drive like a STI as closely as possible in terms of timing, throttle response, etc. We were very surprised and pleased with the results - the car has never felt smoother and it seems to have more grunt down low and it is awesome.

 

Mods:

Basic stage 2 car with catless shorty downpipe, AVO cans, AVO filter. Stock turbo and intercooler. Grimmspeed 3-port BCS in parallel with Hallman MBC. No restrictor pill. Stock clutch and dual mass flywheel. Car is tuned for ~20PSI peak in 4th/5th gear. Fueling is very rich/conservative until I can get to a dyno with a wide band to dial it in. Peak maf g/s I have observed is around 235-240. Local elevation is ~736ft.

 

Tuning details:

-Basic stage 2 open source tune

-Re-scaled Throttle/RPM values in Boost Control maps and imported STI settings (TB, IWD, TD, etc)

-Re-scaled RPM/Load values for Open Loop fueling and adapted existing fuel settings to new values, imported STI settings for all other open loop fuel settings (POLFMS, MAPOLE, MPOLE, POLFC)

-CL/OL delay values adapted to STI settings (they were already almost identical)

-MAF Limit and Engine Load Limit set to STI value, Re-scaled Engine Load Comp RPM and MP values and imported STI settings

-Re-scaled Base Timing and Timing Advance RPM and Load values and imported STI settings, same for all Timing Comp maps, Timing Comp Per Cylinder (running some negative timing on Cyl A and C), etc.

-Re-scaled AVCS RPM and Load values and adapted STI settings (this was tricky as this map has much less space than on the STI ecu)

-Requested Torque and Target Throttle Plate values adapted to STI settings

-Rev limit set to 7000 and imported STI Idle Speed values

-MPS, Closed Loop, Injector, Tip-in Enrichment, Warm-up Enrichment, A/F Learning and Miscellaneous Scalings/Thresholds values remain unchanged

 

We also adjusted the MAF scaling to get the A/F Learning within +/- .2 The throttle and torque changes made the car more responsive and it is much smoother overall. I am really happy and it's like driving a new (properly tuned) car.

Have you logged some pulls in different gears and starting from different RPMs to verify that the boost control works like it should? I'm a little suspicious of using all of the STI's boost control configuration, unchanged, with a VF40.

Yep we did a number of logs after making the changes and the boost control works great. It's a little different on our cars since we are running the parallel setup, but on other LGT's it would be important to log to verify the boost control. The good thing is that the settings are from a car with a bigger turbo being used on a car with a smaller turbo. If it were the other way around, I think it would be more of a concern.

Do you have any wot logs in 3rd gear from 2k rpm to redline that you can post?

Edit: Posted map at bottom.

Edit: I pulled these logs since we have made updates to the tune to resolve the issue. I will post some new ones at the bottom.

Edit: Posted map at bottom.

I decided to just post the map rather than posting up individual tables all the time. This map does not use any data from any commercial roms. Although I have learned from them so it's inevitable that a few things are similar, but the fuel/timing/boost control stuff is all 100% my original work. More details about this tune are in the first post.

 

Questions/suggestions are welcome. If you see something that looks really dumb please tell me. I am still trying to learn. Thanks.

 

Note: I set Wastegate Duty Limit to 0 on this map (it is supposed to be 100). I don't want someone flashing this map without knowing what they are doing and blowing up their engine. This map was designed to be used with a 3-port bcs and a mbc and will not work correctly without them. I am providing it free of charge with no warranty for informational purposes. Use it at your own risk.

 

http://www.subyshop.com/Th3Franz Stage2 LGT.hex

how can we get a map like this and make available to Access Port users if they would like to try and run with it???

 

Just curious if this is possible, or better working - easily possible...

 

I am sure some other fellow LGT owners would be thrilled to use it as well

 

 

 

Flavio Zanetti

Boston, MA

It should not be hard for someone with the AP Race Tuner software to create an AP map based on this map. However I do not have that software so I could not help you.

 

Note if you wanted to run this map without the 3-port bcs and mbc it would certainly be possible to do so, however there are many things in the map that are setup specifically for that so it would require some tweaks.

Weitek...thanks for sharing the map.

I have my FMIC tune pretty buttoned down as far as boost control and fueling/timing goes but I would like to see if I could get a little betterthrottle response.

 

Could I just copy over those 2 DBW tables? i do not think those 2 tables effect any other part of the map, but I wanted to get confirmation before I copy it over and test it out.

 

Thanks.

 

BTW...anyone using this map should be using a WB02..the fueling is pretty agressive (11.3 AFR targets on the high end).

No prob. If you decide to use it let me know if you need any help. Or if you have any suggestions to make it work better.

I have my FMIC tune pretty buttoned down as far as boost control and fueling/timing goes but I would like to see if I could get a little betterthrottle response.

 

Could I just copy over those 2 DBW tables? i do not think those 2 tables effect any other part of the map, but I wanted to get confirmation before I copy it over and test it out.

 

Thanks.

 

BTW...anyone using this map should be using a WB02..the fueling is pretty agressive (11.3 AFR targets on the high end).

 

Yep you should be able to move them over without any other modifications. I would also strongly suggest trying out the Tip-in Enrichment stuff if you are still running stock-ish values (you would want to copy over all 5 tables). That helped a lot with smoothing things out.

 

As for the open loop fueling, it all depends on the MAF sensor scaling. On Franz's car those values still run quite rich (A/F sensor goes rich @ ~5psi and sticks there). He has the stock intake with an AVO filter and I haven't messed with the scaling up top at all, so it *should* be safe on other LGT's with the stock intake box, but it's always a good idea to be careful and log things to make sure.

 

Based on how it runs I suspect his AFR is in the high 10's but without a wide band I obviously can't lean it out any further. We are planning to hit the dyno for some tuning once his AVO tmic arrives though. And after that I think I have convinced him to go E85. Muhahahhaa.

Copied over the DBW tables and my car is undrivable...throttle got way too sensitive off idle. If I just lightly touch the gas the RPMs shoot to 4-5K! I can;t even get it to hold 3K or less..regardless of how lightly I get on the gas. I couldn;t even get it out of my driveway..RPMs just shot up too quickly.

 

I think this is on the right track...because it is def more responsive, just way too sensitive off idle.

and then I'll need a clutch and front LSD

But seriously, I love how the car drives now!

 

Hmm does Spec B have a different drive by wire system?

Copied over the DBW tables and my car is undrivable...throttle got way too sensitive off idle. If I just lightly touch the gas the RPMs shoot to 4-5K! I can;t even get it to hold 3K or less..regardless of how lightly I get on the gas. I couldn;t even get it out of my driveway..RPMs just shot up too quickly.

 

I think this is on the right track...because it is def more responsive, just way too sensitive off idle.

 

I'm betting you just copied the main part of the table only.

 

You need these:

 

[Requested Torque (Accelerator Pedal)]
Accelerator Pedal Angle (%)
0	9.94	17.6	27	32.5	38.5	49.1	54.6	62	64.9	68.4	71.8	85.7	92.9	100

[Requested Torque (Accelerator Pedal)]
Engine Speed (RPM)
800
1400
2000
2400
2800
3200
3600
4000
4400
4800
5200
5600
6000
6800
7000

 

[Target Throttle Plate Position (Requested Torque)]
Requested Torque (raw ecu value)
0	25	50	75	100	125	150	175	200	225	250	275	300	325	350	375	400

 

[Target Throttle Plate Position (Requested Torque)]
Engine Speed (RPM)
800
1200
1600
2000
2400
2800
3200
3600
4000
4400
4800
5200
5600
6000
6400
6800

Copied over the DBW tables and my car is undrivable...throttle got way too sensitive off idle. If I just lightly touch the gas the RPMs shoot to 4-5K! I can;t even get it to hold 3K or less..regardless of how lightly I get on the gas. I couldn;t even get it out of my driveway..RPMs just shot up too quickly.

 

I think this is on the right track...because it is def more responsive, just way too sensitive off idle.

 

Did you ever try out the s# table from the newer SI drive variants?

Oh hmm.. if that car has SI drive I haven't looked at one of those roms yet. If you can't get the map right you could post a copy of your map and I'll patch it in for you. If it's a commercial rom or something you don't want to share just blank out those portions of the rom (fuel, timing, etc).

ahh...let me check the tables, I did it quickly and simply copied from th3Franz rom to my rom..

Okay..just checked the tables, I totally messed up. I failed to copy over the target throttle position table.

 

I will give it another shot soon..

Cool. I'll be around if you have any questions.

Flashed it tonight..feels, well, different, not dramatically but enough for me to notice a little better throttle response. Nice simple little upgrade, I like it!

 

I only used the DBW tables since my tip in tables are already modded for the FMIC.

 

Thanks for sharing.

What did you do to tip-in for the FMIC?

I believe MickeyD made some changes to tip in when he developed the basis for my FMIC tune. Since tip-in tuning is beyond my purview I am not sure exactly what changes were made (I never compared it to stock).

 

You could find my ROM here: http://www.romraider.com/forum/topic3870-135.html