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Thread: LSJ TVS 2.8" Tuning Help

  1. #1
    Tuner csementuh's Avatar
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    LSJ TVS 2.8" Tuning Help

    LSJ TVS 2.8" Tuning Help

    Hello, well I'm running a TVS 2.8" setup on my 2007 Cobalt SS LSJ engine. I am looking for a little feedback concerning the tune I've worked out so far. I ran the setup with the stock 80mm TVS pulley and it seemed strong. I was running the timing tables that I used to run on my 2.7" M62 setup that another tuner tuned for me a couple of years ago. Now I believe I've had to take out soo much timing that the 2.8" setup almost doesn't feel much stronger than the 80mm pulley. I am trying to get pointers and/or help to maximize the tune for this 2.8" setup. I want a strong setup, yet reliable enough to DD.

    The pertinent performance mods are... TVS 1320 w/ 80mm, 80's w/ fuel pump rewire, ZZP S3 H/E, dual pass w/ option B, RAW 3" intake, Full 3" exhaust.

    In the tune I used the 80's data from the injector table floating around on the forum, Dynamic Airflow disable low, MAF only, LTFT is disabled, DFCO is disabled (although the car will still seem to hit DFCO when driving?). The high octance timing table is copied to the low octane table. Once I get timing dialed in I will subtract 4 degrees from the low octane table and run it. Once the whole tune is dialed in I will re-enable the LTFT and DFCO.

    I was using a histogram to record MAF AFR error using my wideband, VE AFR error, and the Timing KR histogram to adjust the tune. I am not sure however if I have the tune looking OK or not now. MY STFT always seem to sway back and forth like crazy no matter how perfectly dialed in my MAF is. Could that simply be a result of the intake giving wacky trims?

    The WOT AFR holds at ~11.7 like is commanded. My biggest concern is my timing table. I feel like I have had to rape it to not hit a ton of knock on this pulley. How can I fix or improve the table?

    Any assistance would be greatly appreciated! I have included my config, tune, and a couple of logs. Thanks!

    EDIT:

    Tune now back to regular HPT version 2.22 and I'm running the stock 80mm pulley. Still can only run about 15-16* of timing.
    Last edited by csementuh; 07-13-2010 at 03:06 PM.

  2. #2
    Advanced Tuner Japeatr's Avatar
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    cory, pump gas or E85?

    384whp/303wtq
    Built 2.0LSJ: TVS w/2.6, 1000cc, Stage 2 cams, custom fuel system, E85, Dual Pass, 3"intake, 3" Catless exhaust, CIA midlength Header

  3. #3
    Advanced Tuner Japeatr's Avatar
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    i get an error when tryin to open your file.

    "Unable to open file. Index was Outside bounds of the array"

    384whp/303wtq
    Built 2.0LSJ: TVS w/2.6, 1000cc, Stage 2 cams, custom fuel system, E85, Dual Pass, 3"intake, 3" Catless exhaust, CIA midlength Header

  4. #4
    Tuner csementuh's Avatar
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    Vaughn, I'd love to run E85, but sadly all I have around is 93 octane pump gas. I'm sure the E85 would really help my timing situation. There is 1 station around, about 15 miles away that has E85, but it's the opposite way of everywhere I normally go. I don't believe that 80's on E85 will support a 2.8" pulley anyways without a return style fuel system... I reallllly don't want to run meth either. I'm willing to give up that little extra meth would help for now..

    The error is caused because the tune was made on the 2.23 BETA version of HPT. I'm not sure if there is an easy way to revert the tune file back to 2.22?

    Thanks!
    Last edited by csementuh; 06-29-2010 at 09:10 PM.

  5. #5
    Advanced Tuner Japeatr's Avatar
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    Ill email support. Currently working in Thailand, but i have some time to kill.

    384whp/303wtq
    Built 2.0LSJ: TVS w/2.6, 1000cc, Stage 2 cams, custom fuel system, E85, Dual Pass, 3"intake, 3" Catless exhaust, CIA midlength Header

  6. #6
    Tuner csementuh's Avatar
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    Quote Originally Posted by Japeatr View Post
    Ill email support. Currently working in Thailand, but i have some time to kill.
    Thank you! I'd appreciate it. Hope you're enjoying the business trip!
    Last edited by csementuh; 06-29-2010 at 09:20 PM.

  7. #7
    Holy knock. When dropping pulleys you have to lower your timing for the most part without using e85/meth.

    I looked at your timing tables and you need to smooth them out. You will want to increase timing while going up your powerband and make it good and smooth. You have a spot where it increases to 16 suddenly and then drops suddenly to 12 right after at around 4000 rpms.

    Keep the bottom right of your timing table at 12 and smooth it out below. You can use the 3d map to see how its looking. Then start adding timing to it till you knock.

    Good luck man.
    E-85 279.5whp/258tq

  8. #8
    Advanced Tuner Japeatr's Avatar
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    downloaded 2.23 so i could help ya Cory.

    384whp/303wtq
    Built 2.0LSJ: TVS w/2.6, 1000cc, Stage 2 cams, custom fuel system, E85, Dual Pass, 3"intake, 3" Catless exhaust, CIA midlength Header

  9. #9
    TVS cars LOVE octane, Your gonna need something to up ur 93. Meth done right can be a gamewinner. I saw AWESOME results with a 220 psi pump on a 5gph nozzle. With a tvs you might even wanna try running a 7gph.

  10. #10
    Tuner csementuh's Avatar
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    Thanks for the input guys. I don't want to go with meth as it seems to be a PITA. If anything eventually I may run E85. Will E85 run OK on 80's and a 2.8 or will I run out of injector?

    I will try to update the timing table. is it as easy as lowering the bottom right of the table to 12, and then using the smoothing functions on the rest of the table? Where should I stop or end the '12' section? Does that mean that I will only be running 12 degress total? Am I losing significant power by having to lower the timing this much? Better to stick with the stock TVS pulley and run more timing? I thought I read that best torque on an LSJ was ~24 degrees?

    Assistance is appreciated!
    Last edited by csementuh; 06-30-2010 at 01:44 AM.

  11. #11
    Advanced Tuner Japeatr's Avatar
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    how is your idle AFR?

    384whp/303wtq
    Built 2.0LSJ: TVS w/2.6, 1000cc, Stage 2 cams, custom fuel system, E85, Dual Pass, 3"intake, 3" Catless exhaust, CIA midlength Header

  12. #12
    Tuner csementuh's Avatar
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    Quote Originally Posted by Japeatr View Post
    how is your idle AFR?
    My idle AFR stabilizes to around 14.7 after warmup. Before then it will run super rich 8.x-10.x until things warm up. I'm no master tuner, so I think it looks OK once the car hits closed loop, but I'm not sure since my STFT fluctuates so much. I hit the MAF cells at idle and dialed those in, and it helped a bit, but I'd still like to know how to adjust the open loop idle AFR settings better.

  13. #13
    Poor little car...

    Yea your timing needs work

  14. #14
    Tuner csementuh's Avatar
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    Quote Originally Posted by elite_cyborg View Post
    Poor little car...

    Yea your timing needs work
    Why's it soo poor lol? Give me some help so I can make it run good.

  15. #15
    Tuner csementuh's Avatar
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    Anyone know of any good timing tutorials? I've been searching a ton and I never found anything decent.

  16. #16
    Quote Originally Posted by csementuh View Post
    Why's it soo poor lol? Give me some help so I can make it run good.
    the amount of knock you had. lol

    Not sure what your timing table looked like but from the log it needs work.
    I don't like using beta for some reason, always has random problems opening files

  17. #17
    Advanced Tuner Japeatr's Avatar
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    only heard the tried and true, add till it knocks then subtract...

    384whp/303wtq
    Built 2.0LSJ: TVS w/2.6, 1000cc, Stage 2 cams, custom fuel system, E85, Dual Pass, 3"intake, 3" Catless exhaust, CIA midlength Header

  18. #18
    Just some advice, make sure they are smooth, and remeber you can use decimals Too, like .5

  19. #19
    Fix your timing table first off. This is how smooth it needs to look


  20. #20
    Tuner csementuh's Avatar
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    OK. So I looked at other TVS tunes and emulated mine to be more like them. I lowered the full timing to 13 and then smoothed the hell out of the whole thing so it blends pretty nicely. Does this look better? New tune attached in original post...



    Should I start with a different timing table such as a GM Stage 2 table or something?

    So when I drive and log this now, what should I be looking for? What/how do I adjust for when I get knock? Apparently just subtracting out the knock shown on the histogram cause large gaps in the timing table. When I go to add timing in, do I add 1-2 degrees to the whole table or only the top end? A certain range I should be working with? eg rpm x to g/cyl y?

    Is this low 12-13 degree timing killing my car's power? Better to run the 80mm stock pulley and run more timing?

    Thanks!