1. We are working on the forum's attachment system. Attachments and avatars will be intermittently affected over the next 24 hours.
    Dismiss Notice

Supercharged Trailblazer 4200 I6

Discussion in 'Engine & Drivetrain' started by bruhaba, Apr 23, 2013.

  1. Mooseman

    Mooseman Moderator

    Messages:
    10,365
    Likes Received:
    4,892
    The PCMs did change after 05, as well as crank reluctor teeth count.

    And guys, please keep the discussion respectful. We're all here for the same reason; to help each other out :thumbsup:
     
    Capote likes this.
  2. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Real easy to figure this out and I hope I'm wrong. Turn your ignition on, take off your intake resonator/tube and have someone press the pedal while you watch the throttle blade.

    No disrespect was ever meant. I just don't see how it would be done in Hptuners. My hope is that I'm missing something.
     
  3. gmcman

    gmcman Well-Known Member

    Messages:
    3,412
    Likes Received:
    710
    Your PCM may have made some small adjustments which could make it feel slower....just a guess.

    I would suggest going with 9lb pulley if possible before a 12, just to see how everything goes.
     
  4. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    I don't understand what you are suggesting by "may have made some small adjustments".

    We'll see how it goes with the boost. I won't get to that for a while yet. Not sure what I'll get for boost.
     
  5. limequat

    limequat Well-Known Member

    Messages:
    378
    Likes Received:
    124
    I always have a speedy throttle after my tunes. I've always assumed it was this table:

    Engine => Torque Management => ETC Limits

    Here's a random log from my Supra. Accelerator% is right on top of Throttle%. This is also a 2006 PCM. The x axis scaling is in 0.2 second increments.

    [​IMG]
     
  6. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Thanks for the post. I guess there is hope somehow...however, I have that table maxed out, always have. Hmmm.
     
  7. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    If you have a chance, Please try logging actual voltage signal from each sensor. There is voodoo magic in the sae tps%.
     
  8. RedRocketZ28

    RedRocketZ28 Well-Known Member

    Messages:
    112
    Likes Received:
    104
    What software are you using to tune this? Sorry if I missed it in your thread. In your scanner does your TPS% go to 100% as soon as you slam the throttle down? I watched your previous videos showing 0-60 runs and throttle response seems normal for a 4.2. The 4.2 is gutless down low IMO and doesn't start making steam until it revs out a bit. Not to mention that supercharger will take a bit of power to spin.
     
  9. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Hp tuners. No, tps takes near 2 seconds to go wot
     
  10. gmcman

    gmcman Well-Known Member

    Messages:
    3,412
    Likes Received:
    710
    I don't know how much or if your PCM will adjust to subsequent driving cycles as far as knock retard etc? What are you using for fuel delivery? Stock? If stock, how much can the stock setup flow to satisfy forced induction?
     
  11. Pittdawg

    Pittdawg Well-Known Member

    Messages:
    538
    Likes Received:
    41
    A proper tune takes care of this. Lower gears (i.e. 410s) and a ported throttle body transforms it into a stump puller.
     
  12. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Changed the crank pulley, sized a new belt and rearranged the location of the tensioner and went for a drive. Looks to be about 12 psi with a stock size small block pulley instead of the underdrive one. No crazy knock reported.

    Who knew 12 psi would be a lot more fun than 5 or 6. I didn't get a chance to tune it properly and really get into it yet but the AFR was spot on at WOT. Airflow was nearing 400 g/s compared with the previous 315 max; stock was 212 I believe.

    Crank pulley broke on me after about 20 minutes of driving; sounded like the engine blew up when I rolled to a stop sign. I took a stupid shortcut and only bolted it through the center without bolting the 3 star pattern to the damper. The underdrive pulley was one piece billet steel and way beefier. This is an AC delco original pulley which is a stamped and welded multipiece. I should have it properly running this week.

    Water injection is on it's way in too. We'll see how long this motor and trans will hang on at this output. Maybe we should start taking bets...
     
    Tiggerr, dmanns67, Mounce and 2 others like this.
  13. Gerbil21

    Gerbil21 Well-Known Member

    Messages:
    833
    Likes Received:
    341
    Any signs of wear on the drive train? Trans Fluid color get dark quick or oil burning?
     
  14. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    no, all looks good. I don't expect it will give warning when something breaks. Probably not a wear out failure but a catastrophic one. Only thing I notice is oil smells like fuel a lot quicker these days but that is common with any boosted richly tuned application. I just change it a bit more frequent.
     
    Tiggerr and BlazingTrails like this.
  15. BlazingTrails

    BlazingTrails Banned

    Messages:
    19,409
    Likes Received:
    10,246
    I think if you upgrade to the pinless billet accumulators, and corvette servo (this is how mine is set up, with (2) hayden 405 coolers) it will help a lot. I would disable torque management (been running mine hard for over a year like this) and just get your shift pressure set to where it feels firm but not too hard and put an aftermarket cooler on there. trans will probably be fine for a while. Just don't break the sunshell up-shifting too hard!

    The shift tables in these truck are horrible to work with smh.....
     
  16. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Thanks. I have the same setup except just one B&M cooler. Also have a boost valve sitting on the shelf. I run some TM below 300ft lb shifts in 1-2 and 2-3 so normal driveability is smooth. Zeroed TM above that with maxed line pressure. It has never felt like it shifts REALLY hard at WOT. Maybe it just can't clamp down hard enough. I'm worried it will break the sunshell but I think that may be inevitable. I guess I've got to rebuild my first tranny sometime or other.
     
    BlazingTrails likes this.
  17. Sparky

    Sparky Moderator

    Messages:
    10,537
    Likes Received:
    5,347
    If it breaks maybe see if there is a way to shoehorn a 4L80E under there.
     
  18. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Round two, fixed the crank pulley; took it out for a spin and the added belt load broke an idler pulley mount. To Be Continued....story of a gearheads life.
     
  19. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    off and running again...need to dial the tune a bunch but did a quick 0-60 uphill on an on ramp Log showed a total of 5.8 seconds and for 0.4 secconds I was stuck at 35mph because the tires were spinning. I think 35 is about when the throttle fully opens.

    Don't know how long this is going to last but it's pretty fun. The normal everyday part throttle acceleration in 2nd gear makes about 10 psi and pulls really hard without making a scene.
     
    Mooseman, dmanns67, Harpo and 3 others like this.
  20. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Trans now slips on 4-3 downshift. If I command 3rd or 4th with hotuners and go wot it doesn't slip. So I'm a bit confused. Kind of indicates to me it might not be smoked clutches or band.

    I'll post a video. I'm not great with auto transmissions maybe someone can help.

     
    Last edited: Jan 3, 2016
  21. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Hit the Atlanta dragstrip in commerce, GA this weekend. It ran a best of 13.9 in the 1/4 at 98. 1/8th time was 8.9. sat in so much traffic to get to the line that each run was .2 faster as the car cooled(3 runs). IAT's were pretty high. This thing is so knock limited on pump gas it barely runs any timing if underhood temps are high.

    It was tough to get it to hook off the line. I have a brand new set of cheap all season 275/45/20's on it. I need to get that water injection in. I've got a feeling 5-10 degrees more timing at WOT will make 75 more hp.

    I was pretty happy with the results. I think mid 13's is a reasonable goal with some more timing and a cool car. 13's is a long way from the ~17.5 @ 81 second factory performance!
     
    Boricua SS, dmanns67 and xavierny25 like this.
  22. Mooseman

    Mooseman Moderator

    Messages:
    10,365
    Likes Received:
    4,892
    When you say "pump gas", do you mean 87 or 91 octane? I'd be running 91 or higher unless your goal is running on regular.

    Still, at least now you can measure the 1/4 mile using a timer instead of a calendar. Not bad at all for a truck.
     
    xavierny25 likes this.
  23. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Pump gas to me has always meant gas you can buy at any corner.... Not race gas. I run 93 because I can get it here. You'd have to be an idiot to run 87 on a supercharged 10.3:1 engine.

    Engine only tolerates ~8 degrees advance at WOT. If I could get that to 15-20 or so with water/meth there is lots of power left in this setup.
     
  24. Mooseman

    Mooseman Moderator

    Messages:
    10,365
    Likes Received:
    4,892
    Cool. Just wondering out loud. Although I would never mod my truck to that level, it's still interesting to see its possibilities and potential.
     
  25. efi-diy

    efi-diy Member

    Messages:
    11
    Likes Received:
    1
    Its been a while - used to post on trailvoy and here - now mostly on the dedicated 4200 engine site.

    On my turbo engine switching from 94 octane pump gas to 100% methanol - we were able to increase the WOT timing under boost close to 18* total - this increased torque output by close to 35% at the same boost/RPM.

    It peaked at 610 lb/ft at 4200 rpm @ 18 psi ( this is on a eddy current chassis dyno).
     
    bruhaba likes this.
  26. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    wow! 610 lb/ft is crazy...so is the 35% delta. Thanks for sharing! I can tell there is power in there with the timing because when the engine is breathing cold air, the couple degrees makes a huge differentce. Same as when it is hot and summer time, feels like a total dog.

    I've been really thinking of running E85...I just don't think I could find the time to properly tune it. I have the tune dialed in well for gas at this point... I haven't carried around my laptop with me for many months.

    Your post motivates me to at least get my meth injection in and see what kind of timing I can run WOT.
     
  27. FearlessAZ

    FearlessAZ Well-Known Member

    Messages:
    124
    Likes Received:
    75
    I gotta say, BEAUTIFUL work. The amount of work put in to all that fab work is amazing. I love it, man. Pure bliss.
     
  28. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Thanks very much!

    A bit of a sad day here...

    I've run this stock engine at 6 and 12 psi for a long time now. Recently, I went to E85 and retuned it. It made a bunch more power, and drove great even in the 100 degree heat here in SC summer. Only downside was the 9mpg...No dyno runs to show the difference, but it tolerated anywhere from 5-10 more degrees timing. Just for reference, the motor has 121K miles on it now. The first 100K it was our summer tow and family vehicle.

    After a few short months on E85, I have a rod knock. Can't say I have much to complain about as this motor owes me nothing at this point with what I have put it through. I daily drive this vehicle and do not go easy on it. Generally redlined every trip I take....that is why I built it.

    Not sure which rod is making the racket, but I performed a cylinder balance test with HPtuners and all are healthy. Pretty sure I caught it early. It was still making good power and there is no smoke, just E85 moonshine [​IMG] coming out the tailpipe.

    I have a spare stock engine here that will go in(22k mi pull which i used for mock up during the build) and I will likely build this one up over time.

    port the blower, finally add the meth injection, oil system mods perhaps, lower compression forged pistons, perhaps stronger rods, ported cylinder head...all on the list one day.
     
    MRRSM, Mooseman, Mounce and 1 other person like this.
  29. Sparky

    Sparky Moderator

    Messages:
    10,537
    Likes Received:
    5,347
    Why do things break?

    To give us an excuse to upgrade them!
     
  30. FearlessAZ

    FearlessAZ Well-Known Member

    Messages:
    124
    Likes Received:
    75
    Sad day indeed!
     
  31. warriorpluto

    warriorpluto Well-Known Member

    Messages:
    194
    Likes Received:
    15
    Any updates?
     
  32. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Update is... Plan changed a little... Haha.

    2wd conversion. I've rebuilt the tranny with lots of goodies and swapped it to 2wd, got an aluminum driveshaft that will have to be shortened for the ss rear. Ripping out the 4wd stuff now.

    Belltech stuff will be going in for a mild drop.

    Then pull the engine and find out what's wrong. If it's oil delivery to the rear rods, I'll mod it somehow as has been suggested by someone around here.

    Started porting the head on the spare motor. I think this is as far as I'll take this engine.

    Meth injection going in. Still thinking if I'll port the blower while I'm at it.

    Finally able to make some progress this week. This is a long list though. So it will be a while.
     
  33. bruhaba

    bruhaba Well-Known Member

    Messages:
    112
    Likes Received:
    114
    Number 3 rod bearing spun. Here it is just pulling the cap.

    IMG_4733.JPG IMG_4732.JPG
     
    Last edited by a moderator: Jan 5, 2017
  34. Nexus1155

    Nexus1155 Well-Known Member

    Messages:
    123
    Likes Received:
    35
    Hey Bruhaba I did not want to start a separate thread for this. I asked you on trailvoy, but never got around to messaging you, but they somehow deleted my account completely?! WHAT?! But if I ever come by SC can I check out your setup.

    I have been going back and forth in between SC and turbo setup, was wondering why you never went with an M62 or M90 supercharger? They use the M62 on the 4.0 Jeeps and it seems to flow enough for 60hp gain? I know our heads flow an amazing amount, but is there any way to decrease package size and reduce the pulley and use the M62 or M90 on these engines and get a decent amount of gains, and not a large amount like you have done for those of us who don't need a beast like you have?
     

Share This Page