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Thread: More low end torque wanted - best way to achieve this? LNF/Kappa

  1. #1

    More low end torque wanted - best way to achieve this? LNF/Kappa

    I'd like more low end grunt from around 1500 rpm to 4000 rpm. I've already changed my auto upshift/downshift points, making it much more of a sport mode which helped a lot. The car was shifting up to 5th at like 35-40 mph under light load!

    Reading through the archives there seems to be several ways to accomplish this. MALT is already set pretty high.

    Should I adjust all tables just a little bit all at once - DAL, OpTq, and WGDCC? Or one at a time starting with? Any table I'm missing?

    Or should I first try tweaking the Optimum Spark tables, which are still stock and don't place much urgency on lower rpm, lighter load?

    Any insight appreciated! New to this, so feel free to treat me like an idiot.

  2. #2
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    i see no one replied back, I'm not an expert & I don't know what Kappa is. On my Cobalt I improved the low end power, but I ended up bringing everything back to stage settings below 3k, because I was slipping the stock clutch while in gear. I put an aftermarket clutch in. Then I started loosing bearings. Also, I remember reading some people claiming you can loose your piston rings by maxing the low end power out, but this was years ago, maybe there is better knowledge of the motor now.

  3. #3
    Thanks for the reply! Kappa is the Saturn Sky Redline/Pontiac Solstice GXP platform with the 2.0 LNF engine.

    I played around with it a bit as well and pretty much went back to stock at lower rpm. Problem is the sudden turbo spool up, going from mild power one minute to major boost a few seconds later in a very narrow range at low rpm. Plus the motor spins up really fast from 1500 to 3000. Automatic makes it hard to control when and how that burst hits.

    I haven't tried the Optimum Spark Tables yet to see if I can add a bit more urgency at lower rpms. I'll post what I find out.

  4. #4
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    Generally speaking, for the sake of longevity it is better to apply power around 4000 rpm and above.

    But eschewing that advice and just looking to apply power like the LNF was some kind of diesel, you can Max out your MALT, Increase your WGDC%, Increase Desired Airload, Pressure Ratio Max, and a few other things. Also, don't advance the timing too high at low rpms, as that can delay spooling.

  5. #5
    Thanks for the advice. Not a big deal, I just was thinking there should be a bit more grunt in the lower range. Most dyno charts I've seen on the LNF show a lot of torque at 2800 - 4000 rpm with peak torque under 4000. I don't really feel it. Maybe because the engine spins up so fast it's out of that range really quickly.

  6. #6
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    Quote Originally Posted by npaz View Post
    Thanks for the advice. Not a big deal, I just was thinking there should be a bit more grunt in the lower range. Most dyno charts I've seen on the LNF show a lot of torque at 2800 - 4000 rpm with peak torque under 4000. I don't really feel it. Maybe because the engine spins up so fast it's out of that range really quickly.
    As was mentioned, you can get a lot of grunt if you tune it that way. Many don't to save the clutch from slipping, or possible damage to bearings or ring lands. I am all in for max power by 3500rpm in 3rd gear, and 4000rpm for 4th and 5th gear. The GMPP clutch I just broke in seems to handle it (but my older stock clutch would not). I don't put artificial limitations for first or 2nd, as it passes by so quickly I don't worry about it (other than modulating my right foot for tire spin). That is just my preference. I use almost completely the gearXrpm torque limiting table to achieve this. Very effective IMHO, allowing you to set MALT and DAL to get maximum air flow at all times and not tune the torque curve with them. I am sure many do it differently though.

    But you can get all you want with enough boost and ignition timing to create a torque "spike" around 3500 rpm if you want (as opposed to a torque "ramp" that is easier on the clutch/bearings/pistons). I have seen plenty of dyno's that show just how quickly you can spool the stock turbo on these cars if you want to max that out for low end power. But there are many tables that can limit and soften that. Probably 4-5 of them can reduce that low end punch.

  7. #7
    Interesting! Never thought of using that map. Tune I have has RPM vs Gear all at 100, using the DAL and WGDC for control. What is up with the 0-1-2-4-5-6-7 Gears?

    MALT hits at 100/2500 which is probably before much is going on anyway.

    Is your Optimum Engine Torque map close to stock or modified as well?
    Last edited by npaz; 09-15-2017 at 01:36 AM.

  8. #8
    Senior Tuner cobaltssoverbooster's Avatar
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    if i remember right....
    0 is neutral
    1 is reverse
    2,3,4,5,6,7 are all forward gears (although 2-6 are only used since its a 5 speed)

    you can check this by logging current gear. might have to drive to get it to report the current gear in manual transmissions but auto-magic transmissions can display demanded gear without driving because of solenoid signal wire feeds.
    2000 Ford Mustang - Top Sportsman

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    Quote Originally Posted by npaz View Post
    Interesting! Never thought of using that map. Tune I have has RPM vs Gear all at 100, using the DAL and WGDC for control. What is up with the 0-1-2-4-5-6-7 Gears?

    MALT hits at 100/2500 which is probably before much is going on anyway.

    Is your Optimum Engine Torque map close to stock or modified as well?
    Not sure which version of HPT you are on but I have 0,1,2,3,4,5,7. In that 1-5 are the forward 1-5 gears. I put 1,2 at 100%, and then tune the other three forward gears. I tune third gear to be 100% in that table by 3500 rpm, along with using DAL and WGDC. MALT always 100% at all rpm in this style of tune.

    If I did not tune the gears independently, I noticed when I had 3rd gear just where I wanted it for ramp in of torque between 2000 and 4000 rpm, I would see more than I wanted in 4th and 5th down low and even up to 4500 rpm boost would over shoot compared to third. Also, I wanted to be able to go WOT in 5th gear at 2500rpm and not feel like it was going t boost 25+ psi and break something, so you can tune that down quite a bit and use the low end torque of 4th and 5th at WOT without worry.

    My optimum torque is stock. It is one of those tables I am sure the real tuners like cobaltssoverbooster might use, but I don't touch that one.

    My optimum spark I tried many variation and like the "shape" of the stock map (shape of optimum-main spark), but thought it was a little "lazy" in urgency. So I just tuned that by using a multiplier of 1.1 or 1.2 for example to optimum-main spark before adding back in my main spark advance. Seems to wake things up nicely and maintain the power delivery response that allowed me to modulate the throttle well still at part throttle out of turns for example.

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    Quote Originally Posted by npaz View Post
    Interesting! Never thought of using that map. Tune I have has RPM vs Gear all at 100, using the DAL and WGDC for control. What is up with the 0-1-2-4-5-6-7 Gears?

    MALT hits at 100/2500 which is probably before much is going on anyway.

    Is your Optimum Engine Torque map close to stock or modified as well?

    The Kappas have a different RPM vs Gear table than the FWD Cobalt and HHR. The FWD cars get a full RPM range for limitation, whereas the Kappa is all set to 100% anyways, but only goes up to like 4000 rpm from what I remember.

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    Learn to tune Optimum Spark, and make sure you turn off torque limiting in the transmission settings.

  12. #12
    Senior Tuner cobaltssoverbooster's Avatar
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    That sounds familiar mike. 7 gear reverse 0 p/n ?

  13. #13
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    Yes CSSOB