Throttle backing off

Hey guys. I?ve been trying to figure out this issue I?m having with my Sonic turbo of and on for a few weeks. It?s backing the throttle off while my foot is hard down. Doesn?t seem to be a rhyme or reason to it that I can see in the logs, but I am pretty new to all this so maybe I?m missing something. I?ll floor it, and it?ll respond for a second and then it chops the throttle itself down to 50% and leaves it there until I get off the gas and back on again. I?m guessing it?s something I?ve done wrong in the tuning, but I can?t figure out what. I can post logs and tune files when I get home later, just wanted to make this post now in case someone already knows what it is from experience. Thanks for any help

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Originally Posted by Derpy Dylan

Hey guys. I?ve been trying to figure out this issue I?m having with my Sonic turbo of and on for a few weeks. It?s backing the throttle off while my foot is hard down. Doesn?t seem to be a rhyme or reason to it that I can see in the logs, but I am pretty new to all this so maybe I?m missing something. I?ll floor it, and it?ll respond for a second and then it chops the throttle itself down to 50% and leaves it there until I get off the gas and back on again. I?m guessing it?s something I?ve done wrong in the tuning, but I can?t figure out what. I can post logs and tune files when I get home later, just wanted to make this post now in case someone already knows what it is from experience. Thanks for any help

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Are you logging torque channels? Depending on mods and tour tune your engine torque may be exceeding your max torque or immediate torque (requested) and the ecu is closing the throttle to keep the actual torque limited. I'm new to all of this but that is the issue I have except mine is pulling timing as the limiter.

I am logging the torque, but it?s not exceeding what I?ve commanded in the tune. I?ve tried using both desired boost and commanded torque to increase the power and I seem to be getting the same result with both.

If you see this fast enough check out goat rope garage he has a live stream and can help. On you tube

FIGURED IT OUT! I?m an idiot lol 😂 it was the ?peak engine torque? parameter. I kept looking right by it for some reason lol

Awesome! Glad it worked out. Happy Friday

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Originally Posted by Derpy Dylan

FIGURED IT OUT! I?m an idiot lol �� it was the ?peak engine torque? parameter. I kept looking right by it for some reason lol

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How much did you have to tweak the table? Were you increasing it to be a certain amount above max at each rpm?

Question for you. Have you looked at or adjusted your desired angle variable camshaft tables at all? I have not yet but got a great tip for mine that I am going to try today. I'm also adjusting my torque tables and polishing up the vve today so hopefully I see some good results

I simply multiplied the stock tables values by 1.5. I have not messed with the cam timing. To be honest I?m a little scared to because I don?t know if it?s possible to change it so much that the pistons hit the valves. All I?ve done at this point is request more boost, increase boost limits, disable DFCO, and enable power enrichment with a target AFR of 12.5-12.7. I?m making almost 180hp as is.

What is the tip? The VVT system is backwards on these cars.

Also messing with VVE or torque is pretty much pointless. Even with every bolt on modification you still have stock heads, intake, cams, etc. Trust me i've spent way too much time on these things. My Cruze with every mod on the market still uses the stock VVE table and is dead nuts on with my wideband.

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Originally Posted by Jeff7577

What is the tip? The VVT system is backwards on these cars.

Also messing with VVE or torque is pretty much pointless. Even with every bolt on modification you still have stock heads, intake, cams, etc. Trust me i've spent way too much time on these things. My Cruze with every mod on the market still uses the stock VVE table and is dead nuts on with my wideband.

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For the variable camshaft adjustment' I copied the high tables over to the medium and low tables on both the intake and exhaust side. I should clarify' I have a Chevy spark that I added a Cruze turbo onto. I also added bigger injectors and a fuel pump. My VVE tables neded to be modified to start and run. The torque tables needed to be adjusted as well or I would exceed the max torque and it would pull significant timing. It's starting to run great but I am only on about 5psi of boost at the moment

if you have access to say a loading dyno where you can test output under steady state accurately, then the intake table retards the cam and the exhaust table advances the cam when numbers increase in magnitude. Usually the cams are moved towards overlap in the middle of the cam table so knowing this you know which way the adjustments are going in terms of +- adjustment.

I have a question for cobaltssoverbooster. I have been looking around for info on basic cam timing for the 1.4l turbo,lobe centers and open and close for in & ex. If I could find these out I believe it would be easier to set them up. I used to drag race Suzuki and Kawasaki bikes that had twin cams and we would move them to make a lot of power any where in the rpm range we wanted. The lobe centers being a very important part of it.

i dont have any cam specs but typically the higher the magnitude of the table value, the intake moves advanced and the exhaust moves retarded which gives more overlap

Thanks with all the things I've read I must have overlooked that. I will write it in my notebook for future reference. I try to write down what is applicable for tuning the 1.4 so I can reference it later.
Jim