IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Auto Tech => Topic started by: TexasT on September 03 2018, 04:51:44 PM
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https://ls1tech.com/forums/automatic-transmission/1884730-how-make-stock-4l60e-survive-high-hp-track.html (https://ls1tech.com/forums/automatic-transmission/1884730-how-make-stock-4l60e-survive-high-hp-track.html)
Was just wondering if any of our people with the newest of the new turboTweak program it yourself computers were willing to share with us their timing strategy at the shift points or if it is even programmable with that system.
It seems as though cutting the timing(as stated in posts #52 & #53)at the shift points a few degrees could help the 2004r live a longer life into the tens or even nine sec runs.
Thanks for the input.
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Quote from that thread. "The transmission would have trouble normally handling 600 ftlbs of torque THROUGH the shift....but by limiting the timing MOMENTARILY and only making say 350 ftlbs at the shift, its much less stress on the parts and then pour the timing right back in."
Buicks make way more torque !!! 200's can take way more that that. BUT if ya don't want to break anything just leave the car alone an drive it. :rock:
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It seems to me that since the 4L60E is electronically shifted it's an easy to cut the timing right before a shift but on the 200R4 the ECM doesn't really know when it will shift so the only strategy is to cut timing a few 100 rpm before the supposed shift RPM and wait for the drop.
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I guess the computer could know when the rpm comes to a certain point in each gear it could cut the timing a bit then pit it back at the bottom of the rpm fall as it accelerates again . Or the change in rpm after it falls a certain amount. I guess I need to look into the parameters of what the computer can do. I'm not even sure.
As far as the 700r4/4l60e strength goes, every one who knows any better, knows the 2004r is a way better design that can take way more power reliably. Especially once the hard parts are upgraded.
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Interesting... .....fortunate ly I need not worry about this for now, as I'm well below the 600 ft/lbs of torque threshold. But I do think the 2004 is a capable trans with the correct calibration and hard parts.
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As for the tuning side of things, the factory ecm's have this nailed down with separate tables for load vs timing. It's not specifically rpm related but they definitely pull timing. If you get a chance to look at an HP tuner log of a stock vehicle going up a hill, it's plain as day on the decrease in timing data vs load to cut down on the heat. The overly rich condition is super evident. I'm no expert but the aftermarket ecu's that I've seen, most if not all of the affordable ecu's don't have this capability. You will see 3 tables, VE, AFR, and Timing with the x and y axis based on rpm and manifold absolute pressure. Tough to cut timing at a shift point on these tables without sacrificing power during the torque peak.
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What about using the nitrous controls to pull timing with a small rpm window during the shift. :player:
In the turbo LS world limiting timing before peak torque and then trickling it back in after is what keeps them alive.
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When you run a 10,000 hp fuel dragster or funny car it makes sense to kill a cylinder or mess with timing for traction or ease the torque on the multi-clutch. 9500 hp will do just fine. Doing this with street/strip 500 hp car will just defeat the idea of going fast and maybe wining. If you cant shake the idea then shift at a higher rpm since the torque starts to drop off. Most people shift too early anyway.
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It was just an idea I saw over at that board while studying up on 4l60e stuff. It seemed to be a viable thing but Jason kinda harpooned the idea as the aftermarket stuff isn't capable just yet. And with the stuff we have not being maxed out I doubt we will see it any time soon. I just know the 2004r isn't a th400/4l80e and can or could take advantage of something to help it live a little longer.
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What about using the nitrous controls to pull timing with a small rpm window during the shift. :player:
In the turbo LS world limiting timing before peak torque and then trickling it back in after is what keeps them alive.
That's pretty sneaky and creative
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It was just an idea I saw over at that board while studying up on 4l60e stuff. It seemed to be a viable thing but Jason kinda harpooned the idea as the aftermarket stuff isn't capable just yet. And with the stuff we have not being maxed out I doubt we will see it any time soon. I just know the 2004r isn't a th400/4l80e and can or could take advantage of something to help it live a little longer.
I didn't say it wasn't capable. I said I'm not capable of doing it
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I see. The way Jason made It sounds was the factory computer has many different tables that it could use and the aftermarket stuff only has the three. I guess I need to study some more so I can understand it too.
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Rich different computer have different feature sets. The pcm that controls the 4l60e trans has advance torque management features for warranty/comfort/etc. Gm has millions in development to be able to do this.
Megasquirt has enough features to keep a racer happy. Like I eluded to, using the pcms nitrous control would allow you to setup the triggers (wot, rpm window) and allow you to pull the timing when the n2o enables, even though your not running nitrous.
Each manufacturer does things a little different, this stuff is simple compared to some of the new stuff. Newer mustangs have like 28 different base timing maps depending on throttle position, load and some other variables, and that’s before you start messing with the variable cam timing.