Luke Posted September 25, 2011 Report Share Posted September 25, 2011 I recently decided to go ahead and have a performance tune done to the computer in my 2006 DTS Lux II. It cost me $300 and I have free re-tunes for life. Conditions: ~65°F with little to no wind. Flat road 3,650 feet elevation My 1/4 mile times: before tune 16.07 @ 96 MPH 7.86s - 0-60 after tune 15.22 @ 103 MPH 7.01s - 0-60 Pretty good gains, I think, but I am going to have some more tuning done soon. I think my tip-in is slow due to my car being a rental car originally. This results in what feels like turbo lag before the power abruptly kicks in. I have the torque management reduced by 40% and I am going to have it further reduced. I am overall pretty happy with these times considering the elevation. I am trying to break into the 14's..... the way Northstars used to be right from the factory!!!! Link to comment Share on other sites More sharing options...
sonjaab Posted September 30, 2011 Report Share Posted September 30, 2011 Who did your PCM burn/tune? I thought there were no aftermarket PCM burn/tunes or performance parts/upgrades for the N-star because GM held all the proprietary (spl) info. from the aftermarket guys ? I would like to put a little more "juice" in my 97 !!!!!!!!!! 93 DeVille-13 Chevy Impala 72 GTO - 77 Triumph Bonneville 84 Z-28 Syracuse NY Link to comment Share on other sites More sharing options...
Luke Posted September 30, 2011 Author Report Share Posted September 30, 2011 I would like to put a little more "juice" in my 97 !!!!!!!!!! Did you mean your 07? Your profile says 2007 DTS. If this is so, you can program the computer. Before 2006, it isn't easy to get an computer tune but it is possible. The 2006+ Northstars used kind of a parts bin computer (same part # as Lucerne and Impala) rather than the Siemens computers of older Northstars. Link to comment Share on other sites More sharing options...
Luke Posted January 22, 2012 Author Report Share Posted January 22, 2012 Wow, I'm surprised how little interest this post garnered since so many are always looking for more power. Anyway, here's an UPDATE! I had a little more work done on my computers. Here's what they did: •Removed ALL torque management •Max downshift points raised by 5 mph •3-4th gear upshift lowered to 40 mph (for in town MPG) These changes have made a huge difference! With the torque management gone, that turbo lag effect is gone. I can actually chirp a tire now. By raising the downshift points 5 mph, the car is much more eager to go. Ever been going 36 and punch the gas and it won't downshift, and just feels doggy? This little adjustment made a huge difference. With passing too! I have not had a chance to get new 1/4 mile times yet but as soon as I do, I will post them here! Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 23, 2012 Report Share Posted January 23, 2012 Thanks for the info, Texas Jim has done his also, and I am sure he will be interested in this info. It is possible that this was just missed, I am surprised that it did not get more attention. I don't recall ever seeing this myself. Please post your 1/4 mile results, Thanks Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
hjb981 Posted January 23, 2012 Report Share Posted January 23, 2012 Interesting to read that so many things can be re-programmed, and good that you are happy with the results! One thing got me curious: What is torque management? Is it what the traction control or Stabilitrak does when it detects wheelspin, or is it something that ragulates initial torque even before there is any wheel spin detected, for softer starts? If it is the latter, does it also apply to earlier Northstars (like my '97 DeVille, for example)? Is this the explanation why theses cars can be so powerful at speed and at the same time so silky-smooth when starting from a stop? Link to comment Share on other sites More sharing options...
Caddyman Posted January 23, 2012 Report Share Posted January 23, 2012 Interesting to read that so many things can be re-programmed, and good that you are happy with the results! One thing got me curious: What is torque management? Is it what the traction control or Stabilitrak does when it detects wheelspin, or is it something that ragulates initial torque even before there is any wheel spin detected, for softer starts? If it is the latter, does it also apply to earlier Northstars (like my '97 DeVille, for example)? Is this the explanation why theses cars can be so powerful at speed and at the same time so silky-smooth when starting from a stop? I believe the torque management is for reducing the engine's power during shifts to reduce the stress on the transmission and to aid in softer shifts. I would, however be concerned about harsh shifting with the 4T80. I'd love to see the new 1/4 mile times. Link to comment Share on other sites More sharing options...
Texas Jim Posted January 23, 2012 Report Share Posted January 23, 2012 I believe the torque management is for reducing the engine's power during shifts to reduce the stress on the transmission and to aid in softer shifts. I would, however be concerned about harsh shifting with the 4T80. I'd love to see the new 1/4 mile times. You are correct about torque management. During a shift... especially at high rpm and large throttle openings ... timing is retarded and fuel delivery is backed off... JUST FOR A SECOND, thus reducing power and making for a smoother shift. About 99 percent of Cadillac drivers will never know this, because they have never "STOOD ON IT" and let it wind up till it shifts at redline. During normal driving, it doesn't really affect things very much. The issue that "I" have, with the newer computer controlled transmissions, is the "WAY" they try to make the shifts so smooth that you don't even feel it shifting. For instance... During the 1 - 2 shift... The bands / clutches for 1st gear start releasing while at the same time the the bands / clutches for 2nd gear start applying. This causes a fair amount of slippage and of course, heat buildup... To minimize the heat, they retard the timing and partially pull fuel, for the second or so that the transmission is actually SHIFTING GEARS.. If you are like me and like to hear the Northstar sing to you at the part of the tach that has the bigger numbers... the torque management causes a very noticeable "PAUSE" ... almost like you let off the gas for a second, every time it shifts gears... All done in the name of smooth operation... so that Grandma will never know when it shifts gears. One thing that can be adjusted in the Transmission controller is the ACTUAL TIME it takes, to shift from one gear to the next. By making it shift QUICKER... you minimize the time that the various clutches and bands are engaging / slipping. Torque management is also adjustable. Line pressure is also adjustable. The max RPM that it shifts to the next gear is also adjustable. The speed at which the torque converter LOCKS UP is also adjustable. The minimum speed for going into 4th gear is also adjustable. The max speed at which it will DOWNSHIFT back to a lower gear is also adjustable. There are many more setting that can be adjusted... I was just giving a few examples. Oh... the engine computer is also adjustable... :D Link to comment Share on other sites More sharing options...
hjb981 Posted January 23, 2012 Report Share Posted January 23, 2012 Ahh, THAT torque management -- I should have realized that. I know very well about that, but for some reason I was stuck thinking it had something to do with taking off from a stop. I was thinking of chirping tires like Luke mentioned, and that led me to think take-off. Luke, did you mean that you can chirp the tires in the 1-2 shift? Anyhow, interesting to read about those parameters being changeable. Personally, I like my torque management the way it is, but that is of course a matter of taste. I perceive the 1-2 up-shift slightly slow at WOT, but I usually try to avoid that anyways. I appreciate the power of the Northstar when passing, and then all the action takes place in second gear most of the time (the only shift is the one going from fourth to second when I push the accelerator, and of course back to fourth once I let it off). There are times when I would like to be able to go into fourth gear at a lower speed, but it is no biggie. Link to comment Share on other sites More sharing options...
Texas Jim Posted January 23, 2012 Report Share Posted January 23, 2012 Ahh, THAT torque management -- I should have realized that. I know very well about that, but for some reason I was stuck thinking it had something to do with taking off from a stop. I was thinking of chirping tires like Luke mentioned, and that led me to think take-off. Luke, did you mean that you can chirp the tires in the 1-2 shift? Anyhow, interesting to read about those parameters being changeable. Personally, I like my torque management the way it is, but that is of course a matter of taste. I perceive the 1-2 up-shift slightly slow at WOT, but I usually try to avoid that anyways. I appreciate the power of the Northstar when passing, and then all the action takes place in second gear most of the time (the only shift is the one going from fourth to second when I push the accelerator, and of course back to fourth once I let it off). There are times when I would like to be able to go into fourth gear at a lower speed, but it is no biggie. Mine goes into 4th at 36MPH.. when using light throttle. I have never intentionally avoided a full throttle upshift... but I don't hesitate to do it if needed... Mine shifts at 6,800 RPM... I did have it at 7000 RPM... but that is just a little bit past the power curve, and the car was actually just a tiny bit slower, shifting at 7000 than at 6800. Mine will chirp the tires at WOT shifts to 2nd. If you are on older asphalt pavement... that has worn very much and is starting to gett a little bit slick... it will do much more than chirp the tires. After holding on to it and fighting torque steer thru 1st gear, while it is spinning the tires...it will spin the tires a fair amount when shifting to 2nd. Sure does surprise the ricer mobiles when you pass them and the tires are spinning a little bit at 40 MPH... But be ready for the front end to try to sometimes jump to the side a little bit when it spins... Link to comment Share on other sites More sharing options...
hjb981 Posted January 23, 2012 Report Share Posted January 23, 2012 Is traction control also disabled, in order to spin the tires that much? Have both of you (Luke and Texas Jim) only modified the shifting behavior and torque management, or have you also had the engines reprogrammed? Link to comment Share on other sites More sharing options...
Texas Jim Posted January 23, 2012 Report Share Posted January 23, 2012 Yes.. TC is off when the wheelspin happens... I keep TC off most of the time... We have also had the engines reprogrammed. I am not sure what all has been done to Luke's engine... On mine.... That's why it shifts at 6800 RPM... and there is no longer a speed limiter on it. Initial timing has also been adjusted.... Total timing has been adjusted... Fuel slopes have been adjusted... Fuel octane tables have been adjusted... Knock sensor sensitivity has been adjusted... Throttle tip in has been adjusted... Throttle "TIP OUT" has been adjusted.. (I really like this) Above 60MPH... when you let off the accelerator... fuel is cut off to the engine, so that you have engine braking like we used to have in older cars. Fuel stays cut off till the car slows to around 52/55 mph. Lots of newer cars have VERY LITTLE engine braking any more. When you let off the gas... they kinda feel like you put it in neutral and are just coasting... Mine doesn't do that... the engine helps slow the car down. The speed where the transmission will downshift back to a lower gear has been adjusted ... Along with numerous other things I can't think of right now.. Link to comment Share on other sites More sharing options...
hjb981 Posted January 23, 2012 Report Share Posted January 23, 2012 OK, that's interesting! Is it correct that the throttle tip out adjustment only determines how quickly you get engine breaking? I thought all fuel-injected engines shut off the fuel completely if the throttle position is 0% (closed) and the engine is being pulled above a certain rpm (something like 1200-1500 rpm) for any extended periods. The tip out behavior should be a short transient, designed to minimize the jolt you could otherwise get if you suddenly let go of the accelerator. Is that correct, or did I get this wrong? Link to comment Share on other sites More sharing options...
Texas Jim Posted January 23, 2012 Report Share Posted January 23, 2012 OK, that's interesting! Is it correct that the throttle tip out adjustment only determines how quickly you get engine breaking? I thought all fuel-injected engines shut off the fuel completely if the throttle position is 0% (closed) and the engine is being pulled above a certain rpm (something like 1200-1500 rpm) for any extended periods. The tip out behavior should be a short transient, designed to minimize the jolt you could otherwise get if you suddenly let go of the accelerator. Is that correct, or did I get this wrong? You are mostly correct about the tip out... A lot of the newer cars that I have driven, in the last 5 or 6 years, have a real long delay between the time you let off of the gas until fuel cutoff happens. Sometimes as much as 10 to 15 seconds. To me... that is too long.. I changed mine to 3 seconds. That way, if I momentarily let off of the gas in a traffic situation and then almost immediately have my foot back on it... it has not yet cut off the fuel, so there is still a smooth transition. A lot of my driving is on multilane freeways, and when coming to an exit... 10 to 15 seconds is entirely too long to wait. At 60+ mph... in 15 seconds, you have covered over 1/4 mile. I drove a new 2012 SRX a few months ago for 3 days. I took a little 400 mile trip in it. Throttle TIP OUT on it was very quick. I liked the way the engine parameters was set up in it. I "DIDN'T" like the way they were setup in my car... thus the reason I changed a lot of them... Link to comment Share on other sites More sharing options...
hjb981 Posted January 24, 2012 Report Share Posted January 24, 2012 Thanks, very interesting to know. I read about torque management, btw. It seems that the Northstars do that for several reasons. During shifting, like you mentioned, but also if you press the accelerator hard from a standstill. So the torque management does include a function for softer starts (not to be confused with traction control, which lowers torque and activates the breaks in the case of wheel spin). I have always wondered how such a powerful car can be so good at not spinning the wheels unintentionally. Now I know. Torque management also reduces the damage on the drive train from abusive use in the case that the driver puts it in gear with a high throttle angle. It will then shut off half of the cylinders (normally it will have a softer approach of retarding spark). Putting the transmission in gear while pushing the gas pedal can still damage the transmission, and should be avoided -- torque management does not eliminate the danger. It only reduces the harm done. Sounds very interesting to be able to change some parameters -- ideally, I would like to have a computer program and an OBD II connector that I could use to change things myself, whenever I wanted. I guess there is no such solution available, though... I could for example think of quicker fuel cut-off at toe out if there is a long delay, and maybe earlier up-shift to overdrive (I would have to try it though, since it also has to work well when driving uphill at speeds close to the shift point). Link to comment Share on other sites More sharing options...
Texas Jim Posted January 24, 2012 Report Share Posted January 24, 2012 Thanks, very interesting to know. I read about torque management, btw. It seems that the Northstars do that for several reasons. During shifting, like you mentioned, but also if you press the accelerator hard from a standstill. So the torque management does include a function for softer starts (not to be confused with traction control, which lowers torque and activates the breaks in the case of wheel spin). I have always wondered how such a powerful car can be so good at not spinning the wheels unintentionally. Now I know. Torque management also reduces the damage on the drive train from abusive use in the case that the driver puts it in gear with a high throttle angle. It will then shut off half of the cylinders (normally it will have a softer approach of retarding spark). Putting the transmission in gear while pushing the gas pedal can still damage the transmission, and should be avoided -- torque management does not eliminate the danger. It only reduces the harm done. Sounds very interesting to be able to change some parameters -- ideally, I would like to have a computer program and an OBD II connector that I could use to change things myself, whenever I wanted. I guess there is no such solution available, though... I could for example think of quicker fuel cut-off at toe out if there is a long delay, and maybe earlier up-shift to overdrive (I would have to try it though, since it also has to work well when driving uphill at speeds close to the shift point). Anyone that drops the transmission into gear at high RPM .. deserves what ever happens to it. This is what I use... It has the OBD II connector and a computer program. http://www.efilive.com/index.php?page=shop.product_details&flypage=flypage_EFILive.tpl&product_id=63&category_id=11&option=com_virtuemart&Itemid=54 At light throttle...Mine will go into overdrive at 36 MPH... At that speed, if you start up a hill, it will shift back to another gear... "IF NEEDED" and then shift back to OD as soon as parameters allow. Link to comment Share on other sites More sharing options...
hjb981 Posted January 24, 2012 Report Share Posted January 24, 2012 Anyone that drops the transmission into gear at high RPM .. deserves what ever happens to it. This is what I use... It has the OBD II connector and a computer program. http://www.efilive.com/index.php?page=shop.product_details&flypage=flypage_EFILive.tpl&product_id=63&category_id=11&option=com_virtuemart&Itemid=54 At light throttle...Mine will go into overdrive at 36 MPH... At that speed, if you start up a hill, it will shift back to another gear... "IF NEEDED" and then shift back to OD as soon as parameters allow. Thanks for the tip, I did not know that you could by something like that . If I ever want to get into reprogramming a car in the future, I know what to get. Link to comment Share on other sites More sharing options...
Texas Jim Posted January 24, 2012 Report Share Posted January 24, 2012 Anyone that drops the transmission into gear at high RPM .. deserves what ever happens to it. This is what I use... It has the OBD II connector and a computer program. http://www.efilive.c...emart&Itemid=54 At light throttle...Mine will go into overdrive at 36 MPH... At that speed, if you start up a hill, it will shift back to another gear... "IF NEEDED" and then shift back to OD as soon as parameters allow. Thanks for the tip, I did not know that you could by something like that . If I ever want to get into reprogramming a car in the future, I know what to get. Be sure to check the list of what cars it works on... It does not work on a lot of older cars and trucks... Link to comment Share on other sites More sharing options...
Luke Posted January 29, 2012 Author Report Share Posted January 29, 2012 I apologize for not replying sooner. Jim and I spoke a while back and discussed some of the parameters to look at. But, We may need to discuss more. I still have not been able to get quarter mile times but will post them as soon as I do. The guy I went to uses EFI Live too. Honestly, I could not find enough information on tip in and out to be able to ask him about it. I have free re-tunes and need to explore this more. The torque management in mine was very intrusive from a stop. It was actually faster to accelerate at 2/3 throttle than it was at WOT. Now, with the torque management removed, it is much faster to accelerate. Before the programs, I was VERY frustrated when I needed to punch it to beet traffic and would irritate people because it just wouldn't accelerate as fast as I needed it to. Especially after my 98 DeVille didn't have this problem as bad. I had the 4th gear upshift changed to 40 mph from the original 45 mph. Figured it may help in town MPG. I'm not sure having it in 4th lower than 40 would help at all in mine with the 3.11 gears. With 3.71, like in Jim's, it would help since the RPM would be higher. Jim, what speed does your torque converter lock up at? Mine was raised to 45 or 50 mph. I'm not sure if this was necessary or not. It doesn't lock up in town at all anymore. With my first tune, I had done a dual 89/91 octane tune. This time, I had them do a 91 octane tune. I would really like to be able to study this and learn exactly what it needs to be and maybe adjust a bit more, if need be. Next time I go, they will be hooking up the wide band to find exactly whet the A/F ratio is and adjust accordingly. This would not have been free though and I was short on money. My shift speed is substantially quicker than stock. At normal driving, it is not noticeable. At WOT, it shifts very quick! Now, I'd say the best thing I did was to have the downshift speeds all raised by 5 mph. May go a bit more next time. Before, if I had to punch it at 36 mph, it would not shift into third and felt very gutless until it wound up. Now, it downshifts and goes like a raped ape! This is for all gears. It gets down and goes a LOT faster for highway passing now as a result. Does anyone know the horsepower and torque curves for a 2006 Y engine? If I could see this, I may move my upshift speeds up a bit more. I think stock was like 5800 rpm and now it is set at 6100 rpm or so. Lastly, some of you may think this is very hard on the transmission. Well, Mark99STS had the original transmission in his STS for years after turbo charging it! I read that he finally had a HD rebuild done but it held up well. Having said that.... if I shell my transmission, I plan to have a heavy duty transmission built with 3.71 gears. The "guru" said that with the lower power curves of the 275 engine, it was actually faster with 3.71 gears that the 300 engine was. Simple computer tune will make the 3.71 gears work in my car. ;-) Link to comment Share on other sites More sharing options...
Texas Jim Posted January 29, 2012 Report Share Posted January 29, 2012 Luke... My DTS will go in 4th gear at 36... My torque converter will lock up at 38 at really light throttle... but of course, will unlock real easy if you give it much gas... Early lockup will save you a little bit of gas, by lowering the RPM's you are running in normal town driving. You can push the button on the center console to turn "OFF" traction control. Stabillatrac will still be on, but TC will be off. It will still start in 1st gear... Tip "OUT" is when it cuts the fuel of to the engine during Deceleration...I have mine set at three seconds... Stock was about 8 seconds... maybe a hair more. You can also tweak the parameters of "WHEN" the ECM tells it to cut fuel. Typically if the AC is on and you are below about 65/70... it will not cut fuel. If AC is OFF... it will cut fuel at about 60... Tip "IN" is how fast the throttle body opens when you step on the gas. If you adjust it TOO MUCH... it will be jerky every time you give it gas, because it is opening the throttle body too quickly and giving it fuel to match the opening. Link to comment Share on other sites More sharing options...
Luke Posted January 29, 2012 Author Report Share Posted January 29, 2012 Thanks Jim. If I could afford EFI Live, I'd buy it and pay you to teach me how to use it. :-) Now, I need to work on my tip in. What's the stock setting? And do you recall where yours is set? When I stomp the pedal, I want that throttle to flop wide open! Thanks for your help on this. I really appreciate it! Link to comment Share on other sites More sharing options...
Texas Jim Posted January 29, 2012 Report Share Posted January 29, 2012 Thanks Jim. If I could afford EFI Live, I'd buy it and pay you to teach me how to use it. :-) Now, I need to work on my tip in. What's the stock setting? And do you recall where yours is set? When I stomp the pedal, I want that throttle to flop wide open! Thanks for your help on this. I really appreciate it! My son is the one who knows how to use it... I am just passing on what I have learned from him... The Northstar don't start really "PULLING GOOD" till after you pass 3000/3500 RPM...or at least mine don't. That's why when you raised the speed that it will change "DOWN" to a lower gear, you saw so much improvement in performance. "NOW" when it downshifts... it is right in the middle of the power band and it's ready to "GO". The Northstar not having much torque is also why my 1/4 mile times suck... It is either a little sluggish off the line...or I get so much wheelspin it still has a poor 60 foot time... I have yet to find a good way to launch it HARD without getting too much wheelspin. I don't remember what the stock tip in is... Just to make sure we are on the same page... when you floor the throttle... it does "FLOP WIDE OPEN"... TIP IN is just the speed at which it opens the first 25%...in relation to the position of your accelerator pedal. If you increase it too much, you will be jerking your neck every time you take off from a light. Too little and it will be kinda sluggish taking off unless you give it more gas. I will have my son look at mine and see where it is set at. I really like how it is set... throttle response is INSTANT but yet it is very controllable on normal takeoff / normal driving and is not JERKY when taking off from a dead stop. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.