I've had the Sonnax plug and play line pressure booster on my 04 QC for over a month, and from the driver's seat I give it a x2
inexpensive mod!
Noticeably firmer shifts at WOT, and after a few miles of city and interstate driving, I've noticed firmer shifting at part throttle. No codes and all the tranny lines are dry, so no issues with the increased pressure.
My mods are a CAI and exhaust with SC3815/87 performance tune, and I won't be damned if I got a second gear scratch out of that old heavy girl on a spirited drive down the on ramp. It was her first
.
It will be an interesting drive when I get around to getting a SC3865 and can program the shifting.
I had a stock trans that was slipping with 5psi boost(367rwhp/407rwtq). Installed the line pressure booster. Fifty to sixty percent less slippage under boost after the computer adjusted the line pressure. Lets face it. Our transmission is not that strong. Anything that we can do to help our trans, is worth it. I use the Sonnex Line Pressure Booster with my Sharadon stage III trans.
I have a Sonnax on my Ram. When I go to check out DTCs on my Flashpaq, it will show a code of "Low Line Pressure". I take it that this is not normal and when I just run it the way it came from the factory the code no longer shows. My understanding there is a resistor that boost the line pressure. So is there a way to repair a Sonnax? Or do I really need it since I am running a Superchips 87 octane with SC torque management and so forth?
Jim, the Sonnax uses a resistor inline with the sensor. i don't remember The value but you should be able to read the continutity by measuring end to end. One of the two wires is 5vdc and the other is the signal source connected to the TCM. The LP sensor is a varible resistor (pressure) and varies the 5 vdc indicating the Line Pressure, the Sonnax lowers the signal voltage indicating the LP is lower than it acrually is and the regulator then agjusts to rise the pressure. I'm thinking that the Sonnax is faulty. Good luck....
Originally posted by Redtruck-VA:
Jim, the Sonnax uses a resistor inline with the sensor. i don't remember The value but you should be able to read the continutity by measuring end to end. One of the two wires is 5vdc and the other is the signal source connected to the TCM. The LP sensor is a varible resistor (pressure) and varies the 5 vdc indicating the Line Pressure, the Sonnax lowers the signal voltage indicating the LP is lower than it acrually is and the regulator then agjusts to rise the pressure. I'm thinking that the Sonnax is faulty. Good luck....
Greg - You nailed it! I had time last night to measure voltage and the ohms of the thicker wire (inline resistor line?) and found it with 'zip' on both test. Little wonder it was throwing a code. Now I need to make a decision on going ahead and spending my next 40 or so dollars to replace the Sonnax or going with a trans tune from Flashpaq to adjust the torque management.
Since you are a 08 I would do the SC trans tune. When I get back I'll PM the value of the Sonnax resistor to you and you should beable to repair it and experiment a little. But without a way to measure the LP it is all seat of the pants. I have a Miller test adapter installed on my 03, but have to connect another gage as the AeroForce sensor failed.
Originally posted by HemiCane:
So, I'm a little confused. Does this do the same thing that we can now do with a tuner or is this still a good/cheap mod? I'm running a SC 3865.
Getting ready to order a sonnax lp booster. Do you disconnect the battery before installation? or is that with the TMR delete mod that you disconnect the battery? Is sonnax just simple "plug and play"?
Originally posted by prod646:
Getting ready to order a sonnax lp booster. Do you disconnect the battery before installation? or is that with the TMR delete mod that you disconnect the battery? Is sonnax just simple "plug and play"?
After some extensive road test research, I have concluded and am reasonable sure the torque management on the SuperChips tuner and the Sonnax Line Pressure Booster don't work very well with each other. At least, that is the way it is, in my ride. SuperChips does offer the option of doing a semi “Custom Tune” (I am still without their transmission tune since I am a “Cheap So & So”). After many trial and errors in tweaking the tune in shift points and still discovering the dreaded DTC of “Low Line Pressure”, I finally opted to set my torque management to stock. I left the shift point to the can tune of SuperChips and have romped it through a 1 to 2 shift without fail several times. Oh, whom am I kidding...A sincere number of times, to be absolutely sure the DTC was gone. So, there was and is the problem. While the tune holds the torque management info to stock in my truck, with the Sonnax in place, it still has some good shifts. I think it can do better. Which leads me to this question...In the can tune version from SuperChips torque management, where do they set theirs at? This might be a taboo question and if it is, let me know. I know, after some research, that stock is at 80%. If it seems doable to me to know the difference between stock and SuperChip's percentage. It might be enough for me to push me to spring for their transmission tune.
Originally posted by RockyMtnXpress:
After some extensive road test research, I have concluded and am reasonable sure the torque management on the SuperChips tuner and the Sonnax Line Pressure Booster don't work very well with each other. At least, that is the way it is, in my ride. SuperChips does offer the option of doing a semi “Custom Tune” (I am still without their transmission tune since I am a “Cheap So & So”). After many trial and errors in tweaking the tune in shift points and still discovering the dreaded DTC of “Low Line Pressure”, I finally opted to set my torque management to stock. I left the shift point to the can tune of SuperChips and have romped it through a 1 to 2 shift without fail several times. Oh, whom am I kidding...A sincere number of times, to be absolutely sure the DTC was gone. So, there was and is the problem. While the tune holds the torque management info to stock in my truck, with the Sonnax in place, it still has some good shifts. I think it can do better. Which leads me to this question...In the can tune version from SuperChips torque management, where do they set theirs at? This might be a taboo question and if it is, let me know. I know, after some research, that stock is at 80%. If it seems doable to me to know the difference between stock and SuperChip's percentage. It might be enough for me to push me to spring for their transmission tune.
Jim, I've played with LP some and have never gotten a DTC. My SC doesn't tune the trans at all. But I've done a TMR mod to eliminate torque management. I also use the Sonnax 30lbs booster. Reading my LP gage I get 50 psi at cruise and 170 psi at WOT launches. Generally accelleration gets 100-125 psi. There is a direct relationship between LP and either TB (TPS) position or Gas pedal position. I feel it is TPS sending a signal to the TCM that raises the LP. I believe there maybe a way to manipulate this signal but just haven't figured it out. Good luck..
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