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.
Fred thing's have changed since this thread was started.The sonnax work's but a custom tcm tune is even better.You can do everything from reduced TQ management to TQ converter lock.My sonnax is not going back on.It's great for the SC guy's but behind the time's for the Diablo user's.
Will the computer relearn this addition and compensate for it over time returning it back to the original setting? Also I'm running SuperChips and you've mentioned it works well with the SC. Any additional information appreciated
Had mine on for quite awhile Doc.It alway's gave a quicker and a little firmer shift.My pcm never tuned it out.I'm using Diablo but have read where several SC guy's liked it too.For the price it was well worth it.
Originally posted by TooCool:
Had mine on for quite awhile Doc.It alway's gave a quicker and a little firmer shift.My pcm never tuned it out.I'm using Diablo but have read where several SC guy's liked it too.For the price it was well worth it.
Manipulating the MAP sensor voltage (engine tuning) changes Transmission line pressure. This is why as soon as folks start making HP and engine tuning the trans often starts slipping. You don't hear about the trans breaking, it is mostly clutch slip and burning up. Line pressure is regulated to the minimum pressure determined by the engineers to work in a stock configuration. They designed LP to the minimum pressure to reduce what they call parasitic losses to improve gas mileage. LP is very dynamitic and is controlled mainly by MAP/RPM (load)input. As soon as we start tuning using the MAP signal it all goes south generally reducing pressure to a dangerous low. I tried momitoring mine using a AeroForce gage and a 0-300 psig senor and it damaged the sensor within a month. Some of the data I got was as little as 28psig at cruise and generally 160 psig under hard acceleration. IMO,If you tune you need a Line Booster. Transgo booster is a little more sophisticated IMO as it is wired parrallel to the LP sensor (think variable resistor, where the Sonnax is in series with the sensor. I am currently using a Sonnax as it give a consistant offset to the signal which raises the pressure a given amount. OBTW, the 03 TMR delete mod is totally different from LP and again IMO works great. Good luck..
For those interested in monitoring their Line Pressure, this what I have done.
I used a MILLER TOOL 8259 PRESSURE TEST ADAPTER FOR 45RFE/545RFE. This replaces the LP sensor where it bolts to the trans and then the original LP sensor bolts to the adaptor. The adopter also has a 1/8 ipt fitting that a gage can be attached to. I special ordered a 0-300 (0-5vdc) sensor from AeroForce to provide a signal to my AeroForce gage. Unfortunately the sensor broke shortly after install and I now intend to go with a standard gage. The LP pressure is very dynamic and is in constant change. Playing with it some I notice that mpg did go up as LP was dimenished. But the one thing I would like everyone to be aware of is that when the MAP signal is manipulated it affects LP. I would recommend anyone who is tuning to monitor their LP as part of the tuning process. And you guys who are running FI systems might even consider generating a custom signal possibly using throttle position or boost. Good luck...
Mine came in the mail today, the plug on the tranny was pretty stubborn and didn't wanna budge, plus the exhaust was freakin hot so I guess I'll just wait until tomorrow and give it another try.
The plugs can be stubborn shoot some WD40 on it pinch the tab tight and use a flat blade screw driver to gain a little leverage. Don't over do it. Good luck.
That's no kidding. I just got around to installing the one I got from Al and the plug pretty much sucked. Of course I broke off the g-d lock tab. After about 15 minutes prying and pulling I thought I saw the damn thing move. Sure enough, I got a wiggle out of it. Just kept working it and it finally came off. It never dawned on me it was just glued together with 5 years worth of road grime, I thought it was still latched and I was going to break something.
WD40 (or my new miracle spray silicone) is a damn good idea, Greg.
I would'nt.They both are resistor's and do the same thing.There value's are probable differant.The sonnax is easier to install and make's a better connection.
The Transgo resitor is placed parallel to the sensor and provides a progressive offset, where the Sonnax is in series whith the sensor and provides a constant offset. I tried to make a hybred of the two but my LP gage failed so I went with the sonnax Line booster until I can fix the gage.
My fault I was talking about the power wire...lol Disregard
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