2008 Trailblazer SS

[oldvettedad]

I always would test thermostats by putting them in a pot of water with the burner on and used a simple thermometer in the water to check opening temps. The guns are new, would never thought of trying that.

[wxo]

I got the aux trans cooler installed last weekend. It's nice to be able to use my welding skills for something useful. I decided to mount the cooler in the center of the radiator to allow as much air as possible to pass unhindered through the A/C condenser and radiator on each side of the cooler. The installation instructions for the B&M Super Cooler suggest using their plastic fasteners that poke through the radiator and tie the cooler directly to it. I didn't like that approach, so I decided to weld some mounting tabs (yellow arrows) onto two rods that serve as grill supports. When the grill support was installed with the mounted cooler, there wasn't much room to spare, but it cleared the condenser and it mounted solidly.



This picture shows the plastic frame installed over the cooler. The frame supplies the mounting points for the headlights and grill.


Tapping into the tranny fluid return line took some research because of the snap-in fittings that GM now uses on the radiator. The fittings are held in with spring clips. I found a new kind of adapter that has a snap-in fitting on one side and a hose barb on the other. I tried all the auto parts in Raleigh I could think of. Finally O'Reilly's came to my rescue and got it to me the same day.

I also learned that GM now has quick disconnects in the fluid line in a convenient place next to the radiator down-tubes on the passenger side. I was able to disconnect the joint, insert the adapter into the female side and attach the hose to the barb and route the hose to the cooler and back. It sounds simple, but turned into a tedious couple of hours getting things to fit right. I'm glad it's done.

I was hoping to get the tranny temperature gauge working before I added the cooler, but that didn't happen. I will get to that as time permits. I'd like to be able to monitor the fluid temp.

[Maverick]

Very clean!! Looks like it belongs there.

[wxo]

Last Thursday I took Smoke to RPM for a dyno tune. Here is the graph of the final run.



Ryan was able to coax 10 extra HP out her to get to 323. Not a spectacular jump, but considering that she's all stock except for the K&N air filter...
The big improvement was in the feel of the shifting. He took 50% of the torque managment out and the shifts are nice and firm but not too firm. Feels just right. Before the tune, downshifting with the gas pedal seemed to take an eternity while the computer thought things over. It's much quicker to get to the lower gears now.

Ryan stated that the torque management cuts back the power significantly when leaving off the line. On our last trip out to Benson dragstrip, I could feel what he described. With traction control off, Smoke just eased off the line with virtually no wheel-spin. I expect the next time she will be leaving a little harder.

I'm still not feeling comfortable about this 4L70's ability to handle the weight of this vehicle in concert with the torque of the LS2. And I know that removing some of the torque management is not helping the situation, but I surely do like how it runs now.

[wxo]

I did some editing of this thread to bring it up to date chronologically.
Here's the time-slip from TRP on 10/08/2011. It was a 75+ degree day in Northern Ohio and we ran hot from the trip from the Chump Car racing at Nelson Ledges.
Smoke was #139 and the rocket in the right lane was considerably faster. Even with giving me a four second head start, he still crossed the line before I did. Either way, I'm pleased with the results.

[wxo]

This was the last post from the Rookie's TBSS thread that was meant for this thread.

Yesterday (Oct 21st), I went with Maverick and his buddy Keith to Concord, NC to his 347's birthplace. On the way, we stopped at Mooresville. Both places are smack in the middle of NASCAR country. There were performance businesses everywhere. We had quite an adventure there, but I'll let Maverick tell the story.
Anyway, I picked up an electric fan kit and an HP Tuner for Smoke. We will be leaving in a few minutes for a short vacation at the beach , so I haven't had an opportunity to check out the goodies yet. Stay tuned...

[wxo]

While Maverick was out scarfing up free motors, I was busy installing the electric fan kit on Smoke.
It's a nice kit from PCMForLess.com. It has quality parts and appears to work well. It is set up to connect into Smoke's ECM. This kit is not for the faint hearted. Pulling apart the connectors to the computer is a bit scary. I had to insert two wires into two different connectors, then the ECM had to be reprogrammed to activate the fans. My only complaint would be that they are louder than I would like. Not a big deal, though.

I was impressed by the size and weight of the viscous fan I removed. I should see some improvement in power and mileage. I'm headed for Atlanta tomorrow, so I'll be monitoring any changes in MPG.

[wxo]

Our trip to Atlanta was not without some drama. I have an UltraGauge that is a glorified trip computer, but can display a selection of engine read-outs. I have selected several including engine temperature and battery voltage. The UltraGauge can also continuously monitor these readings for high and low levels and give an alarm if they are exceeded. Well, on the way, we heard an alarm for "battery voltage too high". The UltraGauge had defaulted to a high reading of 14.9 volts. The displayed voltage was running between 14.9 and 15.2 volts and there were no fans running. We were cruising at 75 MPH. I cut on the headlights and driving lights and the voltage dropped to 14.0 to 14.2 volts..something I consider more normal. We ran for the rest of the trip like this and returned with no further drama. When I got to Atlanta I checked the battery water and had to add a significant amount to each cell, but they were not dry. It is a pain to get to the battery cell covers so I would bet that they have never been checked or topped off from the time Smoke was new.

I had been using this UltraGauge since I got Smoke and it's never alarmed before, so this is something new. Also, to further confuse the issue, if this were really a problem, shouldn't the ECM throw a trouble code and turn on the Engine Check light?

In addition to the electric fans, I had also installed an upgraded battery cable kit from the same company that provided the fan kit. It consists of three cables that parallel the OEM cables. One from the alternator to the battery, one from the engine block to the battery and one from the engine block to the chassis.

I'm also told that from '07 and newer, GM introduced a Power Managment System to further muck up the waters. I don't know yet if this plays a part in the issue or not. I'm still researching...

I've done a lot of reading on the web about normal battery charging voltages and came away with nothing definitive. It would be helpful if I could get an idea of what you guys can tell me about the voltage readings you are seeing on your late model GM vehicles.

[wxo]

I checked the Mitchel's information on the Trailblazer charging system and learned that the ECM monitors the battery voltage and will throw a code when the charging voltage reaches 16 volts for 1 second. So it looks like 15+ volts is within an acceptable range. I'm still wondering why I haven't seen voltage this high for the several months I've owned Smoke. Since we are into fall now, maybe it's outside temperature dependent.

I'm still curious to know if you guys are seeing voltages like this on your vehicles.

[MostMint]

I've only had one car that was overcharging - it was an 87 Camaro. After the first alternator quit charging regularly, I went through several aftermarket alternators with the overcharging problem - from more than one store. It was definitely kicking on the check engine light. Problem was it would only do it when it was hot, so it passed the test at the store. I boycotted the NAPA store in Wadsworth for over 10 years after that incident. Even now I only go there when I have no other choice.

Finally went to the junkyard and bought a used one and the problem stopped.

[wxo]

Well, it appears that the voltages I'm seeing are within specs, so it is now just a curiosity on my part. I'm wondering if 15+ volts will tend to boil away battery water. I will keep a check on that 'til I see some trend. Still in the back of my mind is the question of why has this voltage not been higher than 14.9 volts up 'til now as evidenced by the UltraGauge alarming this weekend?

[AKROVER]

I did quite a bit of research on battery charging when I was trying to minimize generator run time while living in the trailer without an electrical hookup. That was awhile ago, but here is what I remember. Systems that are optimized for battery life charge at only about 13.5 volts. They don't recommend charging conventional batteries above 15 volts although they don't become dangerous until closer to 16. There are some batteries out there (AGM, I think) that can be charged at 16.5. I settled on a charger that put out 14.8. I would have gladly gone a few tenths higher but couldn't find a cheap way to get there. I think automotive systems tend to run on that high end for whatever reason. My van always reads just under 15, if you can believe the gauge. Higher voltages will cause loss of water which is a minor inconvenience. It will also reduce battery life which is a minor cost. Excessive voltage will cause the battery to get hot. It will also increase the evolution of hydrogen gas which can be dangerous. I wouldn't be too concerned about a little over 15, but it would bother me that something changed.

[GMJohnny]

I only have a very little to contribute, but here goes. At work, we have many machines that
need to be maintained. In the over 20 years I have in there, I can only think of one or two
times that we ran into overcharge issues. In those situations, we replaced the alternator and
the problem was solved. We do run into dry battery cells fairly often. Normally this is due to an
old battery. As battery water is very difficult to check on some of these machines, we just don't
check them at regular intervals. We do run into low water in batteries a bunch on electric scissor
lifts. They have a 24 volt system ( 4 6 volt batteries linked together ), but get charged over and
over and over. Every night you plug in a charger that knows when to shut itself off based on the
charge in the battery. Even in these machines, it is rare to have to add water on a machine that
has been on rent for less than one month. If they're out for only a week, we never have to add
water. I can tell you, and we have been told this by the manufacturer of the lifts, that it's best
to put battery acid back in the battery. It's cheap and our local NAPA store carries it. For some
reason, I seem to remember hearing that distilled water is a good second choice, but tap water
is bad for the battery. We have used tap water in the past, which is better than air I'm sure, but
other than minerals in the water that might goof up the cells, I don't know why tap water is bad.

GM

[wxo]

This is all good information, guys. I've been watching the voltage over the last three days while driving around town and have not seen it go over 14.7 volts. I'm becoming more comfortable with it as it is.
My battery is probably original from the factory. I'm wondering if the higher charging voltage may have something to do with the condition of the battery. With this in mind, I found the following interesting info about battery charging:

Battery Charging - Remember you must put back the energy you use immediately. If you don't the battery sulfates and that affects performance and longevity. The alternator is a battery charger. It works well if the battery is not deeply discharged. The alternator tends to overcharge batteries that are very low and the overcharge can damage batteries. In fact an engine starting battery on average has only about 10 deep cycles available when recharged by an alternator. Batteries like to be charged in a certain way, especially when they have been deeply discharged. This type of charging is called 3 step regulated charging. Please note that only special SMART CHARGERS using computer technology can perform 3 step charging techniques. You don't find these types of chargers in parts stores and Wal-Marts. The first step is bulk charging where up to 80% of the battery energy capacity is replaced by the charger at the maximum voltage and current amp rating of the charger. When the battery voltage reaches 14.4 volts this begins the absorption charge step. This is where the voltage is held at a constant 14.4 volts and the current (amps) declines until the battery is 98% charged. Next comes the Float Step. This is a regulated voltage of not more than 13.4 volts and usually less than 1 amp of current. This in time will bring the battery to 100% charged or close to it. The float charge will not boil or heat batteries but will maintain the batteries at 100% readiness and prevent cycling during long term inactivity. Some Gel Cell and AGM batteries may require special settings or chargers.

[oldvettedad]

The following link (and lnks it points to) show a wealth of info about charging. And AGM, GEL and standard lead acid batteries charge and discharge differently. While this is the Deltran site (battery tender), there is another product called Battery Minder which actually has a "de-sulfation" mode which can bring back to life a dead, sulfated battery.

http://batterytender.com/resources/technical-info

Batteryminder

http://www.thebatteryminder.com/12v133a ... -p-29.html

They now also market an "onboard" de sulphater. I haven't tried it, but have read articles about testing it. Seems to work