Hi guy's, today I installed the LG Motorsports Transmission Cooler and the Z06 intake vents in my 2015 Z51 A8. The cooler is wider than the stock cooler so that the two cooler lines need to be spread a few inches apart. This was time consuming. You have to straighten some bends and add some bends to get more length. My 2015 had an aluminum stud that stuck out of the tub 1/2" that the cooler would hit. We had to cut that off with a a hack saw and file smooth. I had to bend the upper mount a little to keep the cooler from hitting the tub. No weatherstrip was included with the kit, so I picked some up from the depot. I put a strip Between the cooler and the tub to stop air leakage and rattles, but nothing at the bottom to let water and debris drain. The most important thing I learned from another post is that when filling and checking the fluid level (Dexron HP only) the car must be running, in park, Trans fluid at 95 - 115 degrees. Just sneak out the fill plug with some angled needle nose pliers and squeeze/pump in one quart. Reinstall the fill plug. Warm up the car until the trans temp reads a little over 100 on the dash and with the car running, remove the fluid level screw. let the excess fluid drain, reinstall screw. I did remove all the screws as mentioned in other posts/instructions on the rear bumper except I did not remove the hatch release cable. I pulled the bumper back a few inches and left it on the car. The tail lite trims are the worst to get off. Small nylon pry bars are the best thing to get them to release. Well I hope this helps, sorry no pics.

 

Can you tell me what your trans fluid temps are on average with the new cooler versus the OEM cooler? I'm toying with this upgrade once I install a centrifugal supercharger system.

 

I just did the install yesterday. I do think it will help me for my purpose. My trans only got really hot once (275) during my last session at Watkins glen as my lap times got better. That was leaving the car in auto and letting it shift itself. It went into limp mode fifteen minutes into that last session. My last track day was at Palmer which is a much slower track. I shifted with the paddles manually, but for the most part you can run that track in third. The tranny never went above 255.

 

I installed the same LG cooler a few weeks ago but haven't had the time to do a write-up. My installation went almost identical to the OP's, and I have circled the protruding stud and the supply lines which need to be 'adjusted' in these pictures. My results are listed after the pics...

JV

Before:




After:




Results:

I did two track days back-to-back and although the improvement was relatively minor, it was enough to keep me on the track in some pretty demanding situations.

The first was a Track Nite in America with ambient temp in the mid 80's and high humidity (New Orleans). Three 20 minute sessions with only about 40 minutes cool down time in between. Trans Temp got up to just over 260 in all three sessions, but never any higher. Considering the limited cool down, that's acceptable for me.

The next day I did an all day Open Track Day, and the scheduled sessions got altered drastically. There was supposed to be really bad weather so the entire Novice group was cancelled. The weather turned out fine, and the Intermediate and Advanced groups combined, with a total of only 14 cars. There was also a race group, so we alternated 30 minute sessions at the top and bottom of every hour. That gave me six 30 minute runs with only 30 minutes cool down between sessions, plus an hour for lunch, a real torture test for the car in the same 85 degree heat and high humidity. The trans temp was the same as the day before until near the end of the third session when it got to red line and the shifts began to go haywire. I pitted and let it cool down in the paddock, then drove to get lunch, which helped it to cool further. The afternoon sessions were just about the same as the first two, with tranny temps holding at 260+ for two very hard sessions.

Overall I was satisfied that it was worth the effort, and I'm looking forward to LG coming out with a larger transmission oil pan soon. With an additional 4 qts, that will really keep the temps down.

JV

 

I have the trans pan for the 2014 it does work on the temps. Never gotten nothing from LG that didn't really help in the car. Great guys also to help you at LG....

I will say this when I first got the pan off and looked at the new one I didn't think it would fit at the back of it very little room. But it does fit and looks great also. Robert

 

I just did my first track day once my new LG transmission cooler and high capacity pan was placed. It helped, but is not a solution. I have a z51 2014 with the A6. Without the upgrade I would get 10 minutes for the first track day run and then 5 minutes each subsequent run after if the rest interval was 40-60 minutes. This was at 65 degrees outside temp.


Yesterday I ran with it and got through a 20 minute period with tranny temps only hitting 250 for my first run at 65 degree ambient temp. With 40 minutes of rest I got 15 minutes until the temps hit 275 and the computer took over shifting and asked me to park the car. With 60 minutes of rest I got 18 minutes.


IMHO the stage 2 will get one through the typical 20 minute session if you don't run hard or you are starting with a cool transmission on the first run. Closely spaced sessions still generate too much heat towards the end. I was told (warned?) by the guys at LG that stage 3 is really the only system that kept the transmission cool when their pro was at the wheel. I assume they put out the stage 2 to help us save a little money thinking it would get most of us through the typical HPDE. It really does make a difference, it just doesn't completely solve GM's mess.


I am pondering options now. Settle for 15-18 minutes, trade in the car, or get the stage 3. Or maybe someone can suggest a way to cool off the tranny fluids faster in between runs? Cryo to the pan or cooler?

 

I sure would like to see a picture of the Stage 3 installed (with the original radiator in its new position)

 

Hey guys. Don't waste your money. None of these solutions work. A forum member contacted me about 6 weeks ago and we talked on the phone. He was excited about trying his new LG cooler. I told him it will not solve the problem and that he needs a secondary cooler at the front of the car. Few days later we talked again and he told me the new cooler didn't solve a thing at the track. A week later he traded in his 2015 A8 Z51 for a manual Z06. I know this transmission very well and posted many threads about tracking it. If you want to continue tracking an A8, then get a secondary cooler upfront similar to 2016 style.
My honest recommendation would be to trade in the car for a manual. I know 3 guys who eventually realized that this is the best option in order to continue running at the track (not counting myself). There are many good deals out there now on new or slightly used C7's.

 

When we do the stage III kits on our cars we mount the secondary cooler (the OEM Z51 cooler) under the car and mounted to the rear suspension cradle. It locates just under the leaf spring at the back of the car.

I'll dig and see if I have any pictures of it.

 

It is going to depend on the driver, track, and weather conditions for sure.

We broke it up as a few drag racers just wanted the pans and an AutoX guy would be ok with doing that or a cooler. Some entry level guys would be just fine with the Stage II.

To add to that, it is a modular system too, so you wouldn't be hit with the cost of doing all of it at once if you needed to break it up a bit too.

 

Great. Thanks. I'm doing some mods in that area and want to make sure I leave enough room for the stage 3 radiator, if decide to go that route. (I've already got your stage 2 setup.)

 

Anthony,
Although a picture is preferred, you may be able to answer my question without one. Once mounted, does the OEM radiator cover anything in the red circle?

 

Does the larger transmission cooler do nothing to lower the temperatures? Or is it just not enough to make the difference between overheating or not when on track in a 2015?

I'm looking into a 2016 or 2017 A8 (will also be a daily driver, so M7 is out of the question) and want to know if the larger LG cooler (along with the secondary cooler up front) would be extra cooling insurance to avoid cooking the transmission.

 

The end of my post #4 above gives my track experience with just the larger cooler.

JV

 

So the original OEM unit can be used as a secondary cooler after replacing it with the larger LG model? I'll definitely do that, but I have a few questions. Btw, I have installed coilovers so my leaf spring has been removed.

First, On my car, a '15 Z51 A8, there is an 'L' shaped tab mounted where the red circle is in the above picture. Its made of hard rubber about 8" wide which hangs down about an inch or so, I assume to divert airflow up into the transaxle cooling fins. I can mount the secondary cooler to the transverse member forward of that piece, but I assume that tab needs to remain where it is. Will installation of the cooler directly in front of it affect its purpose?

Next, do I simply splice into the supply or return line for the new LG cooler and run extensions to the OEM (now secondary) cooler? If so, how do I know which is supply and which is return, or does it even matter? Thanks for any help.

JV

 

The 2016 and 2017 comes with a secondary transmission cooler upfront from the factory and will not overheat transmission. GM realized the problem on the 2014 A6 Z51 and 2015 A8 Z51 and fixed the issue on the 2016 Z51 A8.

 

Yes. My understanding from Anthony is that his Stage 3 kit utilizes the OEM radiator, attaches it top and bottom to the leaf spring brackets (in blue) and he supplies all the connection lines. The result is two in line transmission radiators.

 

No...it sits basically right under the rear leaf spring at a slight angle.

 

Exactly.

 

Yes,

When you do the Stage III kit we modify the OEM lines and send those with the kit that have AN bungs welded inline. This allows the trans to pump out, go through the fender cooler, then it splits off and goes to the second cooler, then back to the trans so you have two coolers ran inline. The OEM cooler can accept AN fittings by removing the screw in quick adapters in there stock.

We use a -6 line as a jumper set going to the OEM cooler now mounted under the car.

It will work with our without the leaf spring, but coil overs cars do have a bit more room there of course.