Car54

So to continue this after I reduced the size of the pics. The first step the technician took was to remove the muffler and tailpipe. The GM method also called for dropping the tunnel plate and x-pipe. The technician said he did not need to drop the X-pipe. To remove the muffler you have to remove the lower rear fascia. Theta has already covered this in a How-To . To remove it you have to remove the reflectors and the air outlets at the outside edges of the fascia. Here is a picture of the rear with those removed:





The Fascia is held by 2 screws behind each reflector, 2 screws behind the license plate and 2 screws above the exhaust tips. Here is the rear after the fascia is removed:





After removing the connection to the NPP and the clamp for the tail pipe to the x-pipe the muffler can be removed and will look like this:




To remove the line at the transmission the Range Selector Lever must be removed from its stud on the transmission because the line runs between the lever and the transmission. Although the picture is dark you can see the lever has already been removed from the stud:




In this picture the line has already been removed from the Transmission. There is only one bolt in the center of the housing.





The GM document that covers the line installation (3963181) says that you must reposition the "electric differential drive motor assembly" to remove the line. The technician did not say whether he did that but the assembly is in the middle of the left side in this picture:




Once you disconnect the trans line from the transmission and remove this clamp:





You should be able to then remove these tube coolers from their mounting on the differential:




After removing the rest of the fasteners that hold the line in the wheel well and removing he line from the existing rear cooler the line can be pulled out toward the transmission:




Then you can reverse the process. Here is what the line will look like at the rear cooler.









As I mentioned in a previous post, the line that connects to the rear cooler and goes over the rear fender liner (23252366) is about 2 inches too long. It is the only one listed in the parts catalog for 2016 Z51 A8 (YY) and 2016 Z06 A8 (YZ) both with extra capacity cooling (V03). That should mean that the cooler for both the Z51 and Z06 are the same and in fact in the parts catalog there is only one rear cooler listed (23283460) for both 2016 Z51 A8 and Z06 A8 with extra capacity cooling. There are however two fans listed. The larger Z06 fan for YZ only (23267979) and the smaller Z51 fan for YY only (22818943). That sounds like they put the larger Z06 cooler on the Z51 with the smaller fan so it would clear the fender. I don't know that for sure but that is what it looks like from the parts catalog. I also noticed in the Ask Tadge section that Tadge says the new A8 transmission starting in May 2015 (24274892) is the same internally but has capacity to hold more transmission fluid to account for the additional and larger coolers. That would indicate that the pan is larger but I do not know yet what the part number is for that pan.

So..for now the front cooler is installed and working. Total cost including Z06 grill and labor to install the line at the transmission is about $1400. Will the "KIT" be cheaper when it comes out at the end of the summer...maybe? I doubt it.

Next test day is Monday at VIR although it will not be much of a test since overnight lows in low 30's and highs in the upper 50's to low 60's.

bill

Car54

I just finished the two best track days ever. March 21-22 at VIR with Trackdaze. Outside temps ranged from 31 degrees with ice on the cars in the morning to high 50's and low 60's. So how were the transmission temperatures??? Maximum Trans temp in Sport 2 mode was 217 degrees. Max trans temp in Race mode was 230. Max water was 212 degrees, max oil was 273 degrees. I ran 10-12 laps per session. The new trans cooler worked really good. Was all of the 55 degree drop in Trans Temp due to the cooler??? doubtful. I would say a good portion of the drop was the cooler temperatures but I will take it nonetheless. Next test at VIR will be end of June with the NCM at VIR event. And did I have a good laptime??? I beat my previous best by 8 seconds. Unbelievable.

However, upon further review as the ref says....My 2:08 lap may have been a 2:10 lap. The video shows that on lap 8 going thru turn 1, the laptime suddenly goes from 12.9 seconds to 10.9 seconds. The referee put 2 seconds back on the clock and I became one more person with the pdr anomaly.

RapidC84B

Nice work.... I skimmed everything so does the rear cooler work in circuit with the new front cooler?

Also, why go to all the trouble of running the fluid up front if a bigger cooler in the stock location like LG makes seems to work? I like the idea of keeping line runs simple and short and keeping the rear cooler doing it's job.

Car54

The fluid runs from the transmission to the rear cooler, then out of the rear cooler to the front cooler and then back to the transmission. Will the LG rear cooler solve all the problems?? It may but I was not completely sold on that since the larger Z06 rear cooler (in conjunction with the front) did not appear to solve all the Z06 A8 transmission temps. The jury is still out on whether my problem is solved until I run in 90 degree heat at VIR at the end of June. If I am able to survive 12 laps there, then I will be happy.

bill

RapidC84B

VIR is my home track and June/July is always brutal. Good test

RichmondC7

True

Car54

I am reluctant to post this since the work is not complete yet but I will anyway. You will note in earlier posts on this thread that I pointed out the line that runs over the rear wheelhouse to the rear cooler was about 2 inches too long indicating that it was meant for the Z06 cooler and not the C7 A8 Z51. However, since that was the only part number that showed up in the catalog that was what the parts counter sold me. Since I had the car in the shop this week to fix the tire rubbing issue and a couple of others I thought I would check again and sure enough the correct part number now shows up. Where was it before? we will probably never know and it is not installed yet hence my reluctance to post this but I did not want someone to buy the z06 line when there really was another one available. The new and I hope correct part is 23347505 and I have corrected it on the first post in this thread as well.

And what was the transmission temp in 90 degree heat at VIR last week? Running in Race Mode and full auto (no paddles) Max was 241 degrees. Water temp was maxed at 234 and Oil was 282 degrees. I would say the front cooler solves the A8 overheating problem and I beat my previous best laptime by 1.5sec.

Car54

Shifting manually at 5500 will not tax the transmission as much as leaving it in auto and letting it do its thing. I am surprised they are wanting you to use paddles if you were using the 2016 with the front cooler installed.

Car54

I have had just about all the fun I can stand. I noted in post 47 that I was reluctant to post something before the work was complete and now I can tell you why. The part number (23252366) for the line that goes over the rear wheelhouse and connects to the rear cooler did indeed change. It did not change because they shortened it to fit the 2016 Z51 A8 cooler. They changed the part number (23347505) because they incorporated the lines (23287156) immediately preceeding it. So I am still stuck with a transmission line that is 2 inches too long because it was made for the Z06 cooler.

Each time I go to my local chevy dealer and give them a vin for a 2016 Z51 A8 and ask them to bring up a picture and part number for the rear cooler and line they give me a picture of the Z06 cooler and part number for the line that connects to it. I do not have access to a 2016 Z51 A8 to look at so I cannot prove that the cooler is the same as 2015. If the 2016 Z51 A8 cooler is the same size as the Z06 cooler how did GM get it to fit into the smaller Z51 fender?

RPOC7R

I was at Spring Mountain June 29/30 and drove a 2016 Stingray Z51 A8. As instructed, I manually shifted the A8 at 5500 RPM and never experienced any transmission overheating issues.

During the last track session that lasted 17 minutes, I in a Z51 was matched up with three Z06's. The air temperature was 107F. I drove the Z51 hard. According to a susbequent Cosworth Toolbox analysis of the PDR SD card that I used, the maximum transmission oil temperature was 225F. The maximum engine oil temperature was 295F!

Based on my experience, I believe that the second transmission cooler added to the 2016 Z51 A8 may have addressed the transmission overheating issue.

Car54

I think you are correct. The addition of the front cooler on my 2015 z51 A8 dropped the transmission temp 55 degrees using race mode and automatic.

Car54

I have updated the parts list to include the Larger Rear Cooler and Baffle. You will remember the earlier posts about the transmission line that runs over the left rear wheelhouse liner being too long presumably because it was made to fit the larger Z06 cooler which we had been led to believe would not fit. Although I have not installed it yet, I am told by reliable sources that the larger Z06 rear cooler and baffle will fit along with the larger Z06 duct but using the smaller Z51 fan. The parts list in the first post should also be the parts that are on the 2016 Z51 A8 and the 2017 Z51 A8 and should be the final parts list for the "kit". It may be a couple of months before I can get the cooler and baffle installed to be sure so for now proceed at your own risk and I will update this thread when I do the final installation.

bill

Car54

You will remember when I started this thread in January, the intent was to install A8 Cooling Kit....that was supposed to be revealed at various times during the past year. I decided to go out on my own and find the parts and install it myself. I got as far as the rear cooler before I ran into trouble. The line that ran over the rear wheelhouse and connected to the stock 2015 Z51 A8 (small) cooler was too long. That was presumably because it was designed to connect to the larger Z06 cooler but we had no information to tell us that the Z06 rear cooler would fit the Z51 and we had every expectation to believe that it would definitely not fit. A couple of months ago I finally received confirmation from someone at GM that when the 2016 Z51 A8 came along it was designed from the beginning with the front mounted Trans cooler like the Z06 and yes indeed it also was designed with the larger rear Z06 Trans cooler but used the smaller Z51 A8 fan. So this is the rest of the story to get the correct transmission line connected to the correct rear cooler, larger baffle to fit the larger cooler and the stock Z51 fan.

Here is the comparison of the stock 2015 Z51 A8 cooler with the Z06 cooler.




Here is the comparison of the stock 2015 Z51 A8 baffle with the Z06 baffle.





Theta's original instructions of removing the lower rear fascia said that you need to remove both the upper and lower fascia as a unit. I did not do that. I only removed the lower and left the upper in place.

There are bolts behind the license plate and behind the reflectors in the upper part of the lower rear fascia. There are also bolts above the exhaust tips and along the very bottom edge that need to be removed. You also need to remove the two verticle grills that tie the upper fascia to the lower fascia at the outside bottom edge. These can be removed with a plastic trim tool and a pick inserted into the grill. There are tabs at the top edge that can use a plastic trip tool to persuade them to allow you to pull the fascia off.




Now you need to remove the drivers rear quarter panel. Theta has covered this in this thread except he gives the gm method which calls for removing the upper fascia also. I did not do that.

Here is the link. I will use part of his method and part mine:

https://www.corvetteforum.com/forums...er-s-side.html

So here is my method. You will need to remove the fender liner and the fuel tank filler pipe housing. Theta has covered this. Then remove the tail light bezel. Behind the tail light bezel there is a torx head screw that holds the quarter panel.



Next remove all of the screws that hold the upper fascia to the tub. Leave the two outside screws in place for now. To get to the screws you will need to remove the molding that covers them. A plastic trim tool will to the trick. Next you will loosen the passenger side screw that holds the upper fascia but do not remove it. Next remove the drivers side screw. Now carefully push the drivers side upper fascia out about an inch or two. This will reveal the bracket that ties the Quarter Panel (fender) to the upper rear fascia. Do not push the fascia out any further than is necessary to get to the screws holding the bracket. Remove the bracket and you will see two more screws that are holding the quarter panel. Remove those. Now remove all the screws along the top of the quarter panel and the ones along the door jam. There is also one screw at the inside leading edge inside of the wheel house that ties the fender to the rocker panel. After removing all of the screws pull the fender out at the bottom and slide it down to clear the glass lip by the baffle vent and slide it away from the rear fascia. After you have it loose and on the floor. Go back and push the rear fascia back in and put the screw in place to hold it while you replace the cooler.

You are now ready to remove the fan. There are 4 bolts holding it to the cooler and what I would call the fan relay has two plugs that need to be removed before you remove the relay than the fan. You can get to all the bolts that hold the fan and cooler without too much trouble. You will want to disconnect the lines before you remove the cooler. These are the GM quick connect lines. You need to use a pick and remove the retaining spring from each line and then pull the line apart. Sometimes they are hard to separate. I used a small block of wood and a long screwdriver as leverage to gently persuade the lines to pop out. Be ready to catch the fluid that drains out. If you have the new cooler already it will come with plastic covers over the inlets and you can use those to cover the small cooler and keep some of the fluid from draining out.

this is a picture after the cooler has been removed but before the old baffle was removed.



This is a picture of the new Z06 cooler installed :







and with the fan installed




This is a picture of the line installed in the new cooler at the rear.




and at the front edge of the cooler. The lines are behind a bracket that ties the upper rear fascia to the tub and must be removed to install the lines. The bracket also provides for some adjustment to line up the fascia with the quarter panel.



If you are starting from scratch, you will be installing the two lines that go over the rear wheelhouse (part number 23347505) and they are shown above with one of them having an orange wrap protecting it from a screw holding the bracket. You will also be installing the line that connects from the rear cooler to the transmission. I had the dealer install this line at the beginning of this thread.

Before I put the quarter panel and fascia back on the car I put the wheel back on, lowered it back to level, started it and put fluid in until it started dripping out the drain at the front of the transmission pan. I will drive it now and repeat that process to make sure the fluid is at the proper level. I would estimate that I only needed 1/2 quart. If you are starting from scratch and have installed the front cooler as well, you will need a lot more.

So ....the "kit" is installed. It is the same as comes standard on the 2016 Z51 A8 and probably on the 2017 Z51 A8. If you have a 2014 Z51 A6 I do not know if this kit will work for you or not. If you track your 2015 A8 then this is what you will have to do to bring the transmission temperatures down to reasonable levels.

Car54

With lots of help from another forum member AP6954 we have identified several of the part numbers that have changed....I should say he identified them not the royal "we". So, I have updated the parts list in the first post in this thread. I am also attaching illustrations from the parts catalog for most of the parts required. I suggest that before you order the parts you take these illustrations to your parts counter and point to the part you want and check to make sure it is the current and most up to date part number. Thank you very much ap6954 for fixing my mistakes and updating the parts list.

This is the illustration from the parts catalog for the front cooler and lines over the front wheelhouse





This is the illustration from the parts catalog for the line thru the rocker panel and the line over the rear wheelhouse to the rear cooler







This is the illustration from the parts catalog for the line from the rear cooler to the transmission; the rear cooler and the baffle part number.

ap6954

Glad we worked out the changes Bill. I will post an update when I get it all installed. Tear down begins tommorow.

gamo

Thanks guys for all the info. I installed the larger LG cooler and Z06 intakes about six months ago but it hasn't helped much. Even shifting manually at lower rpms it's consistently getting to 270. My last track day the transmission started to leak a little before the last session. They just had to retorque the pan. I have been thinking of installing a 6x6 Setrab fan pack under the diffuser passenger side next to the muffler.I am not sure if it would be enough or if the muffler would throw to much heat. How many days labor did it take to install the cooler up front?
Thanks again, Gamo

Car54

How long did it take??? It took me several weeks working off and on but I am old and slow and wanted to be sure I was attaching everything correctly. I started with the line thru the rocker panel first since the popular wisdom said it could not be done. If I could not do it, then I was abandoning the whole thing but once I got the line inserted in the rocker panel I moved to the front and started working my way back. The hardest part was removing the front bumper because of the clips by the headlight. They do not want to come loose and then when you put the bumper back on it never fits flush at the corner by the headlight. It is like it is a one time use thing and after it comes off it elongates the slot where the bumper fits just enough to prevent it from sitting flush. I suppose you could loosen the bolts holding the bracket and move them enough to take up the slack caused by the initial removal but I was not willing to go thru that hassle right away....maybe much later...when I am even older and slower. AP6954 is starting his demolition today I think and said he would post his efforts so maybe he will have a better estimate of time when he finishes. I am sure he will be faster than me.

gamo

Well, I took the nose off once already when I installed the Z06 grille. The rear bumper and both quarter panels to do the larger cooler and vents. Besides I live in New England and have plenty of time.
I have been stalling\waiting for a positive solution to the trans cooler problem and it seems that you may have solved it. I did eleven track days this year and have to solve this before next season.
Now how about an oil cooler?
I always wondered who buys an Orange Corvette!

Car54

Who buys an orange corvette? Not enough of us apparently since the color does not last long. I want to the university of Texas so in 2006 when Daytona Sunset came out I had to have it and the same when Sunrise came out I had to have it. It is as close as I can get to UT Burnt Orange. I love it. Yours looks good with the black stripe.

The front cooler solved my trans heat issues even without the larger rear z06 cooler but you have to put the larger rear cooler on the car because GM does not have a line to fit the smaller cooler and if you use the line for the larger cooler but keep the small cooler it pushes out the fender liner and causes the tire to rub.

Oil cooler...I have not had a problem with oil temps but others have. I contacted Tom Dewitt about 2 or 3 months ago about his oil cooler. It is a replacement for the stock cooler and mounts at a 45degree angle to the same bolts that hold the front trans cooler. I would rather not replace the stock cooler so I asked him about making his cooler so fluid would run from the stock radiator to his cooler and then to the stock oil cooler. He indicated he would work on it but the last time I checked his website I did not see it. Would this arrangement hinder airflow to the stock radiator? Maybe....but the reduced oil temps could also result in decreased water temps...maybe. I am not a fluid dynamics engineer so don't take my word for it.

Bill

gamo

Yes, yes, and yes. You took the words right out of my mouth.
A second oil cooler that I can cover when not on track. My oil temps get up around 270.
I think that with the LG cooler that have the Z06 lines may fit properly.
My last Vet was a 2009 atomic orange convertible. I had to trade it two years ago after I did my first track day in my brother's grandsport. Now I am hooked, no convertibles on track
Thanks, Dave