NTMD8R

Yes, Tom, I am waiting for some feedback... re the TOC/EOC kit.(32-TO)

atljar

Ditto. On the fence. Either all coolant or oil/coolant. I really want to see some track results and if they come back positive I'm a buyer

X25

Thanks for your input, Tom. Is the coolant only kit less restrictive than the dual cooler kits? How does it compare to the OEM aux cooler? What I ultimately would love to get is same air flow as OEM through both AUX and main radiators, but this time AUX cooler does a better job/use (heat exchange) of the same air : )

0Tom@Dewitt

To be clear, we're talking about air restriction....and the answer is no. It's more restrictive because it is smaller.

The GMPP/Aux has 123 sq in of surface and the 32-C7AUX has 183 Sq In.

Below is an image with the GMPP/Aux laying on top of the combo cooler and the red box is our single cooler Aux.cooler to help understand the sizes and restrictions. The GMPP is very open with 3/8" tall fin. I can see why GM did not vent the bottom with this cooler as too much air would have taken this path.

LagunaSecaZ06

I got it Thursday night and I'm installing it today. I'll take pictures to document the process. Thanks!!

LagunaSecaZ06

Install is going fine so far. Thanks Tom!!!

I am trying to do it without make a mess with the coolant. Here are some picts. I am going to start cutting the plastic to make it fit. Keep in mind my car is a M7 2016 Z06/Z07 that I added the GMPP aux radiator to, so my cutting may be different to a 2017+ Z06 that had the Aux radiator from the factory. Pro-tip, wear eye protection. When laying on your back, dirt and bug guts fall on your head when removing parts. Oh, and I will have to remove the hose "clamp" for a longer piece, put temporarily this makes the job easier and cleaner.

0Tom@Dewitt

Watch out for the SC HX when cutting! The wrong angle of the blade and you could poke a hole in it.

'

MSR

Count me in the group of folk who are waiting to see documented results. Thanks!

-michael

LagunaSecaZ06

Tom,

I used a scissors and it was really easy to get a clean cut. I also did not have to worry about cutting the radiator with this method. The heat shield did not work for me, even though I got it installed. I installed my GMPP Aux radiator about 1/4" cockeyed(didn't realize it till doing this install). This caused the left hand fitting to contact the heat shield. This would have been a rattle point. I therefore removed the heat shield. This is not a design issue on your part, it is an install issue on my part.

Thanks,

Mike














I was able to get it installed but had to delete.


I used your radiator for my template to cut. I should have no leaks on the leading edge. The back side is open.

LagunaSecaZ06

Here are two quick video of the installed Dewit Aux radiator. I haveto put the plastics back on and take it for a test drive. It does happen to be pretty cool today, about 73*. It was over 100* on Monday-Wednesday of this past week.

JCSIII

Any idea how much extra engine oil to fill the 32-TO trans/engine oil kit will require to fill the system?

Same procedure to check oil fill as stock? Run up to temperature wait 15min and check oil level?

0Tom@Dewitt

This is a problem. You will a ton of air escaping thru the back and very little will go through the aux or anywhere for that matter. Everything takes the path of least resistance and here you have none. I see where the shroud is gone where we wanted to rivet the baffle in, I would fab up some add on tabs for mounting and get that thing back in there. For normal driving you'll probably be fine but for a real load test this isn't going to tell us much.

When the baffle is sitting in there right, you should have this small little triangle gap left over. (Which you can fill if you like)

pretty good temperature drops though especially with no airflow

LagunaSecaZ06

I hear ya Tom. I do see that the air can escape out the bottom sides. For the GMPP Aux radiator, I did not use the foam piece that comes from GM and it worked pretty good.

I buttoned it back up so I can drive it. I do have a Z07 package so I have the extra bottom piece sealing it. Let see what happens. I think this will be OK.

I have now idled the car on off, a few times, and oil temp seems to stay low at about 150* even though the coolant is running at 185* Normally at idle the coolant would be around 205* and oil would be a similar temp. Today also happens to be pretty cool 75* so maybe that is helping as well.

I'll drive it in a bit and report back. Still cleaning up the garage. Thanks again.

0Tom@Dewitt

Can you spot the triangle gap?​​​​​​​

LagunaSecaZ06

Tom, you have a winner. Period. Great job and thanks!!!
Guys with manual transmission Z06s, this should be the first modification along with a low temp thermostat. Send Tom $699. Install it and enjoy not having timing pulled. Done.

I am not getting paid by Tom, and in fact, I paid to be the first/beta tester. I will schedule a track day ASAP and use the PDR to document it. Again, just buy it. Dewitt 32-C7Aux.

I just got back from a test drive. My car is a 2016 manual and I had installed a GMPP Aux radiator two years ago. I also have the Dewitt 57MM radiator and an LMR housing with a Lingenfelter 174* thermostat. While it is a cool day at 80*, my car ran a coolant temp of 185* while cruising at 50mph(usually this would be 197-200*). At a stop light the temp would slowly climb to 190-195. I would then hit it off line and after a 1/4 mile, the engine coolant would DROP to 188*. Yes, the temp would drop as I hit it off the line and got some good airflow. This would never happen before. The temps would always creep up from 200* to 210-215* and take a while to drop after cruising at 70mph for a mile. The oil temp seemed to stabilize at 205* after about 4 pulls from a dead stop. Even though I had the traction control on, in Track mode, once hooked up the car would spin the tires. This was really easy to do. Previously the car seemed to loose power and I would try a lot harder to get the same effect.

I have owned 4 cars that I tracked. The first two were Mustangs and naturally aspirated (1993 and 2001 Cobra) I would put on the biggest radiator made, a 160* thermostat and under drive pulleys. This combo always worked great. My 2013 ZL1 I documented a Ron Davis radiator at Thunderhill here. I have a basic premise; go with the best mod available that you can afford. For supercharged cars, cooling should always be first. You might as well keep it as cool as possible to avoid timing from being pulled. I would recommend doing the Dewitt Aux radiator before upgrading the main radiator. The main radiator is stacked behind the heat exchanger and the A/C condenser. This is a very compromised design and can only be fixed with the very expensive GSPEED/LG set up. If you have the coin, then go GSPEED/LG. I only track 8-12 times a year and half the time is at Laguna Seca which is always cool. Below is a video with coolant temps, timing, IAT and knock retard, logged in real time (obviously without the new Dewitt Aux radiator). Even with an ambient temp of 59* the coolant was 212* and oil 253* at the end of the session, while chasing a 911 Turbo S. My goal is to keep the car as cool as possible to stop it from pulling timing. 911 GT3s typically run even better than 911 Turbos at the track. I want every advantage I can get.


To sum up, I am like you guys. I want to see proof before I drop $699. Well, there is no way to make a bigger Aux radiator that will fit. (IMHO). The install was straightforward and you don't really need instructions. I only had to replace one hose and Tom includes it. So that's that. Just buy it.

For the Automatic guys. I don't know what to recommend.

BrunoTheMellow

You can make a bigger aux radiator fit. You really can. The problem is cost. $700 is cheap for a direct fit kit. Tom can build you a radiator that fills every square inch of that space. But it will be much more.

BrunoTheMellow

That's not a heat shield. That's there to seal the cavity. You need it or else you're letting a LOT of air through. Just stick a little tiny piece of weather striping or foam between the fitting and shield.

X25

Thanks for the update, LagunaSecaZ06. Looking forward to your results at the track. I have to say, though, your temps of 212 degrees F coolant and 250 degrees F oil are already perfect. At around 80-85 degrees F ambient and 2300 ft elevation, I hit 234 degrees F coolant and 280 degrees F oil in 40 minute session with traffic at times ('19 Z06 with larger Auto Z06 radiator).

BKorsaire

waiting the comments ...you can count me, TOC/EOC

0Tom@Dewitt

Actually it was designed to be both, seal and shield. I think he could just add some tabs or pieces to fix the one he has. In fact if he mocks up something out of aluminum and send it to me I'll weld it together for free.