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Kit Development Setrab Oil Cooler and highest output Spal Fan in the Passenger Cheek
We've been working on putting a Setrab 6 Series 40 Row Pro Line HX in the cheek of the C7.
We had the kit about ready for release, and then we realized there is a larger fan to be used. The larger Spal fan that we fell in love with, flows over quadruple the volume of air per increment of time, with the amount of resistance the cooler and the cheek cavity are likely going to burden the fan.
Assume the static pressure resistance of "15 mm h2o" in the 2 diagrams below. it is 136cfm vs 590cfm... around 4x the air flow. We found this to be important for the people who don't want to cut their nose to their cars yet.
Setrab does not have a housing for this larger fan to be used with their 6x40 cooler, which presented the problem which we then had to solve. It took much longer than we expected, every time we thought we had it solved, a new problem arose. There is not a lot to attach to in the cheek of the C7, so making a kit which is lightweight and yet also stable and strong, was quite the tug of war in conflicting tradeoffs.
To make matters worse, we were originally doing this with the thinner fan which Setrab suggests be used with this cooler. We had the final draft bracket put together for that smaller fan, but then we fell in love with the larger fan once we started studying the flow stats, and then we got greedy.
Fitting the larger fan in was a serious challenge. It was so tedious that we were about to give up and go back to the smaller fan.
I can honestly say, there is no larger Spal fan that could be fit behind the Setrab in the cheek of the c7, and since Spal seem to be the best fans on the planet, I think it can honestly be said that no larger/higher-flowing fan can be fit in the cheek of a C7.
We had to do a lot of careful trimming of the fan to make it clear the brake duct as well as the wheel well, and still keep the fan structurally strong and stable.
As of tonight, we finally came up with a plan that holds the fan and the cooler in a stable fashion, and are ready to put together the finalized bracket now that we figured out how to shape it and how to connect the fan and the Setrab and make it all fit.
We now have to debate whether we CUT the outside bottom mounting bracket off the Setrab, or if we install a plate/pad that keeps the corner of the Setrab from wearing a hole through the front fascia of the car.
We plan to have a headquarters in Florida and also Ohio to install these kits for folks, and also train any shop who wishes to sell these kits. It will require training, the bracket adjustments are full of tradeoffs and learning how to adjust everything takes a lot of time the first time around.
Here are the specs on the fans, the bottom one is the one we went with instead of the one Spal and Setrab normally use on the 6x40 Pro Line Coolers
I'm aware the prototype bracket is anything but beautiful, but now that we know the alignment and that it will work and is strong, we will make a better bracket very shortly.
The cooler we are using is a huge Setrab 640 ProLine Oil cooler. I believe this is the largest oil cooler that can be put into the cheek of a C7 without cutting anything. Even if one did cut things, the constraint is the main frame on one side and then the wheel well liner on the other side, so there really is nowhere else to go. Even though we are keeping the brake duct intact, one might assume there is room to go if the brake duct was removed, but the oil ports and fittings will still hit the frame regardless.
I'm very pleased we have figured out how to get this into the car without having to cut the car, and can put the car back to stock by removing the kit, without a trace it was ever on the car.
The highlighted row above shows the exact cooler we are using. Please take note of the number on the far right. Compare that number to the competitors' kits.
We also look forward to ACS Composites releasing their zr1'esk front end for the rest of the C7 lineup. In the meantime, we have the kit that gets the job done with the stock front end and no cutting needed.
It is possible to add another cooler in front of this one, or behind the fan, if a person really wanted to, but we look forward to demonstrating that sometimes less is more, and the delta (temp difference) between ambient and the HX fluid, is what is most important. Stacking coolers can be detrimental to the overall goal as it kills air flow and reduces delta to the second rear stacked HX.
We will document the testing of this kit in this thread with the larger fan. The smaller fan already had great results, so we are very excited to see how this all unfolds now that we figured out how to make it fit and mount it all in a stable fashion.
Last edited by bbbvettes.com; 05-19-2019 at 11:22 PM.
Here it is in the daylight, and you can start to see how stable the bracket is. The final product bracket will look better and be stronger yet. This prototype bracket was to learn the proper spacing on the fan and the cooler, and the clock angle of the 2, etc.
The way that this kit hangs, defies the way a person's mind assumes it would work... similar to the classic bird beak balance illusion. The heaviest part of the kit is the fan, and the 1,000cfm 25amp fan's heavy motor is actually behind where the majority of the bracket is above.
Cutting the bottom panel to make air flow easier for the HX and fan
It would work on both. The driver's cheek will have the radiator fluid HX on the A8 cars, and the m7 cars could run blower fluid in the driver's side cheek.
I am sorry it has taken us so long to bring these to market, figuring out the bigger fan and other life obstacles have caused large delays. But its finally coming together.
We went back and did more homework in other areas when we found out how common it is for the cars to lose oil pressure from oil starvation.
We were reasearching and talking to all the big names in dry sum systems, seeing if there was a profound solution that needed to be spotlighted more, that we would endorse.
Long story short, there is no simple easy fix to improve the LT dry sump system to prevent the oil starvation.
We were brainstorming to see if it is something we wanted to address, or could address.... and then the irony set in... we found no great solutions for it, but we believe we were preventing it inadvertently with our original plan....
Long story short, we believe that adding oil volume as low as the pan, and on the scavenger line, actually has a benefit to the car...
a bit of a complex topic to visualize... but when the car is running hard and the oil becomes very foamy after the scavenger pump... well that foam forces the rest of the oil levels higher in the car.
This is a good thing... the car can start cold, and the oil is all condensed, and the pistons won't hit the oil, as it will be at the proper height according to where GM wants it.
But, then once the car is running hard, that increased volume of oil which filled the extra added lengths of the large -12 lines to and from the cooler, and also the oil inside the cooler, that oil is all extra oil that the GM system did not normally house before, yet the added oil does not register on the dipstick during the test necessarily... that extra oil is also below the pistons at startup, so its in a safe place, the pistons are in no danger of coming down and slapping the extra oil, which is why overfilling these cars is a negative.
But once the car is run hard, and those added lines and cooler spaces become occupied with foamy oil, that foam displaces the "once dense" oil, and that more dense oil is now up in the tank and in the engine, so odds of oil starvation we believe are greatly reduced.
As mentioned in another thread we started, the reason GM most likely requests racers to add at least an extra half quart of oil before racing is to prevent oil starvation in high G long curves, by bringing the oil levels up to keep the main oil pump fed at all times.
We would love if someone had this engine and a sight glass on the pan and on the dry sump tank, so that we could test our theory that adding volume to the dry sump lines is beneficial.
A friend stopped by today, and we were chatting about the c8. He brought up an interesting point....
"if the c8 can use extra cooling, then all one would have to do is take these coolers off of their c7 upon selling the c7, and then have a new bracket system made up to relocate the cooler and fan to the c8"
I believe he may have been daring us to accomplish this so that people could retrofit their kits.
The more I think about the idea, the more I believe we will try to start with the Setrab 640 and this Spal fan, to enhance c8 cooling for the better, once the car comes along.
Not saying the c8 will have an overheating issue, simply pointing out that extra cooling and lower temps at the track never hurts.
And this way this kit will be a long term investment for folks that they can carry to the next car. Rest assured, if GM has a dry sump tank, the likelihood is 99% they still use the same oval port fittings to-and-from the dry sump.
05-19-2019, 12:56 AM
Kit Development Setrab Oil Cooler and highest output Spal Fan in the Passenger Cheek
