bryanlow

iTrader: (10)

So I decided to go with a Setrab unit. Got it used off e-bay for $70. I like the fact that they are pressure tested to 10 bar. Maybe the cxr ones are too, but there's no mention of it on the website. Also, the Setrab brochure has lots of pretty graphs 'n stuff -- Always a plus. And it's made in Sweden so it must be good.


Mounted in front of the LF tire. Fits very nicely, albeit a little close for comfort.



I'm using the Hayden sandwich adapter plate. It uses a bimetal strip to close the bypass valve. It's clear that it's not a true bypass as some oil will always flow through the cooler. The valve just opens up a path of less resistance. Tested on the stovetop, the bypass closes right around 170°. I did a little porting to clean up the transitions and to remove some casting flash but overall its a good unit.


Heat shrink tubing on the braided stainless




Installed. Had to remove the OE manifold brace.

Word of warning about the Hayden adapter: At first I screwed the OE filter back on. At startup I find oil spraying everywhere. There was about 2 quarts of royal purple on the floor before I realized what was happening and could get the thing shut off. As it turns out, the OE filter is too small for the adapter and didn't seal. There is no mention of this in the instructions. A larger diameter filter fixed the problem.

hustler

iTrader: (6)

I have a 13x6 tru-cool and saw 270-290* temps on the track. Matt Andrews ran the FM oil cooler kit in front of the steering rack with a scooper that Wagz and I made and he never went over 200* on the track with 18psi and 100* ambient temps.

bryanlow

iTrader: (10)

Where's your cooler mounted? Our setups are similar so I'll probably have the same temps as you.

When I planned out this install I considered the spot in front of the rack. It looked way too exposed. I didn't have any shrouding or a lower pan. Now that a pan is in place I see just how much room is down there:


In retrospect I probably should have gone with the rx7 unit. Anyways to promote cooling, I've got a 1/4" gap between the bottom of the airdam and the pan, creating sort of a pseudo-splitter:


When I get on the track I'll use longer standoffs for a 1/2" or maybe 1" gap. Might even create a little downforce.:

Brake duct blows directly onto cooler too:


If cooling issues arise, I'll try ducting from this angle:

hustler

iTrader: (6)

seal up that splitter at the air damn...retard. There's no point in using it with the **** install you have now. I saw 280 on the track...time to copy the racecar set-up.

vehicular

iTrader: (3)

Wait, what? Why would it possibly be a good idea to seal it at the air dam? The gap there is simply letting more air in. Frontal area = good. Sealing it all sorts of other places is almost a requirement (under/ to the sides of the ic/rad, etc) but the air dam? If it stuck out past the air dam, then it wouldn't be producing much downforce like it is, but it doesn't, so I don't see an issue.

bryanlow

iTrader: (10)

No way dude. You're just jealous of my mad injineering skilllz.

I still have to make up a piece of L-metal to go under the intercooler. Then just watch the lap records fall by the wayside. LOL

thesnowboarder

iTrader: (15)

i like the way you mounted that, ive gotta turn mine so i know its full of oil and no air now

j_man

From what I see in your picture, you have the hoses mounted the wrong way - you use the lower port as the return one. The return hose should be the connected to the upper port of the cooler - otherwise you'll end up with air pocket inside the cooler. Swap the hoses (easiest at the sandwich side I guess) and make sure the upper port of the cooler is pointing a bit upwards so the oil pushes the air out into the hose.

hustler

iTrader: (6)

What? Surface area does not increase pressure (Bernoulli). If you seal it then you'll have much lower pressure behind the heat exchangers and air will more through them. You want the pressure differential. Now that the racecar is sealed up on the front with only one opening for the radiator and intercooler, its more efficient. If you saw the tiny 14"x1" opening we're using to cool the car in 100* temps in the desert on the track, you'd flip. I was amazed, but aero works.

Splitters produce downforce by moving the air around the car, rather than under it. What is the point in the splitter/mushroom thingy you made if you don't seal it off to move the air?

bryanlow

iTrader: (10)

Of course pressure differential matters. Empirical data will be collected in a number of different configurations:

hustler

iTrader: (6)

have fun doing the research that Bernoulli already took care of for you.

hustler

iTrader: (6)

edit:
This is your marlin:

bryanlow

iTrader: (10)

I took quite a few physics classes in college but many years have passed and i'd be lying if I said I remember anything more than the very basics. So I've taken a quick google refresher and dude, I think you've hacked up Bernoulli's principle pretty badly. I don't pretend to be an aerodynamicist and I don't think you should either.

Bernoulli's principle applies only when a certain set of parameters are met. Namely:

1. fluid flows smoothly
2. fluid flows without any swirls (which are called "eddies")
3. fluid flows everywhere through the pipe (which means there is no "flow separation")
4. fluid has the same density everywhere (it is "incompressible" like water)

As for #'s 1-3: An intercooler then a radiator then a miata engine would cause a little turbulence in the air trying to flow through them.

As for #4: The 200° radiator and 280° oil cooler will have a non-trivial effect on the density of the air flowing through them, not to mention the air flowing around a glowing red hot turbo and downpipe.

Airflow through the front of a car is a fairly complex system. Boiling it down to one scientific principle is a gross oversimplification. While I have no doubt the Bernoulli principle does have some effect somewhere within the system, it's important to remember that not all pressure differentials are due to the bernoulli principle. IMO, most low pressure zones are probably due to turbulent airflow, the front airdam being the classic example.

You are correct sir. I intended it to flow from bottom to top and I guess I mixed up which port was which. It hit me when I was reading your post: Hey, the top hose did get hot first!

About this, I do concur. Mine is not really a splitter. Call it a "scooper" if you like. It is intended to move air that would otherwise go under the car into the engine bay. It also effectively lowers the airdam, creating lower pressure behind it which will facilitate scavenging of hot air. It should also create a vey small amount of downforce via newton's third law, the moving mass of air being the force.
IMO, a true fallacy would be to create ducting to route air that would normally go over the top of the car into the engine bay a' la the headlight scoop or the between-the-turnsignals hole. This forces air into yet does nothing to improve scavenging in the engine bay.

railz

iTrader: (33)

m2cupcar,

where did you get your lines at? they are 1/2 npt correct?

hustler

iTrader: (6)

on Bernoulli:
increasing frontal area will not increase pressure. Changing geometry of the chamber in front of the heat exchangers will increase pressure. I've spoken about it with people on this forum and Andrew Brilliant who's a real aerodynamacist for real racecars.

on the splitter:
I agree with everything you say, but if you don't seal it up at the bumper, air is still going through the nose, around the heat exchangers, and raising pressure on the wrong side of the heat exchangers. All the air that's hitting the bottom half of the bumper, which is half of what the car sees, is going through the seam gaps.

You have great ideas, just execution failure.

m2cupcar

iTrader: (5)

No- hydraulic lines with adapters. Got them from an industrial (hydraulic supply) vendor. Several here have done the same for various braided lines.

I agree with Hustler here- I think there's lots of improvements to make before increasing the air on the front side of the exchangers. I know with race cars, they aim at optimizing the air that is incoming vs. increasing the amount of air and increasing drag.

hustler

iTrader: (6)

It was 103 or some **** like that at the Willow Springs race. On the 450whp miata with a v-mount and a Racing Beat bumper we had the divider for the radiator so high that only 1.5" of air was coming through and the car was running fine on water temps. Have fun increasing frontal area.

bryanlow

iTrader: (10)

Agrreed. Do you think dropping the airdam will lower pressure?

Expound on this.

I will agree that my splitter doesn't work, to which I say it's not a splitter, and once I have L-metal under the intercooler that air shouldn't bypass the heat exchangers.

Oooh, I'm feeling the power of the second-hand knowlege and the anecdotal evidence! In for pics of 450hp miata!

Yes I will thank you. That's the point isn't it?

Seriously though, good discussion. I still think my design will work and this is why:
1. Worst case scenario, air flow under the car is zero sum. What is taken from below the airdam will be exhausted through the engine bay and out the underside of the car.
2. Best case scenario, airflow under the car will be a negative sum. With the pan angled slightly downward, the airdam is effectively lowered. The air in front of the opening is being rammed into the engine bay. A static pressure will be achieved which then acts as a solid barrier. The rest of the air (since it's not being compressed) will need to go elsewhere, like around the sides, or underneath. Everything behind the opening though will act as sort of a diffuser creating low pressure behind it thereby facilitating the scavenging of the engine bay.

Either way, test data should be interesting.

hustler

iTrader: (6)

Yes its bullshit 2nd hand knowledge, but I spent enough time making Canards, sealing the front of the car and moving the splitter forward to compensate for the "under-body wing" which dramatically increased downforce in the rear of the car.
I only have a few pics:

they sealed-up the headlights and scored a noticeable improvement in handlobraesing:




Creating a chamber in front of the heat exchangers, larger than the mouth, with smooth-ish contours will increase pressure.

bryanlow

iTrader: (10)

Bingo. This is what Mr. Bernoulli is talking about. Smaller to larger + smooth airflow = +pressure.

Gonna take some serious cutting + sheetmetal fab to make this:

look anything like this:


Come to think of it, I wonder if this is the design basis for the NACA duct:

Very cool stuff.

I'm trying not to go too overboard although I'm sooo tempted. Don't want to get my **** stolen. Hell, I'm already having trouble convincing people I'm stock even with my blacked out intercooler and stock rims. Then as soon as people hear the 3" enthuza goodness they know something's up...