Further Lower Under Hood Temps / BAT's

[fortressofcomfort]

OK (series of 2 posts) are ready for reading. (TL;DR do not even attempt to follow, or double up on your Addy dose now).

I'd suggest opening two browser instances... One for following editorial, one for viewing piccys.

OK I'm getting internal server problems (after I download the .zip files and try to expand them I'm getting a "The Compressed (zipped) Folder is invalid or corrupted."

I'm not having any issues via email though. So I will whittle this down from 32 pics to something smaller and work inline here.

Let me define the front "fascia" as the part that hold the Mazda emblem. The front bulkhead is where all the heavy stuff attaches (radiator, condensor, etc). So this "front cowl" that I will describe, and that you will see later, is an actual separate piece that is semi structural and fits between the front fascia and front bulkhead.

OK, 1st pic of relevance: 0001.JPG
- You'll see two sets of vertical slots on each side of your front cowl. Stock, these are the ONLY areas that feed your stock intake system. This theory that air passes through the wide slot in the front fascia (below the Mazda emblem) and feeds the intake air system is false. The wide slot only feeds the condensor and radiator (keep reading).

- 0002.JPG
This is the internal view of what the mating side of the "cross hood air duct" that so many of you have utterly destroyed looks like. This mates DIRECTLY to those funny little vertical slots on the passenger side (see pic 0001.JPG)

- 0004.JPG
This is the "cross hood air duct" in its entirety unmangled. Look closely... you'll see it in approximately the correct left-right positioning just below the intercooler.

- 0006.JPG
This is an "upside down" view of the engine compartment, with the cross hood air duct in its approximate place, with the 2nd piece of hose connected UPSIDE DOWN and glued on. You can see that, when it is all in place, it would shoot air directly onto the cone filter.

- 0008.JPG
There is also another set of those vertial slots in the front cowl on the DRIVER side that leads to simply a round hole. My BEST GUESS is there was part of the stock airbox that ALSO received cold air from this "set of vertical slots" too. You are looking toward the front of the car from near where the cone filter sits.

- 0009.JPG
You can see, that without the stock airbox plumbing, this "hole", fed by the driver's side slots in the cowl, "sort of" feeds air into the area of the engine bay where the cone filter resides. Again you are looking toward the front of the car (there's the BPV on the right).

- 0012.JPG
Here I'm trying to show the relationship between where my special "upside tube" on the cross hood air duct feeds the cone filter in relation to where the driver's side "hole" from the slots does. Other than diameter, they kind of have the same function.

- 0013.JPG
Some of you asked about the "female" plug hanging in the middle-ish area of the cross hood air duct. Here is mine, also not connected to anything. No idea what this is for.

- 0015.JPG
SIDEWALK CHALK TIME. I drew on the fascia where the first set of gaskets on the hood meet the fascia (very near the front) and also the 2nd set of gaskets on the hood meet the cowl. The point here is the "slots" that supposedly feed the stock intake system are located BETWEEN the two sets of gaskets. Peculiar. Maybe it has to do with keeping rain out, I'm not sure.

- 0018.JPG
One Black Mica MS3 with complete front clip removed. Neat huh. I decided to wait until daylight to continue this "project." See, at this point what I wanted to do was completely remove the "cowl" from the car (the part with the little vertical slots), leaving just the fascia and the bulkhead. But you cannot do this without removing the front clip.


(out of room for pics.... see next post; there's only one more post.) I warned you TL;DR

[fortressofcomfort]

OK continuing (THS IS WHERE IT GETS GOOD!)

- 0019.JPG
THIS IS IMPORTANT. With the front clip removed, here is a picture of all the openings where air can pass through from the fascia (the wide slot as well as the lower bumper openings). Notice the "triple slottled" thingy on the passenger side (this is where the "cross engine bay pipe" mates, and also, AHA, the round hole thing on the driver's side. I tried to get an angled shot to show that the hole does not blow directly onto the filter but then again NOTHING INSIDE THE FRONT FASCIA blows directly on anything. It's all a "higher psi forces air through openings" dynamic rather than a directed stream of air anywhere.

- 0020.JPG
OK you are looking, from the inside of the front cowl, at the cowl and fascia. These screws you see (see end of beautiful arm) are why you can't just rip the cowl out of the car and free up many sq meters of breathing area. Also notice high performance styrofoam save your life materials.

- 0021.JPG
Many folks have purported that taking the cross hood air duct out would allow air to blow directly onto the intake manifold. This is sort of true. Obviously in this shot we see the intake manifold right there behind all them holes in the bulkhead. BUT remember we are talking that "pressurized" feed and not a direct shot of air. (it's not like a straw blowing air at someone.... when that front fascia goes back on all we have is a positively pressurized area in front of these holes. There's nothing direct about it.

- 0026.JPG
Interesting tidbit... if you decide to take your cowl out like I did, your Mazda swan flapping in the distance emblem ALSO not becomes a feeder into the innards of the fascia. See straight through to the hood latch. It's not the most durable of pieces but I believe it is strong enough to handle wind at any speed.

- 0027.JPG
If you decide to take the cowl out, you will have no where to hang your hot and cold coolant overflow lines anymore. I chose to use two small hose clamps to tie them up to the stock location. The hot line is in no danger of hitting the fan now.

- 0030.JPG
Here is a limited pic of the entire front clip MINUS cowl. I'm pushing forward to show you the maximum flex toward the rear of the car that the front fascia now has. The cowl is indeed a structural member, but only structural to the fascia (and the Mazda emblem I guess).

- 0031.JPG
Here is a pic of me pulling hard on the front fascia toward the front of the car. As you can see there is a good 4" of deflection here. But look down. NOTHING! No more cowl. Do now all the air entering the front "wide slot" and lower intake of the fascia (and now the Mazda emblem) can pressurize this area without obstruction. The proper fix here is to attatch the two holes on either side of my hand to the two holes on the bulkhead. I'm sure zipties will work but I'm still investigating.

- 0032.JPG (THE LAST PICCY)
This is everything that came out of the car. 2.5lbs worth (it's junk ABS plastic so if you are thinking to yourself that I've compromised the integrity of my car or make it less safe, think again). The piece at the bottom is the infamous cowl. Note blocked off Mazda emblem. The two other pieces, well, I was tired at that point and can't remember where exactly they fit in but trust me they are not load bearing. And one of my kids left you a nice drawing in BLUE to the top right of the shot (they love sidewalk chalk; they only drew on my car once. Once. You can imagine the few lines they got from me).


************************************************** ****************

SO WHAT DOES ALL THIS MEAN?
I HAVE NO FUCKING IDEA.

I figured someone should get in there and stop *some* of the speculation in this thread using fact. Also, IATs/BATs whatever are VERY important esp to us non-E85 guys (politics, remember....)

Here are my initial impressions:
My old setup kept all that shit (cowl, ducts, etc.) in place and directed air at a right angle from little slots and blew it on the filter. It did work. It couldn't have been much air (volume). It worked well at low speeds because I always was proud of my super glue job and how it got the IATs down to 6-8*F over ambient by 30mph from a heat soaked stop. AP verified people! But I ALWAYS noticed in all my logs that the IATs would always rise after about 40mph. By the end of my logged 1/4 mile runs I'm talking IATs 15-20*F over ambient. This always perplexed me. I mean I had air blowing right on the fucking filter! The harder I ran the car, the more they would rise over ambient. When I came to a stop, the IATs shot way up more, but then within moving 30mph they were chilly again. So I thought I had a bombing solution with upside down super glue (some on finger of course) job. It was and is a fairly good low speed solution.

I can say now, without a doubt, but to an unknown degree, that this new cowl-less method helps noticeably more at high speeds (I mean > 40mph, freeway speeds, superbike speeds, etc.) With my old method (think super glued fingers) like I said the IATs would drop when leaving the line, leaving a stop sign/light, but then somewhere around 40-50mph they would start going up again. THIS DOES NOT HAPPEN ANYMORE. It must be a volume issue. Clearly we are getting more ambient air under the hood now.

Regardless there are two facts that I believe to be true:

1) After car is warmed up (mine is black) IATs are ALWAYS at least about 8*F over ambient even when moving. I have no idea why.

2) Turning on the A/C results in IATs up to 50*F over ambient (as opposed to about 25*F over ambient with it off) DURING STOP AND GO TRAFFIC.

Now what?

1) I want to decide what to do with the gaskets at the front of the hood. As you know there are two distinct gaskets (see I think pic 15 with yellow sidewalk chalk). I have a suspicion that removing one or both sets of gaskets (my hunch says remove the forward one) will draw in even more ambient air to the underhood area.

2) I want to decide what to do with the cowl at the BACK of the hood. I've always been leary of taking these off cars due to rain, wiring, electrical issues, although it seems that time has showed us that this is not as big of a deal as we once thought. I'm wondering if a "cross under hood flow" of air is possible.

But we musn't forget our dictum..... even still we have no idea of turbulence, air patterns, swirls, girls, whatever under that hood at speed. But, without cowl, there is definitely MORE air coming into the underhood area, whether it spins a tornado or goes right into the cone filter and cools the intake manifold I don't know yet.

Comments. F off TL;DR

[Voltwings]

Having been able to drive for a few days, i agree with @fortressofcomfort that just removing the initial piece in the OP does not cool any faster, however in the past 3 days my IATs have been an average of 3-5* lower (according to my ultragauge obd-II scanner) and coolant temps have been an average of 5-7* cooler. Being that the Ultragauge is live data viewing, i will remove all the crap from those pics this evening as well and post up some more live numbers.

[fortressofcomfort]

Dude awesome. I wanna see if your results concur. My main finding is that INTAKE TEMPS ARE CLOSER TO AMBIENT AT HIGHER SPEEDS (right, don't cool any faster, but cool BETTER!) WITHOUT ALL THAT COWL SHIT (more volume between fascia and bulkhead aye aye). I saw little to no difference at low speeds, taking off from light/stop, etc. In other words see what you see after heat soaking and then bringing her up to 50mph or something.

But why the heck do you monitor your coolant temp so much? I mean thermostat opens at x, closes at y, opens at x, eats breakfast, etc. Just wondering.

You can get from pic 1 to pic 32 is it in about 3-4 hours. Here's some hints:
1) It has nothing to do with the headlight assemblys.
2) You have to undo lots of belly pan bolts.
2.1) Trust me, there are no amount of bolts you can take off that will allow the "cowl" to just slide up and out. You must unsnap the front clip and move to side (see #3)
3) There are two electrical connections on the passenger side of the front clip. One is super easy to disconnect. The other is like fuck it. That's why you see my front clip kinda angled to one side.
4) The bottle of Rotella is pointless. It's there to give some folks a woodie.
5) Even with all that space/gap/give between pics 30 and 31, you can still easily drive the car all over space.
6) I want your impressions as to which, if either, or both, sets of HOOD gaskets to remove. Once you get your front end cleaned up (pic 32) you'll be able to make a better assessment. I can overnight you some sidewalk chalk if you want. I think the yellow broke in half.

[phate]

Originally Posted by fortressofcomfort Dude awesome. But why the heck do you monitor your coolant temp so much? I mean thermostat opens at x, closes at y, opens at x, eats breakfast, etc. Just wondering.

These cars have a wide operating range which is considered "normal" - anywhere from ~140° to ~238° is where the needle reads normal. The ignition compensation is based on boost air temps AND Coolant temp (BAT vs ECT Ignition Comp tables), so coolant temps are pretty important.

After sitting in traffic for a bit, it's not uncommon to see 210-220° ECT's. Power fluctuates with ECT, alone and aside from ignition compensation. To me, ECT is very important to the tuning process.

[fortressofcomfort]

Gottle love that discreet um needle um yeah.

As usualy thanks man. Hey is there anyway to force the fan on in ATR? Even to a 50% duty or something? Maybe there is a trick to xref ECT at a lower temp, drop the WGDC vs IAT compensation or some shit only you would know.

I think what I might do is just hardwire a switch into the fan to bring it on when I flip the switch. 1960s style. I'm thinking pit lane at track. But I noticed these fans are on resistor so they can be varied from 0-100% (to save 0.0001mpg probably) so I'm not 100% sure where to put break in wiring. You done any of this kind of stuff before @phate?

Why don't we just have an adjustment to have thermostat open at 180*F like on old Mustang to get that extra 1%hp ? Throw in some phenolic spacers too then we'd be cruisin. WTF would the factory want the engine to ever operate at 210-238*F ?

[phate]

Originally Posted by fortressofcomfort Gottle love that discreet um needle um yeah. As usualy thanks man. Hey is there anyway to force the fan on in ATR? Even to a 50% duty or something? Maybe there is a trick to xref ECT at a lower temp, drop the WGDC vs IAT compensation or some shit only you would know. I think what I might do is just hardwire a switch into the fan to bring it on when I flip the switch. 1960s style. I'm thinking pit lane at track. But I noticed these fans are on resistor so they can be varied from 0-100% (to save 0.0001mpg probably) so I'm not 100% sure where to put break in wiring. You done any of this kind of stuff before phate? Why don't we just have an adjustment to have thermostat open at 180*F like on old Mustang to get that extra 1%hp ? Throw in some phenolic spacers too then we'd be cruisin. WTF would the factory want the engine to ever operate at 210-238*F ?

ATR fan control is something we talked about in-depth at one point long ago in another thread, haha. We had fan control table(s) for a while, but it was determined they were on an auxiliary circuit, not controlled directly by the ecu or something like that. In short, they didn't work.

As for tapping into the line with a manual switch, I don't see why not. It's a great idea for low speed or stopped situations.

[Voltwings]

the ultragauge displays 6 parameters at once, so i have IAT and Coolant temps as the main two, then STFT, LTFT, fuel pressure and ummm i think the last one is battery voltage haha so i have everything important at a glance.
Edit: and my version is old so i will have to get it updated but they now have the ability to display AFR on our car.

Also, i decided against removing that stuff behind the flying M because if you look at the design, it actually channels air into the upper portions of the engine, where as if you remove it it seems all the air will go straight into the radiator (not exactly a bad thing). So i suppose they achieve the same goal through different means, cooling all the "ambient air" in the engine bay, or just cooling the hell out of the radiator?? i did remove some of the ducting and cut out the section behind the flying M so i think i still get structural stability and some additional cooling we'll see.

[fortressofcomfort]

I wanted to go to the strip this Friday but my (to be ex) brother in law said he'd put my kids out on the street at 8:31pm if I got home late. So I told him to go fuck himself.

So I guess I/we'll have to wait to see if this did anything.

It drops SO fast but the IATs always bottom out around 8-10*F above ambient. Weird. I mean I had a/c on, in 90*F, etc. IAT was 145 or something. Took off, by the time I hit top of 2nd it was already in the 90s (it was hard launch of course so say 6-7 seconds). So it works but the question is, by how much.

[StayBroke]

On a side note of needing fresh air. If you ever go with a fmic, take the plastic ducting for the tmic out, the rear hood seal, and the stock intake piping(the ram air shit). My hood is a little bouncy but so much heat gets released its nuts.

[fortressofcomfort]

Originally Posted by Voltwings if you look at the design, it actually channels air into the upper portions of the engine, where as if you remove it it seems all the air will go straight into the radiator (not exactly a bad thing).

Interesting. I did not notice anything channeling of any air anywhere.

Originally Posted by Voltwings So i suppose they achieve the same goal through different means, cooling all the "ambient air" in the engine bay, or just cooling the hell out of the radiator??

Well, some air is going to go through the radiator/condensor, and some will get routed over those and into the engine bay. My theory is the more I can open up the areas above the radiator/condensor, the more air will go into the engine bay. It's theory so you may want to wait.

[SLOWHATCH]

So long story short, in your eyes, does removing that additional piece I posted in OP help or not? I am noticing lower bat's cruising. However it does not seem to lower them or fight off heat soak any faster.

It's just hard for me to tell exactly since I run wmi. Once I get in boost bat's drop either way. I can't imagine I / we are better off with "it" still in place?

[Voltwings]

Originally Posted by SLOWHATCH So long story short, in your eyes, does removing that additional piece I posted in OP help or not? I am noticing lower bat's cruising. However it does not seem to lower them or fight off heat soak any faster. It's just hard for me to tell exactly since I run wmi. Once I get in boost bat's drop either way. I can't imagine I / we are better off with "it" still in place?

as far as i can see, my average IAT (and therefore BAT right??) and coolant temp are noticeable lower when cruising. As far as cooling "faster" no it doesn't seem too, or at least its not drastically faster, i don't know what the refresh rate is on the ultragauge however, but i believe its fairly quick .

[Brennan]

I feel better just knowing that plastic piece of shit is out of my engine bay. Thanks.

[Red]

^^ weight reduction LOL...

[f-castrillo]

I've been thinking, we're making decent headway in figuring out how to cool BATs down and lessen the severity of heatsoak. However, there's still the issue of manifold heatsoak just from the fact that it's bolted directly to the cylinder head, which is the biggest generator of heat.

Yes, FMICs have the least heatsoak because of it's position in the engine bay. Yes, we have throttle body and intake mani TIGs to delay the onset of heatsoak acquired from the engine firing away. Yes, these new findings with the removal of intake ducting help combat heatsoak in the manifold as well. However, the fact of the matter is that when you park at a restaurant for 30 minutes and come back, your manifold will most likely be heat soaked, and thus, the MAP sensor (responsible for boost readings and BAT calculation) will be heatsoaked.

I'm not discounting any of your guys' findings so far (I did the tubing delete myself). But I realized that the true problem lies with the fact that no matter the configuration of intercooler we have, the IM and MAP sensor will always be subject to some sort of heat soak.

It takes a long time to get the metallic mass that is the IM back down to optimal temps that won't skew our BAT readings. That could mean a few midrange WOT pulls to get airflow through the IM, or WMI spray to further speed up the process, and FMIC will help in the sense that we don't have heatsoaked charge air heating up the IM further.

I suppose stacking more than one TIG on the IM could help a lot here?

[Voltwings]

in regards to ^^ something just clicked so i wanted to throw it out there. Im good friends with a guy who just did a BT cobalt build. Forged engine, big turbo, powder coated, looks really nice you know. Well he has vacuum lines running all over the damn place so our mutual friend Taylor (the guy who tunes our cars) was kinda bullshitting with the idea of mounting the MAP sensor remotely (fit a nipple on its spot in the manifold and have a hose running to the sensor mounted elsewhere) since theirs sits directly on top of the manifold and is quite frankly an eyesore. While this would be an excellent idea to "trick" heatsoak, i feel it may be dangerous since our tunes adjust for heat soak accordingly. Not trying to discredit Taylor because like i said we were just bullshitting but, Thoughts?

[phate]

BAT sensors (and IAT, as well) are, and should be, placed in the air stream. They are an open element sensor, meaning they react quickly to changes in temperature. You need to compensate for heat accordingly, and that's usually done with ignition timing.

The issue is not the sensor, it's the BAT's and heatsoak. "Tricking" the BAT sensor into reading incorrectly will surely result in more and potentially dangerous issues.

[fortressofcomfort]

I'm finding it hard to "test" to see how fast the underhood temps are coming down because you have to be on the throttle to get the meters to work.

So I'm basically heat soaking the bitch to like 170*F and then just romping it to like 100mph.

In 90*F weather the IATs are like around 100*F by the end of the run (12 seconds).

I'm going to try to get better data tonight with a real log to measure all this. But I think this is how we need to measure (and compare)

I also removed the FORWARD gasket, and left the rearward gasket. So the gasket that mates with the forward (bottommost in pic) line of sidewalk chalk is now gone. My theory is that this lets air come in the gap between hood and front clip for even more air and pressure. I left the rearward gasket to keep water out of engine compartment a little better.

[Voltwings]

Originally Posted by phate BAT sensors (and IAT, as well) are, and should be, placed in the air stream. They are an open element sensor, meaning they react quickly to changes in temperature. You need to compensate for heat accordingly, and that's usually done with ignition timing. The issue is not the sensor, it's the BAT's and heatsoak. "Tricking" the BAT sensor into reading incorrectly will surely result in more and potentially dangerous issues.

This is basically what we decided, but wanted to see if maybe someone knew something we didnt. Thanks.

[SLOWHATCH]

Having the fan on a manual switch would be a great idea. I did that on my SRT4. Now we just need to figure out which wire or fuse to tap into.

[Voltwings]

^^ so are we all kinda waiting for someone else to find which fuse or wire to tap into haha

[SLOWHATCH]

Originally Posted by Voltwings ^^ so are we all kinda waiting for someone else to find which fuse or wire to tap into haha

Lol pretty much. I'm sure one of these smart guys around here will figure it out soon.