Turbo - Thermal and Airflow management

[Martin0660]

A few of us have been moving toward changes to our rides to help manage under hood heat & air flow through intercoolers, etc ... In a lot of areas, the two things can be related.

What really started this thought process for me was track data logs showing a strange thing for my intake air temps (MAT in my case). I would start a pass at ambient temp and be nice through 1st and 2nd ... All through third gear, my MAT would climp nearly with RPM ... Then when I shifted to 4th, the MAT would drop through the gear to the stripe. By the time I got to the pits, my MAT was back near ambient ... So, if you was to put your hand on the intake side, you might think it's working well as there was no heat there but the MAT's told a whole different story.

So there is a kick off ... let's dicscuss :D

[Martin0660]

In a discussion on another forum, a great point was made that to get air in (under hood), you need to get air out (or possible keep it out) ... The air extractor hoods available off the sherlf arent an option for me and a Capri, but this path seems like a great way to go is you can make it work. I was linked these pictures that how a lot of interesting things ...

This is a cowl hood modified with lounver type vents ... Notice that the cowl opening is sealed. This was a road race car, but the owner claimed huge coolant temp drops with this modification ...



This is also a modifed cowl hood with two things going on ... First the heat extractor type outlets have been added ... plus the addition of GT500 vents to the sides. The owner of this was having over heating issues at the start of this and now blocks off 1/3 of his radiator to get temp INTO the engine ...

[Martin0660]

In my case, this all drove me to swap intercoolers this year and put some effort into air flow into that as a first step ... The Capri isn't exactly slippery up front with a mostly vertical front end, but I do have openings to work with ...



As you can see I haver an upper grill opening (that will feed radiator only) and a lower air dam opneing that will feed intercooler only.

The lower opening is 24" wide but only 4 1/2 high. This will be feeding to a 24" wide a 12 high intercooler. What I plan to do is cut back the bottom of my inner bumper support ... I'm only going to leave about 2" of the lower part. This will give me a point to fasten ducting, and from there to the top of the intercooler will be about a 45 degree angle ...



I am also going to replace the current platic filler (with holes) with a solid aluminum plate from the air dam to the IC core ... Of course after the top and bottom are made the sides will be enclosed.



This will then effectively make a box duct from the front air damn to the intercooler. I wasnt real keen on the opening being a fair amount smaller than the IC core, but there is at least some theory that says this could be better. In Corky Bell's book (maximum boost) he talks a about this design. He recomends a smaller opening to as little as 25% of the core surface. In my case I will be about 40% so there is some optimism.

[Martin0660]

Another point ... I was debating on putting a "flap" across the bottom of the intercooler core instead of the bottom plate on my duct ... The thinking (wrong) is that that air dam would pile air up into the core and make the existing opening more effective ...

At this point I am going to hang a large flap across the bottom of my core support but my beleive how it will work is to create LOW pressure behind the core support to allow the openings I have to flow better.

I also will be putting efforts into closing the opening beside my radiator, etc to get the flow either through where I want it, or around to get it out of the way.

A pile of random thoughts in all of this but lets have a discussion :D

[went9s]

(Engine temps)
Around town my turbo hatch ran cooler(engine temp)with the cowl hood.
On the Highway if I taped the holes in the rear of the cowl hood it would run 15 degrees cooler(engine temp). I heard that cowl hood caused turbulence and the air wouldn't run out the bottom of the car.

(Engine temps and air charge temp)
I used to have the intercooler smack up against the rad. I moved it 2 inches away and it reduced the Air and engine temp down about 15deg. I now think I will extend the factory air dam 2 inches to get more air to the rad. Hopefully bringing the temp downs and air temps even further.

(Air charge cooling)
I had two problem with air temps. One was adressed with the turbo being so close to the charge pipe(installed a tubo blanket) works awsome.
The second problem was the intake soaking up to much heat(and holding it).
I put a bag of ice on it to would melt it in a half hour. I have purchased a super victor efi that has the underside open. hoping to get that under control.

[went9s]

I am also tring to find a old magazine article (mmf or 5.0) where they used a thermal coating on the intake manifold that decressed the air temps the more they ran it. It was a. stock intake if i remember correctly

[wick]

I have purchased a super victor efi that has the underside open. hoping to get that under control.

Thats how my Victor 5.0 intake is. I can tell you it runs a good bit cooler. Cant really give many true numbers but when I got tuned with Lund two years ago, I was at 180 on the IAT's. When the now defunct company SGS did my last tune, I was at 110 IAT on a warmer day. But I also had the intercooler for the SGS tune. NOT for the Lund tune.

Lund tune was SysteMax II intake, no cooler. IAT 180
SGS tune was Vic 5.0 intake with intercooler. IAT 110

[Martin0660]

(Engine temps)
Around town my turbo hatch ran cooler(engine temp)with the cowl hood.
On the Highway if I taped the holes in the rear of the cowl hood it would run 15 degrees cooler(engine temp). I heard that cowl hood caused turbulence and the air wouldn't run out the bottom of the car.

This is a lot the same as I've been hearing. I intend to play with the cowl open and plugged (foam plug) and see what I can see at the track.

The open question for me is if we get the airflow "right" (better?) around the front (create low pressure behind core support) if the cowl effect will change.

I had two problem with air temps. One was adressed with the turbo being so close to the charge pipe(installed a tubo blanket) works awsome.

X2 on the blanket. I can make a pass and effectively touch the outside of the blanket after a pass. I wouldn't leave my hand there, but I can touch it. It did a great job of cutting radiant heat from the turbine housing for sure ...

[biminiLX]

Great post Bob, as you know I'll be doing some things this winter through Street Lethal for the same effect.
First, yes, the turbo blanket and header/cross-over/DP wrap is very important. The rest with aerodynamics/airflow management/heat extraction is stuff I'm starting to research now.
On the hood, the factory Cobra and GT500 hoods with heat extractors tell me how this is very important to OEMs and something we should do.
I understand you're kinda stuck with your hood, but luckily Cervini's makes the heat extractor Cobra hood for us aero-Fox guys and it is what I plan on using.
You are also right on the closed rear cowl. I was discussing this with the guy who makes Boss Inc. hoods at the Columbus NMRA show several years ago how my cowl hood was open in the back and his 2000 Cobra R Fox was closed. He said his was an exact copy of Fords and how having it closed is actually better at speed, basically what you guys (went12s) mentioned. He did say the rear part of the meets the cowl so that it actually helps pull heat trapped under the dome out, as Ford intended.
As far as the radiator/cooler airflow, I read about some guys using some insulation foam block stuff you can get at hardware stores and cut to box-in the intercooler so that air going into the front opening can only go through the cooler then the radiator.
In your case, I would think you could possibly partition the upper grille just for the radiator and the lower just for the cooler?
I think the factory lower air dam is beneficial to keep.
I also think the upper radiator support cover Scott Rod made me helps more airflow into the radiator. Obviously a fan shroud should be kept, Scott Rod made me a nice one too.
OK, enough for now, continue to discuss
-J

I am also tring to find a old magazine article (mmf or 5.0) where they used a thermal coating on the intake manifold that decressed the air temps the more they ran it. It was a. stock intake if i remember correctly

Swain Tech makes the thermal coating from the article you're thinking of, check out their website, good shit.
-J

[Black Vert]

Some hood ideas I've been tossin around. Been having overheating issues on warm days ever since I installed the C4 trans. Originally had the trans cooler in between the radiator and IC, moved the trans cooler to the rear of car with its own fan, dramatically reduced coolant temp. but still higher than I want it. The temp of the hood gets to 230 deg over top of the turbo, have a shield but need to get blanket. Intake air temps are high too, around 180 deg and drop 15 deg by the end of the 1/4. Intake air tube and down pipe are less than a 1/4 inch apart, down pipe is wrapped helps a little. But those are my heat issues, hoping a vented hood will help, still using stock hood.

[Black Vert]

Or maybe a Shelby heat extractor on my stock hood like this one.

http://www.f150online.com/forums/art...rley-f150.html

http://www.dariusrudis.com/2009_GT500_Hood_Vent/

[biminiLX]

Seems like we're thinking alike Chad, I'd had the same exact ideas but never saw a GT500 scoop incorporated and haven't found a clean addition of vents to a Fox hood. So far the '03-04 Cobra style extractor is the only one that passes my visual requirements, clean and subtle :) I plan on using the billet inserts some places make to replace the factory Cobra vents, gotta match the billet wheels right, bling bling ;)
-J

[biminiLX]

Also thinking about this for more rad airflow:
http://www.classicdesignconcepts.com...t_detail&p=228
-J

[went9s]

Is there a pic of the rear of the gray convertable. I want to see the rear quarters.(another project)lol

[Black Vert]

Also thinking about this for more rad airflow:
http://www.classicdesignconcepts.com...t_detail&p=228
-J

Thats interesting, like to see it on another car besides the one they have shown. The heat extractor hood with the billet inserts would be the way to go , but not in my budget right now. Im trying to go on the cheap, my cost on the Shelby vent on the black stang in the pic is $50, found a carbon fiber one online for $150. I'd like to try to keep my stock hood and install a vent without it looking to ricey .

[Black Vert]

Is there a pic of the rear of the gray convertable. I want to see the rear quarters.(another project)lol

I have another pic of that car from a 45 deg angle from the front, but you can see the rear quarter better. On my laptop at home, I'll post later.

[went9s]

I have another pic of that car from a 45 deg angle from the front, but you can see the rear quarter better. On my laptop at home, I'll post later.

sweet thanks

[Martin0660]

luckily Cervini's makes the heat extractor Cobra hood for us aero-Fox guys and it is what I plan on using.

Again, it does me no good, but what I wonder about those is if anyone actually did the engineering to see if they create the required low pressure area to work? The frontal area of a Fox stang is very different than a new edge car.

In your case, I would think you could possibly partition the upper grille just for the radiator and the lower just for the cooler?

That is exactly what is planned. The lowewr air dam opening will feed the intercooler with the upper opening feeding the radiator. The open question is how much area I leave open up top. The REALLY good news in my case isthat I have no issues with coolant temperature, the car runs very cool.

I think the factory lower air dam is beneficial to keep.

I'm not sure what you mean by this, but if you mean the air dam it's staying for sure. My car has nothing behind / below that so I will be building a 3-4" air dam right off the bottom of the core support. The intent of this will be to create a low pressure area behind the core support.

I think this is key in al lthis heat management discussion ... don;t look at this as air flow, look at this like a fluid flowing from a high pressure are to a low pressure area. If the pressures are equal, there is no transfer. If you can create low pressure areas, the air will go there.

Or maybe a Shelby heat extractor on my stock hood like this one.

This has been suggested to me by several people. As you posted, it rather inexpensive. The debate for me is it will look odd on my car ... form over function ??? LOL ... I might try and get my hands on one of those vents to play with it.

[Martin0660]

BTW - Chad, are you a member on Corner Carvers? I understand that is where the pictures I posted came from and it looks like we have some of the same car ;) You have to be a member there to see pics and they arent exactly "New member friendly" over there. I understand there is a monster thread on this topic over there.

[Black Vert]

This has been suggested to me by several people. As you posted, it rather inexpensive. The debate for me is it will look odd on my car ... form over function ??? LOL ... I might try and get my hands on one of those vents to play with it.

Im thinking it will look a little odd on mine too, but black on black I'm hoping it wont stand out too much. I'm willing to start cutting . And if it works I wont be worried about how it looks. I would just hate to spend a grand on a hood (painted) and it doesnt work.