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proxlamus©

After doing some reading.. I blocked off the upper grill *pics*

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Thanks prox. Here is a straight picture to better visualize where i want the "ramp" the air up.

 

SDC12193.jpg

 

 

If you want to be technical call that arrangement a diffuser, now you need something like that behind the radiator to complete the effect.

 

Just keep in mind that if the maximum angle of the surrounds, sides etc, is more than ~12 degrees then there will be air separation inducing turbulence. The airflow will separate from the surrounds because it is being asked to turn more than it can.

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If you want to be technical call that arrangement a diffuser, now you need something like that behind the radiator to complete the effect.

 

Just keep in mind that if the maximum angle of the surrounds, sides etc, is more than ~12 degrees then there will be air separation inducing turbulence. The airflow will separate from the surrounds because it is being asked to turn more than it can.

Your rule for separation is for a diffuser going into a vacuum (unless I'm mistaken). For a diffuser going into a pressurized area, I think the reality may be some what different. Would there still be separation? Probably. Does that mean that the whole of the radiator wouldn't be used? Possibly. Would that matter? Maybe. It might be that by eliminating all the ways the air can get past the radiator without going through it you might see gains in overall cooling capacity even if the duct has separation in it.

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Hmmm. The only way I see that I can keep the angle less than 12 degrees is to shorten the actual top of that leaving the radiator "exposed" behind the second piece covering the main "mouth" of the car.

 

The other option would be to extend the bottom out and have multiple angles in it. So instead of one angle in the the goes from the opening to the top of the radiator make it two angles. It would technically still cover the whole radiator and keep all angles under 12 degrees if im visualizing it correctly.

 

To get the sides to be under 12 degrees though I would have to make the rectangular opening wider.

 

As far as continuing it on the other side. I have been trying to think of a clean way to do it. I saw the recent "radiator exhaust" thread and have keep my eye on it. Think is I would like to refrain from cutting up my hood or my car. I did get the idea of pushing the air down and outward towards the brakes. But I would think that would create lift If im not mistaken?

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Hmmm. The only way I see that I can keep the angle less than 12 degrees is to shorten the actual top of that leaving the radiator "exposed" behind the second piece covering the main "mouth" of the car.

Make the opening bigger, cut out the rad support and lay the radiator down, put the duct higher and split the angle top and bottom. There are a couple ideas. Not sure any of them are necessary.

 

As far as continuing it on the other side. I have been trying to think of a clean way to do it. I saw the recent "radiator exhaust" thread and have keep my eye on it. Think is I would like to refrain from cutting up my hood or my car. I did get the idea of pushing the air down and outward towards the brakes. But I would think that would create lift If im not mistaken?

It doesn't need to go down, just to the sides. Even if it did go down, you'd still get downforce from it, because all that air that can come through the huge stock grill opening and around the radiator and under it, wouldn't be getting trapped under the hood as it normally is.

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Make the opening bigger, cut out the rad support and lay the radiator down, put the duct higher and split the angle top and bottom. There are a couple ideas. Not sure any of them are necessary.

 

Trying not to cut up the car. But maybe i can somehow move the radiator to the front of the car and angle it? Wouldnt this do the same concept? Ill do some measuring to see if it will even fit or is worth that much work. Id like to refrain from cutting the car.

 

It doesn't need to go down, just to the sides. Even if it did go down, you'd still get downforce from it, because all that air that can come through the huge stock grill opening and around the radiator and under it, wouldn't be getting trapped under the hood as it normally is.

Makes sense. But it would have to go down before it went to the sides but I get what you mean. I was thinking to basically make a shallower (skinnier) version of the front piece on the back side. Where the rectangular piece is now on the front piece, would be where i would split the air to go on either side to the brakes. Ill make something out of card board to better show my idea. I dont think it would be too much work considering I was going to put the car on the lift anyway to stretch the air dam lower, using aluminum on the same way people are using the Home Depot door molding stuff (Im going to try and angle the aluminum though instead of straight up and down), and build a belly pan while im down there. Stretching it lower should get the pan closer to the ground like its suppose to be anyway while giving me a bit of clearance to tuck the back side of the radiator exhaust to the brakes.

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I have no idea on the fluid properties of the ducting (maybe next year once Ive taken fluids classes :) ) but I have to say that your design looks great. Be sure to post pics as you work on it more. Ill hopefully work on something similar this winter since I ditched my last one.

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I wouldn't worry about getting all sides down to 12 degrees, its just something to aim for if its possible in a particular situation. In the present context any ducting that effectively reduces the radiator opening is good and a very worthwhile improvement and good on you for doing it.

 

All flow separation will do here is create some turbulence but it will be far far less than stock.

 

Incidentially, I've used similar reduced opening ducting on my intercooler and oil cooler. It seems to work very well.

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After several configurations I think I've come to a good cooling setup for both the radiator and intercooler. It's a sort-of V-configuration with the intercooler receiving air from a scoop and exiting out of the hood vents. It's not ideal but after many other setups it seems to work best. The fit issue is because the intercooler is huge, with a 12x24x4 core. That and the added complexity of the oil cooler up front.

 

The area below the bumper is dedicated to the radiator and above the bumper to the intercooler. The shroud seals up against the hood to ensure air cannot rout around the intercooler.

 

here are some pics of it apart and finished.

 

4334063878_c5b6663035_o.jpg

4333322481_7202e633cd_o.jpg

4334067964_fbe56eb9f3_o.jpg

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Mark:

 

Hope you dont mind some friendly criticism:

 

From what Ive read, ducting should point like this / instead of like this / . This makes it harder for air to go around the ducting and is forced to go through the radiator/intercooler.

 

But that is great craftman ship. I admire your car alot.

 

This is how I blocked off the front of my car as well. I still need to get out there and take some pictures.

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Mark:

 

Hope you dont mind some friendly criticism:

 

From what Ive read, ducting should point like this / instead of like this / . This makes it harder for air to go around the ducting and is forced to go through the radiator/intercooler.

 

But that is great craftman ship. I admire your car alot.

 

This is how I blocked off the front of my car as well. I still need to get out there and take some pictures.

 

no problem. It's not ideal but it seemed best for the situation. Here's the schematic I started with;

 

4334852958_5f504bb376_o.jpg

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So my car runs hot, and I've made some wholesale changes to try and help it run a little cooler. I'm running A/C, and before these changes it would run okay with the A/C off, but as soon as I'd turn it on it would run about 15 degrees hotter. So here's my mockup that I thought I'd share to see what you think.

 

med_gallery_824_764_413328.jpg

med_gallery_824_764_287429.jpg

med_gallery_824_764_639850.jpg

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So based on the testing on my setup, it made my car run hotter. Has anyone actually decreased their operating temperatures using a very small inlet with steep angles? While I think that some ducting can be helpful, it can actually hurt if done incorrectly. I made shorter ducts with less of an angle to avoid unwanted turbulence, os I hope I get beter results with this setup.

autismz004.jpg

autismz006.jpg

autismz005.jpg

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Good call Jon..

 

I was planning on finishing everything up tomarrow..

 

just some pics and hopefully a brief discussion on what would be the best thing to do =)

You've made great strides towards increasing your downforce and reducing drag.I know people freak out about small radiator openings,but if the details are managed[hood vents and such],the system works.The SDI blue Z in the tunnel tests has run the same nose seen in there for about twos years.Many events are run in the hot stick Southern Summer.25 to 30 minute session.I have NO FAN.We run the CSR Electric Water Pump,and the temp's have never gone over 185 degrees...Except when I forget to turn on the pump.OOPS!

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Never did update this thread. Heres is what i ended up with. After 3 track days, im happy with it (for now). Added brake ducts and front splitter as well.

 

with brake ducts-

168578_10150386706315156_842495155_16870170_1442328_n.jpg

 

before the brake ducts -

13443_1486842776013_1382238366_31338541_5664725_n.jpg

 

grill still hides everything when its not on track duty-

29692_10150198457750156_842495155_12645275_2539877_n.jpg

 

167108_10150384793565156_842495155_16837298_3755909_n.jpg

 

mock up -

168629_10150373626830156_842495155_16611585_5677159_n.jpg

 

brake ducts (while it was under construction)

167529_10150373626730156_842495155_16611584_3512546_n.jpg

 

front spitter (still needs to be finished a bit better, i dont like the current fitment)-

66030_10150296144385156_842495155_15253490_1134547_n.jpg

 

 

 

 

Ill get better pictures for you guys.

Edited by aziza z

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Never did update this thread. Heres is what i ended up with. After 3 track days, im happy with it (for now). Added brake ducts and front splitter as well.

Matt,

With the testing you've done are you able to say that the ducting has actually succeeded in making your car run cooler? I've been playing with this for a while, and I'm not convinced I've been able to get it to run any cooler than it does without any ducting whatsoever.

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I'll bite. This has been in the back of my mind for a long while, and just entered into my personal "skunkwerks" production last night. I had to do SOMETHING with all these empty boxes from Summit piling up!!! Its obviously not done, not even to the prototype phase. Plans are to make it out of sheet aluminium, maybe a fiberglass model. I would have liked to weld sections of it together, but I only have the ability to weld steel. So I'll probably end up using clecos, pop rivets and/or maybe some countersunk bolts.

 

005-1.jpg

004-4.jpg

006-2.jpg

 

The intercooler as you can see rests on a piece of steel bar stock. This was the original way I mounted it when I first swapped the L28ET in the car. I'm retaining that bar stock, but cutting out the middle section inwards of the lower intercooler mount bosses. Then I'll reweld sections of it to the lower rad support in a triangle shape. In the void created, I'll be mounting a low profile oil cooler in a "V" angle in relation to the intercooler (clearance issues, especially with the -10 inlet/outlet).

 

007-2.jpg

 

I'm also thinking about enlarging the hole on the right side of the radiator support (below where I pass my intercooler plumbing) to pass plumbing for a cold air intake. The filer will be about half the size shown protruding into the ducting. Of course, it will be sealed in.

 

008-1.jpg

 

The whole idea of the design is to block off the upper portion of the grill as others have done, but also retain a stock look from a distance. So I've designed it to fit neatly behind the stock 240z upper grill. I originally was going to drill out the spot welds and remove the 280z turn signal brackets, but they work PERFECTLY for mounting this setup

Edited by Oddmanout84

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So based on the testing on my setup, it made my car run hotter. Has anyone actually decreased their operating temperatures using a very small inlet with steep angles? While I think that some ducting can be helpful, it can actually hurt if done incorrectly. I made shorter ducts with less of an angle to avoid unwanted turbulence, os I hope I get beter results with this setup.

autismz004.jpg

autismz006.jpg

autismz005.jpg

Bartman, as we were discussing in another thread, I have a similar situation. What was the outcome of this second version of your ducting? And what did you finally settle on for a solution?

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Bartman, as we were discussing in another thread, I have a similar situation. What was the outcome of this second version of your ducting? And what did you finally settle on for a solution?

My current setup is essentially identical to the cardboard mockup I posted pictures of. I'm very happy with the results and it seems to have noticeably brought down my operating temperature. In conjunction with the ducting I have functional fender vents with fans to force hot air out of the engine compartment, and I'm installing an even bigger 4 row radiator.

med_gallery_824_764_693338.jpg

med_gallery_824_764_487021.jpg

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