IC Duct for Greddy SMIC - Design
 

I recently installed my Greddy SMIC and was debating on what to do about the excellent "IC ducting" provided with the Greddy IC :rlaugh: . If you bought one, you know what I mean!

Having been a aerospace engineer (in a previous life), I decided I could design something better than what was provided (well, so could a 2-year old if you've seen what Greddy provided).

Here's my the design concept. My plan is to get an STL model made up to test the fit and then have the actual part made out of carbon fiber. I'll be adding a flange on the top of the duct to mate with the two threaded holes provided on the top front of the Greddy unit. I'm also thinking about extending the "sides" of the duct to wrap around the side edges of the IC (about an inch).

Here are some concept pis of the design so far. This took about an hour of my time this evening. Let me know what you guys think.

It would be good if you can design an extension to the opening to make it larger and get more air like the one that comes with the ASP...Looks very good BTW:bigthumb:

The opening of the stock IC duct is roughly 10.6" wide and just under 2"high (outside dimension). I designed this one to have an opening of same width (10.6") but 2.5" high. One of the largest "air flow" contraints is the location of the radiator/fan assembly. If you have an aftermarket radiator (and I do) you have to adjust for the additional thickness of the radiator. I checked the cross section of this design by using a cardboard template to ensure the clearence was correct (hopefully). The STL model should verify this.

Anyway thanks for the input.

The snout part that goes into the nose above the radiator is a real pain in the butt to get right. You could make it a little smaller I suppose and have it fit nicely, but then you're losing air. It's a good idea to make one though, you could actually sell a fair number of them if it's done well. At one time I even thought about modifying one of my existing molds to mate up with the Greddy as they don't really have one and there are quite a few of them out there.

Your snout part looks a little long, I doubt you'll actually be able to get it to slide down into the nose.

Mind if I ask what you're paying for an STL? That's a pretty big STL no less.

Kevin T. Wyum

Make sure you let me know once you make them. I'd like to get one :bigthumb:

If your design fits properly with an aftermarket radiator (I am a fluidyne), what would you think of having multiples made ;) because I would definately be interested in buying one :D

Don't listen to clud9! Make one that will fit perfectly with KOYO Radiator. :D

I got a pal in the "business". He actually sells the STL machines. One of the reasons for doing the STL is I can check for fitment issues prior to actually getting it made. Again this is a prototype. Once I get it test fitted I'll post some pics. It will probably be a couple of weeks. My work schedule is pretty tight this time of year.

I believe on Rob Robinette's site he said that he used a pettit duct and slightly modified it to work with his greddy intercooler. You may want to consider that route if your prototype has fitment issues.

Good stuff! I think you'd have a good seller if you can get that made up.

Gotta love the mechanical engineers around here! :)

Dale

Good work, on a product deffiently needed.
I am also ducting a Greddy witha Fluidyne Rad

I am making a C/K duct (had the material) and the red Kevlar matches my car. But have used the trial and error cut and paste method. Built mold from carboard templates and chopped up OEM ducting .. then foamed a plug, and reworked and reworked. Still not ready to throw $100 of C/K cloth at it. If I was not so far down the road, I would have jumped in on your project.

Regarding Pettit, the new style Pettit duct does not fit up to the Greddy and they do not have any stock or desire (I think they told me that they got rid of the molds) to make any more of the old style

Looks good. I'd recommend rounding the corners more so at the inlet to the duct. Different radiator combinations make it a tight fit in the corners sometimes.

Can you do variable rounds in Autodesk?

SIGN ME UP!!!

I'm running the Greddy IC and a really crappy duct. My air temps could be much better.

Please give us a rough estimate of when these could be available and a cost.. I'm thinking 100-150 because most ducts are around $100 or so, but this one is CF.

Yep... You can in Inventor (I'm using a beta version of our next upcoming release). Good idea on the inlet corners, right now they're at .25", maybe go to .50"? I'll run a couple more variations and post a couple more pics. Besides, I forgot how much fun this was :)!

Right now it's still in the concept phase and depending on the unit cost it maybe cost prohibitive for most people. My original plan was to make it CF, but there are cheaper alternatives regarding materials.

Once I get the mockup made and test fitted I'll start shopping around for a place that deals in making CF parts.

Looks good at this point, Richard. Nice work. How did you fashion the cardboard template, and how did it work out as far as clearance to the radiator fan bracket? I'm just curious if you had any clearance problems with the Greddy IC itself (I imagine not, since you didn't mention it). When I installed a PWR radiator, its additional thickness caused clearance problems with the Greddy IC; the front lower leading edge of the IC was contacting the fan bracket, which prevented the radiator brackets on the lower portion (part of the stock anti-sway bar mount) from seating properly. No amount of IC repositioning (what little ability there is) could solve the fan bracket binding problem.

On that same design point, I'm wondering about additional clearance for the radiator fans, as far as spacing from the bracket to the bottom of the duct. The Greddy's additional thickness, plus the duct, blocks off significantly more area behind the radiator than the stock IC duct setup. Have you thought any about that aspect? Probably not a problem, just wondering if perhaps it may be something to think about and discuss.

Thanks Kento. I have given quite a bit of thought to the radiator clearance issue. I have Ron Davis radiator (Mazda Comp) which is 1.5" thick (compared to the stock which is about 1.0") That effectively moves the fan assembly .5" "into" the location for the IC ducting. I took this into account when designing this duct. The cardboard template was done the old fashion way, cut, test fit, cut, test fit. It took about an hour or so until I felt I had it they way I wanted. Then a just digitized it and used it in my design concept model.

The big question is, there appears to be some interest in putting this project in to a limited production run and unless everyone is using the same radiator (as in thickness) there could be some potential fitment issues with the bottom of the IC duct and the fan assembly. I suppose if I had the cross sectional "templates" that would represent the bottom curve of the IC duct for both Koyo and Fluidyne I could make the bottom curve of the IC duct fit the worst case senario. Then the IC duct would fit all three radiator fan assemblies.

I'm open to any design suggestions that would make this project a value to everyone with a Greddy SMIC. As you know there is a lot of variances between how people install things. I have seen posts/pics of the Greddy SMIC (in terms of location, angle of the IC, etc.) installed different ways. This creates a major problem when trying to design an aftermarket product, in this case the IC ducting, to solve a particular problem.

And besides, design by comittee is always fun. Just look at the former Soviet Union... it worked for them didn't it? :D

i'm not really familiar with the Greddy IC so forgive my ignorance... would it be possibel to make new mounting brackets that would move it further away from the radiator/fans assembly and increase the volume of the little "bell" in the duct where it meets the IC... or what about a little fan unit that mounts to the back of the IC in order to constanly be pulling a minimum amount of air throught the IC even when sitting still???

just spouting off stupid thoughts here.

Check out BATMAN's Greddy SMIC duct.

https://www.rx7club.com/showthread.p...ht=greddy+smic

Last I checked with him he was getting temp readings of high 20'sC - low 40'sC on the freeway at 50F - 60F outside temps.

Here is a pic of it installed in the FD:

http://www.illstreet.com/image/batman/engine.jpg

Looks good! I saw this post when I originally did my search for an alternative duct. I decided I wanted do something alittle different for my car.

Updated Design for IC Ducting
 

Here's version 2. I included suggestions made by turbojeff (variable radius, i.e. larger radius on the "nose" section). I also included long tabs to overlap the sides of the Greddy to help seal it. I also incorporated the top mounting flange to mate up with the two existing holes provided on the top front of the IC.

Comments are welcome ;).

I wonder where u got that top flap idea from? ;)

Yeah... I know... I know... it's pretty much the best thing about "their" design! Besides the holes are already there. :bigthumb:

I also have a m-comp rad (1.38" core) and Greddy smic. The rad was a very poor fit, as fan bracket no longer nested against the core, and stand-off was excessive. Called Davis to alert him about it. I had to machine down the upper mounting stubs, and cut off the lower plates that hold the bottom of the rad fan bracket pins, to move the fans close to the core. Also mod's fan bracket. If your m-comp rad was also like that, I'd fix those first. Basic problem was mc core was less that 12 x 24", as stock oem one was.

I like the idea of a real duct for this IC. i have a butchered Pettit. The carbon would be just show, larger market would be FRP or abs ... KTW may have some suggestions for vendors. I aslo think tilting the rad down, at the upper mounts as koyo guys often do, would allow an even deeper slot. Goal would be to hit about 40% of gross core frontal area.

Good luck.

I had the same problem with my Fluidyne rad. The rad is thicker but the main problem with IC duct fit was the fans were held off from the rad core by ~3/8-1/2" due to higher than stock mounting bosses on the top side. The bottom side mounting tabs also held the fans higher than the stock position.

Once I lowered the height of the mounting bosses, the IC duct fit much better.