Quarter window scoop/plug

[H@xtGSX]

This may be a bit above the Noob section stuff, but I don't post much unless I have experience with the subject... and since this is my first DSM, I haven't posted much.

I've searched a lot for any info about using the quarter window spot for FUNCTIONAL scoop, not some drag inducing piece of garbage ricer trim, and come up empty. I have seen 1 company that makes some rather hideous fake window scoops that just cap the quarter window glass, but that isn't what I'm trying to do. These will serve a purpose, and I'll fabricate them myself if I need to, but I figured I'd ask before buying supplies. Lemme explain:

I'm switching my intercooler out for a 600hp liquid to air intercooler. I am using a radiator nearly as large as the stock 2g radiator to dissipate heat and prevent heat soaking. That's going to be plumbed to a 3 gallon reservoir mounted in the spare tire pit, next to the washer tank (which is now the water injection tank). I want the radiator mounted in the back, against the bottom of the rear interior chassis steel, as low as possible. This is to prevent the engine radiator from overheating due to restricted air flow, isolate the exchanger from the engine bay heat, and keep the extra weight low and to the rear. It will have a fan for idle time, but I want to make a set of plenums running from the quarter windows to a sealed chamber built around the radiator to flow air through it at speed.

Is there anyone who's done something like this? Or am I obligated to order resin and carbon fiber cloth and mold something myself? Thanks for taking the time to read this novel, and any input is appreciated.

 

[agarc023]

There was one guy trying out the same thing you were doing. Let me see if I can find the thread

Here it is. Someone suggested using the quarter windows, but I don't think he took that route

http://www.dsmtuners.com/forums/newbie-forum/382654-rear-mount-radiator-relocation.html

 

[H@xtGSX]

Yes, that's similar in concept. I was thinking of the negative pressure at the lower rear bumper instead of from underneath, but his train of thought for tuning the undercar pressure is interesting. I'm not going to be doing that much chopping up of the interior though. This isn't a race car, and I want the interior to stay just as comfortable as it is stock. Granted, the shoulder room in the rear will be sacrificed a little, but I rarely have more than 1 passenger. The advantages I was thinking of is that it'd be a major sleeper without the incredibly obvious fmic, weight distribution, throttle response, and just because I like to push the custom "wow" factor with interesting functional modifications. Fabrication is 9/10ths of the fun for me, and experimentation is in my blood... so this car is getting messed with regardless, just to see what happens.

I was thinking I'd mount the radiator at a 30 degree incline, centerline, top closest to the rear. I'll plumb ducts along the sides over the rear shock towers, which will then turn inward and down at roughly that same 30 degree slope, and the air exit would be a slot cut lengthwise in the bottom section of the rear bumper. I was thinking I'd put a FG sealed door over the spare pit, have the radiator chamber on top of that with another FG door, and mount the radiator with a pivot mount down low, and a set of clamps up top, so the radiator could be moved out of the way when I need to access the reservoirs and pumps. I was planning on finishing this like you would a custom speaker box, so that it blends with the interior better.

As a side thought, in that other thread, wouldn't cutting that much steel away from the floor steel compromise the structural rigidity of the car??

Edit: Looking at my design sketch, I don't think the reservoirs need to be separated from the radiator chamber as long as the front of the radiator covers the inlet, and the exhaust fan pulls from a sealed pipe from just above the spare pit. Then the tanks could just be covered over lightly with a piece of lexan cut to the circumference of the tire well... which would look kinda cool, I think.

 

[drxlcarfreak]

I have been thinking doing about something similar myself with the radiator and if I decide to keep AC, put the condensor back there as well. My thought being both the FMIC and radiator are able to run more efficiently without a mass of heat sitting directly behind it (Radiator for the FMIC, the turbine housing/block for the radiator). I think it would really help keep the engine bay as a whole a bit cooler and maybe not heat soak the charge pipes so much. Plus, it would really open up quite a bit of room up front for more interesting forced induction systems.

I havent had a chance to look at underside of the car too much yet to see what room there is, as I have been playing around mostly in the engine bay, but I was thinking of doing the flat floor route and mounting the radiator where the spare tire well was at a 30 deg incline to pull air from under the car and exhaust it out ducts on either side of the license plate.

As a structural engineer (in building design), I know there is some structural impact of the wheel well, but I think if you either weld a flat sheet back in, or at least reinforce the cut out with tube stock or something of the like you wouldn't notice a deterioration of the structural integrity. Keep in mind that the original engeers had to design for things like severe rust and still keep the structural integrity.

I cant quite picture your design. Do you have a sketch or picture of what you are talking about? It sounds like you are keeping the radiator inside of the cabin??

 

[2GEffect6]

I highly doubt your are going to be able to find something that fits and looks like you want it to if I were you I would buy the resin and fiberglass cloth and do it yourself. Much cheaper too.

 

[H@xtGSX]

Agreed. There isn't anything out there that will fit the bill, so I'm getting a spare quarter window set to mold from. I'm going to make it so that it can be glassed in to the contour of the steel, so it appears it was made that way.

To answer drxlcarfreak: Yes, you are correct. I intend to have the radiator in the cabin, but it will be sealed off with a fiberglass enclosure. My reasoning is because of the very reason you stated. Cutting into the steel without perpendicular reinforcement along the strongest chassis in the rear (right around the rear shock towers) will add a significant amount of flex under lateral strain. No sway bar or shock tower crossbar will compensate for that completely. The skin of the rear chassis is designed to withstand a substantial amount of stress, without holes... if this car is going to drive the way I want it to, I need every bit of rigidity I can get and then some. Now, in the case of the amount cut away in the other thread, I forgot that car would have to have a roll cage installed, so that would compensate for most of the steel cut away. Without an accurate model in Solidworks or similar though, I won't make any guesses about rigidity under load. So, I figure I can use the space between the rear exterior steel and the interior trim to make a small circular cut braced with a matching plate of 14ga steel welded in place on the cut to duct the airflow down to a slit cut along the furthest rearward protruding section on the bottom of the bumper. That should help take advantage of the negative pressure created there at speed, but also reduce it somewhat concurrently. I'm sure that if designed correctly for diffusion, it could possibly reduce the drag there and make the car a little more "slippery".... but I don't know if the effect would offset the drag created by the scoops. My instincts say no, but it's a theory of one of my friends.

Lastly, I cut the glass away from the window frame to mold to, but looking at it now, I think I could just remove the glass and foam sculpt a scoop to fit to the existing frame. If one wanted to replicate or purchase a similar scoop in the future, it'd be a hell of a lot easier to make it fit to the glass frame than to remove the window assembly entirely and fill the resulting hole.

 

[jw4free]

Just wondering if this is a coolness cosmetic thing, do it because it's different, etc. That's cool. I'd like to see it done nice.

There is a post somewhere here that discusses the malidies of a water to air intercooler for any usage other than drag racing durations. I'm sure you're familiar with it.

http://www.dsmtuners.com/forums/bol...-air-water-merged-7-7-intercooler-liquid.html

 

[H@xtGSX]

These aren't just for looks, though I do want them to look cool. They will serve a purpose cooling the IC coolant loop. I do think the departure from normal 2g appearance will be interesting though... hopefully I do it well the first shot and don't make anything people will think is goofy or lame... not that that will make a difference, but I don't want to look like a doofus.

As for the second point: Yes, I'm quite familiar with that misconception, but I've only glanced at the threads regarding it because of the controversy they always seem to cause, regardless of the vehicle. I can say from experience though that a properly executed WTAIC will beat the pants off any conventional ATAIC in nearly every situation and aspect, except for 2 things... simplicity and reliability. They are not simple and there's a lot more potential equipment failures with the pumps and IC integrity. There's also a lot of crappy designs being sold that really don't utilize the cooling core properly, so if you haven't done your homework, yea, you'll be driving around with a heatsoaked IC that causes nothing but trouble. I'm no n00b when it comes to mechanics and fabrication, so the added complexity isn't a major drawback for me. I wouldn't go recommending them to anyone not willing to take the extra time to do the maintenance they require.