bump.

Do some before/after downforce testing.

XoticGT: To properly setup a diffuser, you'd need a wind tunnel, or a LOT of time and access to a test track.

Work on the diffuser is going kinda slow. I ran out of resin (bought more today), plus was busy with other stuff. The fins are turning out to be pretty labor-intensive, also. If I ever do this again, I'll make the fins out of aluminum. Here's a quick shot of the fins:

quote Originally posted by Blacktree: XoticGT: To properly setup a diffuser, you'd need a wind tunnel, or a LOT of time and access to a test track. Work on the diffuser is going kinda slow. I ran out of resin (bought more today), plus was busy with other stuff. The fins are turning out to be pretty labor-intensive, also. If I ever do this again, I'll make the fins out of aluminum. Here's a quick shot of the fins:

Just wondering. Why did you choose wood? Couldn't you have used somthing like insulating foam, sanded it to shape, covered it in Elmers glue and then glassed them? Did you pick the wood for strength?

Elmers glue? Really? I never thought of that.

quote cire36 said: Just wondering. Why did you choose wood? Couldn't you have used somthing like insulating foam, sanded it to shape, covered it in Elmers glue and then glassed them? Did you pick the wood for strength?

I'm more comfortable working with wood than styrofoam. I hate styrofoam.

On a side note, you won't need the Elmer's glue if you use epoxy resin.

quote Originally posted by THE BEAST: Could you share a little bit on your flat underbody panel? I looks like aluminum to me, but for safety it should be made of something softer. (to allow breaking under an accident without grabing or dragin anything). Just as a note, Ferraris under-panels are made off very cheap fiberglass. JG

It's 3/32" black ABS plastic. I used two 4'x4' sheets. The middle section is covered perfectly by a 4'x4' sheet. The front is trimmed to shape and there is some left over. I'll be using a combination of ABS and aluminum for the rear (aluminum around the muffler since the ABS melts and sags).

quote Originally posted by Steven Snyder: It's 3/32" black ABS plastic. I used two 4'x4' sheets. The middle section is covered perfectly by a 4'x4' sheet. The front is trimmed to shape and there is some left over. I'll be using a combination of ABS and aluminum for the rear (aluminum around the muffler since the ABS melts and sags).

Perfect, and now I will try to do the same on my car. I have always being interested in improving my Fiero's aerodynamics and this is one good place to do so.

THanks,
JG

Looks good and all but, have you even made sure its going to fit?

The recessed section you cut out -




That section needs to be there in order to clear the bottom of the trunk. Your fascia will have major interference issues with that. Do you plan on cutting out 8" from the bottom of the trunk for clearance?

im not sure i understand either.

the place you have cut out, wont be in direct airflow... from the back, wont you be able to see the frame and everything?? usually when i see this kind of rear, its extended down so its in the airflow. what am i missing.

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Blacktree, I cant post a pic, but I emailed youa picture of what your setup with steven's would look like

quote Originally posted by XzotikGT: Blacktree, I cant post a pic, but I emailed youa picture of what your setup with steven's would look like

I use myfiero.com to post pics

That photo is on my webserver now:



Now, to answer some questions.

Yes, I'll need to chop the trunk to make the fascia fit. I could probably get away with notching the sides of the trunk, but will instead just cut off the bottom 3" or so. Then I'll make a new trunk floor. Plus I'll need to modify the trunk carpet.

I've already explained that this "diffuser" will not really function as an honest-to-goodness diffuser. The airflow will be "spoiled" by the engine cradle and rear suspension. However, it will provide alot of open vent area for air to escape from under the car.

And yes, the engine cradle will be quite visible with the modded fascia installed. But that's OK. I like seeing my car's bare essentials. I guess it's a good thing I painted the cradle with POR15, eh?

I don't think your version of a diffuser will be a just looks thing because it should atleast help tame the turbulent air coming off the ass end. I have been thinking about a belly pan.

Blacktree what do you think of canards? Any good or hype?

[This message has been edited by goatnipples2002 (edited 10-21-2006).]

quote Originally posted by Blacktree: That photo is on my webserver now:

Is that your car?What kind is it?Do you have a link to more pics of this car?

that is a ssc UHm, Well it's made by shelby super cars, its an american car, but I forgot the model name. It's supposed to be the faster than the bugatti, and stable to 273mph. Here's the link to their site.

http://www.sscautos.com/

[This message has been edited by XzotikGT (edited 10-18-2006).]

Work on the fins is coming along, slowly but surely. They'll take another day or two to finish.



Meanwhile, the fascia is ready for paint. I'm hoping I can test-fit it on the car today. (crossing my fingers)

hhhhhmmmm.............can you say citybilly? I would have like to see you spend a little bit more money on a better outlet for your exhaust system....running a cherry bomb right out the back just doesn't do this rear end any justice....too bad you couldn't create a flush mounted exhaust exit on the flat part under the license plate...that would have looked sinisterly sickening!!! keep up the good work and don't let one yokel git ya down


Brian

Well I still think it looks pretty damn good. Minus the fact that you can't really make out the fine details in the pictures you posted :P. The "raw stuff" looked great.

quote Originally posted by Blacktree: .

Are you covering the inside of your Plate box? (The side facing the engine bay) Other wise you are going to make a hell of a parachute out of it...and create drag which contradicts the purpose of what you are trying to do with your rear diffuser

JG

depending on what he did with his trunk he may not have to....

Well, I had lots of fun and adventure today (sarcasm). I got to play with my angle grinder and make lotsa sparks. I also got to make the final adjustments to the fascia and muffler. I was able to install them just before dark. There wasn't enough light to get any good photos of that. But I got a couple shots of the trunk mods.

First of all, I had to chop out the bottom 3" or so of the trunk. As mentioned above, I needed a way to mount the fascia so the center portion didn't droop. That was accomplished using some angle aluminum. I made a bracket that hangs off the bottom edge of the trunk, and a matching bracket on the top edge of the fascia. These two brackets match up when the fascia is installed, and are attached using machine bolts.

Here is a shot of the bracket on the trunk:



Also notice the exhaust hanger on the right side of the cradle. That's what holds the muffler in place. Just above where the exhaust pipe comes through the cradle, there's a bolt hole for one of the stock muffler's mounting brackets. It's perfectly placed for my exhaust hanger.

Anyway, back to the trunk. In the next photo, you're standing behind the car looking down into the trunk. You can see the trunk bracket and fascia bracket attached to each other. You can also see that the "license plate pod" is not open to the engine compartment. It's boxed off. The rest of the diffuser will hug the bottom of the trunk.



Unfortunately, I didn't have time to build the trunk floor. Maybe next week...

Oh, and I'll get some nice photos tomorrow.

[This message has been edited by Blacktree (edited 10-20-2006).]

I got some photos today. Unfortunately, the black just does not want to show any detail on my camera.

Anyway, here's a "money shot" for ya:



And here's a better one:

[This message has been edited by Blacktree (edited 10-21-2006).]

Now that is cool.

Wanna make me one

btw, I thought I'd make a few small alterations to your car out of curiosity....



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[This message has been edited by doublec4 (edited 10-21-2006).]

Nice. Very nice.

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"Anyone can make a copy of something, it may look good but it ever is the real car. Make something from your imagination, something unique, something nobody has, anything is possible and, ideas can be a reality."

Did you make that front lip? And would you consider selling one, or that rear bumper. Not the one on your car, but could you make another?

looks pretty good, but i think a duel exhaust is needed... actually that photoshop is awesome, do that!

ps: what in holy hell is holding on that spoiler?

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Nice Photochop job there. I was wondering how the spoiler would look if it was molded to the deck. Thanks!

I really like what you did there! that rear diffuser makes the back end of your car look good! Hell, it looks like that's what all of the Fiero's should have come with from the factory!

IMO, the Fiero looks exotic as it is, you add something like that, it just enhances the natural look of the car.

Dual exhaust makes the back end more even! I always thought that an exhaust that passes through the license plate would be cool! Center exit exhaust would be cool, with some nice chrome tips. I just don't know how it could be accomplished!

bump so I can find and bookmark...
Bob

definatly a slick ride with the dual exhaust on it...I would as said before like to see what a photoshop of flush mounted exhaust would look like...IMO that would really slicken up the back end and give greater use of the diffuser...


Brian A.

Wow, if I could give out more that one rating, you'd have like three positives from me by now. That thing is awesome, way to go!

looks awesome, man, nice work!

glad I could help, anything else?

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Awesome work blacktree.

Did u ever consider going with more than just 2 fins ?

Got a chance to see this mod up close and personal this past week, when mike stopped by the house to help me and Alex de Jorge work on my ugly duckling GT (below).



Blacktrees work is something to behold. Very impressed by all the mods he has done to the car.











very nice engine job !!





The diffusser is much more impressive in person.



It photographs like crap due to the black color and lack of lighting underneath, but in person it is awesome !

Thanks Mike for all the help !

[This message has been edited by exoticse (edited 11-06-2006).]

How are the edges of the clam hood holding up? Any stress cracks?
--everything looks awsome!

Thanks for the compliments, guys.

So far, the modded hood is still in one piece. I haven't seen any signs of splitting or cracking. This winter should be a good test of its structural integrity. The cold will make the materials more prone to forming stress cracks. I'm keeping my fingers crossed.

Also, I think the "fiberglass season" is over. Winter is finally here. The temperatures are getting too cold for fiberglass work. So I get to drive around with no trunk floor for a few months. That ought to be fun.

There's also another mod I'd like to perform on the rear end. But I'll need to find an '84 decklid for that. I'm having trouble finding one, though.

Fiberglass is back in season!

Now I can finally make the trunk functional again. If you remember, I had to cut about 3" off the bottom to fit the diffuser. So now I'm molding a new trunk floor from fiberglass.

The method I used was to cover a piece of wood with garbage bag plastic, use a floor jack to push it up against the bottom of the trunk, and lay the fiberglass on it. The resin doesn't stick to garbage bag plastic. I also placed some pieces of wood between layers of fiberglass to form "tunnels" in the fiberglass. This will increase structural strength.

A couple photos:






More to follow as time permits.