Why not use wood, provide skeletal framework with metal brackets, and also coat the wood so it doesn't get wet?
Saves money, possibly lighter depending on what type of wood you use, also is safer for drivers behind you when it rips off the car. You can also take the template and get it molded to make a 1 piece fiberglass version of it.

not sure how thick of a metal ur planning on using, but the thinner it is, generally the more slats you'd probably want.

 

I just saw an ARC down force meter. Maybe this could be useful in testing the under tray's usefulness. I am unsure yet how the down force meter actually works but it could be interesting to see what is says if it can be used in this application

 

I may be looking at this the wrong way,but are there not diffusers available ready to buy that would fit your needs?Or,modify one to meet the aerodynamics that you are looking for.
How sure are you/where are you getting the data for building a unit from scratch
that give you the needed results?
Do you have a wind tunnel or something?
How bout some pics of your engine&turbos...

 

as for pictures you can see them at link below
https://my350z.com/forum/members/albums/

as for diffuser available yes their is for front bumper and rear diffuser with no data or aerodynamics testing for 90% of marketed diffuser from different company's. the only two companies that i know of build their kit based on data are ASM and Voltex from japan. when you order these parts for most cases have a 3 to 6 month lead time from what i know. i don't want to wait for these part that long. also now that i went back home to Kuwait shipping pricing are extremely expensive compared to parts cost

my knowledge come from reading articles about diffuser aerodynamic and searching on forums as i stated before so, it going to be based on trail and error to see what best route

as for material tech recommend 3mm aluminum

 

Hope fully by end of next week every thing will come to gather

Now am working with computer tech to draw the design, after that I'm taking the design to aluminum shop to cut it using water jet machine for precisely cuts , then take it back to the shop to bolts in on

 

Awesome can't wait to see how it looks

 

now everyone can see the process i when throng i order to build my diffuser. shop going to start working on my car this saturday hopefully every thing will go as we planed

 

Actually curious about how this is going..

 

I made a full undertray last year out of lexan for my roadster. The hardest part from a fabrication standpoint was getting all of the spacing correct to have mount points throughout the length and middle of the car to keep the tray from flexing/deflecting in certain areas. The other challenge was to make it safe and simple to regularly/repetitively remove a section for maintenance, but still insure there were no gaps between sections where airflow would be negatively affected. Additionally, I had to take special care around the rear suspension area because of travel, exhaust, bracing and everything else that is going on back there.

I did not get to the point of making a rear diffuser to tie in. I did make sure that the car and under tray was raked. However, I could tell that mine negatively influenced the handling of my car at higher speeds and that it seemed to introduce more lift instead of downforce. It was noticeable enough at highway speeds that I removed it and stopped any further work on the project. I'm not saying that to influence you in any way, other than to encourage you to be patient and realize that your initial design may prove better or worse than stock aero. I'm just an old country boy trying things out on my car for the fun of it and I didn't have the time to commit to all of the R&D to develop a product that would provide confident/proven positive results. I really hope that you're able to get this right, so that I can either buy it or copy it.

 

no offense taken. appreciate your input and well keep them in mind, as far as it might not work as i want it its a risk that i'm aware of and i hope to over come it

sorry for keeping you all waiting am dying for it as much as any one off you. the shop is busy that they stall my project but they assure me they will work on it this week.

 

Nice progress...

 

definitely interested in seeing the end results...

 

new update .... the car is not finished yet still working in progress but though i share

 

part 2

 

part 3

as you can see there is about two finger gap between under-tray and OEM sides cause of greddy exhaust hang low. so,i though of bending the aluminum in V shape at the end on each side so it doesn't look like big-box hanging under the car

 

Any input ?

 

Great attempt, but I think you may have wasted a lot of time here. The best way for a under tray/diffuser to be functional is to have bends and curves to cradle the bottom of the car as close as possible yet make it slippery smooth. Cutting out a few pieces of flat metal isn't probably going to do much for you, especially with 8" bolts with massive amounts of gap holding the things on. They don't look stable enough. The rear end does not look good at all.

There's my 2 Cents.

 

^ not to be rude or anything but do you work in aerodynamics or taken any fluid dynamics classes?

I didn't realize the exhaust hung that low you definitely can't have that gap between the side skirts and the undertray. You could try to slightly bend the metal up to seal it up on the sides. Do some testing and see what happens. You might have to end up doing what is on the GTR and splitting the undertray around the mid pipe.

 

Great progress OP. You're definitely the first one to actually make progress on this. Many have "talked" about building a completely flat under tray in the past. Can't wait to see this completed.

 

Sub'd to see how this ends up!